1 //===-- Mips16ISelLowering.h - Mips16 DAG Lowering Interface ----*- C++ -*-===//
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 // Subclass of MipsTargetLowering specialized for mips16.
11 //
12 //===----------------------------------------------------------------------===//
13 #include "Mips16ISelLowering.h"
14 #include "MCTargetDesc/MipsBaseInfo.h"
15 #include "Mips16HardFloatInfo.h"
16 #include "MipsMachineFunction.h"
17 #include "MipsRegisterInfo.h"
18 #include "MipsTargetMachine.h"
19 #include "llvm/CodeGen/MachineInstrBuilder.h"
20 #include "llvm/Support/CommandLine.h"
21 #include "llvm/Target/TargetInstrInfo.h"
22 
23 using namespace llvm;
24 
25 #define DEBUG_TYPE "mips-lower"
26 
27 static cl::opt<bool> DontExpandCondPseudos16(
28   "mips16-dont-expand-cond-pseudo",
29   cl::init(false),
30   cl::desc("Don't expand conditional move related "
31            "pseudos for Mips 16"),
32   cl::Hidden);
33 
34 namespace {
35 struct Mips16Libcall {
36   RTLIB::Libcall Libcall;
37   const char *Name;
38 
39   bool operator<(const Mips16Libcall &RHS) const {
40     return std::strcmp(Name, RHS.Name) < 0;
41   }
42 };
43 
44 struct Mips16IntrinsicHelperType{
45   const char* Name;
46   const char* Helper;
47 
48   bool operator<(const Mips16IntrinsicHelperType &RHS) const {
49     return std::strcmp(Name, RHS.Name) < 0;
50   }
51   bool operator==(const Mips16IntrinsicHelperType &RHS) const {
52     return std::strcmp(Name, RHS.Name) == 0;
53   }
54 };
55 }
56 
57 // Libcalls for which no helper is generated. Sorted by name for binary search.
58 static const Mips16Libcall HardFloatLibCalls[] = {
59   { RTLIB::ADD_F64, "__mips16_adddf3" },
60   { RTLIB::ADD_F32, "__mips16_addsf3" },
61   { RTLIB::DIV_F64, "__mips16_divdf3" },
62   { RTLIB::DIV_F32, "__mips16_divsf3" },
63   { RTLIB::OEQ_F64, "__mips16_eqdf2" },
64   { RTLIB::OEQ_F32, "__mips16_eqsf2" },
65   { RTLIB::FPEXT_F32_F64, "__mips16_extendsfdf2" },
66   { RTLIB::FPTOSINT_F64_I32, "__mips16_fix_truncdfsi" },
67   { RTLIB::FPTOSINT_F32_I32, "__mips16_fix_truncsfsi" },
68   { RTLIB::SINTTOFP_I32_F64, "__mips16_floatsidf" },
69   { RTLIB::SINTTOFP_I32_F32, "__mips16_floatsisf" },
70   { RTLIB::UINTTOFP_I32_F64, "__mips16_floatunsidf" },
71   { RTLIB::UINTTOFP_I32_F32, "__mips16_floatunsisf" },
72   { RTLIB::OGE_F64, "__mips16_gedf2" },
73   { RTLIB::OGE_F32, "__mips16_gesf2" },
74   { RTLIB::OGT_F64, "__mips16_gtdf2" },
75   { RTLIB::OGT_F32, "__mips16_gtsf2" },
76   { RTLIB::OLE_F64, "__mips16_ledf2" },
77   { RTLIB::OLE_F32, "__mips16_lesf2" },
78   { RTLIB::OLT_F64, "__mips16_ltdf2" },
79   { RTLIB::OLT_F32, "__mips16_ltsf2" },
80   { RTLIB::MUL_F64, "__mips16_muldf3" },
81   { RTLIB::MUL_F32, "__mips16_mulsf3" },
82   { RTLIB::UNE_F64, "__mips16_nedf2" },
83   { RTLIB::UNE_F32, "__mips16_nesf2" },
84   { RTLIB::UNKNOWN_LIBCALL, "__mips16_ret_dc" }, // No associated libcall.
85   { RTLIB::UNKNOWN_LIBCALL, "__mips16_ret_df" }, // No associated libcall.
86   { RTLIB::UNKNOWN_LIBCALL, "__mips16_ret_sc" }, // No associated libcall.
87   { RTLIB::UNKNOWN_LIBCALL, "__mips16_ret_sf" }, // No associated libcall.
