1 //===-- TargetLowering.cpp - Implement the TargetLowering class -----------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This implements the TargetLowering class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Target/TargetLowering.h" 15 #include "llvm/MC/MCAsmInfo.h" 16 #include "llvm/MC/MCExpr.h" 17 #include "llvm/Target/TargetData.h" 18 #include "llvm/Target/TargetLoweringObjectFile.h" 19 #include "llvm/Target/TargetMachine.h" 20 #include "llvm/Target/TargetRegisterInfo.h" 21 #include "llvm/GlobalVariable.h" 22 #include "llvm/DerivedTypes.h" 23 #include "llvm/CodeGen/Analysis.h" 24 #include "llvm/CodeGen/MachineFrameInfo.h" 25 #include "llvm/CodeGen/MachineJumpTableInfo.h" 26 #include "llvm/CodeGen/MachineFunction.h" 27 #include "llvm/CodeGen/SelectionDAG.h" 28 #include "llvm/ADT/STLExtras.h" 29 #include "llvm/Support/CommandLine.h" 30 #include "llvm/Support/ErrorHandling.h" 31 #include "llvm/Support/MathExtras.h" 32 #include <cctype> 33 using namespace llvm; 34 35 /// We are in the process of implementing a new TypeLegalization action 36 /// - the promotion of vector elements. This feature is disabled by default 37 /// and only enabled using this flag. 38 static cl::opt<bool> 39 AllowPromoteIntElem("promote-elements", cl::Hidden, 40 cl::desc("Allow promotion of integer vector element types")); 41 42 namespace llvm { 43 TLSModel::Model getTLSModel(const GlobalValue *GV, Reloc::Model reloc) { 44 bool isLocal = GV->hasLocalLinkage(); 45 bool isDeclaration = GV->isDeclaration(); 46 // FIXME: what should we do for protected and internal visibility? 47 // For variables, is internal different from hidden? 48 bool isHidden = GV->hasHiddenVisibility(); 49 50 if (reloc == Reloc::PIC_) { 51 if (isLocal || isHidden) 52 return TLSModel::LocalDynamic; 53 else 54 return TLSModel::GeneralDynamic; 55 } else { 56 if (!isDeclaration || isHidden) 57 return TLSModel::LocalExec; 58 else 59 return TLSModel::InitialExec; 60 } 61 } 62 } 63 64 /// InitLibcallNames - Set default libcall names. 65 /// 66 static void InitLibcallNames(const char **Names) { 67 Names[RTLIB::SHL_I16] = "__ashlhi3"; 68 Names[RTLIB::SHL_I32] = "__ashlsi3"; 69 Names[RTLIB::SHL_I64] = "__ashldi3"; 70 Names[RTLIB::SHL_I128] = "__ashlti3"; 71 Names[RTLIB::SRL_I16] = "__lshrhi3"; 72 Names[RTLIB::SRL_I32] = "__lshrsi3"; 73 Names[RTLIB::SRL_I64] = "__lshrdi3"; 74 Names[RTLIB::SRL_I128] = "__lshrti3"; 75 Names[RTLIB::SRA_I16] = "__ashrhi3"; 76 Names[RTLIB::SRA_I32] = "__ashrsi3"; 77 Names[RTLIB::SRA_I64] = "__ashrdi3"; 78 Names[RTLIB::SRA_I128] = "__ashrti3"; 79 Names[RTLIB::MUL_I8] = "__mulqi3"; 80 Names[RTLIB::MUL_I16] = "__mulhi3"; 81 Names[RTLIB::MUL_I32] = "__mulsi3"; 82 Names[RTLIB::MUL_I64] = "__muldi3"; 83 Names[RTLIB::MUL_I128] = "__multi3"; 84 Names[RTLIB::SDIV_I8] = "__divqi3"; 85 Names[RTLIB::SDIV_I16] = "__divhi3"; 86 Names[RTLIB::SDIV_I32] = "__divsi3"; 87 Names[RTLIB::SDIV_I64] = "__divdi3"; 88 Names[RTLIB::SDIV_I128] = "__divti3"; 89 Names[RTLIB::UDIV_I8] = "__udivqi3"; 90 Names[RTLIB::UDIV_I16] = "__udivhi3"; 91 Names[RTLIB::UDIV_I32] = "__udivsi3"; 92 Names[RTLIB::UDIV_I64] = "__udivdi3"; 93 Names[RTLIB::UDIV_I128] = "__udivti3"; 94 Names[RTLIB::SREM_I8] = "__modqi3"; 95 Names[RTLIB::SREM_I16] = "__modhi3"; 96 Names[RTLIB::SREM_I32] = "__modsi3"; 97 Names[RTLIB::SREM_I64] = "__moddi3"; 98 Names[RTLIB::SREM_I128] = "__modti3"; 99 Names[RTLIB::UREM_I8] = "__umodqi3"; 100 Names[RTLIB::UREM_I16] = "__umodhi3"; 101 Names[RTLIB::UREM_I32] = "__umodsi3"; 102 Names[RTLIB::UREM_I64] = "__umoddi3"; 103 Names[RTLIB::UREM_I128] = "__umodti3"; 104 105 // These are generally not available. 106 Names[RTLIB::SDIVREM_I8] = 0; 107 Names[RTLIB::SDIVREM_I16] = 0; 108 Names[RTLIB::SDIVREM_I32] = 0; 109 Names[RTLIB::SDIVREM_I64] = 0; 110 Names[RTLIB::SDIVREM_I128] = 0; 111 Names[RTLIB::UDIVREM_I8] = 0; 112 Names[RTLIB::UDIVREM_I16] = 0; 113 Names[RTLIB::UDIVREM_I32] = 0; 114 Names[RTLIB::UDIVREM_I64] = 0; 115 Names[RTLIB::UDIVREM_I128] = 0; 116 117 Names[RTLIB::NEG_I32] = "__negsi2"; 118 Names[RTLIB::NEG_I64] = "__negdi2"; 119 Names[RTLIB::ADD_F32] = "__addsf3"; 120 Names[RTLIB::ADD_F64] = "__adddf3"; 121 Names[RTLIB::ADD_F80] = "__addxf3"; 122 Names[RTLIB::ADD_PPCF128] = "__gcc_qadd"; 123 Names[RTLIB::SUB_F32] = "__subsf3"; 124 Names[RTLIB::SUB_F64] = "__subdf3"; 125 Names[RTLIB::SUB_F80] = "__subxf3"; 126 Names[RTLIB::SUB_PPCF128] = "__gcc_qsub"; 127 Names[RTLIB::MUL_F32] = "__mulsf3"; 128 Names[RTLIB::MUL_F64] = "__muldf3"; 129 Names[RTLIB::MUL_F80] = "__mulxf3"; 130 Names[RTLIB::MUL_PPCF128] = "__gcc_qmul"; 131 Names[RTLIB::DIV_F32] = "__divsf3"; 132 Names[RTLIB::DIV_F64] = "__divdf3"; 133 Names[RTLIB::DIV_F80] = "__divxf3"; 134 Names[RTLIB::DIV_PPCF128] = "__gcc_qdiv"; 135 Names[RTLIB::REM_F32] = "fmodf"; 136 Names[RTLIB::REM_F64] = "fmod"; 137 Names[RTLIB::REM_F80] = "fmodl"; 138 Names[RTLIB::REM_PPCF128] = "fmodl"; 139 Names[RTLIB::POWI_F32] = "__powisf2"; 140 Names[RTLIB::POWI_F64] = "__powidf2"; 141 Names[RTLIB::POWI_F80] = "__powixf2"; 142 Names[RTLIB::POWI_PPCF128] = "__powitf2"; 143 Names[RTLIB::SQRT_F32] = "sqrtf"; 144 Names[RTLIB::SQRT_F64] = "sqrt"; 145 Names[RTLIB::SQRT_F80] = "sqrtl"; 146 Names[RTLIB::SQRT_PPCF128] = "sqrtl"; 147 Names[RTLIB::LOG_F32] = "logf"; 148 Names[RTLIB::LOG_F64] = "log"; 149 Names[RTLIB::LOG_F80] = "logl"; 150 Names[RTLIB::LOG_PPCF128] = "logl"; 151 Names[RTLIB::LOG2_F32] = "log2f"; 152 Names[RTLIB::LOG2_F64] = "log2"; 153 Names[RTLIB::LOG2_F80] = "log2l"; 154 Names[RTLIB::LOG2_PPCF128] = "log2l"; 155 Names[RTLIB::LOG10_F32] = "log10f"; 156 Names[RTLIB::LOG10_F64] = "log10"; 157 Names[RTLIB::LOG10_F80] = "log10l"; 158 Names[RTLIB::LOG10_PPCF128] = "log10l"; 159 Names[RTLIB::EXP_F32] = "expf"; 160 Names[RTLIB::EXP_F64] = "exp"; 161 Names[RTLIB::EXP_F80] = "expl"; 162 Names[RTLIB::EXP_PPCF128] = "expl"; 163 Names[RTLIB::EXP2_F32] = "exp2f"; 164 Names[RTLIB::EXP2_F64] = "exp2"; 165 Names[RTLIB::EXP2_F80] = "exp2l"; 166 Names[RTLIB::EXP2_PPCF128] = "exp2l"; 167 Names[RTLIB::SIN_F32] = "sinf"; 168 Names[RTLIB::SIN_F64] = "sin"; 169 Names[RTLIB::SIN_F80] = "sinl"; 170 Names[RTLIB::SIN_PPCF128] = "sinl"; 171 Names[RTLIB::COS_F32] = "cosf"; 172 Names[RTLIB::COS_F64] = "cos"; 173 Names[RTLIB::COS_F80] = "cosl"; 174 Names[RTLIB::COS_PPCF128] = "cosl"; 175 Names[RTLIB::POW_F32] = "powf"; 176 Names[RTLIB::POW_F64] = "pow"; 177 Names[RTLIB::POW_F80] = "powl"; 178 Names[RTLIB::POW_PPCF128] = "powl"; 179 Names[RTLIB::CEIL_F32] = "ceilf"; 180 Names[RTLIB::CEIL_F64] = "ceil"; 181 Names[RTLIB::CEIL_F80] = "ceill"; 182 Names[RTLIB::CEIL_PPCF128] = "ceill"; 183 Names[RTLIB::TRUNC_F32] = "truncf"; 184 Names[RTLIB::TRUNC_F64] = "trunc"; 185 Names[RTLIB::TRUNC_F80] = "truncl"; 186 Names[RTLIB::TRUNC_PPCF128] = "truncl"; 187 Names[RTLIB::RINT_F32] = "rintf"; 188 Names[RTLIB::RINT_F64] = "rint"; 189 Names[RTLIB::RINT_F80] = "rintl"; 190 Names[RTLIB::RINT_PPCF128] = "rintl"; 191 Names[RTLIB::NEARBYINT_F32] = "nearbyintf"; 192 Names[RTLIB::NEARBYINT_F64] = "nearbyint"; 193 Names[RTLIB::NEARBYINT_F80] = "nearbyintl"; 194 Names[RTLIB::NEARBYINT_PPCF128] = "nearbyintl"; 195 Names[RTLIB::FLOOR_F32] = "floorf"; 196 Names[RTLIB::FLOOR_F64] = "floor"; 197 Names[RTLIB::FLOOR_F80] = "floorl"; 198 Names[RTLIB::FLOOR_PPCF128] = "floorl"; 199 Names[RTLIB::COPYSIGN_F32] = "copysignf"; 200 Names[RTLIB::COPYSIGN_F64] = "copysign"; 201 Names[RTLIB::COPYSIGN_F80] = "copysignl"; 202 Names[RTLIB::COPYSIGN_PPCF128] = "copysignl"; 203 Names[RTLIB::FPEXT_F32_F64] = "__extendsfdf2"; 204 Names[RTLIB::FPEXT_F16_F32] = "__gnu_h2f_ieee"; 205 Names[RTLIB::FPROUND_F32_F16] = "__gnu_f2h_ieee"; 206 Names[RTLIB::FPROUND_F64_F32] = "__truncdfsf2"; 207 Names[RTLIB::FPROUND_F80_F32] = "__truncxfsf2"; 208 Names[RTLIB::FPROUND_PPCF128_F32] = "__trunctfsf2"; 209 Names[RTLIB::FPROUND_F80_F64] = "__truncxfdf2"; 210 Names[RTLIB::FPROUND_PPCF128_F64] = "__trunctfdf2"; 211 Names[RTLIB::FPTOSINT_F32_I8] = "__fixsfqi"; 212 Names[RTLIB::FPTOSINT_F32_I16] = "__fixsfhi"; 213 Names[RTLIB::FPTOSINT_F32_I32] = "__fixsfsi"; 214 Names[RTLIB::FPTOSINT_F32_I64] = "__fixsfdi"; 215 Names[RTLIB::FPTOSINT_F32_I128] = "__fixsfti"; 216 Names[RTLIB::FPTOSINT_F64_I8] = "__fixdfqi"; 217 Names[RTLIB::FPTOSINT_F64_I16] = "__fixdfhi"; 218 Names[RTLIB::FPTOSINT_F64_I32] = "__fixdfsi"; 219 Names[RTLIB::FPTOSINT_F64_I64] = "__fixdfdi"; 220 Names[RTLIB::FPTOSINT_F64_I128] = "__fixdfti"; 221 Names[RTLIB::FPTOSINT_F80_I32] = "__fixxfsi"; 222 Names[RTLIB::FPTOSINT_F80_I64] = "__fixxfdi"; 223 Names[RTLIB::FPTOSINT_F80_I128] = "__fixxfti"; 224 Names[RTLIB::FPTOSINT_PPCF128_I32] = "__fixtfsi"; 225 Names[RTLIB::FPTOSINT_PPCF128_I64] = "__fixtfdi"; 226 Names[RTLIB::FPTOSINT_PPCF128_I128] = "__fixtfti"; 227 Names[RTLIB::FPTOUINT_F32_I8] = "__fixunssfqi"; 228 Names[RTLIB::FPTOUINT_F32_I16] = "__fixunssfhi"; 229 Names[RTLIB::FPTOUINT_F32_I32] = "__fixunssfsi"; 230 Names[RTLIB::FPTOUINT_F32_I64] = "__fixunssfdi"; 231 Names[RTLIB::FPTOUINT_F32_I128] = "__fixunssfti"; 232 Names[RTLIB::FPTOUINT_F64_I8] = "__fixunsdfqi"; 233 Names[RTLIB::FPTOUINT_F64_I16] = "__fixunsdfhi"; 234 Names[RTLIB::FPTOUINT_F64_I32] = "__fixunsdfsi"; 235 Names[RTLIB::FPTOUINT_F64_I64] = "__fixunsdfdi"; 236 Names[RTLIB::FPTOUINT_F64_I128] = "__fixunsdfti"; 237 Names[RTLIB::FPTOUINT_F80_I32] = "__fixunsxfsi"; 238 Names[RTLIB::FPTOUINT_F80_I64] = "__fixunsxfdi"; 239 Names[RTLIB::FPTOUINT_F80_I128] = "__fixunsxfti"; 240 Names[RTLIB::FPTOUINT_PPCF128_I32] = "__fixunstfsi"; 241 Names[RTLIB::FPTOUINT_PPCF128_I64] = "__fixunstfdi"; 242 Names[RTLIB::FPTOUINT_PPCF128_I128] = "__fixunstfti"; 243 Names[RTLIB::SINTTOFP_I32_F32] = "__floatsisf"; 244 Names[RTLIB::SINTTOFP_I32_F64] = "__floatsidf"; 245 Names[RTLIB::SINTTOFP_I32_F80] = "__floatsixf"; 246 Names[RTLIB::SINTTOFP_I32_PPCF128] = "__floatsitf"; 247 Names[RTLIB::SINTTOFP_I64_F32] = "__floatdisf"; 248 Names[RTLIB::SINTTOFP_I64_F64] = "__floatdidf"; 249 Names[RTLIB::SINTTOFP_I64_F80] = "__floatdixf"; 250 Names[RTLIB::SINTTOFP_I64_PPCF128] = "__floatditf"; 251 Names[RTLIB::SINTTOFP_I128_F32] = "__floattisf"; 252 Names[RTLIB::SINTTOFP_I128_F64] = "__floattidf"; 253 Names[RTLIB::SINTTOFP_I128_F80] = "__floattixf"; 254 Names[RTLIB::SINTTOFP_I128_PPCF128] = "__floattitf"; 255 Names[RTLIB::UINTTOFP_I32_F32] = "__floatunsisf"; 256 Names[RTLIB::UINTTOFP_I32_F64] = "__floatunsidf"; 257 Names[RTLIB::UINTTOFP_I32_F80] = "__floatunsixf"; 258 Names[RTLIB::UINTTOFP_I32_PPCF128] = "__floatunsitf"; 259 Names[RTLIB::UINTTOFP_I64_F32] = "__floatundisf"; 260 Names[RTLIB::UINTTOFP_I64_F64] = "__floatundidf"; 261 Names[RTLIB::UINTTOFP_I64_F80] = "__floatundixf"; 262 Names[RTLIB::UINTTOFP_I64_PPCF128] = "__floatunditf"; 263 Names[RTLIB::UINTTOFP_I128_F32] = "__floatuntisf"; 264 Names[RTLIB::UINTTOFP_I128_F64] = "__floatuntidf"; 265 Names[RTLIB::UINTTOFP_I128_F80] = "__floatuntixf"; 266 Names[RTLIB::UINTTOFP_I128_PPCF128] = "__floatuntitf"; 267 Names[RTLIB::OEQ_F32] = "__eqsf2"; 268 Names[RTLIB::OEQ_F64] = "__eqdf2"; 269 Names[RTLIB::UNE_F32] = "__nesf2"; 270 Names[RTLIB::UNE_F64] = "__nedf2"; 271 Names[RTLIB::OGE_F32] = "__gesf2"; 272 Names[RTLIB::OGE_F64] = "__gedf2"; 273 Names[RTLIB::OLT_F32] = "__ltsf2"; 274 Names[RTLIB::OLT_F64] = "__ltdf2"; 275 Names[RTLIB::OLE_F32] = "__lesf2"; 276 Names[RTLIB::OLE_F64] = "__ledf2"; 277 Names[RTLIB::OGT_F32] = "__gtsf2"; 278 Names[RTLIB::OGT_F64] = "__gtdf2"; 279 Names[RTLIB::UO_F32] = "__unordsf2"; 280 Names[RTLIB::UO_F64] = "__unorddf2"; 281 Names[RTLIB::O_F32] = "__unordsf2"; 282 Names[RTLIB::O_F64] = "__unorddf2"; 283 Names[RTLIB::MEMCPY] = "memcpy"; 284 Names[RTLIB::MEMMOVE] = "memmove"; 285 Names[RTLIB::MEMSET] = "memset"; 286 Names[RTLIB::UNWIND_RESUME] = "_Unwind_Resume"; 287 Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_1] = "__sync_val_compare_and_swap_1"; 288 Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_2] = "__sync_val_compare_and_swap_2"; 289 Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_4] = "__sync_val_compare_and_swap_4"; 290 Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_8] = "__sync_val_compare_and_swap_8"; 291 Names[RTLIB::SYNC_LOCK_TEST_AND_SET_1] = "__sync_lock_test_and_set_1"; 292 Names[RTLIB::SYNC_LOCK_TEST_AND_SET_2] = "__sync_lock_test_and_set_2"; 293 Names[RTLIB::SYNC_LOCK_TEST_AND_SET_4] = "__sync_lock_test_and_set_4"; 294 Names[RTLIB::SYNC_LOCK_TEST_AND_SET_8] = "__sync_lock_test_and_set_8"; 295 Names[RTLIB::SYNC_FETCH_AND_ADD_1] = "__sync_fetch_and_add_1"; 296 Names[RTLIB::SYNC_FETCH_AND_ADD_2] = "__sync_fetch_and_add_2"; 297 Names[RTLIB::SYNC_FETCH_AND_ADD_4] = "__sync_fetch_and_add_4"; 298 Names[RTLIB::SYNC_FETCH_AND_ADD_8] = "__sync_fetch_and_add_8"; 299 Names[RTLIB::SYNC_FETCH_AND_SUB_1] = "__sync_fetch_and_sub_1"; 300 Names[RTLIB::SYNC_FETCH_AND_SUB_2] = "__sync_fetch_and_sub_2"; 301 Names[RTLIB::SYNC_FETCH_AND_SUB_4] = "__sync_fetch_and_sub_4"; 302 Names[RTLIB::SYNC_FETCH_AND_SUB_8] = "__sync_fetch_and_sub_8"; 303 Names[RTLIB::SYNC_FETCH_AND_AND_1] = "__sync_fetch_and_and_1"; 304 Names[RTLIB::SYNC_FETCH_AND_AND_2] = "__sync_fetch_and_and_2"; 305 Names[RTLIB::SYNC_FETCH_AND_AND_4] = "__sync_fetch_and_and_4"; 306 Names[RTLIB::SYNC_FETCH_AND_AND_8] = "__sync_fetch_and_and_8"; 307 Names[RTLIB::SYNC_FETCH_AND_OR_1] = "__sync_fetch_and_or_1"; 308 Names[RTLIB::SYNC_FETCH_AND_OR_2] = "__sync_fetch_and_or_2"; 309 Names[RTLIB::SYNC_FETCH_AND_OR_4] = "__sync_fetch_and_or_4"; 310 Names[RTLIB::SYNC_FETCH_AND_OR_8] = "__sync_fetch_and_or_8"; 311 Names[RTLIB::SYNC_FETCH_AND_XOR_1] = "__sync_fetch_and_xor_1"; 312 Names[RTLIB::SYNC_FETCH_AND_XOR_2] = "__sync_fetch_and_xor_2"; 313 Names[RTLIB::SYNC_FETCH_AND_XOR_4] = "__sync_fetch_and-xor_4"; 314 Names[RTLIB::SYNC_FETCH_AND_XOR_8] = "__sync_fetch_and_xor_8"; 315 Names[RTLIB::SYNC_FETCH_AND_NAND_1] = "__sync_fetch_and_nand_1"; 316 Names[RTLIB::SYNC_FETCH_AND_NAND_2] = "__sync_fetch_and_nand_2"; 317 Names[RTLIB::SYNC_FETCH_AND_NAND_4] = "__sync_fetch_and_nand_4"; 318 Names[RTLIB::SYNC_FETCH_AND_NAND_8] = "__sync_fetch_and_nand_8"; 319 } 320 321 /// InitLibcallCallingConvs - Set default libcall CallingConvs. 