1 //===-- AArch64TargetMachine.cpp - Define TargetMachine for AArch64 -------===//
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 //===----------------------------------------------------------------------===//
11 //===----------------------------------------------------------------------===//
14 #include "AArch64TargetMachine.h"
15 #include "llvm/PassManager.h"
16 #include "llvm/CodeGen/Passes.h"
17 #include "llvm/Support/CommandLine.h"
18 #include "llvm/Support/TargetRegistry.h"
19 #include "llvm/Target/TargetOptions.h"
20 #include "llvm/Transforms/Scalar.h"
24 EnableCCMP("aarch64-ccmp", cl::desc("Enable the CCMP formation pass"),
25 cl::init(true), cl::Hidden);
28 EnableStPairSuppress("aarch64-stp-suppress", cl::desc("Suppress STP for AArch64"),
29 cl::init(true), cl::Hidden);
32 EnableAdvSIMDScalar("aarch64-simd-scalar", cl::desc("Enable use of AdvSIMD scalar"
33 " integer instructions"), cl::init(false), cl::Hidden);
36 EnablePromoteConstant("aarch64-promote-const", cl::desc("Enable the promote "
37 "constant pass"), cl::init(true), cl::Hidden);
40 EnableCollectLOH("aarch64-collect-loh", cl::desc("Enable the pass that emits the"
41 " linker optimization hints (LOH)"), cl::init(true),
45 EnableDeadRegisterElimination("aarch64-dead-def-elimination", cl::Hidden,
46 cl::desc("Enable the pass that removes dead"
47 " definitons and replaces stores to"
48 " them with stores to the zero"
53 EnableLoadStoreOpt("aarch64-load-store-opt", cl::desc("Enable the load/store pair"
54 " optimization pass"), cl::init(true), cl::Hidden);
57 EnableAtomicTidy("aarch64-atomic-cfg-tidy", cl::Hidden,
58 cl::desc("Run SimplifyCFG after expanding atomic operations"
59 " to make use of cmpxchg flow-based information"),
62 extern "C" void LLVMInitializeAArch64Target() {
63 // Register the target.
64 RegisterTargetMachine<AArch64leTargetMachine> X(TheAArch64leTarget);
65 RegisterTargetMachine<AArch64beTargetMachine> Y(TheAArch64beTarget);
67 RegisterTargetMachine<AArch64leTargetMachine> Z(TheARM64leTarget);
68 RegisterTargetMachine<AArch64beTargetMachine> W(TheARM64beTarget);
71 /// TargetMachine ctor - Create an AArch64 architecture model.
73 AArch64TargetMachine::AArch64TargetMachine(const Target &T, StringRef TT,
74 StringRef CPU, StringRef FS,
75 const TargetOptions &Options,
76 Reloc::Model RM, CodeModel::Model CM,
79 : LLVMTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL),
80 Subtarget(TT, CPU, FS, LittleEndian),
81 // This nested ternary is horrible, but DL needs to be properly
83 // before TLInfo is constructed.
84 DL(Subtarget.isTargetMachO()
85 ? "e-m:o-i64:64-i128:128-n32:64-S128"
86 : (LittleEndian ? "e-m:e-i64:64-i128:128-n32:64-S128"
87 : "E-m:e-i64:64-i128:128-n32:64-S128")),
88 InstrInfo(Subtarget), TLInfo(*this), FrameLowering(*this, Subtarget),
93 void AArch64leTargetMachine::anchor() { }
95 AArch64leTargetMachine::
96 AArch64leTargetMachine(const Target &T, StringRef TT,
97 StringRef CPU, StringRef FS, const TargetOptions &Options,
98 Reloc::Model RM, CodeModel::Model CM,
100 : AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, true) {}
102 void AArch64beTargetMachine::anchor() { }
104 AArch64beTargetMachine::
105 AArch64beTargetMachine(const Target &T, StringRef TT,
106 StringRef CPU, StringRef FS, const TargetOptions &Options,
107 Reloc::Model RM, CodeModel::Model CM,
108 CodeGenOpt::Level OL)
109 : AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, false) {}
112 /// AArch64 Code Generator Pass Configuration Options.