88   { RTLIB::SUB_F64, "__mips16_subdf3" },
89   { RTLIB::SUB_F32, "__mips16_subsf3" },
90   { RTLIB::FPROUND_F64_F32, "__mips16_truncdfsf2" },
91   { RTLIB::UO_F64, "__mips16_unorddf2" },
92   { RTLIB::UO_F32, "__mips16_unordsf2" }
93 };
94 
95 static const Mips16IntrinsicHelperType Mips16IntrinsicHelper[] = {
96   {"__fixunsdfsi", "__mips16_call_stub_2" },
97   {"ceil",  "__mips16_call_stub_df_2"},
98   {"ceilf", "__mips16_call_stub_sf_1"},
99   {"copysign",  "__mips16_call_stub_df_10"},
100   {"copysignf", "__mips16_call_stub_sf_5"},
101   {"cos",  "__mips16_call_stub_df_2"},
102   {"cosf", "__mips16_call_stub_sf_1"},
103   {"exp2",  "__mips16_call_stub_df_2"},
104   {"exp2f", "__mips16_call_stub_sf_1"},
105   {"floor",  "__mips16_call_stub_df_2"},
106   {"floorf", "__mips16_call_stub_sf_1"},
107   {"log2",  "__mips16_call_stub_df_2"},
108   {"log2f", "__mips16_call_stub_sf_1"},
109   {"nearbyint",  "__mips16_call_stub_df_2"},
110   {"nearbyintf", "__mips16_call_stub_sf_1"},
111   {"rint",  "__mips16_call_stub_df_2"},
112   {"rintf", "__mips16_call_stub_sf_1"},
113   {"sin",  "__mips16_call_stub_df_2"},
114   {"sinf", "__mips16_call_stub_sf_1"},
115   {"sqrt",  "__mips16_call_stub_df_2"},
116   {"sqrtf", "__mips16_call_stub_sf_1"},
117   {"trunc",  "__mips16_call_stub_df_2"},
118   {"truncf", "__mips16_call_stub_sf_1"},
119 };
120 
121 Mips16TargetLowering::Mips16TargetLowering(const MipsTargetMachine &TM,
122                                            const MipsSubtarget &STI)
123     : MipsTargetLowering(TM, STI) {
124 
125   // Set up the register classes
126   addRegisterClass(MVT::i32, &Mips::CPU16RegsRegClass);
127 
128   if (!Subtarget.useSoftFloat())
129     setMips16HardFloatLibCalls();
130 
131   setOperationAction(ISD::ATOMIC_FENCE,       MVT::Other, Expand);
132   setOperationAction(ISD::ATOMIC_CMP_SWAP,    MVT::i32,   Expand);
133   setOperationAction(ISD::ATOMIC_SWAP,        MVT::i32,   Expand);
134   setOperationAction(ISD::ATOMIC_LOAD_ADD,    MVT::i32,   Expand);
135   setOperationAction(ISD::ATOMIC_LOAD_SUB,    MVT::i32,   Expand);
136   setOperationAction(ISD::ATOMIC_LOAD_AND,    MVT::i32,   Expand);
137   setOperationAction(ISD::ATOMIC_LOAD_OR,     MVT::i32,   Expand);
138   setOperationAction(ISD::ATOMIC_LOAD_XOR,    MVT::i32,   Expand);
139   setOperationAction(ISD::ATOMIC_LOAD_NAND,   MVT::i32,   Expand);
140   setOperationAction(ISD::ATOMIC_LOAD_MIN,    MVT::i32,   Expand);
141   setOperationAction(ISD::ATOMIC_LOAD_MAX,    MVT::i32,   Expand);
142   setOperationAction(ISD::ATOMIC_LOAD_UMIN,   MVT::i32,   Expand);
143   setOperationAction(ISD::ATOMIC_LOAD_UMAX,   MVT::i32,   Expand);
144 
145   setOperationAction(ISD::ROTR, MVT::i32,  Expand);
146   setOperationAction(ISD::ROTR, MVT::i64,  Expand);
147   setOperationAction(ISD::BSWAP, MVT::i32, Expand);
148   setOperationAction(ISD::BSWAP, MVT::i64, Expand);
149 
150   computeRegisterProperties(STI.getRegisterInfo());
151 }
152 
153 const MipsTargetLowering *
154 llvm::createMips16TargetLowering(const MipsTargetMachine &TM,
155                                  const MipsSubtarget &STI) {
156   return new Mips16TargetLowering(TM, STI);
157 }
158 
159 bool
160 Mips16TargetLowering::allowsMisalignedMemoryAccesses(EVT VT,
161                                                      unsigned,
162                                                      unsigned,
163                                                      bool *Fast) const {
164   return false;
165 }
166 
167 MachineBasicBlock *
168 Mips16TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
169                                                   MachineBasicBlock *BB) const {
170   switch (MI->getOpcode()) {
171   default:
172     return MipsTargetLowering::EmitInstrWithCustomInserter(MI, BB);
