1 //===-- MipsTargetMachine.cpp - Define TargetMachine for Mips -------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implements the info about Mips target spec.
12 //===----------------------------------------------------------------------===//
14 #include "MipsTargetMachine.h"
16 #include "Mips16FrameLowering.h"
17 #include "Mips16ISelDAGToDAG.h"
18 #include "Mips16ISelLowering.h"
19 #include "Mips16InstrInfo.h"
20 #include "MipsFrameLowering.h"
21 #include "MipsInstrInfo.h"
22 #include "MipsSEFrameLowering.h"
23 #include "MipsSEISelDAGToDAG.h"
24 #include "MipsSEISelLowering.h"
25 #include "MipsSEInstrInfo.h"
26 #include "MipsTargetObjectFile.h"
27 #include "MCTargetDesc/MipsMCAsmInfo.h"
28 #include "llvm/Analysis/TargetTransformInfo.h"
29 #include "llvm/CodeGen/Passes.h"
30 #include "llvm/IR/LegacyPassManager.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/TargetRegistry.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/Transforms/Scalar.h"
38 #define DEBUG_TYPE "mips"
40 extern "C" void LLVMInitializeMipsTarget() {
41 // Register the target.
42 RegisterTargetMachine<MipsebTargetMachine> X(TheMipsTarget);
43 RegisterTargetMachine<MipselTargetMachine> Y(TheMipselTarget);
44 RegisterTargetMachine<MipsebTargetMachine> A(TheMips64Target);
45 RegisterTargetMachine<MipselTargetMachine> B(TheMips64elTarget);
48 static std::string computeDataLayout(StringRef TT, StringRef CPU,
49 const TargetOptions &Options,
53 MipsABIInfo::computeTargetABI(Triple(TT), CPU, Options.MCOptions);
55 // There are both little and big endian mips.
63 // Pointers are 32 bit on some ABIs.
67 // 8 and 16 bit integers only need no have natural alignment, but try to
68 // align them to 32 bits. 64 bit integers have natural alignment.
69 Ret += "-i8:8:32-i16:16:32-i64:64";
71 // 32 bit registers are always available and the stack is at least 64 bit
72 // aligned. On N64 64 bit registers are also available and the stack is
74 if (ABI.IsN64() || ABI.IsN32())
75 Ret += "-n32:64-S128";
82 // On function prologue, the stack is created by decrementing
83 // its pointer. Once decremented, all references are done with positive
84 // offset from the stack/frame pointer, using StackGrowsUp enables
85 // an easier handling.
86 // Using CodeModel::Large enables different CALL behavior.
87 MipsTargetMachine::MipsTargetMachine(const Target &T, StringRef TT,
88 StringRef CPU, StringRef FS,
89 const TargetOptions &Options,
90 Reloc::Model RM, CodeModel::Model CM,
91 CodeGenOpt::Level OL, bool isLittle)
92 : LLVMTargetMachine(T, computeDataLayout(TT, CPU, Options, isLittle), TT,
93 CPU, FS, Options, RM, CM, OL),
94 isLittle(isLittle), TLOF(make_unique<MipsTargetObjectFile>()),
95 ABI(MipsABIInfo::computeTargetABI(Triple(TT), CPU, Options.MCOptions)),
96 Subtarget(nullptr), DefaultSubtarget(TT, CPU, FS, isLittle, *this),
97 NoMips16Subtarget(TT, CPU, FS.empty() ? "-mips16" : FS.str() + ",-mips16",
99 Mips16Subtarget(TT, CPU, FS.empty() ? "+mips16" : FS.str() + ",+mips16",
101 Subtarget = &DefaultSubtarget;
105 MipsTargetMachine::~MipsTargetMachine() {}
107 void MipsebTargetMachine::anchor() { }
109 MipsebTargetMachine::
110 MipsebTargetMachine(const Target &T, StringRef TT,
111 StringRef CPU, StringRef FS, const TargetOptions &Options,
112 Reloc::Model RM, CodeModel::Model CM,
113 CodeGenOpt::Level OL)
114 : MipsTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, false) {}
116 void MipselTargetMachine::anchor() { }
118 MipselTargetMachine::
119 MipselTargetMachine(const Target &T, StringRef TT,
120 StringRef CPU, StringRef FS, const TargetOptions &Options,
121 Reloc::Model RM, CodeModel::Model CM,
122 CodeGenOpt::Level OL)
123 : MipsTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, true) {}
125 const MipsSubtarget *
126 MipsTargetMachine::getSubtargetImpl(const Function &F) const {
127 Attribute CPUAttr = F.getFnAttribute("target-cpu");
128 Attribute FSAttr = F.getFnAttribute("target-features");
130 std::string CPU = !CPUAttr.hasAttribute(Attribute::None)
131 ? CPUAttr.getValueAsString().str()
133 std::string FS = !FSAttr.hasAttribute(Attribute::None)
134 ? FSAttr.getValueAsString().str()
137 !F.getFnAttribute("mips16").hasAttribute(Attribute::None);
138 bool hasNoMips16Attr =
139 !F.getFnAttribute("nomips16").hasAttribute(Attribute::None);
141 // FIXME: This is related to the code below to reset the target options,
142 // we need to know whether or not the soft float flag is set on the
143 // function, so we can enable it as a subtarget feature.