113 class AArch64PassConfig : public TargetPassConfig {
115 AArch64PassConfig(AArch64TargetMachine *TM, PassManagerBase &PM)
116 : TargetPassConfig(TM, PM) {}
118 AArch64TargetMachine &getAArch64TargetMachine() const {
119 return getTM<AArch64TargetMachine>();
122 void addIRPasses() override;
123 bool addPreISel() override;
124 bool addInstSelector() override;
125 bool addILPOpts() override;
126 bool addPreRegAlloc() override;
127 bool addPostRegAlloc() override;
128 bool addPreSched2() override;
129 bool addPreEmitPass() override;
133 void AArch64TargetMachine::addAnalysisPasses(PassManagerBase &PM) {
134 // Add first the target-independent BasicTTI pass, then our AArch64 pass. This
135 // allows the AArch64 pass to delegate to the target independent layer when
137 PM.add(createBasicTargetTransformInfoPass(this));
138 PM.add(createAArch64TargetTransformInfoPass(this));
141 TargetPassConfig *AArch64TargetMachine::createPassConfig(PassManagerBase &PM) {
142 return new AArch64PassConfig(this, PM);
145 void AArch64PassConfig::addIRPasses() {
146 // Always expand atomic operations, we don't deal with atomicrmw or cmpxchg
148 addPass(createAtomicExpandLoadLinkedPass(TM));
150 // Cmpxchg instructions are often used with a subsequent comparison to
151 // determine whether it succeeded. We can exploit existing control-flow in
152 // ldrex/strex loops to simplify this, but it needs tidying up.
153 if (TM->getOptLevel() != CodeGenOpt::None && EnableAtomicTidy)
154 addPass(createCFGSimplificationPass());
156 TargetPassConfig::addIRPasses();
159 // Pass Pipeline Configuration
160 bool AArch64PassConfig::addPreISel() {
161 // Run promote constant before global merge, so that the promoted constants
162 // get a chance to be merged
163 if (TM->getOptLevel() != CodeGenOpt::None && EnablePromoteConstant)
164 addPass(createAArch64PromoteConstantPass());
165 if (TM->getOptLevel() != CodeGenOpt::None)
166 addPass(createGlobalMergePass(TM));
167 if (TM->getOptLevel() != CodeGenOpt::None)
168 addPass(createAArch64AddressTypePromotionPass());
173 bool AArch64PassConfig::addInstSelector() {
174 addPass(createAArch64ISelDag(getAArch64TargetMachine(), getOptLevel()));
176 // For ELF, cleanup any local-dynamic TLS accesses (i.e. combine as many
177 // references to _TLS_MODULE_BASE_ as possible.
178 if (TM->getSubtarget<AArch64Subtarget>().isTargetELF() &&
179 getOptLevel() != CodeGenOpt::None)
180 addPass(createAArch64CleanupLocalDynamicTLSPass());
185 bool AArch64PassConfig::addILPOpts() {
187 addPass(createAArch64ConditionalCompares());
188 addPass(&EarlyIfConverterID);
189 if (EnableStPairSuppress)
190 addPass(createAArch64StorePairSuppressPass());
194 bool AArch64PassConfig::addPreRegAlloc() {
195 // Use AdvSIMD scalar instructions whenever profitable.
196 if (TM->getOptLevel() != CodeGenOpt::None && EnableAdvSIMDScalar)
197 addPass(createAArch64AdvSIMDScalar());
201 bool AArch64PassConfig::addPostRegAlloc() {
202 // Change dead register definitions to refer to the zero register.
203 if (TM->getOptLevel() != CodeGenOpt::None && EnableDeadRegisterElimination)
204 addPass(createAArch64DeadRegisterDefinitions());
208 bool AArch64PassConfig::addPreSched2() {
209 // Expand some pseudo instructions to allow proper scheduling.
210 addPass(createAArch64ExpandPseudoPass());
211 // Use load/store pair instructions when possible.
212 if (TM->getOptLevel() != CodeGenOpt::None && EnableLoadStoreOpt)
213 addPass(createAArch64LoadStoreOptimizationPass());
217 bool AArch64PassConfig::addPreEmitPass() {
218 // Relax conditional branch instructions if they're otherwise out of
219 // range of their destination.
220 addPass(createAArch64BranchRelaxation());
221 if (TM->getOptLevel() != CodeGenOpt::None && EnableCollectLOH &&
222 TM->getSubtarget<AArch64Subtarget>().isTargetMachO())
223 addPass(createAArch64CollectLOHPass());