173   case Mips::SelBeqZ:
174     return emitSel16(Mips::BeqzRxImm16, MI, BB);
175   case Mips::SelBneZ:
176     return emitSel16(Mips::BnezRxImm16, MI, BB);
177   case Mips::SelTBteqZCmpi:
178     return emitSeliT16(Mips::Bteqz16, Mips::CmpiRxImmX16, MI, BB);
179   case Mips::SelTBteqZSlti:
180     return emitSeliT16(Mips::Bteqz16, Mips::SltiRxImmX16, MI, BB);
181   case Mips::SelTBteqZSltiu:
182     return emitSeliT16(Mips::Bteqz16, Mips::SltiuRxImmX16, MI, BB);
183   case Mips::SelTBtneZCmpi:
184     return emitSeliT16(Mips::Btnez16, Mips::CmpiRxImmX16, MI, BB);
185   case Mips::SelTBtneZSlti:
186     return emitSeliT16(Mips::Btnez16, Mips::SltiRxImmX16, MI, BB);
187   case Mips::SelTBtneZSltiu:
188     return emitSeliT16(Mips::Btnez16, Mips::SltiuRxImmX16, MI, BB);
189   case Mips::SelTBteqZCmp:
190     return emitSelT16(Mips::Bteqz16, Mips::CmpRxRy16, MI, BB);
191   case Mips::SelTBteqZSlt:
192     return emitSelT16(Mips::Bteqz16, Mips::SltRxRy16, MI, BB);
193   case Mips::SelTBteqZSltu:
194     return emitSelT16(Mips::Bteqz16, Mips::SltuRxRy16, MI, BB);
195   case Mips::SelTBtneZCmp:
196     return emitSelT16(Mips::Btnez16, Mips::CmpRxRy16, MI, BB);
197   case Mips::SelTBtneZSlt:
198     return emitSelT16(Mips::Btnez16, Mips::SltRxRy16, MI, BB);
199   case Mips::SelTBtneZSltu:
200     return emitSelT16(Mips::Btnez16, Mips::SltuRxRy16, MI, BB);
201   case Mips::BteqzT8CmpX16:
202     return emitFEXT_T8I816_ins(Mips::Bteqz16, Mips::CmpRxRy16, MI, BB);
203   case Mips::BteqzT8SltX16:
204     return emitFEXT_T8I816_ins(Mips::Bteqz16, Mips::SltRxRy16, MI, BB);
205   case Mips::BteqzT8SltuX16:
206     // TBD: figure out a way to get this or remove the instruction
207     // altogether.
208     return emitFEXT_T8I816_ins(Mips::Bteqz16, Mips::SltuRxRy16, MI, BB);
209   case Mips::BtnezT8CmpX16:
210     return emitFEXT_T8I816_ins(Mips::Btnez16, Mips::CmpRxRy16, MI, BB);
211   case Mips::BtnezT8SltX16:
212     return emitFEXT_T8I816_ins(Mips::Btnez16, Mips::SltRxRy16, MI, BB);
213   case Mips::BtnezT8SltuX16:
214     // TBD: figure out a way to get this or remove the instruction
215     // altogether.
216     return emitFEXT_T8I816_ins(Mips::Btnez16, Mips::SltuRxRy16, MI, BB);
217   case Mips::BteqzT8CmpiX16: return emitFEXT_T8I8I16_ins(
218     Mips::Bteqz16, Mips::CmpiRxImm16, Mips::CmpiRxImmX16, false, MI, BB);
219   case Mips::BteqzT8SltiX16: return emitFEXT_T8I8I16_ins(
220     Mips::Bteqz16, Mips::SltiRxImm16, Mips::SltiRxImmX16, true, MI, BB);
221   case Mips::BteqzT8SltiuX16: return emitFEXT_T8I8I16_ins(
222     Mips::Bteqz16, Mips::SltiuRxImm16, Mips::SltiuRxImmX16, false, MI, BB);
223   case Mips::BtnezT8CmpiX16: return emitFEXT_T8I8I16_ins(
224     Mips::Btnez16, Mips::CmpiRxImm16, Mips::CmpiRxImmX16, false, MI, BB);
225   case Mips::BtnezT8SltiX16: return emitFEXT_T8I8I16_ins(
226     Mips::Btnez16, Mips::SltiRxImm16, Mips::SltiRxImmX16, true, MI, BB);
227   case Mips::BtnezT8SltiuX16: return emitFEXT_T8I8I16_ins(
228     Mips::Btnez16, Mips::SltiuRxImm16, Mips::SltiuRxImmX16, false, MI, BB);
229     break;
230   case Mips::SltCCRxRy16:
231     return emitFEXT_CCRX16_ins(Mips::SltRxRy16, MI, BB);
232     break;
233   case Mips::SltiCCRxImmX16:
234     return emitFEXT_CCRXI16_ins
235       (Mips::SltiRxImm16, Mips::SltiRxImmX16, MI, BB);
236   case Mips::SltiuCCRxImmX16:
237     return emitFEXT_CCRXI16_ins
238       (Mips::SltiuRxImm16, Mips::SltiuRxImmX16, MI, BB);
239   case Mips::SltuCCRxRy16:
240     return emitFEXT_CCRX16_ins
241       (Mips::SltuRxRy16, MI, BB);
242   }
243 }
244 
245 bool Mips16TargetLowering::isEligibleForTailCallOptimization(
246     const CCState &CCInfo, unsigned NextStackOffset,
247     const MipsFunctionInfo &FI) const {
248   // No tail call optimization for mips16.