322 /// 323 static void InitLibcallCallingConvs(CallingConv::ID *CCs) { 324 for (int i = 0; i < RTLIB::UNKNOWN_LIBCALL; ++i) { 325 CCs[i] = CallingConv::C; 326 } 327 } 328 329 /// getFPEXT - Return the FPEXT_*_* value for the given types, or 330 /// UNKNOWN_LIBCALL if there is none. 331 RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) { 332 if (OpVT == MVT::f32) { 333 if (RetVT == MVT::f64) 334 return FPEXT_F32_F64; 335 } 336 337 return UNKNOWN_LIBCALL; 338 } 339 340 /// getFPROUND - Return the FPROUND_*_* value for the given types, or 341 /// UNKNOWN_LIBCALL if there is none. 342 RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) { 343 if (RetVT == MVT::f32) { 344 if (OpVT == MVT::f64) 345 return FPROUND_F64_F32; 346 if (OpVT == MVT::f80) 347 return FPROUND_F80_F32; 348 if (OpVT == MVT::ppcf128) 349 return FPROUND_PPCF128_F32; 350 } else if (RetVT == MVT::f64) { 351 if (OpVT == MVT::f80) 352 return FPROUND_F80_F64; 353 if (OpVT == MVT::ppcf128) 354 return FPROUND_PPCF128_F64; 355 } 356 357 return UNKNOWN_LIBCALL; 358 } 359 360 /// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or 361 /// UNKNOWN_LIBCALL if there is none. 362 RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) { 363 if (OpVT == MVT::f32) { 364 if (RetVT == MVT::i8) 365 return FPTOSINT_F32_I8; 366 if (RetVT == MVT::i16) 367 return FPTOSINT_F32_I16; 368 if (RetVT == MVT::i32) 369 return FPTOSINT_F32_I32; 370 if (RetVT == MVT::i64) 371 return FPTOSINT_F32_I64; 372 if (RetVT == MVT::i128) 373 return FPTOSINT_F32_I128; 374 } else if (OpVT == MVT::f64) { 375 if (RetVT == MVT::i8) 376 return FPTOSINT_F64_I8; 377 if (RetVT == MVT::i16) 378 return FPTOSINT_F64_I16; 379 if (RetVT == MVT::i32) 380 return FPTOSINT_F64_I32; 381 if (RetVT == MVT::i64) 382 return FPTOSINT_F64_I64; 383 if (RetVT == MVT::i128) 384 return FPTOSINT_F64_I128; 385 } else if (OpVT == MVT::f80) { 386 if (RetVT == MVT::i32) 387 return FPTOSINT_F80_I32; 388 if (RetVT == MVT::i64) 389 return FPTOSINT_F80_I64; 390 if (RetVT == MVT::i128) 391 return FPTOSINT_F80_I128; 392 } else if (OpVT == MVT::ppcf128) { 393 if (RetVT == MVT::i32) 394 return FPTOSINT_PPCF128_I32; 395 if (RetVT == MVT::i64) 396 return FPTOSINT_PPCF128_I64; 397 if (RetVT == MVT::i128) 398 return FPTOSINT_PPCF128_I128; 399 } 400 return UNKNOWN_LIBCALL; 401 } 402 403 /// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or 404 /// UNKNOWN_LIBCALL if there is none. 405 RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) { 406 if (OpVT == MVT::f32) { 407 if (RetVT == MVT::i8) 408 return FPTOUINT_F32_I8; 409 if (RetVT == MVT::i16) 410 return FPTOUINT_F32_I16; 411 if (RetVT == MVT::i32) 412 return FPTOUINT_F32_I32; 413 if (RetVT == MVT::i64) 414 return FPTOUINT_F32_I64; 415 if (RetVT == MVT::i128) 416 return FPTOUINT_F32_I128; 417 } else if (OpVT == MVT::f64) { 418 if (RetVT == MVT::i8) 419 return FPTOUINT_F64_I8; 420 if (RetVT == MVT::i16) 421 return FPTOUINT_F64_I16; 422 if (RetVT == MVT::i32) 423 return FPTOUINT_F64_I32; 424 if (RetVT == MVT::i64) 425 return FPTOUINT_F64_I64; 426 if (RetVT == MVT::i128) 427 return FPTOUINT_F64_I128; 428 } else if (OpVT == MVT::f80) { 429 if (RetVT == MVT::i32) 430 return FPTOUINT_F80_I32; 431 if (RetVT == MVT::i64) 432 return FPTOUINT_F80_I64; 433 if (RetVT == MVT::i128) 434 return FPTOUINT_F80_I128; 435 } else if (OpVT == MVT::ppcf128) { 436 if (RetVT == MVT::i32) 437 return FPTOUINT_PPCF128_I32; 438 if (RetVT == MVT::i64) 439 return FPTOUINT_PPCF128_I64; 440 if (RetVT == MVT::i128) 441 return FPTOUINT_PPCF128_I128; 442 } 443 return UNKNOWN_LIBCALL; 444 } 445 446 /// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or 447 /// UNKNOWN_LIBCALL if there is none. 448 RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) { 449 if (OpVT == MVT::i32) { 450 if (RetVT == MVT::f32) 451 return SINTTOFP_I32_F32; 452 else if (RetVT == MVT::f64) 453 return SINTTOFP_I32_F64; 454 else if (RetVT == MVT::f80) 455 return SINTTOFP_I32_F80; 456 else if (RetVT == MVT::ppcf128) 457 return SINTTOFP_I32_PPCF128; 458 } else if (OpVT == MVT::i64) { 459 if (RetVT == MVT::f32) 460 return SINTTOFP_I64_F32; 461 else if (RetVT == MVT::f64) 462 return SINTTOFP_I64_F64; 463 else if (RetVT == MVT::f80) 464 return SINTTOFP_I64_F80; 465 else if (RetVT == MVT::ppcf128) 466 return SINTTOFP_I64_PPCF128; 467 } else if (OpVT == MVT::i128) { 468 if (RetVT == MVT::f32) 469 return SINTTOFP_I128_F32; 470 else if (RetVT == MVT::f64) 471 return SINTTOFP_I128_F64; 472 else if (RetVT == MVT::f80) 473 return SINTTOFP_I128_F80; 474 else if (RetVT == MVT::ppcf128) 475 return SINTTOFP_I128_PPCF128; 476 } 477 return UNKNOWN_LIBCALL; 478 } 479 480 /// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or 481 /// UNKNOWN_LIBCALL if there is none. 482 RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) { 483 if (OpVT == MVT::i32) { 484 if (RetVT == MVT::f32) 485 return UINTTOFP_I32_F32; 486 else if (RetVT == MVT::f64) 487 return UINTTOFP_I32_F64; 488 else if (RetVT == MVT::f80) 489 return UINTTOFP_I32_F80; 490 else if (RetVT == MVT::ppcf128) 491 return UINTTOFP_I32_PPCF128; 492 } else if (OpVT == MVT::i64) { 493 if (RetVT == MVT::f32) 494 return UINTTOFP_I64_F32; 495 else if (RetVT == MVT::f64) 496 return UINTTOFP_I64_F64; 497 else if (RetVT == MVT::f80) 498 return UINTTOFP_I64_F80; 499 else if (RetVT == MVT::ppcf128) 500 return UINTTOFP_I64_PPCF128; 501 } else if (OpVT == MVT::i128) { 502 if (RetVT == MVT::f32) 503 return UINTTOFP_I128_F32; 504 else if (RetVT == MVT::f64) 505 return UINTTOFP_I128_F64; 506 else if (RetVT == MVT::f80) 507 return UINTTOFP_I128_F80; 508 else if (RetVT == MVT::ppcf128) 509 return UINTTOFP_I128_PPCF128; 510 } 511 return UNKNOWN_LIBCALL; 512 } 513 514 /// InitCmpLibcallCCs - Set default comparison libcall CC. 515 /// 516 static void InitCmpLibcallCCs(ISD::CondCode *CCs) { 517 memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL); 518 CCs[RTLIB::OEQ_F32] = ISD::SETEQ; 519 CCs[RTLIB::OEQ_F64] = ISD::SETEQ; 520 CCs[RTLIB::UNE_F32] = ISD::SETNE; 521 CCs[RTLIB::UNE_F64] = ISD::SETNE; 522 CCs[RTLIB::OGE_F32] = ISD::SETGE; 523 CCs[RTLIB::OGE_F64] = ISD::SETGE; 524 CCs[RTLIB::OLT_F32] = ISD::SETLT; 525 CCs[RTLIB::OLT_F64] = ISD::SETLT; 526 CCs[RTLIB::OLE_F32] = ISD::SETLE; 527 CCs[RTLIB::OLE_F64] = ISD::SETLE; 528 CCs[RTLIB::OGT_F32] = ISD::SETGT; 529 CCs[RTLIB::OGT_F64] = ISD::SETGT; 530 CCs[RTLIB::UO_F32] = ISD::SETNE; 531 CCs[RTLIB::UO_F64] = ISD::SETNE; 532 CCs[RTLIB::O_F32] = ISD::SETEQ; 533 CCs[RTLIB::O_F64] = ISD::SETEQ; 534 } 535 536 /// NOTE: The constructor takes ownership of TLOF. 537 TargetLowering::TargetLowering(const TargetMachine &tm, 538 const TargetLoweringObjectFile *tlof) 539 : TM(tm), TD(TM.getTargetData()), TLOF(*tlof), 540 mayPromoteElements(AllowPromoteIntElem) { 541 // All operations default to being supported. 542 memset(OpActions, 0, sizeof(OpActions)); 543 memset(LoadExtActions, 0, sizeof(LoadExtActions)); 544 memset(TruncStoreActions, 0, sizeof(TruncStoreActions)); 545 memset(IndexedModeActions, 0, sizeof(IndexedModeActions)); 546 memset(CondCodeActions, 0, sizeof(CondCodeActions)); 547 548 // Set default actions for various operations. 549 for (unsigned VT = 0; VT != (unsigned)MVT::LAST_VALUETYPE; ++VT) { 550 // Default all indexed load / store to expand. 551 for (unsigned IM = (unsigned)ISD::PRE_INC; 552 IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) { 553 setIndexedLoadAction(IM, (MVT::SimpleValueType)VT, Expand); 554 setIndexedStoreAction(IM, (MVT::SimpleValueType)VT, Expand); 555 } 556 557 // These operations default to expand. 558 setOperationAction(ISD::FGETSIGN, (MVT::SimpleValueType)VT, Expand); 559 setOperationAction(ISD::CONCAT_VECTORS, (MVT::SimpleValueType)VT, Expand); 560 } 561 562 // Most targets ignore the @llvm.prefetch intrinsic. 563 setOperationAction(ISD::PREFETCH, MVT::Other, Expand); 564 565 // ConstantFP nodes default to expand. Targets can either change this to 566 // Legal, in which case all fp constants are legal, or use isFPImmLegal() 567 // to optimize expansions for certain constants. 568 setOperationAction(ISD::ConstantFP, MVT::f32, Expand); 569 setOperationAction(ISD::ConstantFP, MVT::f64, Expand); 570 setOperationAction(ISD::ConstantFP, MVT::f80, Expand); 571 572 // These library functions default to expand. 573 setOperationAction(ISD::FLOG , MVT::f64, Expand); 574 setOperationAction(ISD::FLOG2, MVT::f64, Expand); 575 setOperationAction(ISD::FLOG10,MVT::f64, Expand); 576 setOperationAction(ISD::FEXP , MVT::f64, Expand); 577 setOperationAction(ISD::FEXP2, MVT::f64, Expand); 578 setOperationAction(ISD::FLOG , MVT::f32, Expand); 579 setOperationAction(ISD::FLOG2, MVT::f32, Expand); 580 setOperationAction(ISD::FLOG10,MVT::f32, Expand); 581 setOperationAction(ISD::FEXP , MVT::f32, Expand); 582 setOperationAction(ISD::FEXP2, MVT::f32, Expand); 583 584 // Default ISD::TRAP to expand (which turns it into abort). 585 setOperationAction(ISD::TRAP, MVT::Other, Expand); 586 587 IsLittleEndian = TD->isLittleEndian(); 588 PointerTy = MVT::getIntegerVT(8*TD->getPointerSize()); 589 memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*)); 590 memset(TargetDAGCombineArray, 0, array_lengthof(TargetDAGCombineArray)); 591 maxStoresPerMemset = maxStoresPerMemcpy = maxStoresPerMemmove = 8; 592 maxStoresPerMemsetOptSize = maxStoresPerMemcpyOptSize 593 = maxStoresPerMemmoveOptSize = 4; 594 benefitFromCodePlacementOpt = false; 595 UseUnderscoreSetJmp = false; 596 UseUnderscoreLongJmp = false; 597 SelectIsExpensive = false; 598 IntDivIsCheap = false; 599 Pow2DivIsCheap = false; 600 JumpIsExpensive = false; 601 StackPointerRegisterToSaveRestore = 0; 602 ExceptionPointerRegister = 0; 603 ExceptionSelectorRegister = 0; 604 BooleanContents = UndefinedBooleanContent; 605 SchedPreferenceInfo = Sched::Latency; 606 JumpBufSize = 0; 607 JumpBufAlignment = 0; 608 MinFunctionAlignment = 0; 609 PrefFunctionAlignment = 0; 610 PrefLoopAlignment = 0; 611 MinStackArgumentAlignment = 1; 612 ShouldFoldAtomicFences = false; 613 614 InitLibcallNames(LibcallRoutineNames); 615 InitCmpLibcallCCs(CmpLibcallCCs); 616 InitLibcallCallingConvs(LibcallCallingConvs); 617 } 618 619 TargetLowering::~TargetLowering() { 620 delete &TLOF; 621 } 622 623 MVT TargetLowering::getShiftAmountTy(EVT LHSTy) const { 624 return MVT::getIntegerVT(8*TD->getPointerSize()); 625 } 626 627 /// canOpTrap - Returns true if the operation can trap for the value type. 628 /// VT must be a legal type. 629 bool TargetLowering::canOpTrap(unsigned Op, EVT VT) const { 630 assert(isTypeLegal(VT)); 631 switch (Op) { 632 default: 633 return false; 634 case ISD::FDIV: 635 case ISD::FREM: 636 case ISD::SDIV: 637 case ISD::UDIV: 638 case ISD::SREM: 639 case ISD::UREM: 640 return true; 641 } 642 } 643 644 645 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT, 646 unsigned &NumIntermediates, 647 EVT &RegisterVT, 648 TargetLowering *TLI) { 649 // Figure out the right, legal destination reg to copy into. 650 unsigned NumElts = VT.getVectorNumElements(); 651 MVT EltTy = VT.getVectorElementType(); 652 653 unsigned NumVectorRegs = 1; 654 655 // FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we 656 // could break down into LHS/RHS like LegalizeDAG does. 657 if (!isPowerOf2_32(NumElts)) { 658 NumVectorRegs = NumElts; 659 NumElts = 1; 660 } 661 662 // Divide the input until we get to a supported size. This will always 663 // end with a scalar if the target doesn't support vectors. 664 while (NumElts > 1 && !TLI->isTypeLegal(MVT::getVectorVT(EltTy, NumElts))) { 665 NumElts >>= 1; 666 NumVectorRegs <<= 1; 667 } 668 669 NumIntermediates = NumVectorRegs; 670 671 MVT NewVT = MVT::getVectorVT(EltTy, NumElts); 672 if (!TLI->isTypeLegal(NewVT)) 673 NewVT = EltTy; 674 IntermediateVT = NewVT; 675 676 EVT DestVT = TLI->getRegisterType(NewVT); 677 RegisterVT = DestVT; 678 if (EVT(DestVT).bitsLT(NewVT)) // Value is expanded, e.g. i64 -> i16. 679 return NumVectorRegs*(NewVT.getSizeInBits()/DestVT.getSizeInBits()); 680 681 // Otherwise, promotion or legal types use the same number of registers as 682 // the vector decimated to the appropriate level. 683 return NumVectorRegs; 684 } 685 686 /// isLegalRC - Return true if the value types that can be represented by the 687 /// specified register class are all legal. 688 bool TargetLowering::isLegalRC(const TargetRegisterClass *RC) const { 689 for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end(); 690 I != E; ++I) { 691 if (isTypeLegal(*I)) 692 return true; 693 } 694 return false; 695 } 696 697 /// hasLegalSuperRegRegClasses - Return true if the specified register class 698 /// has one or more super-reg register classes that are legal. 699 bool 700 TargetLowering::hasLegalSuperRegRegClasses(const TargetRegisterClass *RC) const{ 701 if (*RC->superregclasses_begin() == 0) 702 return false; 703 for (TargetRegisterInfo::regclass_iterator I = RC->superregclasses_begin(), 704 E = RC->superregclasses_end(); I != E; ++I) { 705 const TargetRegisterClass *RRC = *I; 706 if (isLegalRC(RRC)) 707 return true; 708 } 709 return false; 710 } 711 712 /// findRepresentativeClass - Return the largest legal super-reg register class 713 /// of the register class for the specified type and its associated "cost". 714 std::pair<const TargetRegisterClass*, uint8_t> 715 TargetLowering::findRepresentativeClass(EVT VT) const { 716 const TargetRegisterClass *RC = RegClassForVT[VT.getSimpleVT().SimpleTy]; 717 if (!RC) 718 return std::make_pair(RC, 0); 719 const TargetRegisterClass *BestRC = RC; 720 for (TargetRegisterInfo::regclass_iterator I = RC->superregclasses_begin(), 721 E = RC->superregclasses_end(); I != E; ++I) { 722 const TargetRegisterClass *RRC = *I; 723 if (RRC->isASubClass() || !isLegalRC(RRC)) 724 continue; 725 if (!hasLegalSuperRegRegClasses(RRC)) 726 return std::make_pair(RRC, 1); 727 BestRC = RRC; 728 } 729 return std::make_pair(BestRC, 1); 730 } 731 732 733 /// computeRegisterProperties - Once all of the register classes are added, 734 /// this allows us to compute derived properties we expose. 735 void TargetLowering::computeRegisterProperties() { 736 assert(MVT::LAST_VALUETYPE <= MVT::MAX_ALLOWED_VALUETYPE && 737 "Too many value types for ValueTypeActions to hold!"); 738 739 // Everything defaults to needing one register. 740 for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) { 741 NumRegistersForVT[i] = 1; 742 RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i; 743 } 744 // ...except isVoid, which doesn't need any registers. 745 NumRegistersForVT[MVT::isVoid] = 0; 746 747 // Find the largest integer register class. 748 unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE; 749 for (; RegClassForVT[LargestIntReg] == 0; --LargestIntReg) 750 assert(LargestIntReg != MVT::i1 && "No integer registers defined!"); 751 752 // Every integer value type larger than this largest register takes twice as 753 // many registers to represent as the previous ValueType. 754 for (unsigned ExpandedReg = LargestIntReg + 1; ; ++ExpandedReg) { 755 EVT ExpandedVT = (MVT::SimpleValueType)ExpandedReg; 756 if (!ExpandedVT.isInteger()) 757 break; 758 NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1]; 759 RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg; 760 TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1); 761 ValueTypeActions.setTypeAction(ExpandedVT, TypeExpandInteger); 762 } 763 764 // Inspect all of the ValueType's smaller than the largest integer 765 // register to see which ones need promotion. 766 unsigned LegalIntReg = LargestIntReg; 767 for (unsigned IntReg = LargestIntReg - 1; 768 IntReg >= (unsigned)MVT::i1; --IntReg) { 769 EVT IVT = (MVT::SimpleValueType)IntReg; 770 if (isTypeLegal(IVT)) { 771 LegalIntReg = IntReg; 772 } else { 773 RegisterTypeForVT[IntReg] = TransformToType[IntReg] = 774 (MVT::SimpleValueType)LegalIntReg; 775 ValueTypeActions.setTypeAction(IVT, TypePromoteInteger); 776 } 777 } 778 779 // ppcf128 type is really two f64's. 780 if (!isTypeLegal(MVT::ppcf128)) { 781 NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64]; 782 RegisterTypeForVT[MVT::ppcf128] = MVT::f64; 783 TransformToType[MVT::ppcf128] = MVT::f64; 784 ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat); 785 } 786 787 // Decide how to handle f64. If the target does not have native f64 support, 788 // expand it to i64 and we will be generating soft float library calls. 789 if (!isTypeLegal(MVT::f64)) { 790 NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64]; 791 RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64]; 792 TransformToType[MVT::f64] = MVT::i64; 793 ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat); 794 } 795 796 // Decide how to handle f32. If the target does not have native support for 797 // f32, promote it to f64 if it is legal. Otherwise, expand it to i32. 798 if (!isTypeLegal(MVT::f32)) { 799 if (isTypeLegal(MVT::f64)) { 800 NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::f64]; 801 RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::f64]; 802 TransformToType[MVT::f32] = MVT::f64; 803 ValueTypeActions.setTypeAction(MVT::f32, TypePromoteInteger); 804 } else { 805 NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32]; 806 RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32]; 807 TransformToType[MVT::f32] = MVT::i32; 808 ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat); 809 } 810 } 811 812 // Loop over all of the vector value types to see which need transformations. 813 for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE; 814 i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) { 815 MVT VT = (MVT::SimpleValueType)i; 816 if (isTypeLegal(VT)) continue; 817 818 // Determine if there is a legal wider type. If so, we should promote to 819 // that wider vector type. 820 EVT EltVT = VT.getVectorElementType(); 821 unsigned NElts = VT.getVectorNumElements(); 822 if (NElts != 1) { 823 bool IsLegalWiderType = false; 824 for (unsigned nVT = i+1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) { 825 EVT SVT = (MVT::SimpleValueType)nVT; 826 827 // If we allow the promotion of vector elements using a flag, 828 // then return TypePromoteInteger on vector elements. 