1 //===-- PPCTargetMachine.cpp - Define TargetMachine for PowerPC -----------===//
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 // Top-level implementation for the PowerPC target.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "PPC.h"
15 #include "PPCMCAsmInfo.h"
16 #include "PPCTargetMachine.h"
17 #include "llvm/PassManager.h"
18 #include "llvm/Target/TargetOptions.h"
19 #include "llvm/Target/TargetRegistry.h"
20 #include "llvm/Support/FormattedStream.h"
21 using namespace llvm;
22 
23 static const MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
24   Triple TheTriple(TT);
25   bool isPPC64 = TheTriple.getArch() == Triple::ppc64;
26   if (TheTriple.getOS() == Triple::Darwin)
27     return new PPCMCAsmInfoDarwin(isPPC64);
28   return new PPCLinuxMCAsmInfo(isPPC64);
29 
30 }
31 
32 extern "C" void LLVMInitializePowerPCTarget() {
33   // Register the targets
34   RegisterTargetMachine<PPC32TargetMachine> A(ThePPC32Target);
35   RegisterTargetMachine<PPC64TargetMachine> B(ThePPC64Target);
36 
37   RegisterAsmInfoFn C(ThePPC32Target, createMCAsmInfo);
38   RegisterAsmInfoFn D(ThePPC64Target, createMCAsmInfo);
39 }
40 
41 
42 PPCTargetMachine::PPCTargetMachine(const Target &T, const std::string &TT,
43                                    const std::string &FS, bool is64Bit)
44   : LLVMTargetMachine(T, TT),
45     Subtarget(TT, FS, is64Bit),
46     DataLayout(Subtarget.getTargetDataString()), InstrInfo(*this),
47     FrameInfo(*this, is64Bit), JITInfo(*this, is64Bit), TLInfo(*this),
48     InstrItins(Subtarget.getInstrItineraryData()) {
49 
50   if (getRelocationModel() == Reloc::Default) {
51     if (Subtarget.isDarwin())
52       setRelocationModel(Reloc::DynamicNoPIC);
53     else
54       setRelocationModel(Reloc::Static);
55   }
56 }
57 
58 /// Override this for PowerPC.  Tail merging happily breaks up instruction issue
59 /// groups, which typically degrades performance.
60 bool PPCTargetMachine::getEnableTailMergeDefault() const { return false; }
61 
62 PPC32TargetMachine::PPC32TargetMachine(const Target &T, const std::string &TT,
63                                        const std::string &FS)
64   : PPCTargetMachine(T, TT, FS, false) {
65 }
66 
67 
68 PPC64TargetMachine::PPC64TargetMachine(const Target &T, const std::string &TT,
69                                        const std::string &FS)
70   : PPCTargetMachine(T, TT, FS, true) {
71 }
72 
73 
74 //===----------------------------------------------------------------------===//
75 // Pass Pipeline Configuration
76 //===----------------------------------------------------------------------===//
77 
78 bool PPCTargetMachine::addInstSelector(PassManagerBase &PM,
79                                        CodeGenOpt::Level OptLevel) {
80   // Install an instruction selector.
81   PM.add(createPPCISelDag(*this));
82   return false;
83 }
84 
85 bool PPCTargetMachine::addPreEmitPass(PassManagerBase &PM,
86                                       CodeGenOpt::Level OptLevel) {
87   // Must run branch selection immediately preceding the asm printer.
88   PM.add(createPPCBranchSelectionPass());
89   return false;
90 }
91 
92 bool PPCTargetMachine::addCodeEmitter(PassManagerBase &PM,
93                                       CodeGenOpt::Level OptLevel,
94                                       JITCodeEmitter &JCE) {
95   // The JIT should use the static relocation model in ppc32 mode, PIC in ppc64.
96   // FIXME: This should be moved to TargetJITInfo!!
97   if (Subtarget.isPPC64()) {
98     // We use PIC codegen in ppc64 mode, because otherwise we'd have to use many
99     // instructions to materialize arbitrary global variable + function +
100     // constant pool addresses.
101     setRelocationModel(Reloc::PIC_);
102     // Temporary workaround for the inability of PPC64 JIT to handle jump
103     // tables.
104     DisableJumpTables = true;
105   } else {
106     setRelocationModel(Reloc::Static);
107   }
108 
109   // Inform the subtarget that we are in JIT mode.  FIXME: does this break macho
110   // writing?
111   Subtarget.SetJITMode();
112 
113   // Machine code emitter pass for PowerPC.
114   PM.add(createPPCJITCodeEmitterPass(*this, JCE));
115 
116   return false;
117 }
118