249   return false;
250 }
251 
252 void Mips16TargetLowering::setMips16HardFloatLibCalls() {
253   for (unsigned I = 0; I != array_lengthof(HardFloatLibCalls); ++I) {
254     assert((I == 0 || HardFloatLibCalls[I - 1] < HardFloatLibCalls[I]) &&
255            "Array not sorted!");
256     if (HardFloatLibCalls[I].Libcall != RTLIB::UNKNOWN_LIBCALL)
257       setLibcallName(HardFloatLibCalls[I].Libcall, HardFloatLibCalls[I].Name);
258   }
259 
260   setLibcallName(RTLIB::O_F64, "__mips16_unorddf2");
261   setLibcallName(RTLIB::O_F32, "__mips16_unordsf2");
262 }
263 
264 //
265 // The Mips16 hard float is a crazy quilt inherited from gcc. I have a much
266 // cleaner way to do all of this but it will have to wait until the traditional
267 // gcc mechanism is completed.
268 //
269 // For Pic, in order for Mips16 code to call Mips32 code which according the abi
270 // have either arguments or returned values placed in floating point registers,
271 // we use a set of helper functions. (This includes functions which return type
272 //  complex which on Mips are returned in a pair of floating point registers).
273 //
274 // This is an encoding that we inherited from gcc.
275 // In Mips traditional O32, N32 ABI, floating point numbers are passed in
276 // floating point argument registers 1,2 only when the first and optionally
277 // the second arguments are float (sf) or double (df).
278 // For Mips16 we are only concerned with the situations where floating point
279 // arguments are being passed in floating point registers by the ABI, because
280 // Mips16 mode code cannot execute floating point instructions to load those
281 // values and hence helper functions are needed.
282 // The possibilities are (), (sf), (sf, sf), (sf, df), (df), (df, sf), (df, df)
283 // the helper function suffixs for these are:
284 //                        0,  1,    5,        9,         2,   6,        10
285 // this suffix can then be calculated as follows:
286 // for a given argument Arg:
287 //     Arg1x, Arg2x = 1 :  Arg is sf
288 //                    2 :  Arg is df
289 //                    0:   Arg is neither sf or df
290 // So this stub is the string for number Arg1x + Arg2x*4.
291 // However not all numbers between 0 and 10 are possible, we check anyway and
292 // assert if the impossible exists.
293 //
294 
295 unsigned int Mips16TargetLowering::getMips16HelperFunctionStubNumber
296   (ArgListTy &Args) const {
297   unsigned int resultNum = 0;
298   if (Args.size() >= 1) {
299     Type *t = Args[0].Ty;
300     if (t->isFloatTy()) {
301       resultNum = 1;
302     }
303     else if (t->isDoubleTy()) {
304       resultNum = 2;
305     }
306   }
307   if (resultNum) {
308     if (Args.size() >=2) {
309       Type *t = Args[1].Ty;
310       if (t->isFloatTy()) {
311         resultNum += 4;
312       }
313       else if (t->isDoubleTy()) {
314         resultNum += 8;
315       }
316     }
317   }
318   return resultNum;
319 }
320 
321 //
322 // Prefixes are attached to stub numbers depending on the return type.
323 // return type: float  sf_
324 //              double df_
325 //              single complex sc_
326 //              double complext dc_
327 //              others  NO PREFIX
328 //
329 //
330 // The full name of a helper function is__mips16_call_stub +
331 //    return type dependent prefix + stub number
332 //
333 // FIXME: This is something that probably should be in a different source file
334 // and perhaps done differently but my main purpose is to not waste runtime
335 // on something that we can enumerate in the source. Another possibility is
336 // to have a python script to generate these mapping tables. This will do
337 // for now. There are a whole series of helper function mapping arrays, one
338 // for each return type class as outlined above. There there are 11 possible
339 // entries. Ones with 0 are ones which should never be selected.