829 if (mayPromoteElements) { 830 // Promote vectors of integers to vectors with the same number 831 // of elements, with a wider element type. 832 if (SVT.getVectorElementType().getSizeInBits() > EltVT.getSizeInBits() 833 && SVT.getVectorNumElements() == NElts && 834 isTypeLegal(SVT) && SVT.getScalarType().isInteger()) { 835 TransformToType[i] = SVT; 836 RegisterTypeForVT[i] = SVT; 837 NumRegistersForVT[i] = 1; 838 ValueTypeActions.setTypeAction(VT, TypePromoteInteger); 839 IsLegalWiderType = true; 840 break; 841 } 842 } 843 844 if (SVT.getVectorElementType() == EltVT && 845 SVT.getVectorNumElements() > NElts && 846 isTypeLegal(SVT)) { 847 TransformToType[i] = SVT; 848 RegisterTypeForVT[i] = SVT; 849 NumRegistersForVT[i] = 1; 850 ValueTypeActions.setTypeAction(VT, TypeWidenVector); 851 IsLegalWiderType = true; 852 break; 853 } 854 } 855 if (IsLegalWiderType) continue; 856 } 857 858 MVT IntermediateVT; 859 EVT RegisterVT; 860 unsigned NumIntermediates; 861 NumRegistersForVT[i] = 862 getVectorTypeBreakdownMVT(VT, IntermediateVT, NumIntermediates, 863 RegisterVT, this); 864 RegisterTypeForVT[i] = RegisterVT; 865 866 EVT NVT = VT.getPow2VectorType(); 867 if (NVT == VT) { 868 // Type is already a power of 2. The default action is to split. 869 TransformToType[i] = MVT::Other; 870 unsigned NumElts = VT.getVectorNumElements(); 871 ValueTypeActions.setTypeAction(VT, 872 NumElts > 1 ? TypeSplitVector : TypeScalarizeVector); 873 } else { 874 TransformToType[i] = NVT; 875 ValueTypeActions.setTypeAction(VT, TypeWidenVector); 876 } 877 } 878 879 // Determine the 'representative' register class for each value type. 880 // An representative register class is the largest (meaning one which is 881 // not a sub-register class / subreg register class) legal register class for 882 // a group of value types. For example, on i386, i8, i16, and i32 883 // representative would be GR32; while on x86_64 it's GR64. 884 for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) { 885 const TargetRegisterClass* RRC; 886 uint8_t Cost; 887 tie(RRC, Cost) = findRepresentativeClass((MVT::SimpleValueType)i); 888 RepRegClassForVT[i] = RRC; 889 RepRegClassCostForVT[i] = Cost; 890 } 891 } 892 893 const char *TargetLowering::getTargetNodeName(unsigned Opcode) const { 894 return NULL; 895 } 896 897 898 MVT::SimpleValueType TargetLowering::getSetCCResultType(EVT VT) const { 899 return PointerTy.SimpleTy; 900 } 901 902 MVT::SimpleValueType TargetLowering::getCmpLibcallReturnType() const { 903 return MVT::i32; // return the default value 904 } 905 906 /// getVectorTypeBreakdown - Vector types are broken down into some number of 907 /// legal first class types. For example, MVT::v8f32 maps to 2 MVT::v4f32 908 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack. 909 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86. 910 /// 911 /// This method returns the number of registers needed, and the VT for each 912 /// register. It also returns the VT and quantity of the intermediate values 913 /// before they are promoted/expanded. 914 /// 915 unsigned TargetLowering::getVectorTypeBreakdown(LLVMContext &Context, EVT VT, 916 EVT &IntermediateVT, 917 unsigned &NumIntermediates, 918 EVT &RegisterVT) const { 919 unsigned NumElts = VT.getVectorNumElements(); 920 921 // If there is a wider vector type with the same element type as this one, 922 // we should widen to that legal vector type. This handles things like 923 // <2 x float> -> <4 x float>. 924 if (NumElts != 1 && getTypeAction(Context, VT) == TypeWidenVector) { 925 RegisterVT = getTypeToTransformTo(Context, VT); 926 if (isTypeLegal(RegisterVT)) { 927 IntermediateVT = RegisterVT; 928 NumIntermediates = 1; 929 return 1; 930 } 931 } 932 933 // Figure out the right, legal destination reg to copy into. 934 EVT EltTy = VT.getVectorElementType(); 935 936 unsigned NumVectorRegs = 1; 937 938 // FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we 939 // could break down into LHS/RHS like LegalizeDAG does. 940 if (!isPowerOf2_32(NumElts)) { 941 NumVectorRegs = NumElts; 942 NumElts = 1; 943 } 944 945 // Divide the input until we get to a supported size. This will always 946 // end with a scalar if the target doesn't support vectors. 947 while (NumElts > 1 && !isTypeLegal( 948 EVT::getVectorVT(Context, EltTy, NumElts))) { 949 NumElts >>= 1; 950 NumVectorRegs <<= 1; 951 } 952 953 NumIntermediates = NumVectorRegs; 954 955 EVT NewVT = EVT::getVectorVT(Context, EltTy, NumElts); 956 if (!isTypeLegal(NewVT)) 957 NewVT = EltTy; 958 IntermediateVT = NewVT; 959 960 EVT DestVT = getRegisterType(Context, NewVT); 961 RegisterVT = DestVT; 962 if (DestVT.bitsLT(NewVT)) // Value is expanded, e.g. i64 -> i16. 963 return NumVectorRegs*(NewVT.getSizeInBits()/DestVT.getSizeInBits()); 964 965 // Otherwise, promotion or legal types use the same number of registers as 966 // the vector decimated to the appropriate level. 967 return NumVectorRegs; 968 } 969 970 /// Get the EVTs and ArgFlags collections that represent the legalized return 971 /// type of the given function. This does not require a DAG or a return value, 972 /// and is suitable for use before any DAGs for the function are constructed. 973 /// TODO: Move this out of TargetLowering.cpp. 974 void llvm::GetReturnInfo(const Type* ReturnType, Attributes attr, 975 SmallVectorImpl<ISD::OutputArg> &Outs, 976 const TargetLowering &TLI, 977 SmallVectorImpl<uint64_t> *Offsets) { 978 SmallVector<EVT, 4> ValueVTs; 979 ComputeValueVTs(TLI, ReturnType, ValueVTs); 980 unsigned NumValues = ValueVTs.size(); 981 if (NumValues == 0) return; 982 unsigned Offset = 0; 983 984 for (unsigned j = 0, f = NumValues; j != f; ++j) { 985 EVT VT = ValueVTs[j]; 986 ISD::NodeType ExtendKind = ISD::ANY_EXTEND; 987 988 if (attr & Attribute::SExt) 989 ExtendKind = ISD::SIGN_EXTEND; 990 else if (attr & Attribute::ZExt) 991 ExtendKind = ISD::ZERO_EXTEND; 992 993 // FIXME: C calling convention requires the return type to be promoted to 994 // at least 32-bit. But this is not necessary for non-C calling 995 // conventions. The frontend should mark functions whose return values 996 // require promoting with signext or zeroext attributes. 997 if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) { 998 EVT MinVT = TLI.getRegisterType(ReturnType->getContext(), MVT::i32); 999 if (VT.bitsLT(MinVT)) 1000 VT = MinVT; 1001 } 1002 1003 unsigned NumParts = TLI.getNumRegisters(ReturnType->getContext(), VT); 1004 EVT PartVT = TLI.getRegisterType(ReturnType->getContext(), VT); 1005 unsigned PartSize = TLI.getTargetData()->getTypeAllocSize( 1006 PartVT.getTypeForEVT(ReturnType->getContext())); 1007 1008 // 'inreg' on function refers to return value 1009 ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy(); 1010 if (attr & Attribute::InReg) 1011 Flags.setInReg(); 1012 1013 // Propagate extension type if any 1014 if (attr & Attribute::SExt) 1015 Flags.setSExt(); 1016 else if (attr & Attribute::ZExt) 1017 Flags.setZExt(); 1018 1019 for (unsigned i = 0; i < NumParts; ++i) { 1020 Outs.push_back(ISD::OutputArg(Flags, PartVT, /*isFixed=*/true)); 1021 if (Offsets) { 1022 Offsets->push_back(Offset); 1023 Offset += PartSize; 1024 } 1025 } 1026 } 1027 } 1028 1029 /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate 1030 /// function arguments in the caller parameter area. This is the actual 1031 /// alignment, not its logarithm. 1032 unsigned TargetLowering::getByValTypeAlignment(const Type *Ty) const { 1033 return TD->getCallFrameTypeAlignment(Ty); 1034 } 1035 1036 /// getJumpTableEncoding - Return the entry encoding for a jump table in the 1037 /// current function. The returned value is a member of the 1038 /// MachineJumpTableInfo::JTEntryKind enum. 1039 unsigned TargetLowering::getJumpTableEncoding() const { 1040 // In non-pic modes, just use the address of a block. 1041 if (getTargetMachine().getRelocationModel() != Reloc::PIC_) 1042 return MachineJumpTableInfo::EK_BlockAddress; 1043 1044 // In PIC mode, if the target supports a GPRel32 directive, use it. 1045 if (getTargetMachine().getMCAsmInfo()->getGPRel32Directive() != 0) 1046 return MachineJumpTableInfo::EK_GPRel32BlockAddress; 1047 1048 // Otherwise, use a label difference. 1049 return MachineJumpTableInfo::EK_LabelDifference32; 1050 } 1051 1052 SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table, 1053 SelectionDAG &DAG) const { 1054 // If our PIC model is GP relative, use the global offset table as the base. 1055 if (getJumpTableEncoding() == MachineJumpTableInfo::EK_GPRel32BlockAddress) 1056 return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy()); 1057 return Table; 1058 } 1059 1060 /// getPICJumpTableRelocBaseExpr - This returns the relocation base for the 1061 /// given PIC jumptable, the same as getPICJumpTableRelocBase, but as an 1062 /// MCExpr. 1063 const MCExpr * 1064 TargetLowering::getPICJumpTableRelocBaseExpr(const MachineFunction *MF, 1065 unsigned JTI,MCContext &Ctx) const{ 1066 // The normal PIC reloc base is the label at the start of the jump table. 1067 return MCSymbolRefExpr::Create(MF->getJTISymbol(JTI, Ctx), Ctx); 1068 } 1069 1070 bool 1071 TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const { 1072 // Assume that everything is safe in static mode. 1073 if (getTargetMachine().getRelocationModel() == Reloc::Static) 1074 return true; 1075 1076 // In dynamic-no-pic mode, assume that known defined values are safe. 1077 if (getTargetMachine().getRelocationModel() == Reloc::DynamicNoPIC && 1078 GA && 1079 !GA->getGlobal()->isDeclaration() && 1080 !GA->getGlobal()->isWeakForLinker()) 1081 return true; 1082 1083 // Otherwise assume nothing is safe. 1084 return false; 1085 } 1086 1087 //===----------------------------------------------------------------------===// 1088 // Optimization Methods 1089 //===----------------------------------------------------------------------===// 1090 1091 /// ShrinkDemandedConstant - Check to see if the specified operand of the 1092 /// specified instruction is a constant integer. If so, check to see if there 1093 /// are any bits set in the constant that are not demanded. If so, shrink the 1094 /// constant and return true. 1095 bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDValue Op, 1096 const APInt &Demanded) { 1097 DebugLoc dl = Op.getDebugLoc(); 1098 1099 // FIXME: ISD::SELECT, ISD::SELECT_CC 1100 switch (Op.getOpcode()) { 1101 default: break; 1102 case ISD::XOR: 1103 case ISD::AND: 1104 case ISD::OR: { 1105 ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1)); 1106 if (!C) return false; 1107 1108 if (Op.getOpcode() == ISD::XOR && 1109 (C->getAPIntValue() | (~Demanded)).isAllOnesValue()) 1110 return false; 1111 1112 // if we can expand it to have all bits set, do it 1113 if (C->getAPIntValue().intersects(~Demanded)) { 1114 EVT VT = Op.getValueType(); 1115 SDValue New = DAG.getNode(Op.getOpcode(), dl, VT, Op.getOperand(0), 1116 DAG.getConstant(Demanded & 1117 C->getAPIntValue(), 1118 VT)); 1119 return CombineTo(Op, New); 1120 } 1121 1122 break; 1123 } 1124 } 1125 1126 return false; 1127 } 1128 1129 /// ShrinkDemandedOp - Convert x+y to (VT)((SmallVT)x+(SmallVT)y) if the 1130 /// casts are free. This uses isZExtFree and ZERO_EXTEND for the widening 1131 /// cast, but it could be generalized for targets with other types of 1132 /// implicit widening casts. 1133 bool 1134 TargetLowering::TargetLoweringOpt::ShrinkDemandedOp(SDValue Op, 1135 unsigned BitWidth, 1136 const APInt &Demanded, 1137 DebugLoc dl) { 1138 assert(Op.getNumOperands() == 2 && 1139 "ShrinkDemandedOp only supports binary operators!"); 1140 assert(Op.getNode()->getNumValues() == 1 && 1141 "ShrinkDemandedOp only supports nodes with one result!"); 1142 1143 // Don't do this if the node has another user, which may require the 1144 // full value. 1145 if (!Op.getNode()->hasOneUse()) 1146 return false; 1147 1148 // Search for the smallest integer type with free casts to and from 1149 // Op's type. For expedience, just check power-of-2 integer types. 1150 const TargetLowering &TLI = DAG.getTargetLoweringInfo(); 1151 unsigned SmallVTBits = BitWidth - Demanded.countLeadingZeros(); 1152 if (!isPowerOf2_32(SmallVTBits)) 1153 SmallVTBits = NextPowerOf2(SmallVTBits); 1154 for (; SmallVTBits < BitWidth; SmallVTBits = NextPowerOf2(SmallVTBits)) { 1155 EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), SmallVTBits); 1156 if (TLI.isTruncateFree(Op.getValueType(), SmallVT) && 1157 TLI.isZExtFree(SmallVT, Op.getValueType())) { 1158 // We found a type with free casts. 1159 SDValue X = DAG.getNode(Op.getOpcode(), dl, SmallVT, 1160 DAG.getNode(ISD::TRUNCATE, dl, SmallVT, 1161 Op.getNode()->getOperand(0)), 1162 DAG.getNode(ISD::TRUNCATE, dl, SmallVT, 1163 Op.getNode()->getOperand(1))); 1164 SDValue Z = DAG.getNode(ISD::ZERO_EXTEND, dl, Op.getValueType(), X); 1165 return CombineTo(Op, Z); 1166 } 1167 } 1168 return false; 1169 } 1170 1171 /// SimplifyDemandedBits - Look at Op. At this point, we know that only the 1172 /// DemandedMask bits of the result of Op are ever used downstream. If we can 1173 /// use this information to simplify Op, create a new simplified DAG node and 1174 /// return true, returning the original and new nodes in Old and New. Otherwise, 1175 /// analyze the expression and return a mask of KnownOne and KnownZero bits for 1176 /// the expression (used to simplify the caller). The KnownZero/One bits may 1177 /// only be accurate for those bits in the DemandedMask. 1178 bool TargetLowering::SimplifyDemandedBits(SDValue Op, 1179 const APInt &DemandedMask, 1180 APInt &KnownZero, 1181 APInt &KnownOne, 1182 TargetLoweringOpt &TLO, 1183 unsigned Depth) const { 1184 unsigned BitWidth = DemandedMask.getBitWidth(); 1185 assert(Op.getValueType().getScalarType().getSizeInBits() == BitWidth && 1186 "Mask size mismatches value type size!"); 1187 APInt NewMask = DemandedMask; 1188 DebugLoc dl = Op.getDebugLoc(); 1189 1190 // Don't know anything. 1191 KnownZero = KnownOne = APInt(BitWidth, 0); 1192 1193 // Other users may use these bits. 1194 if (!Op.getNode()->hasOneUse()) { 1195 if (Depth != 0) { 1196 // If not at the root, Just compute the KnownZero/KnownOne bits to 1197 // simplify things downstream. 1198 TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth); 1199 return false; 1200 } 1201 // If this is the root being simplified, allow it to have multiple uses, 1202 // just set the NewMask to all bits. 1203 NewMask = APInt::getAllOnesValue(BitWidth); 1204 } else if (DemandedMask == 0) { 1205 // Not demanding any bits from Op. 1206 if (Op.getOpcode() != ISD::UNDEF) 1207 return TLO.CombineTo(Op, TLO.DAG.getUNDEF(Op.getValueType())); 1208 return false; 1209 } else if (Depth == 6) { // Limit search depth. 1210 return false; 1211 } 1212 1213 APInt KnownZero2, KnownOne2, KnownZeroOut, KnownOneOut; 1214 switch (Op.getOpcode()) { 1215 case ISD::Constant: 1216 // We know all of the bits for a constant! 1217 KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue() & NewMask; 1218 KnownZero = ~KnownOne & NewMask; 1219 return false; // Don't fall through, will infinitely loop. 1220 case ISD::AND: 1221 // If the RHS is a constant, check to see if the LHS would be zero without 1222 // using the bits from the RHS. Below, we use knowledge about the RHS to 1223 // simplify the LHS, here we're using information from the LHS to simplify 1224 // the RHS. 1225 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { 1226 APInt LHSZero, LHSOne; 1227 // Do not increment Depth here; that can cause an infinite loop. 1228 TLO.DAG.ComputeMaskedBits(Op.getOperand(0), NewMask, 1229 LHSZero, LHSOne, Depth); 1230 // If the LHS already has zeros where RHSC does, this and is dead. 1231 if ((LHSZero & NewMask) == (~RHSC->getAPIntValue() & NewMask)) 1232 return TLO.CombineTo(Op, Op.getOperand(0)); 1233 // If any of the set bits in the RHS are known zero on the LHS, shrink 1234 // the constant. 1235 if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & NewMask)) 1236 return true; 1237 } 1238 1239 if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero, 1240 KnownOne, TLO, Depth+1)) 1241 return true; 1242 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1243 if (SimplifyDemandedBits(Op.getOperand(0), ~KnownZero & NewMask, 1244 KnownZero2, KnownOne2, TLO, Depth+1)) 1245 return true; 1246 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 1247 1248 // If all of the demanded bits are known one on one side, return the other. 