145 F.hasFnAttribute("use-soft-float") &&
146 F.getFnAttribute("use-soft-float").getValueAsString() == "true";
149 FS += FS.empty() ? "+mips16" : ",+mips16";
150 else if (hasNoMips16Attr)
151 FS += FS.empty() ? "-mips16" : ",-mips16";
153 FS += FS.empty() ? "+soft-float" : ",+soft-float";
155 auto &I = SubtargetMap[CPU + FS];
157 // This needs to be done before we create a new subtarget since any
158 // creation will depend on the TM and the code generation flags on the
159 // function that reside in TargetOptions.
160 resetTargetOptions(F);
161 I = llvm::make_unique<MipsSubtarget>(TargetTriple, CPU, FS, isLittle, *this);
166 void MipsTargetMachine::resetSubtarget(MachineFunction *MF) {
167 DEBUG(dbgs() << "resetSubtarget\n");
169 Subtarget = const_cast<MipsSubtarget *>(getSubtargetImpl(*MF->getFunction()));
170 MF->setSubtarget(Subtarget);
175 /// Mips Code Generator Pass Configuration Options.
176 class MipsPassConfig : public TargetPassConfig {
178 MipsPassConfig(MipsTargetMachine *TM, PassManagerBase &PM)
179 : TargetPassConfig(TM, PM) {
180 // The current implementation of long branch pass requires a scratch
181 // register ($at) to be available before branch instructions. Tail merging
182 // can break this requirement, so disable it when long branch pass is
184 EnableTailMerge = !getMipsSubtarget().enableLongBranchPass();
187 MipsTargetMachine &getMipsTargetMachine() const {
188 return getTM<MipsTargetMachine>();
191 const MipsSubtarget &getMipsSubtarget() const {
192 return *getMipsTargetMachine().getSubtargetImpl();
195 void addIRPasses() override;
196 bool addInstSelector() override;
197 void addMachineSSAOptimization() override;
198 void addPreEmitPass() override;
200 void addPreRegAlloc() override;
205 TargetPassConfig *MipsTargetMachine::createPassConfig(PassManagerBase &PM) {
206 return new MipsPassConfig(this, PM);
209 void MipsPassConfig::addIRPasses() {
210 TargetPassConfig::addIRPasses();
211 addPass(createAtomicExpandPass(&getMipsTargetMachine()));
212 if (getMipsSubtarget().os16())
213 addPass(createMipsOs16Pass(getMipsTargetMachine()));
214 if (getMipsSubtarget().inMips16HardFloat())
215 addPass(createMips16HardFloatPass(getMipsTargetMachine()));
217 // Install an instruction selector pass using
218 // the ISelDag to gen Mips code.
219 bool MipsPassConfig::addInstSelector() {
220 addPass(createMipsModuleISelDagPass(getMipsTargetMachine()));
221 addPass(createMips16ISelDag(getMipsTargetMachine()));
222 addPass(createMipsSEISelDag(getMipsTargetMachine()));
226 void MipsPassConfig::addMachineSSAOptimization() {
227 addPass(createMipsOptimizePICCallPass(getMipsTargetMachine()));
228 TargetPassConfig::addMachineSSAOptimization();
231 void MipsPassConfig::addPreRegAlloc() {
232 if (getOptLevel() == CodeGenOpt::None)
233 addPass(createMipsOptimizePICCallPass(getMipsTargetMachine()));
236 TargetIRAnalysis MipsTargetMachine::getTargetIRAnalysis() {
237 return TargetIRAnalysis([this](Function &F) {
238 if (Subtarget->allowMixed16_32()) {
239 DEBUG(errs() << "No Target Transform Info Pass Added\n");
240 // FIXME: This is no longer necessary as the TTI returned is per-function.
241 return TargetTransformInfo(getDataLayout());
244 DEBUG(errs() << "Target Transform Info Pass Added\n");
245 return TargetTransformInfo(BasicTTIImpl(this, F));
249 // Implemented by targets that want to run passes immediately before
250 // machine code is emitted. return true if -print-machineinstrs should
251 // print out the code after the passes.
252 void MipsPassConfig::addPreEmitPass() {
253 MipsTargetMachine &TM = getMipsTargetMachine();
254 addPass(createMipsDelaySlotFillerPass(TM));
255 addPass(createMipsLongBranchPass(TM));
256 addPass(createMipsConstantIslandPass(TM));