340 //
341 // All the arrays are similar except for ones which return neither
342 // sf, df, sc, dc, in which we only care about ones which have sf or df as a
343 // first parameter.
344 //
345 #define P_ "__mips16_call_stub_"
346 #define MAX_STUB_NUMBER 10
347 #define T1 P "1", P "2", 0, 0, P "5", P "6", 0, 0, P "9", P "10"
348 #define T P "0" , T1
349 #define P P_
350 static char const * vMips16Helper[MAX_STUB_NUMBER+1] =
351   {nullptr, T1 };
352 #undef P
353 #define P P_ "sf_"
354 static char const * sfMips16Helper[MAX_STUB_NUMBER+1] =
355   { T };
356 #undef P
357 #define P P_ "df_"
358 static char const * dfMips16Helper[MAX_STUB_NUMBER+1] =
359   { T };
360 #undef P
361 #define P P_ "sc_"
362 static char const * scMips16Helper[MAX_STUB_NUMBER+1] =
363   { T };
364 #undef P
365 #define P P_ "dc_"
366 static char const * dcMips16Helper[MAX_STUB_NUMBER+1] =
367   { T };
368 #undef P
369 #undef P_
370 
371 
372 const char* Mips16TargetLowering::
373   getMips16HelperFunction
374     (Type* RetTy, ArgListTy &Args, bool &needHelper) const {
375   const unsigned int stubNum = getMips16HelperFunctionStubNumber(Args);
376 #ifndef NDEBUG
377   const unsigned int maxStubNum = 10;
378   assert(stubNum <= maxStubNum);
379   const bool validStubNum[maxStubNum+1] =
380     {true, true, true, false, false, true, true, false, false, true, true};
381   assert(validStubNum[stubNum]);
382 #endif
383   const char *result;
384   if (RetTy->isFloatTy()) {
385     result = sfMips16Helper[stubNum];
386   }
387   else if (RetTy ->isDoubleTy()) {
388     result = dfMips16Helper[stubNum];
389   }
390   else if (RetTy->isStructTy()) {
391     // check if it's complex
392     if (RetTy->getNumContainedTypes() == 2) {
393       if ((RetTy->getContainedType(0)->isFloatTy()) &&
394           (RetTy->getContainedType(1)->isFloatTy())) {
395         result = scMips16Helper[stubNum];
396       }
397       else if ((RetTy->getContainedType(0)->isDoubleTy()) &&
398                (RetTy->getContainedType(1)->isDoubleTy())) {
399         result = dcMips16Helper[stubNum];
400       }
401       else {
402         llvm_unreachable("Uncovered condition");
403       }
404     }
405     else {
406       llvm_unreachable("Uncovered condition");
407     }
408   }
409   else {
410     if (stubNum == 0) {
411       needHelper = false;
412       return "";
413     }
414     result = vMips16Helper[stubNum];
415   }
416   needHelper = true;
417   return result;
418 }
419 
420 void Mips16TargetLowering::
421 getOpndList(SmallVectorImpl<SDValue> &Ops,
422             std::deque< std::pair<unsigned, SDValue> > &RegsToPass,
423             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
424             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
425             SDValue Chain) const {
426   SelectionDAG &DAG = CLI.DAG;
427   MachineFunction &MF = DAG.getMachineFunction();
428   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
429   const char* Mips16HelperFunction = nullptr;
430   bool NeedMips16Helper = false;
431 
432   if (Subtarget.inMips16HardFloat()) {
433     //
434     // currently we don't have symbols tagged with the mips16 or mips32
435     // qualifier so we will assume that we don't know what kind it is.
436     // and generate the helper
437     //
438     bool LookupHelper = true;
439     if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(CLI.Callee)) {
440       Mips16Libcall Find = { RTLIB::UNKNOWN_LIBCALL, S->getSymbol() };
441 
442       if (std::binary_search(std::begin(HardFloatLibCalls),
443                              std::end(HardFloatLibCalls), Find))
444         LookupHelper = false;
445       else {
446         const char *Symbol = S->getSymbol();
447         Mips16IntrinsicHelperType IntrinsicFind = { Symbol, "" };
448         const Mips16HardFloatInfo::FuncSignature *Signature =
449             Mips16HardFloatInfo::findFuncSignature(Symbol);
450         if (!IsPICCall && (Signature && (FuncInfo->StubsNeeded.find(Symbol) ==
451                                          FuncInfo->StubsNeeded.end()))) {
452           FuncInfo->StubsNeeded[Symbol] = Signature;
453           //
454           // S2 is normally saved if the stub is for a function which
455           // returns a float or double value and is not otherwise. This is
456           // because more work is required after the function the stub
457           // is calling completes, and so the stub cannot directly return
458           // and the stub has no stack space to store the return address so
459           // S2 is used for that purpose.