1249 // These bits cannot contribute to the result of the 'and'. 1250 if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask)) 1251 return TLO.CombineTo(Op, Op.getOperand(0)); 1252 if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask)) 1253 return TLO.CombineTo(Op, Op.getOperand(1)); 1254 // If all of the demanded bits in the inputs are known zeros, return zero. 1255 if ((NewMask & (KnownZero|KnownZero2)) == NewMask) 1256 return TLO.CombineTo(Op, TLO.DAG.getConstant(0, Op.getValueType())); 1257 // If the RHS is a constant, see if we can simplify it. 1258 if (TLO.ShrinkDemandedConstant(Op, ~KnownZero2 & NewMask)) 1259 return true; 1260 // If the operation can be done in a smaller type, do so. 1261 if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl)) 1262 return true; 1263 1264 // Output known-1 bits are only known if set in both the LHS & RHS. 1265 KnownOne &= KnownOne2; 1266 // Output known-0 are known to be clear if zero in either the LHS | RHS. 1267 KnownZero |= KnownZero2; 1268 break; 1269 case ISD::OR: 1270 if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero, 1271 KnownOne, TLO, Depth+1)) 1272 return true; 1273 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1274 if (SimplifyDemandedBits(Op.getOperand(0), ~KnownOne & NewMask, 1275 KnownZero2, KnownOne2, TLO, Depth+1)) 1276 return true; 1277 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 1278 1279 // If all of the demanded bits are known zero on one side, return the other. 1280 // These bits cannot contribute to the result of the 'or'. 1281 if ((NewMask & ~KnownOne2 & KnownZero) == (~KnownOne2 & NewMask)) 1282 return TLO.CombineTo(Op, Op.getOperand(0)); 1283 if ((NewMask & ~KnownOne & KnownZero2) == (~KnownOne & NewMask)) 1284 return TLO.CombineTo(Op, Op.getOperand(1)); 1285 // If all of the potentially set bits on one side are known to be set on 1286 // the other side, just use the 'other' side. 1287 if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask)) 1288 return TLO.CombineTo(Op, Op.getOperand(0)); 1289 if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask)) 1290 return TLO.CombineTo(Op, Op.getOperand(1)); 1291 // If the RHS is a constant, see if we can simplify it. 1292 if (TLO.ShrinkDemandedConstant(Op, NewMask)) 1293 return true; 1294 // If the operation can be done in a smaller type, do so. 1295 if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl)) 1296 return true; 1297 1298 // Output known-0 bits are only known if clear in both the LHS & RHS. 1299 KnownZero &= KnownZero2; 1300 // Output known-1 are known to be set if set in either the LHS | RHS. 1301 KnownOne |= KnownOne2; 1302 break; 1303 case ISD::XOR: 1304 if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero, 1305 KnownOne, TLO, Depth+1)) 1306 return true; 1307 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1308 if (SimplifyDemandedBits(Op.getOperand(0), NewMask, KnownZero2, 1309 KnownOne2, TLO, Depth+1)) 1310 return true; 1311 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 1312 1313 // If all of the demanded bits are known zero on one side, return the other. 1314 // These bits cannot contribute to the result of the 'xor'. 1315 if ((KnownZero & NewMask) == NewMask) 1316 return TLO.CombineTo(Op, Op.getOperand(0)); 1317 if ((KnownZero2 & NewMask) == NewMask) 1318 return TLO.CombineTo(Op, Op.getOperand(1)); 1319 // If the operation can be done in a smaller type, do so. 1320 if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl)) 1321 return true; 1322 1323 // If all of the unknown bits are known to be zero on one side or the other 1324 // (but not both) turn this into an *inclusive* or. 1325 // e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0 1326 if ((NewMask & ~KnownZero & ~KnownZero2) == 0) 1327 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, dl, Op.getValueType(), 1328 Op.getOperand(0), 1329 Op.getOperand(1))); 1330 1331 // Output known-0 bits are known if clear or set in both the LHS & RHS. 1332 KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2); 1333 // Output known-1 are known to be set if set in only one of the LHS, RHS. 1334 KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2); 1335 1336 // If all of the demanded bits on one side are known, and all of the set 1337 // bits on that side are also known to be set on the other side, turn this 1338 // into an AND, as we know the bits will be cleared. 1339 // e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2 1340 if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known 1341 if ((KnownOne & KnownOne2) == KnownOne) { 1342 EVT VT = Op.getValueType(); 1343 SDValue ANDC = TLO.DAG.getConstant(~KnownOne & NewMask, VT); 1344 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, dl, VT, 1345 Op.getOperand(0), ANDC)); 1346 } 1347 } 1348 1349 // If the RHS is a constant, see if we can simplify it. 1350 // for XOR, we prefer to force bits to 1 if they will make a -1. 1351 // if we can't force bits, try to shrink constant 1352 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { 1353 APInt Expanded = C->getAPIntValue() | (~NewMask); 1354 // if we can expand it to have all bits set, do it 1355 if (Expanded.isAllOnesValue()) { 1356 if (Expanded != C->getAPIntValue()) { 1357 EVT VT = Op.getValueType(); 1358 SDValue New = TLO.DAG.getNode(Op.getOpcode(), dl,VT, Op.getOperand(0), 1359 TLO.DAG.getConstant(Expanded, VT)); 1360 return TLO.CombineTo(Op, New); 1361 } 1362 // if it already has all the bits set, nothing to change 1363 // but don't shrink either! 1364 } else if (TLO.ShrinkDemandedConstant(Op, NewMask)) { 1365 return true; 1366 } 1367 } 1368 1369 KnownZero = KnownZeroOut; 1370 KnownOne = KnownOneOut; 1371 break; 1372 case ISD::SELECT: 1373 if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero, 1374 KnownOne, TLO, Depth+1)) 1375 return true; 1376 if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero2, 1377 KnownOne2, TLO, Depth+1)) 1378 return true; 1379 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1380 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 1381 1382 // If the operands are constants, see if we can simplify them. 1383 if (TLO.ShrinkDemandedConstant(Op, NewMask)) 1384 return true; 1385 1386 // Only known if known in both the LHS and RHS. 1387 KnownOne &= KnownOne2; 1388 KnownZero &= KnownZero2; 1389 break; 1390 case ISD::SELECT_CC: 1391 if (SimplifyDemandedBits(Op.getOperand(3), NewMask, KnownZero, 1392 KnownOne, TLO, Depth+1)) 1393 return true; 1394 if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero2, 1395 KnownOne2, TLO, Depth+1)) 1396 return true; 1397 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1398 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 1399 1400 // If the operands are constants, see if we can simplify them. 1401 if (TLO.ShrinkDemandedConstant(Op, NewMask)) 1402 return true; 1403 1404 // Only known if known in both the LHS and RHS. 1405 KnownOne &= KnownOne2; 1406 KnownZero &= KnownZero2; 1407 break; 1408 case ISD::SHL: 1409 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { 1410 unsigned ShAmt = SA->getZExtValue(); 1411 SDValue InOp = Op.getOperand(0); 1412 1413 // If the shift count is an invalid immediate, don't do anything. 1414 if (ShAmt >= BitWidth) 1415 break; 1416 1417 // If this is ((X >>u C1) << ShAmt), see if we can simplify this into a 1418 // single shift. We can do this if the bottom bits (which are shifted 1419 // out) are never demanded. 1420 if (InOp.getOpcode() == ISD::SRL && 1421 isa<ConstantSDNode>(InOp.getOperand(1))) { 1422 if (ShAmt && (NewMask & APInt::getLowBitsSet(BitWidth, ShAmt)) == 0) { 1423 unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue(); 1424 unsigned Opc = ISD::SHL; 1425 int Diff = ShAmt-C1; 1426 if (Diff < 0) { 1427 Diff = -Diff; 1428 Opc = ISD::SRL; 1429 } 1430 1431 SDValue NewSA = 1432 TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType()); 1433 EVT VT = Op.getValueType(); 1434 return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT, 1435 InOp.getOperand(0), NewSA)); 1436 } 1437 } 1438 1439 if (SimplifyDemandedBits(InOp, NewMask.lshr(ShAmt), 1440 KnownZero, KnownOne, TLO, Depth+1)) 1441 return true; 1442 1443 // Convert (shl (anyext x, c)) to (anyext (shl x, c)) if the high bits 1444 // are not demanded. This will likely allow the anyext to be folded away. 1445 if (InOp.getNode()->getOpcode() == ISD::ANY_EXTEND) { 1446 SDValue InnerOp = InOp.getNode()->getOperand(0); 1447 EVT InnerVT = InnerOp.getValueType(); 1448 if ((APInt::getHighBitsSet(BitWidth, 1449 BitWidth - InnerVT.getSizeInBits()) & 1450 DemandedMask) == 0 && 1451 isTypeDesirableForOp(ISD::SHL, InnerVT)) { 1452 EVT ShTy = getShiftAmountTy(InnerVT); 1453 if (!APInt(BitWidth, ShAmt).isIntN(ShTy.getSizeInBits())) 1454 ShTy = InnerVT; 1455 SDValue NarrowShl = 1456 TLO.DAG.getNode(ISD::SHL, dl, InnerVT, InnerOp, 1457 TLO.DAG.getConstant(ShAmt, ShTy)); 1458 return 1459 TLO.CombineTo(Op, 1460 TLO.DAG.getNode(ISD::ANY_EXTEND, dl, Op.getValueType(), 1461 NarrowShl)); 1462 } 1463 } 1464 1465 KnownZero <<= SA->getZExtValue(); 1466 KnownOne <<= SA->getZExtValue(); 1467 // low bits known zero. 1468 KnownZero |= APInt::getLowBitsSet(BitWidth, SA->getZExtValue()); 1469 } 1470 break; 1471 case ISD::SRL: 1472 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { 1473 EVT VT = Op.getValueType(); 1474 unsigned ShAmt = SA->getZExtValue(); 1475 unsigned VTSize = VT.getSizeInBits(); 1476 SDValue InOp = Op.getOperand(0); 1477 1478 // If the shift count is an invalid immediate, don't do anything. 1479 if (ShAmt >= BitWidth) 1480 break; 1481 1482 // If this is ((X << C1) >>u ShAmt), see if we can simplify this into a 1483 // single shift. We can do this if the top bits (which are shifted out) 1484 // are never demanded. 1485 if (InOp.getOpcode() == ISD::SHL && 1486 isa<ConstantSDNode>(InOp.getOperand(1))) { 1487 if (ShAmt && (NewMask & APInt::getHighBitsSet(VTSize, ShAmt)) == 0) { 1488 unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue(); 1489 unsigned Opc = ISD::SRL; 1490 int Diff = ShAmt-C1; 1491 if (Diff < 0) { 1492 Diff = -Diff; 1493 Opc = ISD::SHL; 1494 } 1495 1496 SDValue NewSA = 1497 TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType()); 1498 return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT, 1499 InOp.getOperand(0), NewSA)); 1500 } 1501 } 1502 1503 // Compute the new bits that are at the top now. 1504 if (SimplifyDemandedBits(InOp, (NewMask << ShAmt), 1505 KnownZero, KnownOne, TLO, Depth+1)) 1506 return true; 1507 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1508 KnownZero = KnownZero.lshr(ShAmt); 1509 KnownOne = KnownOne.lshr(ShAmt); 1510 1511 APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt); 1512 KnownZero |= HighBits; // High bits known zero. 1513 } 1514 break; 1515 case ISD::SRA: 1516 // If this is an arithmetic shift right and only the low-bit is set, we can 1517 // always convert this into a logical shr, even if the shift amount is 1518 // variable. The low bit of the shift cannot be an input sign bit unless 1519 // the shift amount is >= the size of the datatype, which is undefined. 1520 if (DemandedMask == 1) 1521 return TLO.CombineTo(Op, 1522 TLO.DAG.getNode(ISD::SRL, dl, Op.getValueType(), 1523 Op.getOperand(0), Op.getOperand(1))); 1524 1525 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) { 1526 EVT VT = Op.getValueType(); 1527 unsigned ShAmt = SA->getZExtValue(); 1528 1529 // If the shift count is an invalid immediate, don't do anything. 1530 if (ShAmt >= BitWidth) 1531 break; 1532 1533 APInt InDemandedMask = (NewMask << ShAmt); 1534 1535 // If any of the demanded bits are produced by the sign extension, we also 1536 // demand the input sign bit. 1537 APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt); 1538 if (HighBits.intersects(NewMask)) 1539 InDemandedMask |= APInt::getSignBit(VT.getScalarType().getSizeInBits()); 1540 1541 if (SimplifyDemandedBits(Op.getOperand(0), InDemandedMask, 1542 KnownZero, KnownOne, TLO, Depth+1)) 1543 return true; 1544 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1545 KnownZero = KnownZero.lshr(ShAmt); 1546 KnownOne = KnownOne.lshr(ShAmt); 1547 1548 // Handle the sign bit, adjusted to where it is now in the mask. 1549 APInt SignBit = APInt::getSignBit(BitWidth).lshr(ShAmt); 1550 1551 // If the input sign bit is known to be zero, or if none of the top bits 1552 // are demanded, turn this into an unsigned shift right. 1553 if (KnownZero.intersects(SignBit) || (HighBits & ~NewMask) == HighBits) { 1554 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, VT, 1555 Op.getOperand(0), 1556 Op.getOperand(1))); 1557 } else if (KnownOne.intersects(SignBit)) { // New bits are known one. 1558 KnownOne |= HighBits; 1559 } 1560 } 1561 break; 1562 case ISD::SIGN_EXTEND_INREG: { 1563 EVT EVT = cast<VTSDNode>(Op.getOperand(1))->getVT(); 1564 1565 // Sign extension. Compute the demanded bits in the result that are not 1566 // present in the input. 1567 APInt NewBits = 1568 APInt::getHighBitsSet(BitWidth, 1569 BitWidth - EVT.getScalarType().getSizeInBits()); 1570 1571 // If none of the extended bits are demanded, eliminate the sextinreg. 1572 if ((NewBits & NewMask) == 0) 1573 return TLO.CombineTo(Op, Op.getOperand(0)); 1574 1575 APInt InSignBit = 1576 APInt::getSignBit(EVT.getScalarType().getSizeInBits()).zext(BitWidth); 1577 APInt InputDemandedBits = 1578 APInt::getLowBitsSet(BitWidth, 1579 EVT.getScalarType().getSizeInBits()) & 1580 NewMask; 1581 1582 // Since the sign extended bits are demanded, we know that the sign 1583 // bit is demanded. 1584 InputDemandedBits |= InSignBit; 1585 1586 if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits, 1587 KnownZero, KnownOne, TLO, Depth+1)) 1588 return true; 1589 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1590 1591 // If the sign bit of the input is known set or clear, then we know the 1592 // top bits of the result. 1593 1594 // If the input sign bit is known zero, convert this into a zero extension. 1595 if (KnownZero.intersects(InSignBit)) 1596 return TLO.CombineTo(Op, 1597 TLO.DAG.getZeroExtendInReg(Op.getOperand(0),dl,EVT)); 1598 1599 if (KnownOne.intersects(InSignBit)) { // Input sign bit known set 1600 KnownOne |= NewBits; 1601 KnownZero &= ~NewBits; 1602 } else { // Input sign bit unknown 1603 KnownZero &= ~NewBits; 1604 KnownOne &= ~NewBits; 1605 } 1606 break; 1607 } 1608 case ISD::ZERO_EXTEND: { 1609 unsigned OperandBitWidth = 1610 Op.getOperand(0).getValueType().getScalarType().getSizeInBits(); 1611 APInt InMask = NewMask.trunc(OperandBitWidth); 1612 1613 // If none of the top bits are demanded, convert this into an any_extend. 1614 APInt NewBits = 1615 APInt::getHighBitsSet(BitWidth, BitWidth - OperandBitWidth) & NewMask; 1616 if (!NewBits.intersects(NewMask)) 1617 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND, dl, 1618 Op.getValueType(), 1619 Op.getOperand(0))); 1620 1621 if (SimplifyDemandedBits(Op.getOperand(0), InMask, 1622 KnownZero, KnownOne, TLO, Depth+1)) 1623 return true; 1624 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1625 KnownZero = KnownZero.zext(BitWidth); 1626 KnownOne = KnownOne.zext(BitWidth); 1627 KnownZero |= NewBits; 1628 break; 1629 } 1630 case ISD::SIGN_EXTEND: { 1631 EVT InVT = Op.getOperand(0).getValueType(); 1632 unsigned InBits = InVT.getScalarType().getSizeInBits(); 1633 APInt InMask = APInt::getLowBitsSet(BitWidth, InBits); 1634 APInt InSignBit = APInt::getBitsSet(BitWidth, InBits - 1, InBits); 1635 APInt NewBits = ~InMask & NewMask; 1636 1637 // If none of the top bits are demanded, convert this into an any_extend. 1638 if (NewBits == 0) 1639 return TLO.CombineTo(Op,TLO.DAG.getNode(ISD::ANY_EXTEND, dl, 1640 Op.getValueType(), 1641 Op.getOperand(0))); 1642 1643 // Since some of the sign extended bits are demanded, we know that the sign 1644 // bit is demanded. 1645 APInt InDemandedBits = InMask & NewMask; 1646 InDemandedBits |= InSignBit; 1647 InDemandedBits = InDemandedBits.trunc(InBits); 1648 1649 if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero, 1650 KnownOne, TLO, Depth+1)) 1651 return true; 1652 KnownZero = KnownZero.zext(BitWidth); 1653 KnownOne = KnownOne.zext(BitWidth); 1654 1655 // If the sign bit is known zero, convert this to a zero extend. 1656 if (KnownZero.intersects(InSignBit)) 1657 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND, dl, 1658 Op.getValueType(), 1659 Op.getOperand(0))); 1660 1661 // If the sign bit is known one, the top bits match. 1662 if (KnownOne.intersects(InSignBit)) { 1663 KnownOne |= NewBits; 1664 KnownZero &= ~NewBits; 1665 } else { // Otherwise, top bits aren't known. 1666 KnownOne &= ~NewBits; 1667 KnownZero &= ~NewBits; 1668 } 1669 break; 1670 } 1671 case ISD::ANY_EXTEND: { 1672 unsigned OperandBitWidth = 1673 Op.getOperand(0).getValueType().getScalarType().getSizeInBits(); 1674 APInt InMask = NewMask.trunc(OperandBitWidth); 1675 if (SimplifyDemandedBits(Op.getOperand(0), InMask, 1676 KnownZero, KnownOne, TLO, Depth+1)) 1677 return true; 1678 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1679 KnownZero = KnownZero.zext(BitWidth); 1680 KnownOne = KnownOne.zext(BitWidth); 1681 break; 1682 } 1683 case ISD::TRUNCATE: { 1684 // Simplify the input, using demanded bit information, and compute the known 1685 // zero/one bits live out. 1686 unsigned OperandBitWidth = 1687 Op.getOperand(0).getValueType().getScalarType().getSizeInBits(); 1688 APInt TruncMask = NewMask.zext(OperandBitWidth); 1689 if (SimplifyDemandedBits(Op.getOperand(0), TruncMask, 1690 KnownZero, KnownOne, TLO, Depth+1)) 1691 return true; 1692 KnownZero = KnownZero.trunc(BitWidth); 1693 KnownOne = KnownOne.trunc(BitWidth); 1694 1695 // If the input is only used by this truncate, see if we can shrink it based 1696 // on the known demanded bits. 1697 if (Op.getOperand(0).getNode()->hasOneUse()) { 1698 SDValue In = Op.getOperand(0); 1699 switch (In.getOpcode()) { 1700 default: break; 1701 case ISD::SRL: 1702 // Shrink SRL by a constant if none of the high bits shifted in are 1703 // demanded. 1704 if (TLO.LegalTypes() && 1705 !isTypeDesirableForOp(ISD::SRL, Op.getValueType())) 1706 // Do not turn (vt1 truncate (vt2 srl)) into (vt1 srl) if vt1 is 1707 // undesirable. 1708 break; 1709 ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1)); 1710 if (!ShAmt) 1711 break; 1712 SDValue Shift = In.getOperand(1); 1713 if (TLO.LegalTypes()) { 1714 uint64_t ShVal = ShAmt->getZExtValue(); 1715 Shift = 1716 TLO.DAG.getConstant(ShVal, getShiftAmountTy(Op.getValueType())); 1717 } 1718 1719 APInt HighBits = APInt::getHighBitsSet(OperandBitWidth, 1720 OperandBitWidth - BitWidth); 1721 HighBits = HighBits.lshr(ShAmt->getZExtValue()).trunc(BitWidth); 1722 1723 if (ShAmt->getZExtValue() < BitWidth && !(HighBits & NewMask)) { 1724 // None of the shifted in bits are needed. Add a truncate of the 1725 // shift input, then shift it. 1726 SDValue NewTrunc = TLO.DAG.getNode(ISD::TRUNCATE, dl, 1727 Op.getValueType(), 1728 In.getOperand(0)); 1729 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, 1730 Op.getValueType(), 1731 NewTrunc, 1732 Shift)); 1733 } 1734 break; 1735 } 1736 } 1737 1738 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1739 break; 1740 } 1741 case ISD::AssertZext: { 1742 // Demand all the bits of the input that are demanded in the output. 1743 // The low bits are obvious; the high bits are demanded because we're 1744 // asserting that they're zero here. 1745 if (SimplifyDemandedBits(Op.getOperand(0), NewMask, 1746 KnownZero, KnownOne, TLO, Depth+1)) 1747 return true; 1748 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 1749 1750 EVT VT = cast<VTSDNode>(Op.getOperand(1))->getVT(); 1751 APInt InMask = APInt::getLowBitsSet(BitWidth, 1752 VT.getSizeInBits()); 1753 KnownZero |= ~InMask & NewMask; 1754 break; 1755 } 1756 case ISD::BITCAST: 1757 // If this is an FP->Int bitcast and if the sign bit is the only thing that 1758 // is demanded, turn this into a FGETSIGN. 1759 if (NewMask == APInt::getSignBit(Op.getValueType().getSizeInBits()) && 1760 Op.getOperand(0).getValueType().isFloatingPoint() && 1761 !Op.getOperand(0).getValueType().isVector()) { 1762 if (isOperationLegalOrCustom(ISD::FGETSIGN, MVT::i32)) { 1763 EVT Ty = (isOperationLegalOrCustom(ISD::FGETSIGN, Op.getValueType())) ? 1764 Op.getValueType() : MVT::i32; 1765 // Make a FGETSIGN + SHL to move the sign bit into the appropriate 1766 // place. We expect the SHL to be eliminated by other optimizations. 1767 SDValue Sign = TLO.DAG.getNode(ISD::FGETSIGN, dl, Ty, Op.getOperand(0)); 1768 if (Ty != Op.getValueType()) 1769 Sign = TLO.DAG.getNode(ISD::ZERO_EXTEND, dl, Op.getValueType(), Sign); 1770 unsigned ShVal = Op.getValueType().getSizeInBits()-1; 1771 SDValue ShAmt = TLO.DAG.getConstant(ShVal, Op.getValueType()); 1772 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, dl, 1773 Op.getValueType(), 1774 Sign, ShAmt)); 1775 } 1776 } 1777 break; 1778 case ISD::ADD: 1779 case ISD::MUL: 1780 case ISD::SUB: { 1781 // Add, Sub, and Mul don't demand any bits in positions beyond that 1782 // of the highest bit demanded of them. 1783 APInt LoMask = APInt::getLowBitsSet(BitWidth, 1784 BitWidth - NewMask.countLeadingZeros()); 1785 if (SimplifyDemandedBits(Op.getOperand(0), LoMask, KnownZero2, 1786 KnownOne2, TLO, Depth+1)) 1787 return true; 1788 if (SimplifyDemandedBits(Op.getOperand(1), LoMask, KnownZero2, 1789 KnownOne2, TLO, Depth+1)) 1790 return true; 1791 // See if the operation should be performed at a smaller bit width. 1792 if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl)) 1793 return true; 1794 } 1795 // FALL THROUGH 1796 default: 1797 // Just use ComputeMaskedBits to compute output bits. 1798 TLO.DAG.ComputeMaskedBits(Op, NewMask, KnownZero, KnownOne, Depth); 1799 break; 1800 } 1801 1802 // If we know the value of all of the demanded bits, return this as a 1803 // constant. 1804 if ((NewMask & (KnownZero|KnownOne)) == NewMask) 1805 return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType())); 1806 1807 return false; 1808 } 1809 1810 /// computeMaskedBitsForTargetNode - Determine which of the bits specified 1811 /// in Mask are known to be either zero or one and return them in the 1812 /// KnownZero/KnownOne bitsets. 1813 void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op, 1814 const APInt &Mask, 1815 APInt &KnownZero, 1816 APInt &KnownOne, 1817 const SelectionDAG &DAG, 1818 unsigned Depth) const { 1819 assert((Op.getOpcode() >= ISD::BUILTIN_OP_END || 1820 Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN || 1821 Op.getOpcode() == ISD::INTRINSIC_W_CHAIN || 1822 Op.getOpcode() == ISD::INTRINSIC_VOID) && 1823 "Should use MaskedValueIsZero if you don't know whether Op" 1824 " is a target node!"); 1825 KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0); 1826 } 1827 1828 /// ComputeNumSignBitsForTargetNode - This method can be implemented by 1829 /// targets that want to expose additional information about sign bits to the 1830 /// DAG Combiner. 1831 unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op, 1832 unsigned Depth) const { 1833 assert((Op.getOpcode() >= ISD::BUILTIN_OP_END || 1834 Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN || 1835 Op.getOpcode() == ISD::INTRINSIC_W_CHAIN || 1836 Op.getOpcode() == ISD::INTRINSIC_VOID) && 1837 "Should use ComputeNumSignBits if you don't know whether Op" 1838 " is a target node!"); 1839 return 1; 1840 } 1841 1842 /// ValueHasExactlyOneBitSet - Test if the given value is known to have exactly 1843 /// one bit set. This differs from ComputeMaskedBits in that it doesn't need to 1844 /// determine which bit is set. 1845 /// 1846 static bool ValueHasExactlyOneBitSet(SDValue Val, const SelectionDAG &DAG) { 1847 // A left-shift of a constant one will have exactly one bit set, because 1848 // shifting the bit off the end is undefined. 1849 if (Val.getOpcode() == ISD::SHL) 1850 if (ConstantSDNode *C = 1851 dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0))) 1852 if (C->getAPIntValue() == 1) 1853 return true; 1854 1855 // Similarly, a right-shift of a constant sign-bit will have exactly 1856 // one bit set. 1857 if (Val.getOpcode() == ISD::SRL) 1858 if (ConstantSDNode *C = 1859 dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0))) 1860 if (C->getAPIntValue().isSignBit()) 1861 return true; 1862 1863 // More could be done here, though the above checks are enough 1864 // to handle some common cases. 1865 1866 // Fall back to ComputeMaskedBits to catch other known cases. 1867 EVT OpVT = Val.getValueType(); 1868 unsigned BitWidth = OpVT.getScalarType().getSizeInBits(); 1869 APInt Mask = APInt::getAllOnesValue(BitWidth); 1870 APInt KnownZero, KnownOne; 1871 DAG.ComputeMaskedBits(Val, Mask, KnownZero, KnownOne); 1872 return (KnownZero.countPopulation() == BitWidth - 1) && 1873 (KnownOne.countPopulation() == 1); 1874 } 1875 1876 /// SimplifySetCC - Try to simplify a setcc built with the specified operands 1877 /// and cc. If it is unable to simplify it, return a null SDValue. 1878 SDValue 1879 TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1, 1880 ISD::CondCode Cond, bool foldBooleans, 1881 DAGCombinerInfo &DCI, DebugLoc dl) const { 1882 SelectionDAG &DAG = DCI.DAG; 1883 1884 // These setcc operations always fold. 1885 switch (Cond) { 1886 default: break; 1887 case ISD::SETFALSE: 1888 case ISD::SETFALSE2: return DAG.getConstant(0, VT); 1889 case ISD::SETTRUE: 1890 case ISD::SETTRUE2: return DAG.getConstant(1, VT); 1891 } 1892 1893 // Ensure that the constant occurs on the RHS, and fold constant 1894 // comparisons. 1895 if (isa<ConstantSDNode>(N0.getNode())) 1896 return DAG.getSetCC(dl, VT, N1, N0, ISD::getSetCCSwappedOperands(Cond)); 1897 1898 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode())) { 1899 const APInt &C1 = N1C->getAPIntValue(); 1900 1901 // If the LHS is '(srl (ctlz x), 5)', the RHS is 0/1, and this is an 1902 // equality comparison, then we're just comparing whether X itself is 1903 // zero. 1904 if (N0.getOpcode() == ISD::SRL && (C1 == 0 || C1 == 1) && 1905 N0.getOperand(0).getOpcode() == ISD::CTLZ && 1906 N0.getOperand(1).getOpcode() == ISD::Constant) { 1907 const APInt &ShAmt 1908 = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue(); 1909 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) && 1910 ShAmt == Log2_32(N0.getValueType().getSizeInBits())) { 1911 if ((C1 == 0) == (Cond == ISD::SETEQ)) { 1912 // (srl (ctlz x), 5) == 0 -> X != 0 1913 // (srl (ctlz x), 5) != 1 -> X != 0 1914 Cond = ISD::SETNE; 1915 } else { 1916 // (srl (ctlz x), 5) != 0 -> X == 0 1917 // (srl (ctlz x), 5) == 1 -> X == 0 1918 Cond = ISD::SETEQ; 1919 } 1920 SDValue Zero = DAG.getConstant(0, N0.getValueType()); 1921 return DAG.getSetCC(dl, VT, N0.getOperand(0).getOperand(0), 1922 Zero, Cond); 1923 } 1924 } 1925 1926 SDValue CTPOP = N0; 1927 // Look through truncs that don't change the value of a ctpop. 1928 if (N0.hasOneUse() && N0.getOpcode() == ISD::TRUNCATE) 1929 CTPOP = N0.getOperand(0); 1930 1931 if (CTPOP.hasOneUse() && CTPOP.getOpcode() == ISD::CTPOP && 1932 (N0 == CTPOP || N0.getValueType().getSizeInBits() > 1933 Log2_32_Ceil(CTPOP.getValueType().getSizeInBits()))) { 1934 EVT CTVT = CTPOP.getValueType(); 1935 SDValue CTOp = CTPOP.getOperand(0); 1936 1937 // (ctpop x) u< 2 -> (x & x-1) == 0 1938 // (ctpop x) u> 1 -> (x & x-1) != 0 1939 if ((Cond == ISD::SETULT && C1 == 2) || (Cond == ISD::SETUGT && C1 == 1)){ 1940 SDValue Sub = DAG.getNode(ISD::SUB, dl, CTVT, CTOp, 1941 DAG.getConstant(1, CTVT)); 1942 SDValue And = DAG.getNode(ISD::AND, dl, CTVT, CTOp, Sub); 1943 ISD::CondCode CC = Cond == ISD::SETULT ? ISD::SETEQ : ISD::SETNE; 1944 return DAG.getSetCC(dl, VT, And, DAG.getConstant(0, CTVT), CC); 1945 } 1946 1947 // TODO: (ctpop x) == 1 -> x && (x & x-1) == 0 iff ctpop is illegal. 1948 } 1949 1950 // (zext x) == C --> x == (trunc C) 1951 if (DCI.isBeforeLegalize() && N0->hasOneUse() && 1952 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) { 1953 unsigned MinBits = N0.getValueSizeInBits(); 1954 SDValue PreZExt; 1955 if (N0->getOpcode() == ISD::ZERO_EXTEND) { 1956 // ZExt 1957 MinBits = N0->getOperand(0).getValueSizeInBits(); 1958 PreZExt = N0->getOperand(0); 1959 } else if (N0->getOpcode() == ISD::AND) { 1960 // DAGCombine turns costly ZExts into ANDs 1961 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0->getOperand(1))) 1962 if ((C->getAPIntValue()+1).isPowerOf2()) { 1963 MinBits = C->getAPIntValue().countTrailingOnes(); 1964 PreZExt = N0->getOperand(0); 1965 } 1966 } else if (LoadSDNode *LN0 = dyn_cast<LoadSDNode>(N0)) { 1967 // ZEXTLOAD 1968 if (LN0->getExtensionType() == ISD::ZEXTLOAD) { 1969 MinBits = LN0->getMemoryVT().getSizeInBits(); 1970 PreZExt = N0; 1971 } 1972 } 1973 1974 // Make sure we're not loosing bits from the constant. 1975 if (MinBits < C1.getBitWidth() && MinBits > C1.getActiveBits()) { 1976 EVT MinVT = EVT::getIntegerVT(*DAG.getContext(), MinBits); 1977 if (isTypeDesirableForOp(ISD::SETCC, MinVT)) { 1978 // Will get folded away. 1979 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MinVT, PreZExt); 1980 SDValue C = DAG.getConstant(C1.trunc(MinBits), MinVT); 1981 return DAG.getSetCC(dl, VT, Trunc, C, Cond); 1982 } 1983 } 1984 } 1985 1986 // If the LHS is '(and load, const)', the RHS is 0, 1987 // the test is for equality or unsigned, and all 1 bits of the const are 1988 // in the same partial word, see if we can shorten the load. 1989 if (DCI.isBeforeLegalize() && 1990 N0.getOpcode() == ISD::AND && C1 == 0 && 1991 N0.getNode()->hasOneUse() && 1992 isa<LoadSDNode>(N0.getOperand(0)) && 1993 N0.getOperand(0).getNode()->hasOneUse() && 1994 isa<ConstantSDNode>(N0.getOperand(1))) { 1995 LoadSDNode *Lod = cast<LoadSDNode>(N0.getOperand(0)); 1996 APInt bestMask; 1997 unsigned bestWidth = 0, bestOffset = 0; 1998 if (!Lod->isVolatile() && Lod->isUnindexed()) { 1999 unsigned origWidth = N0.getValueType().getSizeInBits(); 2000 unsigned maskWidth = origWidth; 2001 // We can narrow (e.g.) 16-bit extending loads on 32-bit target to 2002 // 8 bits, but have to be careful... 2003 if (Lod->getExtensionType() != ISD::NON_EXTLOAD) 2004 origWidth = Lod->getMemoryVT().getSizeInBits(); 2005 const APInt &Mask = 2006 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue(); 2007 for (unsigned width = origWidth / 2; width>=8; width /= 2) { 2008 APInt newMask = APInt::getLowBitsSet(maskWidth, width); 2009 for (unsigned offset=0; offset<origWidth/width; offset++) { 2010 if ((newMask & Mask) == Mask) { 2011 if (!TD->isLittleEndian()) 2012 bestOffset = (origWidth/width - offset - 1) * (width/8); 2013 else 2014 bestOffset = (uint64_t)offset * (width/8); 2015 bestMask = Mask.lshr(offset * (width/8) * 8); 2016 bestWidth = width; 2017 break; 2018 } 2019 newMask = newMask << width; 2020 } 2021 } 2022 } 2023 if (bestWidth) { 2024 EVT newVT = EVT::getIntegerVT(*DAG.getContext(), bestWidth); 2025 if (newVT.isRound()) { 2026 EVT PtrType = Lod->getOperand(1).getValueType(); 2027 SDValue Ptr = Lod->getBasePtr(); 2028 if (bestOffset != 0) 2029 Ptr = DAG.getNode(ISD::ADD, dl, PtrType, Lod->getBasePtr(), 2030 DAG.getConstant(bestOffset, PtrType)); 2031 unsigned NewAlign = MinAlign(Lod->getAlignment(), bestOffset); 2032 SDValue NewLoad = DAG.getLoad(newVT, dl, Lod->getChain(), Ptr, 2033 Lod->getPointerInfo().getWithOffset(bestOffset), 2034 false, false, NewAlign); 2035 return DAG.getSetCC(dl, VT, 2036 DAG.getNode(ISD::AND, dl, newVT, NewLoad, 2037 DAG.getConstant(bestMask.trunc(bestWidth), 2038 newVT)), 2039 DAG.getConstant(0LL, newVT), Cond); 2040 } 2041 } 2042 } 2043 2044 // If the LHS is a ZERO_EXTEND, perform the comparison on the input. 2045 if (N0.getOpcode() == ISD::ZERO_EXTEND) { 2046 unsigned InSize = N0.getOperand(0).getValueType().getSizeInBits(); 2047 2048 // If the comparison constant has bits in the upper part, the 2049 // zero-extended value could never match. 