460           // In order to take advantage of not saving S2, we need to also
461           // optimize the call in the stub and this requires some further
462           // functionality in MipsAsmPrinter which we don't have yet.
463           // So for now we always save S2. The optimization will be done
464           // in a follow-on patch.
465           //
466           if (1 || (Signature->RetSig != Mips16HardFloatInfo::NoFPRet))
467             FuncInfo->setSaveS2();
468         }
469         // one more look at list of intrinsics
470         const Mips16IntrinsicHelperType *Helper =
471             std::lower_bound(std::begin(Mips16IntrinsicHelper),
472                              std::end(Mips16IntrinsicHelper), IntrinsicFind);
473         if (Helper != std::end(Mips16IntrinsicHelper) &&
474             *Helper == IntrinsicFind) {
475           Mips16HelperFunction = Helper->Helper;
476           NeedMips16Helper = true;
477           LookupHelper = false;
478         }
479 
480       }
481     } else if (GlobalAddressSDNode *G =
482                    dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
483       Mips16Libcall Find = { RTLIB::UNKNOWN_LIBCALL,
484                              G->getGlobal()->getName().data() };
485 
486       if (std::binary_search(std::begin(HardFloatLibCalls),
487                              std::end(HardFloatLibCalls), Find))
488         LookupHelper = false;
489     }
490     if (LookupHelper)
491       Mips16HelperFunction =
492         getMips16HelperFunction(CLI.RetTy, CLI.getArgs(), NeedMips16Helper);
493   }
494 
495   SDValue JumpTarget = Callee;
496 
497   // T9 should contain the address of the callee function if
498   // -relocation-model=pic or it is an indirect call.
499   if (IsPICCall || !GlobalOrExternal) {
500     unsigned V0Reg = Mips::V0;
501     if (NeedMips16Helper) {
502       RegsToPass.push_front(std::make_pair(V0Reg, Callee));
503       JumpTarget = DAG.getExternalSymbol(Mips16HelperFunction,
504                                          getPointerTy(DAG.getDataLayout()));
505       ExternalSymbolSDNode *S = cast<ExternalSymbolSDNode>(JumpTarget);
506       JumpTarget = getAddrGlobal(S, CLI.DL, JumpTarget.getValueType(), DAG,
507                                  MipsII::MO_GOT, Chain,
508                                  FuncInfo->callPtrInfo(S->getSymbol()));
509     } else
510       RegsToPass.push_front(std::make_pair((unsigned)Mips::T9, Callee));
511   }
512 
513   Ops.push_back(JumpTarget);
514 
515   MipsTargetLowering::getOpndList(Ops, RegsToPass, IsPICCall, GlobalOrExternal,
516                                   InternalLinkage, IsCallReloc, CLI, Callee,
517                                   Chain);
518 }
519 
520 MachineBasicBlock *Mips16TargetLowering::
521 emitSel16(unsigned Opc, MachineInstr *MI, MachineBasicBlock *BB) const {
522   if (DontExpandCondPseudos16)
523     return BB;
524   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
525   DebugLoc DL = MI->getDebugLoc();
526   // To "insert" a SELECT_CC instruction, we actually have to insert the
527   // diamond control-flow pattern.  The incoming instruction knows the
528   // destination vreg to set, the condition code register to branch on, the
529   // true/false values to select between, and a branch opcode to use.
530   const BasicBlock *LLVM_BB = BB->getBasicBlock();
531   MachineFunction::iterator It = ++BB->getIterator();
532 
533   //  thisMBB:
534   //  ...
535   //   TrueVal = ...
536   //   setcc r1, r2, r3
537   //   bNE   r1, r0, copy1MBB
538   //   fallthrough --> copy0MBB
539   MachineBasicBlock *thisMBB  = BB;
540   MachineFunction *F = BB->getParent();
541   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
542   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
543   F->insert(It, copy0MBB);
544   F->insert(It, sinkMBB);
545 
546   // Transfer the remainder of BB and its successor edges to sinkMBB.
547   sinkMBB->splice(sinkMBB->begin(), BB,
548                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
549   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
550 
551   // Next, add the true and fallthrough blocks as its successors.
552   BB->addSuccessor(copy0MBB);
553   BB->addSuccessor(sinkMBB);
554 
555   BuildMI(BB, DL, TII->get(Opc)).addReg(MI->getOperand(3).getReg())
556     .addMBB(sinkMBB);
557 
558   //  copy0MBB:
559   //   %FalseValue = ...