2050 if (C1.intersects(APInt::getHighBitsSet(C1.getBitWidth(), 2051 C1.getBitWidth() - InSize))) { 2052 switch (Cond) { 2053 case ISD::SETUGT: 2054 case ISD::SETUGE: 2055 case ISD::SETEQ: return DAG.getConstant(0, VT); 2056 case ISD::SETULT: 2057 case ISD::SETULE: 2058 case ISD::SETNE: return DAG.getConstant(1, VT); 2059 case ISD::SETGT: 2060 case ISD::SETGE: 2061 // True if the sign bit of C1 is set. 2062 return DAG.getConstant(C1.isNegative(), VT); 2063 case ISD::SETLT: 2064 case ISD::SETLE: 2065 // True if the sign bit of C1 isn't set. 2066 return DAG.getConstant(C1.isNonNegative(), VT); 2067 default: 2068 break; 2069 } 2070 } 2071 2072 // Otherwise, we can perform the comparison with the low bits. 2073 switch (Cond) { 2074 case ISD::SETEQ: 2075 case ISD::SETNE: 2076 case ISD::SETUGT: 2077 case ISD::SETUGE: 2078 case ISD::SETULT: 2079 case ISD::SETULE: { 2080 EVT newVT = N0.getOperand(0).getValueType(); 2081 if (DCI.isBeforeLegalizeOps() || 2082 (isOperationLegal(ISD::SETCC, newVT) && 2083 getCondCodeAction(Cond, newVT)==Legal)) 2084 return DAG.getSetCC(dl, VT, N0.getOperand(0), 2085 DAG.getConstant(C1.trunc(InSize), newVT), 2086 Cond); 2087 break; 2088 } 2089 default: 2090 break; // todo, be more careful with signed comparisons 2091 } 2092 } else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG && 2093 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) { 2094 EVT ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT(); 2095 unsigned ExtSrcTyBits = ExtSrcTy.getSizeInBits(); 2096 EVT ExtDstTy = N0.getValueType(); 2097 unsigned ExtDstTyBits = ExtDstTy.getSizeInBits(); 2098 2099 // If the constant doesn't fit into the number of bits for the source of 2100 // the sign extension, it is impossible for both sides to be equal. 2101 if (C1.getMinSignedBits() > ExtSrcTyBits) 2102 return DAG.getConstant(Cond == ISD::SETNE, VT); 2103 2104 SDValue ZextOp; 2105 EVT Op0Ty = N0.getOperand(0).getValueType(); 2106 if (Op0Ty == ExtSrcTy) { 2107 ZextOp = N0.getOperand(0); 2108 } else { 2109 APInt Imm = APInt::getLowBitsSet(ExtDstTyBits, ExtSrcTyBits); 2110 ZextOp = DAG.getNode(ISD::AND, dl, Op0Ty, N0.getOperand(0), 2111 DAG.getConstant(Imm, Op0Ty)); 2112 } 2113 if (!DCI.isCalledByLegalizer()) 2114 DCI.AddToWorklist(ZextOp.getNode()); 2115 // Otherwise, make this a use of a zext. 2116 return DAG.getSetCC(dl, VT, ZextOp, 2117 DAG.getConstant(C1 & APInt::getLowBitsSet( 2118 ExtDstTyBits, 2119 ExtSrcTyBits), 2120 ExtDstTy), 2121 Cond); 2122 } else if ((N1C->isNullValue() || N1C->getAPIntValue() == 1) && 2123 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) { 2124 // SETCC (SETCC), [0|1], [EQ|NE] -> SETCC 2125 if (N0.getOpcode() == ISD::SETCC && 2126 isTypeLegal(VT) && VT.bitsLE(N0.getValueType())) { 2127 bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getAPIntValue() != 1); 2128 if (TrueWhenTrue) 2129 return DAG.getNode(ISD::TRUNCATE, dl, VT, N0); 2130 // Invert the condition. 2131 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get(); 2132 CC = ISD::getSetCCInverse(CC, 2133 N0.getOperand(0).getValueType().isInteger()); 2134 return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC); 2135 } 2136 2137 if ((N0.getOpcode() == ISD::XOR || 2138 (N0.getOpcode() == ISD::AND && 2139 N0.getOperand(0).getOpcode() == ISD::XOR && 2140 N0.getOperand(1) == N0.getOperand(0).getOperand(1))) && 2141 isa<ConstantSDNode>(N0.getOperand(1)) && 2142 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue() == 1) { 2143 // If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We 2144 // can only do this if the top bits are known zero. 2145 unsigned BitWidth = N0.getValueSizeInBits(); 2146 if (DAG.MaskedValueIsZero(N0, 2147 APInt::getHighBitsSet(BitWidth, 2148 BitWidth-1))) { 2149 // Okay, get the un-inverted input value. 2150 SDValue Val; 2151 if (N0.getOpcode() == ISD::XOR) 2152 Val = N0.getOperand(0); 2153 else { 2154 assert(N0.getOpcode() == ISD::AND && 2155 N0.getOperand(0).getOpcode() == ISD::XOR); 2156 // ((X^1)&1)^1 -> X & 1 2157 Val = DAG.getNode(ISD::AND, dl, N0.getValueType(), 2158 N0.getOperand(0).getOperand(0), 2159 N0.getOperand(1)); 2160 } 2161 2162 return DAG.getSetCC(dl, VT, Val, N1, 2163 Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ); 2164 } 2165 } else if (N1C->getAPIntValue() == 1 && 2166 (VT == MVT::i1 || 2167 getBooleanContents() == ZeroOrOneBooleanContent)) { 2168 SDValue Op0 = N0; 2169 if (Op0.getOpcode() == ISD::TRUNCATE) 2170 Op0 = Op0.getOperand(0); 2171 2172 if ((Op0.getOpcode() == ISD::XOR) && 2173 Op0.getOperand(0).getOpcode() == ISD::SETCC && 2174 Op0.getOperand(1).getOpcode() == ISD::SETCC) { 2175 // (xor (setcc), (setcc)) == / != 1 -> (setcc) != / == (setcc) 2176 Cond = (Cond == ISD::SETEQ) ? ISD::SETNE : ISD::SETEQ; 2177 return DAG.getSetCC(dl, VT, Op0.getOperand(0), Op0.getOperand(1), 2178 Cond); 2179 } else if (Op0.getOpcode() == ISD::AND && 2180 isa<ConstantSDNode>(Op0.getOperand(1)) && 2181 cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) { 2182 // If this is (X&1) == / != 1, normalize it to (X&1) != / == 0. 2183 if (Op0.getValueType().bitsGT(VT)) 2184 Op0 = DAG.getNode(ISD::AND, dl, VT, 2185 DAG.getNode(ISD::TRUNCATE, dl, VT, Op0.getOperand(0)), 2186 DAG.getConstant(1, VT)); 2187 else if (Op0.getValueType().bitsLT(VT)) 2188 Op0 = DAG.getNode(ISD::AND, dl, VT, 2189 DAG.getNode(ISD::ANY_EXTEND, dl, VT, Op0.getOperand(0)), 2190 DAG.getConstant(1, VT)); 2191 2192 return DAG.getSetCC(dl, VT, Op0, 2193 DAG.getConstant(0, Op0.getValueType()), 2194 Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ); 2195 } 2196 } 2197 } 2198 2199 APInt MinVal, MaxVal; 2200 unsigned OperandBitSize = N1C->getValueType(0).getSizeInBits(); 2201 if (ISD::isSignedIntSetCC(Cond)) { 2202 MinVal = APInt::getSignedMinValue(OperandBitSize); 2203 MaxVal = APInt::getSignedMaxValue(OperandBitSize); 2204 } else { 2205 MinVal = APInt::getMinValue(OperandBitSize); 2206 MaxVal = APInt::getMaxValue(OperandBitSize); 2207 } 2208 2209 // Canonicalize GE/LE comparisons to use GT/LT comparisons. 2210 if (Cond == ISD::SETGE || Cond == ISD::SETUGE) { 2211 if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true 2212 // X >= C0 --> X > (C0-1) 2213 return DAG.getSetCC(dl, VT, N0, 2214 DAG.getConstant(C1-1, N1.getValueType()), 2215 (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT); 2216 } 2217 2218 if (Cond == ISD::SETLE || Cond == ISD::SETULE) { 2219 if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true 2220 // X <= C0 --> X < (C0+1) 2221 return DAG.getSetCC(dl, VT, N0, 2222 DAG.getConstant(C1+1, N1.getValueType()), 2223 (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT); 2224 } 2225 2226 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal) 2227 return DAG.getConstant(0, VT); // X < MIN --> false 2228 if ((Cond == ISD::SETGE || Cond == ISD::SETUGE) && C1 == MinVal) 2229 return DAG.getConstant(1, VT); // X >= MIN --> true 2230 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal) 2231 return DAG.getConstant(0, VT); // X > MAX --> false 2232 if ((Cond == ISD::SETLE || Cond == ISD::SETULE) && C1 == MaxVal) 2233 return DAG.getConstant(1, VT); // X <= MAX --> true 2234 2235 // Canonicalize setgt X, Min --> setne X, Min 2236 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal) 2237 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE); 2238 // Canonicalize setlt X, Max --> setne X, Max 2239 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal) 2240 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE); 2241 2242 // If we have setult X, 1, turn it into seteq X, 0 2243 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1) 2244 return DAG.getSetCC(dl, VT, N0, 2245 DAG.getConstant(MinVal, N0.getValueType()), 2246 ISD::SETEQ); 2247 // If we have setugt X, Max-1, turn it into seteq X, Max 2248 else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1) 2249 return DAG.getSetCC(dl, VT, N0, 2250 DAG.getConstant(MaxVal, N0.getValueType()), 2251 ISD::SETEQ); 2252 2253 // If we have "setcc X, C0", check to see if we can shrink the immediate 2254 // by changing cc. 2255 2256 // SETUGT X, SINTMAX -> SETLT X, 0 2257 if (Cond == ISD::SETUGT && 2258 C1 == APInt::getSignedMaxValue(OperandBitSize)) 2259 return DAG.getSetCC(dl, VT, N0, 2260 DAG.getConstant(0, N1.getValueType()), 2261 ISD::SETLT); 2262 2263 // SETULT X, SINTMIN -> SETGT X, -1 2264 if (Cond == ISD::SETULT && 2265 C1 == APInt::getSignedMinValue(OperandBitSize)) { 2266 SDValue ConstMinusOne = 2267 DAG.getConstant(APInt::getAllOnesValue(OperandBitSize), 2268 N1.getValueType()); 2269 return DAG.getSetCC(dl, VT, N0, ConstMinusOne, ISD::SETGT); 2270 } 2271 2272 // Fold bit comparisons when we can. 2273 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) && 2274 (VT == N0.getValueType() || 2275 (isTypeLegal(VT) && VT.bitsLE(N0.getValueType()))) && 2276 N0.getOpcode() == ISD::AND) 2277 if (ConstantSDNode *AndRHS = 2278 dyn_cast<ConstantSDNode>(N0.getOperand(1))) { 2279 EVT ShiftTy = DCI.isBeforeLegalize() ? 2280 getPointerTy() : getShiftAmountTy(N0.getValueType()); 2281 if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3 2282 // Perform the xform if the AND RHS is a single bit. 2283 if (AndRHS->getAPIntValue().isPowerOf2()) { 2284 return DAG.getNode(ISD::TRUNCATE, dl, VT, 2285 DAG.getNode(ISD::SRL, dl, N0.getValueType(), N0, 2286 DAG.getConstant(AndRHS->getAPIntValue().logBase2(), ShiftTy))); 2287 } 2288 } else if (Cond == ISD::SETEQ && C1 == AndRHS->getAPIntValue()) { 2289 // (X & 8) == 8 --> (X & 8) >> 3 2290 // Perform the xform if C1 is a single bit. 2291 if (C1.isPowerOf2()) { 2292 return DAG.getNode(ISD::TRUNCATE, dl, VT, 2293 DAG.getNode(ISD::SRL, dl, N0.getValueType(), N0, 2294 DAG.getConstant(C1.logBase2(), ShiftTy))); 2295 } 2296 } 2297 } 2298 } 2299 2300 if (isa<ConstantFPSDNode>(N0.getNode())) { 2301 // Constant fold or commute setcc. 2302 SDValue O = DAG.FoldSetCC(VT, N0, N1, Cond, dl); 2303 if (O.getNode()) return O; 2304 } else if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1.getNode())) { 2305 // If the RHS of an FP comparison is a constant, simplify it away in 2306 // some cases. 2307 if (CFP->getValueAPF().isNaN()) { 2308 // If an operand is known to be a nan, we can fold it. 2309 switch (ISD::getUnorderedFlavor(Cond)) { 2310 default: llvm_unreachable("Unknown flavor!"); 2311 case 0: // Known false. 2312 return DAG.getConstant(0, VT); 2313 case 1: // Known true. 2314 return DAG.getConstant(1, VT); 2315 case 2: // Undefined. 2316 return DAG.getUNDEF(VT); 2317 } 2318 } 2319 2320 // Otherwise, we know the RHS is not a NaN. Simplify the node to drop the 2321 // constant if knowing that the operand is non-nan is enough. We prefer to 2322 // have SETO(x,x) instead of SETO(x, 0.0) because this avoids having to 2323 // materialize 0.0. 2324 if (Cond == ISD::SETO || Cond == ISD::SETUO) 2325 return DAG.getSetCC(dl, VT, N0, N0, Cond); 2326 2327 // If the condition is not legal, see if we can find an equivalent one 2328 // which is legal. 2329 if (!isCondCodeLegal(Cond, N0.getValueType())) { 2330 // If the comparison was an awkward floating-point == or != and one of 2331 // the comparison operands is infinity or negative infinity, convert the 2332 // condition to a less-awkward <= or >=. 2333 if (CFP->getValueAPF().isInfinity()) { 2334 if (CFP->getValueAPF().isNegative()) { 2335 if (Cond == ISD::SETOEQ && 2336 isCondCodeLegal(ISD::SETOLE, N0.getValueType())) 2337 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLE); 2338 if (Cond == ISD::SETUEQ && 2339 isCondCodeLegal(ISD::SETOLE, N0.getValueType())) 2340 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULE); 2341 if (Cond == ISD::SETUNE && 2342 isCondCodeLegal(ISD::SETUGT, N0.getValueType())) 2343 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGT); 2344 if (Cond == ISD::SETONE && 2345 isCondCodeLegal(ISD::SETUGT, N0.getValueType())) 2346 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGT); 2347 } else { 2348 if (Cond == ISD::SETOEQ && 2349 isCondCodeLegal(ISD::SETOGE, N0.getValueType())) 2350 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGE); 2351 if (Cond == ISD::SETUEQ && 2352 isCondCodeLegal(ISD::SETOGE, N0.getValueType())) 2353 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGE); 2354 if (Cond == ISD::SETUNE && 2355 isCondCodeLegal(ISD::SETULT, N0.getValueType())) 2356 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULT); 2357 if (Cond == ISD::SETONE && 2358 isCondCodeLegal(ISD::SETULT, N0.getValueType())) 2359 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLT); 2360 } 2361 } 2362 } 2363 } 2364 2365 if (N0 == N1) { 2366 // We can always fold X == X for integer setcc's. 2367 if (N0.getValueType().isInteger()) 2368 return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT); 2369 unsigned UOF = ISD::getUnorderedFlavor(Cond); 2370 if (UOF == 2) // FP operators that are undefined on NaNs. 2371 return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT); 2372 if (UOF == unsigned(ISD::isTrueWhenEqual(Cond))) 2373 return DAG.getConstant(UOF, VT); 2374 // Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO 2375 // if it is not already. 2376 ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO; 2377 if (NewCond != Cond) 2378 return DAG.getSetCC(dl, VT, N0, N1, NewCond); 2379 } 2380 2381 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) && 2382 N0.getValueType().isInteger()) { 2383 if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB || 2384 N0.getOpcode() == ISD::XOR) { 2385 // Simplify (X+Y) == (X+Z) --> Y == Z 2386 if (N0.getOpcode() == N1.getOpcode()) { 2387 if (N0.getOperand(0) == N1.getOperand(0)) 2388 return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(1), Cond); 2389 if (N0.getOperand(1) == N1.getOperand(1)) 2390 return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(0), Cond); 2391 if (DAG.isCommutativeBinOp(N0.getOpcode())) { 2392 // If X op Y == Y op X, try other combinations. 2393 if (N0.getOperand(0) == N1.getOperand(1)) 2394 return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(0), 2395 Cond); 2396 if (N0.getOperand(1) == N1.getOperand(0)) 2397 return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(1), 2398 Cond); 2399 } 2400 } 2401 2402 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) { 2403 if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) { 2404 // Turn (X+C1) == C2 --> X == C2-C1 2405 if (N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse()) { 2406 return DAG.getSetCC(dl, VT, N0.getOperand(0), 2407 DAG.getConstant(RHSC->getAPIntValue()- 2408 LHSR->getAPIntValue(), 2409 N0.getValueType()), Cond); 2410 } 2411 2412 // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0. 2413 if (N0.getOpcode() == ISD::XOR) 2414 // If we know that all of the inverted bits are zero, don't bother 2415 // performing the inversion. 2416 if (DAG.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getAPIntValue())) 2417 return 2418 DAG.getSetCC(dl, VT, N0.getOperand(0), 2419 DAG.getConstant(LHSR->getAPIntValue() ^ 2420 RHSC->getAPIntValue(), 2421 N0.getValueType()), 2422 Cond); 2423 } 2424 2425 // Turn (C1-X) == C2 --> X == C1-C2 2426 if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) { 2427 if (N0.getOpcode() == ISD::SUB && N0.getNode()->hasOneUse()) { 2428 return 2429 DAG.getSetCC(dl, VT, N0.getOperand(1), 2430 DAG.getConstant(SUBC->getAPIntValue() - 2431 RHSC->getAPIntValue(), 2432 N0.getValueType()), 2433 Cond); 2434 } 2435 } 2436 } 2437 2438 // Simplify (X+Z) == X --> Z == 0 2439 if (N0.getOperand(0) == N1) 2440 return DAG.getSetCC(dl, VT, N0.getOperand(1), 2441 DAG.getConstant(0, N0.getValueType()), Cond); 2442 if (N0.getOperand(1) == N1) { 2443 if (DAG.isCommutativeBinOp(N0.getOpcode())) 2444 return DAG.getSetCC(dl, VT, N0.getOperand(0), 2445 DAG.getConstant(0, N0.getValueType()), Cond); 2446 else if (N0.getNode()->hasOneUse()) { 2447 assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!"); 2448 // (Z-X) == X --> Z == X<<1 2449 SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), 2450 N1, 2451 DAG.getConstant(1, getShiftAmountTy(N1.getValueType()))); 2452 if (!DCI.isCalledByLegalizer()) 2453 DCI.AddToWorklist(SH.getNode()); 2454 return DAG.getSetCC(dl, VT, N0.getOperand(0), SH, Cond); 2455 } 2456 } 2457 } 2458 2459 if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB || 2460 N1.getOpcode() == ISD::XOR) { 2461 // Simplify X == (X+Z) --> Z == 0 2462 if (N1.getOperand(0) == N0) { 2463 return DAG.getSetCC(dl, VT, N1.getOperand(1), 2464 DAG.getConstant(0, N1.getValueType()), Cond); 2465 } else if (N1.getOperand(1) == N0) { 2466 if (DAG.isCommutativeBinOp(N1.getOpcode())) { 2467 return DAG.getSetCC(dl, VT, N1.getOperand(0), 2468 DAG.getConstant(0, N1.getValueType()), Cond); 2469 } else if (N1.getNode()->hasOneUse()) { 2470 assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!"); 2471 // X == (Z-X) --> X<<1 == Z 2472 SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N0, 2473 DAG.getConstant(1, getShiftAmountTy(N0.getValueType()))); 2474 if (!DCI.isCalledByLegalizer()) 2475 DCI.AddToWorklist(SH.getNode()); 2476 return DAG.getSetCC(dl, VT, SH, N1.getOperand(0), Cond); 2477 } 2478 } 2479 } 2480 2481 // Simplify x&y == y to x&y != 0 if y has exactly one bit set. 2482 // Note that where y is variable and is known to have at most 2483 // one bit set (for example, if it is z&1) we cannot do this; 2484 // the expressions are not equivalent when y==0. 2485 if (N0.getOpcode() == ISD::AND) 2486 if (N0.getOperand(0) == N1 || N0.getOperand(1) == N1) { 2487 if (ValueHasExactlyOneBitSet(N1, DAG)) { 2488 Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true); 2489 SDValue Zero = DAG.getConstant(0, N1.getValueType()); 2490 return DAG.getSetCC(dl, VT, N0, Zero, Cond); 2491 } 2492 } 2493 if (N1.getOpcode() == ISD::AND) 2494 if (N1.getOperand(0) == N0 || N1.getOperand(1) == N0) { 2495 if (ValueHasExactlyOneBitSet(N0, DAG)) { 2496 Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true); 2497 SDValue Zero = DAG.getConstant(0, N0.getValueType()); 2498 return DAG.getSetCC(dl, VT, N1, Zero, Cond); 2499 } 2500 } 2501 } 2502 2503 // Fold away ALL boolean setcc's. 2504 SDValue Temp; 2505 if (N0.getValueType() == MVT::i1 && foldBooleans) { 2506 switch (Cond) { 2507 default: llvm_unreachable("Unknown integer setcc!"); 2508 case ISD::SETEQ: // X == Y -> ~(X^Y) 2509 Temp = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1); 2510 N0 = DAG.getNOT(dl, Temp, MVT::i1); 2511 if (!DCI.isCalledByLegalizer()) 2512 DCI.AddToWorklist(Temp.getNode()); 2513 break; 2514 case ISD::SETNE: // X != Y --> (X^Y) 2515 N0 = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1); 2516 break; 2517 case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> ~X & Y 2518 case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> ~X & Y 2519 Temp = DAG.getNOT(dl, N0, MVT::i1); 2520 N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N1, Temp); 2521 if (!DCI.isCalledByLegalizer()) 2522 DCI.AddToWorklist(Temp.getNode()); 2523 break; 2524 case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> ~Y & X 2525 case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> ~Y & X 2526 Temp = DAG.getNOT(dl, N1, MVT::i1); 2527 N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N0, Temp); 2528 if (!DCI.isCalledByLegalizer()) 2529 DCI.AddToWorklist(Temp.getNode()); 2530 break; 2531 case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> ~X | Y 2532 case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> ~X | Y 2533 Temp = DAG.getNOT(dl, N0, MVT::i1); 2534 N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N1, Temp); 2535 if (!DCI.isCalledByLegalizer()) 2536 DCI.AddToWorklist(Temp.getNode()); 2537 break; 2538 case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> ~Y | X 2539 case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> ~Y | X 2540 Temp = DAG.getNOT(dl, N1, MVT::i1); 2541 N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N0, Temp); 2542 break; 2543 } 2544 if (VT != MVT::i1) { 2545 if (!DCI.isCalledByLegalizer()) 2546 DCI.AddToWorklist(N0.getNode()); 2547 // FIXME: If running after legalize, we probably can't do this. 2548 N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, N0); 2549 } 2550 return N0; 2551 } 2552 2553 // Could not fold it. 2554 return SDValue(); 2555 } 2556 2557 /// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the 2558 /// node is a GlobalAddress + offset. 2559 bool TargetLowering::isGAPlusOffset(SDNode *N, const GlobalValue *&GA, 2560 int64_t &Offset) const { 2561 if (isa<GlobalAddressSDNode>(N)) { 2562 GlobalAddressSDNode *GASD = cast<GlobalAddressSDNode>(N); 2563 GA = GASD->getGlobal(); 2564 Offset += GASD->getOffset(); 2565 return true; 2566 } 2567 2568 if (N->getOpcode() == ISD::ADD) { 2569 SDValue N1 = N->getOperand(0); 2570 SDValue N2 = N->getOperand(1); 2571 if (isGAPlusOffset(N1.getNode(), GA, Offset)) { 2572 ConstantSDNode *V = dyn_cast<ConstantSDNode>(N2); 2573 if (V) { 2574 Offset += V->getSExtValue(); 2575 return true; 2576 } 2577 } else if (isGAPlusOffset(N2.getNode(), GA, Offset)) { 2578 ConstantSDNode *V = dyn_cast<ConstantSDNode>(N1); 2579 if (V) { 2580 Offset += V->getSExtValue(); 2581 return true; 2582 } 2583 } 2584 } 2585 2586 return false; 2587 } 2588 2589 2590 SDValue TargetLowering:: 2591 PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const { 2592 // Default implementation: no optimization. 2593 return SDValue(); 2594 } 2595 2596 //===----------------------------------------------------------------------===// 2597 // Inline Assembler Implementation Methods 2598 //===----------------------------------------------------------------------===// 2599 2600 2601 TargetLowering::ConstraintType 2602 TargetLowering::getConstraintType(const std::string &Constraint) const { 2603 // FIXME: lots more standard ones to handle. 2604 if (Constraint.size() == 1) { 2605 switch (Constraint[0]) { 2606 default: break; 2607 case 'r': return C_RegisterClass; 2608 case 'm': // memory 2609 case 'o': // offsetable 2610 case 'V': // not offsetable 2611 return C_Memory; 2612 case 'i': // Simple Integer or Relocatable Constant 2613 case 'n': // Simple Integer 2614 case 'E': // Floating Point Constant 2615 case 'F': // Floating Point Constant 2616 case 's': // Relocatable Constant 2617 case 'p': // Address. 2618 case 'X': // Allow ANY value. 2619 case 'I': // Target registers. 2620 case 'J': 2621 case 'K': 2622 case 'L': 2623 case 'M': 2624 case 'N': 2625 case 'O': 2626 case 'P': 2627 case '<': 2628 case '>': 2629 return C_Other; 2630 } 2631 } 2632 2633 if (Constraint.size() > 1 && Constraint[0] == '{' && 2634 Constraint[Constraint.size()-1] == '}') 2635 return C_Register; 2636 return C_Unknown; 2637 } 2638 2639 /// LowerXConstraint - try to replace an X constraint, which matches anything, 2640 /// with another that has more specific requirements based on the type of the 2641 /// corresponding operand. 2642 const char *TargetLowering::LowerXConstraint(EVT ConstraintVT) const{ 2643 if (ConstraintVT.isInteger()) 2644 return "r"; 2645 if (ConstraintVT.isFloatingPoint()) 2646 return "f"; // works for many targets 2647 return 0; 2648 } 2649 2650 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops 2651 /// vector. If it is invalid, don't add anything to Ops. 2652 void TargetLowering::LowerAsmOperandForConstraint(SDValue Op, 2653 std::string &Constraint, 2654 std::vector<SDValue> &Ops, 2655 SelectionDAG &DAG) const { 2656 2657 if (Constraint.length() > 1) return; 2658 2659 char ConstraintLetter = Constraint[0]; 2660 switch (ConstraintLetter) { 2661 default: break; 2662 case 'X': // Allows any operand; labels (basic block) use this. 2663 if (Op.getOpcode() == ISD::BasicBlock) { 2664 Ops.push_back(Op); 2665 return; 2666 } 2667 // fall through 2668 case 'i': // Simple Integer or Relocatable Constant 2669 case 'n': // Simple Integer 2670 case 's': { // Relocatable Constant 2671 // These operands are interested in values of the form (GV+C), where C may 2672 // be folded in as an offset of GV, or it may be explicitly added. Also, it 2673 // is possible and fine if either GV or C are missing. 2674 ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op); 2675 GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op); 2676 2677 // If we have "(add GV, C)", pull out GV/C 2678 if (Op.getOpcode() == ISD::ADD) { 2679 C = dyn_cast<ConstantSDNode>(Op.getOperand(1)); 2680 GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(0)); 2681 if (C == 0 || GA == 0) { 2682 C = dyn_cast<ConstantSDNode>(Op.getOperand(0)); 2683 GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(1)); 2684 } 2685 if (C == 0 || GA == 0) 2686 C = 0, GA = 0; 2687 } 2688 2689 // If we find a valid operand, map to the TargetXXX version so that the 2690 // value itself doesn't get selected. 2691 if (GA) { // Either &GV or &GV+C 2692 if (ConstraintLetter != 'n') { 2693 int64_t Offs = GA->getOffset(); 2694 if (C) Offs += C->getZExtValue(); 2695 Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(), 2696 C ? C->getDebugLoc() : DebugLoc(), 2697 Op.getValueType(), Offs)); 2698 return; 2699 } 2700 } 2701 if (C) { // just C, no GV. 2702 // Simple constants are not allowed for 's'. 2703 if (ConstraintLetter != 's') { 2704 // gcc prints these as sign extended. Sign extend value to 64 bits 2705 // now; without this it would get ZExt'd later in 2706 // ScheduleDAGSDNodes::EmitNode, which is very generic. 2707 Ops.push_back(DAG.getTargetConstant(C->getAPIntValue().getSExtValue(), 2708 MVT::i64)); 2709 return; 2710 } 2711 } 2712 break; 2713 } 2714 } 2715 } 2716 2717 std::vector<unsigned> TargetLowering:: 2718 getRegClassForInlineAsmConstraint(const std::string &Constraint, 2719 EVT VT) const { 2720 return std::vector<unsigned>(); 2721 } 2722 2723 2724 std::pair<unsigned, const TargetRegisterClass*> TargetLowering:: 2725 getRegForInlineAsmConstraint(const std::string &Constraint, 2726 EVT VT) const { 2727 if (Constraint[0] != '{') 2728 return std::make_pair(0u, static_cast<TargetRegisterClass*>(0)); 2729 assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?"); 2730 2731 // Remove the braces from around the name. 2732 StringRef RegName(Constraint.data()+1, Constraint.size()-2); 2733 2734 // Figure out which register class contains this reg. 2735 const TargetRegisterInfo *RI = TM.getRegisterInfo(); 2736 for (TargetRegisterInfo::regclass_iterator RCI = RI->regclass_begin(), 2737 E = RI->regclass_end(); RCI != E; ++RCI) { 2738 const TargetRegisterClass *RC = *RCI; 2739 2740 // If none of the value types for this register class are valid, we 2741 // can't use it. For example, 64-bit reg classes on 32-bit targets. 2742 bool isLegal = false; 2743 for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end(); 2744 I != E; ++I) { 2745 if (isTypeLegal(*I)) { 2746 isLegal = true; 2747 break; 2748 } 2749 } 2750 2751 if (!isLegal) continue; 2752 2753 for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end(); 2754 I != E; ++I) { 2755 if (RegName.equals_lower(RI->getName(*I))) 2756 return std::make_pair(*I, RC); 2757 } 2758 } 2759 2760 return std::make_pair(0u, static_cast<const TargetRegisterClass*>(0)); 2761 } 2762 2763 //===----------------------------------------------------------------------===// 2764 // Constraint Selection. 2765 2766 /// isMatchingInputConstraint - Return true of this is an input operand that is 2767 /// a matching constraint like "4". 2768 bool TargetLowering::AsmOperandInfo::isMatchingInputConstraint() const { 2769 assert(!ConstraintCode.empty() && "No known constraint!"); 2770 return isdigit(ConstraintCode[0]); 2771 } 2772 2773 /// getMatchedOperand - If this is an input matching constraint, this method 2774 /// returns the output operand it matches. 2775 unsigned TargetLowering::AsmOperandInfo::getMatchedOperand() const { 2776 assert(!ConstraintCode.empty() && "No known constraint!"); 2777 return atoi(ConstraintCode.c_str()); 2778 } 2779 2780 2781 /// ParseConstraints - Split up the constraint string from the inline 2782 /// assembly value into the specific constraints and their prefixes, 2783 /// and also tie in the associated operand values. 2784 /// If this returns an empty vector, and if the constraint string itself 2785 /// isn't empty, there was an error parsing. 2786 TargetLowering::AsmOperandInfoVector TargetLowering::ParseConstraints( 2787 ImmutableCallSite CS) const { 2788 /// ConstraintOperands - Information about all of the constraints. 2789 AsmOperandInfoVector ConstraintOperands; 2790 const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue()); 2791 unsigned maCount = 0; // Largest number of multiple alternative constraints. 2792 2793 // Do a prepass over the constraints, canonicalizing them, and building up the 2794 // ConstraintOperands list. 2795 InlineAsm::ConstraintInfoVector 2796 ConstraintInfos = IA->ParseConstraints(); 2797 2798 unsigned ArgNo = 0; // ArgNo - The argument of the CallInst. 2799 unsigned ResNo = 0; // ResNo - The result number of the next output. 2800 2801 for (unsigned i = 0, e = ConstraintInfos.size(); i != e; ++i) { 2802 ConstraintOperands.push_back(AsmOperandInfo(ConstraintInfos[i])); 2803 AsmOperandInfo &OpInfo = ConstraintOperands.back(); 2804 2805 // Update multiple alternative constraint count. 2806 if (OpInfo.multipleAlternatives.size() > maCount) 2807 maCount = OpInfo.multipleAlternatives.size(); 2808 2809 OpInfo.ConstraintVT = MVT::Other; 2810 2811 // Compute the value type for each operand. 2812 switch (OpInfo.Type) { 2813 case InlineAsm::isOutput: 2814 // Indirect outputs just consume an argument. 2815 if (OpInfo.isIndirect) { 2816 OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++)); 2817 break; 2818 } 2819 2820 // The return value of the call is this value. As such, there is no 2821 // corresponding argument. 2822 assert(!CS.getType()->isVoidTy() && 2823 "Bad inline asm!"); 2824 if (const StructType *STy = dyn_cast<StructType>(CS.getType())) { 2825 OpInfo.ConstraintVT = getValueType(STy->getElementType(ResNo)); 2826 } else { 2827 assert(ResNo == 0 && "Asm only has one result!"); 2828 OpInfo.ConstraintVT = getValueType(CS.getType()); 2829 } 2830 ++ResNo; 2831 break; 2832 case InlineAsm::isInput: 2833 OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++)); 2834 break; 2835 case InlineAsm::isClobber: 2836 // Nothing to do. 2837 break; 2838 } 2839 2840 if (OpInfo.CallOperandVal) { 2841 const llvm::Type *OpTy = OpInfo.CallOperandVal->getType(); 2842 if (OpInfo.isIndirect) { 2843 const llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy); 2844 if (!PtrTy) 2845 report_fatal_error("Indirect operand for inline asm not a pointer!"); 2846 OpTy = PtrTy->getElementType(); 2847 } 2848 2849 // Look for vector wrapped in a struct. e.g. { <16 x i8> }. 2850 if (const StructType *STy = dyn_cast<StructType>(OpTy)) 2851 if (STy->getNumElements() == 1) 2852 OpTy = STy->getElementType(0); 2853 2854 // If OpTy is not a single value, it may be a struct/union that we 2855 // can tile with integers. 2856 if (!OpTy->isSingleValueType() && OpTy->isSized()) { 2857 unsigned BitSize = TD->getTypeSizeInBits(OpTy); 2858 switch (BitSize) { 2859 default: break; 2860 case 1: 2861 case 8: 2862 case 16: 2863 case 32: 2864 case 64: 2865 case 128: 2866 OpInfo.ConstraintVT = 2867 EVT::getEVT(IntegerType::get(OpTy->getContext(), BitSize), true); 2868 break; 2869 } 2870 } else if (dyn_cast<PointerType>(OpTy)) { 2871 OpInfo.ConstraintVT = MVT::getIntegerVT(8*TD->getPointerSize()); 2872 } else { 2873 OpInfo.ConstraintVT = EVT::getEVT(OpTy, true); 2874 } 2875 } 2876 } 2877 2878 // If we have multiple alternative constraints, select the best alternative. 2879 if (ConstraintInfos.size()) { 2880 if (maCount) { 2881 unsigned bestMAIndex = 0; 2882 int bestWeight = -1; 2883 // weight: -1 = invalid match, and 0 = so-so match to 5 = good match. 2884 int weight = -1; 2885 unsigned maIndex; 2886 // Compute the sums of the weights for each alternative, keeping track 2887 // of the best (highest weight) one so far. 2888 for (maIndex = 0; maIndex < maCount; ++maIndex) { 2889 int weightSum = 0; 2890 for (unsigned cIndex = 0, eIndex = ConstraintOperands.size(); 2891 cIndex != eIndex; ++cIndex) { 2892 AsmOperandInfo& OpInfo = ConstraintOperands[cIndex]; 2893 if (OpInfo.Type == InlineAsm::isClobber) 2894 continue; 2895 2896 // If this is an output operand with a matching input operand, 2897 // look up the matching input. If their types mismatch, e.g. one 2898 // is an integer, the other is floating point, or their sizes are 2899 // different, flag it as an maCantMatch. 