560   //   # fallthrough to sinkMBB
561   BB = copy0MBB;
562 
563   // Update machine-CFG edges
564   BB->addSuccessor(sinkMBB);
565 
566   //  sinkMBB:
567   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
568   //  ...
569   BB = sinkMBB;
570 
571   BuildMI(*BB, BB->begin(), DL,
572           TII->get(Mips::PHI), MI->getOperand(0).getReg())
573     .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB)
574     .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB);
575 
576   MI->eraseFromParent();   // The pseudo instruction is gone now.
577   return BB;
578 }
579 
580 MachineBasicBlock *
581 Mips16TargetLowering::emitSelT16(unsigned Opc1, unsigned Opc2, MachineInstr *MI,
582                                  MachineBasicBlock *BB) const {
583   if (DontExpandCondPseudos16)
584     return BB;
585   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
586   DebugLoc DL = MI->getDebugLoc();
587   // To "insert" a SELECT_CC instruction, we actually have to insert the
588   // diamond control-flow pattern.  The incoming instruction knows the
589   // destination vreg to set, the condition code register to branch on, the
590   // true/false values to select between, and a branch opcode to use.
591   const BasicBlock *LLVM_BB = BB->getBasicBlock();
592   MachineFunction::iterator It = ++BB->getIterator();
593 
594   //  thisMBB:
595   //  ...
596   //   TrueVal = ...
597   //   setcc r1, r2, r3
598   //   bNE   r1, r0, copy1MBB
599   //   fallthrough --> copy0MBB
600   MachineBasicBlock *thisMBB  = BB;
601   MachineFunction *F = BB->getParent();
602   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
603   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
604   F->insert(It, copy0MBB);
605   F->insert(It, sinkMBB);
606 
607   // Transfer the remainder of BB and its successor edges to sinkMBB.
608   sinkMBB->splice(sinkMBB->begin(), BB,
609                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
610   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
611 
612   // Next, add the true and fallthrough blocks as its successors.
613   BB->addSuccessor(copy0MBB);
614   BB->addSuccessor(sinkMBB);
615 
616   BuildMI(BB, DL, TII->get(Opc2)).addReg(MI->getOperand(3).getReg())
617     .addReg(MI->getOperand(4).getReg());
618   BuildMI(BB, DL, TII->get(Opc1)).addMBB(sinkMBB);
619 
620   //  copy0MBB:
621   //   %FalseValue = ...
622   //   # fallthrough to sinkMBB
623   BB = copy0MBB;
624 
625   // Update machine-CFG edges
626   BB->addSuccessor(sinkMBB);
627 
628   //  sinkMBB:
629   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
630   //  ...
631   BB = sinkMBB;
632 
633   BuildMI(*BB, BB->begin(), DL,
634           TII->get(Mips::PHI), MI->getOperand(0).getReg())
635     .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB)
636     .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB);
637 
638   MI->eraseFromParent();   // The pseudo instruction is gone now.
639   return BB;
640 
641 }
642 
643 MachineBasicBlock *
644 Mips16TargetLowering::emitSeliT16(unsigned Opc1, unsigned Opc2,
645                                   MachineInstr *MI,
646                                   MachineBasicBlock *BB) const {
647   if (DontExpandCondPseudos16)
648     return BB;
649   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
650   DebugLoc DL = MI->getDebugLoc();
651   // To "insert" a SELECT_CC instruction, we actually have to insert the
652   // diamond control-flow pattern.  The incoming instruction knows the
653   // destination vreg to set, the condition code register to branch on, the
654   // true/false values to select between, and a branch opcode to use.
655   const BasicBlock *LLVM_BB = BB->getBasicBlock();
656   MachineFunction::iterator It = ++BB->getIterator();
657 
658   //  thisMBB:
659   //  ...
660   //   TrueVal = ...
661   //   setcc r1, r2, r3
662   //   bNE   r1, r0, copy1MBB
663   //   fallthrough --> copy0MBB
664   MachineBasicBlock *thisMBB  = BB;
665   MachineFunction *F = BB->getParent();
666   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
667   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
668   F->insert(It, copy0MBB);
669   F->insert(It, sinkMBB);
670 
671   // Transfer the remainder of BB and its successor edges to sinkMBB.
672   sinkMBB->splice(sinkMBB->begin(), BB,
673                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
674   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
675 
676   // Next, add the true and fallthrough blocks as its successors.
677   BB->addSuccessor(copy0MBB);
678   BB->addSuccessor(sinkMBB);
679 
680   BuildMI(BB, DL, TII->get(Opc2)).addReg(MI->getOperand(3).getReg())
681     .addImm(MI->getOperand(4).getImm());
682   BuildMI(BB, DL, TII->get(Opc1)).addMBB(sinkMBB);
683 
684   //  copy0MBB:
685   //   %FalseValue = ...