2900 if (OpInfo.hasMatchingInput()) { 2901 AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput]; 2902 if (OpInfo.ConstraintVT != Input.ConstraintVT) { 2903 if ((OpInfo.ConstraintVT.isInteger() != 2904 Input.ConstraintVT.isInteger()) || 2905 (OpInfo.ConstraintVT.getSizeInBits() != 2906 Input.ConstraintVT.getSizeInBits())) { 2907 weightSum = -1; // Can't match. 2908 break; 2909 } 2910 } 2911 } 2912 weight = getMultipleConstraintMatchWeight(OpInfo, maIndex); 2913 if (weight == -1) { 2914 weightSum = -1; 2915 break; 2916 } 2917 weightSum += weight; 2918 } 2919 // Update best. 2920 if (weightSum > bestWeight) { 2921 bestWeight = weightSum; 2922 bestMAIndex = maIndex; 2923 } 2924 } 2925 2926 // Now select chosen alternative in each constraint. 2927 for (unsigned cIndex = 0, eIndex = ConstraintOperands.size(); 2928 cIndex != eIndex; ++cIndex) { 2929 AsmOperandInfo& cInfo = ConstraintOperands[cIndex]; 2930 if (cInfo.Type == InlineAsm::isClobber) 2931 continue; 2932 cInfo.selectAlternative(bestMAIndex); 2933 } 2934 } 2935 } 2936 2937 // Check and hook up tied operands, choose constraint code to use. 2938 for (unsigned cIndex = 0, eIndex = ConstraintOperands.size(); 2939 cIndex != eIndex; ++cIndex) { 2940 AsmOperandInfo& OpInfo = ConstraintOperands[cIndex]; 2941 2942 // If this is an output operand with a matching input operand, look up the 2943 // matching input. If their types mismatch, e.g. one is an integer, the 2944 // other is floating point, or their sizes are different, flag it as an 2945 // error. 2946 if (OpInfo.hasMatchingInput()) { 2947 AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput]; 2948 2949 if (OpInfo.ConstraintVT != Input.ConstraintVT) { 2950 if ((OpInfo.ConstraintVT.isInteger() != 2951 Input.ConstraintVT.isInteger()) || 2952 (OpInfo.ConstraintVT.getSizeInBits() != 2953 Input.ConstraintVT.getSizeInBits())) { 2954 report_fatal_error("Unsupported asm: input constraint" 2955 " with a matching output constraint of" 2956 " incompatible type!"); 2957 } 2958 } 2959 2960 } 2961 } 2962 2963 return ConstraintOperands; 2964 } 2965 2966 2967 /// getConstraintGenerality - Return an integer indicating how general CT 2968 /// is. 2969 static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) { 2970 switch (CT) { 2971 default: llvm_unreachable("Unknown constraint type!"); 2972 case TargetLowering::C_Other: 2973 case TargetLowering::C_Unknown: 2974 return 0; 2975 case TargetLowering::C_Register: 2976 return 1; 2977 case TargetLowering::C_RegisterClass: 2978 return 2; 2979 case TargetLowering::C_Memory: 2980 return 3; 2981 } 2982 } 2983 2984 /// Examine constraint type and operand type and determine a weight value. 2985 /// This object must already have been set up with the operand type 2986 /// and the current alternative constraint selected. 2987 TargetLowering::ConstraintWeight 2988 TargetLowering::getMultipleConstraintMatchWeight( 2989 AsmOperandInfo &info, int maIndex) const { 2990 InlineAsm::ConstraintCodeVector *rCodes; 2991 if (maIndex >= (int)info.multipleAlternatives.size()) 2992 rCodes = &info.Codes; 2993 else 2994 rCodes = &info.multipleAlternatives[maIndex].Codes; 2995 ConstraintWeight BestWeight = CW_Invalid; 2996 2997 // Loop over the options, keeping track of the most general one. 2998 for (unsigned i = 0, e = rCodes->size(); i != e; ++i) { 2999 ConstraintWeight weight = 3000 getSingleConstraintMatchWeight(info, (*rCodes)[i].c_str()); 3001 if (weight > BestWeight) 3002 BestWeight = weight; 3003 } 3004 3005 return BestWeight; 3006 } 3007 3008 /// Examine constraint type and operand type and determine a weight value. 3009 /// This object must already have been set up with the operand type 3010 /// and the current alternative constraint selected. 3011 TargetLowering::ConstraintWeight 3012 TargetLowering::getSingleConstraintMatchWeight( 3013 AsmOperandInfo &info, const char *constraint) const { 3014 ConstraintWeight weight = CW_Invalid; 3015 Value *CallOperandVal = info.CallOperandVal; 3016 // If we don't have a value, we can't do a match, 3017 // but allow it at the lowest weight. 3018 if (CallOperandVal == NULL) 3019 return CW_Default; 3020 // Look at the constraint type. 3021 switch (*constraint) { 3022 case 'i': // immediate integer. 3023 case 'n': // immediate integer with a known value. 3024 if (isa<ConstantInt>(CallOperandVal)) 3025 weight = CW_Constant; 3026 break; 3027 case 's': // non-explicit intregal immediate. 3028 if (isa<GlobalValue>(CallOperandVal)) 3029 weight = CW_Constant; 3030 break; 3031 case 'E': // immediate float if host format. 3032 case 'F': // immediate float. 3033 if (isa<ConstantFP>(CallOperandVal)) 3034 weight = CW_Constant; 3035 break; 3036 case '<': // memory operand with autodecrement. 3037 case '>': // memory operand with autoincrement. 3038 case 'm': // memory operand. 3039 case 'o': // offsettable memory operand 3040 case 'V': // non-offsettable memory operand 3041 weight = CW_Memory; 3042 break; 3043 case 'r': // general register. 3044 case 'g': // general register, memory operand or immediate integer. 3045 // note: Clang converts "g" to "imr". 3046 if (CallOperandVal->getType()->isIntegerTy()) 3047 weight = CW_Register; 3048 break; 3049 case 'X': // any operand. 3050 default: 3051 weight = CW_Default; 3052 break; 3053 } 3054 return weight; 3055 } 3056 3057 /// ChooseConstraint - If there are multiple different constraints that we 3058 /// could pick for this operand (e.g. "imr") try to pick the 'best' one. 3059 /// This is somewhat tricky: constraints fall into four classes: 3060 /// Other -> immediates and magic values 3061 /// Register -> one specific register 3062 /// RegisterClass -> a group of regs 3063 /// Memory -> memory 3064 /// Ideally, we would pick the most specific constraint possible: if we have 3065 /// something that fits into a register, we would pick it. The problem here 3066 /// is that if we have something that could either be in a register or in 3067 /// memory that use of the register could cause selection of *other* 3068 /// operands to fail: they might only succeed if we pick memory. Because of 3069 /// this the heuristic we use is: 3070 /// 3071 /// 1) If there is an 'other' constraint, and if the operand is valid for 3072 /// that constraint, use it. This makes us take advantage of 'i' 3073 /// constraints when available. 3074 /// 2) Otherwise, pick the most general constraint present. This prefers 3075 /// 'm' over 'r', for example. 3076 /// 3077 static void ChooseConstraint(TargetLowering::AsmOperandInfo &OpInfo, 3078 const TargetLowering &TLI, 3079 SDValue Op, SelectionDAG *DAG) { 3080 assert(OpInfo.Codes.size() > 1 && "Doesn't have multiple constraint options"); 3081 unsigned BestIdx = 0; 3082 TargetLowering::ConstraintType BestType = TargetLowering::C_Unknown; 3083 int BestGenerality = -1; 3084 3085 // Loop over the options, keeping track of the most general one. 3086 for (unsigned i = 0, e = OpInfo.Codes.size(); i != e; ++i) { 3087 TargetLowering::ConstraintType CType = 3088 TLI.getConstraintType(OpInfo.Codes[i]); 3089 3090 // If this is an 'other' constraint, see if the operand is valid for it. 3091 // For example, on X86 we might have an 'rI' constraint. If the operand 3092 // is an integer in the range [0..31] we want to use I (saving a load 3093 // of a register), otherwise we must use 'r'. 3094 if (CType == TargetLowering::C_Other && Op.getNode()) { 3095 assert(OpInfo.Codes[i].size() == 1 && 3096 "Unhandled multi-letter 'other' constraint"); 3097 std::vector<SDValue> ResultOps; 3098 TLI.LowerAsmOperandForConstraint(Op, OpInfo.Codes[i], 3099 ResultOps, *DAG); 3100 if (!ResultOps.empty()) { 3101 BestType = CType; 3102 BestIdx = i; 3103 break; 3104 } 3105 } 3106 3107 // Things with matching constraints can only be registers, per gcc 3108 // documentation. This mainly affects "g" constraints. 3109 if (CType == TargetLowering::C_Memory && OpInfo.hasMatchingInput()) 3110 continue; 3111 3112 // This constraint letter is more general than the previous one, use it. 3113 int Generality = getConstraintGenerality(CType); 3114 if (Generality > BestGenerality) { 3115 BestType = CType; 3116 BestIdx = i; 3117 BestGenerality = Generality; 3118 } 3119 } 3120 3121 OpInfo.ConstraintCode = OpInfo.Codes[BestIdx]; 3122 OpInfo.ConstraintType = BestType; 3123 } 3124 3125 /// ComputeConstraintToUse - Determines the constraint code and constraint 3126 /// type to use for the specific AsmOperandInfo, setting 3127 /// OpInfo.ConstraintCode and OpInfo.ConstraintType. 3128 void TargetLowering::ComputeConstraintToUse(AsmOperandInfo &OpInfo, 3129 SDValue Op, 3130 SelectionDAG *DAG) const { 3131 assert(!OpInfo.Codes.empty() && "Must have at least one constraint"); 3132 3133 // Single-letter constraints ('r') are very common. 3134 if (OpInfo.Codes.size() == 1) { 3135 OpInfo.ConstraintCode = OpInfo.Codes[0]; 3136 OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode); 3137 } else { 3138 ChooseConstraint(OpInfo, *this, Op, DAG); 3139 } 3140 3141 // 'X' matches anything. 3142 if (OpInfo.ConstraintCode == "X" && OpInfo.CallOperandVal) { 3143 // Labels and constants are handled elsewhere ('X' is the only thing 3144 // that matches labels). For Functions, the type here is the type of 3145 // the result, which is not what we want to look at; leave them alone. 3146 Value *v = OpInfo.CallOperandVal; 3147 if (isa<BasicBlock>(v) || isa<ConstantInt>(v) || isa<Function>(v)) { 3148 OpInfo.CallOperandVal = v; 3149 return; 3150 } 3151 3152 // Otherwise, try to resolve it to something we know about by looking at 3153 // the actual operand type. 3154 if (const char *Repl = LowerXConstraint(OpInfo.ConstraintVT)) { 3155 OpInfo.ConstraintCode = Repl; 3156 OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode); 3157 } 3158 } 3159 } 3160 3161 //===----------------------------------------------------------------------===// 3162 // Loop Strength Reduction hooks 3163 //===----------------------------------------------------------------------===// 3164 3165 /// isLegalAddressingMode - Return true if the addressing mode represented 3166 /// by AM is legal for this target, for a load/store of the specified type. 3167 bool TargetLowering::isLegalAddressingMode(const AddrMode &AM, 3168 const Type *Ty) const { 3169 // The default implementation of this implements a conservative RISCy, r+r and 3170 // r+i addr mode. 3171 3172 // Allows a sign-extended 16-bit immediate field. 3173 if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1) 3174 return false; 3175 3176 // No global is ever allowed as a base. 3177 if (AM.BaseGV) 3178 return false; 3179 3180 // Only support r+r, 3181 switch (AM.Scale) { 3182 case 0: // "r+i" or just "i", depending on HasBaseReg. 3183 break; 3184 case 1: 3185 if (AM.HasBaseReg && AM.BaseOffs) // "r+r+i" is not allowed. 3186 return false; 3187 // Otherwise we have r+r or r+i. 3188 break; 3189 case 2: 3190 if (AM.HasBaseReg || AM.BaseOffs) // 2*r+r or 2*r+i is not allowed. 3191 return false; 3192 // Allow 2*r as r+r. 3193 break; 3194 } 3195 3196 return true; 3197 } 3198 3199 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant, 3200 /// return a DAG expression to select that will generate the same value by 3201 /// multiplying by a magic number. See: 3202 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html> 3203 SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG, 3204 std::vector<SDNode*>* Created) const { 3205 EVT VT = N->getValueType(0); 3206 DebugLoc dl= N->getDebugLoc(); 3207 3208 // Check to see if we can do this. 3209 // FIXME: We should be more aggressive here. 3210 if (!isTypeLegal(VT)) 3211 return SDValue(); 3212 3213 APInt d = cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue(); 3214 APInt::ms magics = d.magic(); 3215 3216 // Multiply the numerator (operand 0) by the magic value 3217 // FIXME: We should support doing a MUL in a wider type 3218 SDValue Q; 3219 if (isOperationLegalOrCustom(ISD::MULHS, VT)) 3220 Q = DAG.getNode(ISD::MULHS, dl, VT, N->getOperand(0), 3221 DAG.getConstant(magics.m, VT)); 3222 else if (isOperationLegalOrCustom(ISD::SMUL_LOHI, VT)) 3223 Q = SDValue(DAG.getNode(ISD::SMUL_LOHI, dl, DAG.getVTList(VT, VT), 3224 N->getOperand(0), 3225 DAG.getConstant(magics.m, VT)).getNode(), 1); 3226 else 3227 return SDValue(); // No mulhs or equvialent 3228 // If d > 0 and m < 0, add the numerator 3229 if (d.isStrictlyPositive() && magics.m.isNegative()) { 3230 Q = DAG.getNode(ISD::ADD, dl, VT, Q, N->getOperand(0)); 3231 if (Created) 3232 Created->push_back(Q.getNode()); 3233 } 3234 // If d < 0 and m > 0, subtract the numerator. 3235 if (d.isNegative() && magics.m.isStrictlyPositive()) { 3236 Q = DAG.getNode(ISD::SUB, dl, VT, Q, N->getOperand(0)); 3237 if (Created) 3238 Created->push_back(Q.getNode()); 3239 } 3240 // Shift right algebraic if shift value is nonzero 3241 if (magics.s > 0) { 3242 Q = DAG.getNode(ISD::SRA, dl, VT, Q, 3243 DAG.getConstant(magics.s, getShiftAmountTy(Q.getValueType()))); 3244 if (Created) 3245 Created->push_back(Q.getNode()); 3246 } 3247 // Extract the sign bit and add it to the quotient 3248 SDValue T = 3249 DAG.getNode(ISD::SRL, dl, VT, Q, DAG.getConstant(VT.getSizeInBits()-1, 3250 getShiftAmountTy(Q.getValueType()))); 3251 if (Created) 3252 Created->push_back(T.getNode()); 3253 return DAG.getNode(ISD::ADD, dl, VT, Q, T); 3254 } 3255 3256 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant, 3257 /// return a DAG expression to select that will generate the same value by 3258 /// multiplying by a magic number. See: 3259 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html> 3260 SDValue TargetLowering::BuildUDIV(SDNode *N, SelectionDAG &DAG, 3261 std::vector<SDNode*>* Created) const { 3262 EVT VT = N->getValueType(0); 3263 DebugLoc dl = N->getDebugLoc(); 3264 3265 // Check to see if we can do this. 3266 // FIXME: We should be more aggressive here. 3267 if (!isTypeLegal(VT)) 3268 return SDValue(); 3269 3270 // FIXME: We should use a narrower constant when the upper 3271 // bits are known to be zero. 3272 const APInt &N1C = cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue(); 3273 APInt::mu magics = N1C.magicu(); 3274 3275 SDValue Q = N->getOperand(0); 3276 3277 // If the divisor is even, we can avoid using the expensive fixup by shifting 3278 // the divided value upfront. 3279 if (magics.a != 0 && !N1C[0]) { 3280 unsigned Shift = N1C.countTrailingZeros(); 3281 Q = DAG.getNode(ISD::SRL, dl, VT, Q, 3282 DAG.getConstant(Shift, getShiftAmountTy(Q.getValueType()))); 3283 if (Created) 3284 Created->push_back(Q.getNode()); 3285 3286 // Get magic number for the shifted divisor. 3287 magics = N1C.lshr(Shift).magicu(Shift); 3288 assert(magics.a == 0 && "Should use cheap fixup now"); 3289 } 3290 3291 // Multiply the numerator (operand 0) by the magic value 3292 // FIXME: We should support doing a MUL in a wider type 3293 if (isOperationLegalOrCustom(ISD::MULHU, VT)) 3294 Q = DAG.getNode(ISD::MULHU, dl, VT, Q, DAG.getConstant(magics.m, VT)); 3295 else if (isOperationLegalOrCustom(ISD::UMUL_LOHI, VT)) 3296 Q = SDValue(DAG.getNode(ISD::UMUL_LOHI, dl, DAG.getVTList(VT, VT), Q, 3297 DAG.getConstant(magics.m, VT)).getNode(), 1); 3298 else 3299 return SDValue(); // No mulhu or equvialent 3300 if (Created) 3301 Created->push_back(Q.getNode()); 3302 3303 if (magics.a == 0) { 3304 assert(magics.s < N1C.getBitWidth() && 3305 "We shouldn't generate an undefined shift!"); 3306 return DAG.getNode(ISD::SRL, dl, VT, Q, 3307 DAG.getConstant(magics.s, getShiftAmountTy(Q.getValueType()))); 3308 } else { 3309 SDValue NPQ = DAG.getNode(ISD::SUB, dl, VT, N->getOperand(0), Q); 3310 if (Created) 3311 Created->push_back(NPQ.getNode()); 3312 NPQ = DAG.getNode(ISD::SRL, dl, VT, NPQ, 3313 DAG.getConstant(1, getShiftAmountTy(NPQ.getValueType()))); 3314 if (Created) 3315 Created->push_back(NPQ.getNode()); 3316 NPQ = DAG.getNode(ISD::ADD, dl, VT, NPQ, Q); 3317 if (Created) 3318 Created->push_back(NPQ.getNode()); 3319 return DAG.getNode(ISD::SRL, dl, VT, NPQ, 3320 DAG.getConstant(magics.s-1, getShiftAmountTy(NPQ.getValueType()))); 3321 } 3322 } 3323