686   //   # fallthrough to sinkMBB
687   BB = copy0MBB;
688 
689   // Update machine-CFG edges
690   BB->addSuccessor(sinkMBB);
691 
692   //  sinkMBB:
693   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
694   //  ...
695   BB = sinkMBB;
696 
697   BuildMI(*BB, BB->begin(), DL,
698           TII->get(Mips::PHI), MI->getOperand(0).getReg())
699     .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB)
700     .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB);
701 
702   MI->eraseFromParent();   // The pseudo instruction is gone now.
703   return BB;
704 
705 }
706 
707 MachineBasicBlock *
708 Mips16TargetLowering::emitFEXT_T8I816_ins(unsigned BtOpc, unsigned CmpOpc,
709                                           MachineInstr *MI,
710                                           MachineBasicBlock *BB) const {
711   if (DontExpandCondPseudos16)
712     return BB;
713   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
714   unsigned regX = MI->getOperand(0).getReg();
715   unsigned regY = MI->getOperand(1).getReg();
716   MachineBasicBlock *target = MI->getOperand(2).getMBB();
717   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(CmpOpc)).addReg(regX)
718     .addReg(regY);
719   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(BtOpc)).addMBB(target);
720   MI->eraseFromParent();   // The pseudo instruction is gone now.
721   return BB;
722 }
723 
724 MachineBasicBlock *Mips16TargetLowering::emitFEXT_T8I8I16_ins(
725     unsigned BtOpc, unsigned CmpiOpc, unsigned CmpiXOpc, bool ImmSigned,
726     MachineInstr *MI, MachineBasicBlock *BB) const {
727   if (DontExpandCondPseudos16)
728     return BB;
729   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
730   unsigned regX = MI->getOperand(0).getReg();
731   int64_t imm = MI->getOperand(1).getImm();
732   MachineBasicBlock *target = MI->getOperand(2).getMBB();
733   unsigned CmpOpc;
734   if (isUInt<8>(imm))
735     CmpOpc = CmpiOpc;
736   else if ((!ImmSigned && isUInt<16>(imm)) ||
737            (ImmSigned && isInt<16>(imm)))
738     CmpOpc = CmpiXOpc;
739   else
740     llvm_unreachable("immediate field not usable");
741   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(CmpOpc)).addReg(regX)
742     .addImm(imm);
743   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(BtOpc)).addMBB(target);
744   MI->eraseFromParent();   // The pseudo instruction is gone now.
745   return BB;
746 }
747 
748 static unsigned Mips16WhichOp8uOr16simm
749   (unsigned shortOp, unsigned longOp, int64_t Imm) {
750   if (isUInt<8>(Imm))
751     return shortOp;
752   else if (isInt<16>(Imm))
753     return longOp;
754   else
755     llvm_unreachable("immediate field not usable");
756 }
757 
758 MachineBasicBlock *
759 Mips16TargetLowering::emitFEXT_CCRX16_ins(unsigned SltOpc, MachineInstr *MI,
760                                           MachineBasicBlock *BB) const {
761   if (DontExpandCondPseudos16)
762     return BB;
763   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
764   unsigned CC = MI->getOperand(0).getReg();
765   unsigned regX = MI->getOperand(1).getReg();
766   unsigned regY = MI->getOperand(2).getReg();
767   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(SltOpc)).addReg(regX).addReg(
768       regY);
769   BuildMI(*BB, MI, MI->getDebugLoc(),
770           TII->get(Mips::MoveR3216), CC).addReg(Mips::T8);
771   MI->eraseFromParent();   // The pseudo instruction is gone now.
772   return BB;
773 }
774 
775 MachineBasicBlock *
776 Mips16TargetLowering::emitFEXT_CCRXI16_ins(unsigned SltiOpc, unsigned SltiXOpc,
777                                            MachineInstr *MI,
778                                            MachineBasicBlock *BB) const {
779   if (DontExpandCondPseudos16)
780     return BB;
781   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
782   unsigned CC = MI->getOperand(0).getReg();
783   unsigned regX = MI->getOperand(1).getReg();
784   int64_t Imm = MI->getOperand(2).getImm();
785   unsigned SltOpc = Mips16WhichOp8uOr16simm(SltiOpc, SltiXOpc, Imm);
786   BuildMI(*BB, MI, MI->getDebugLoc(),
787           TII->get(SltOpc)).addReg(regX).addImm(Imm);
788   BuildMI(*BB, MI, MI->getDebugLoc(),
789           TII->get(Mips::MoveR3216), CC).addReg(Mips::T8);
790   MI->eraseFromParent();   // The pseudo instruction is gone now.
791   return BB;
792 
793 }
794