diff options
Diffstat (limited to 'contrib/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp b/contrib/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp new file mode 100644 index 0000000..a210074 --- /dev/null +++ b/contrib/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp @@ -0,0 +1,102 @@ +//===-- SystemZTargetMachine.cpp - Define TargetMachine for SystemZ -------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "SystemZTargetMachine.h" +#include "llvm/CodeGen/Passes.h" +#include "llvm/Support/TargetRegistry.h" +#include "llvm/Transforms/Scalar.h" +#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h" + +using namespace llvm; + +extern "C" void LLVMInitializeSystemZTarget() { + // Register the target. + RegisterTargetMachine<SystemZTargetMachine> X(TheSystemZTarget); +} + +SystemZTargetMachine::SystemZTargetMachine(const Target &T, StringRef TT, + StringRef CPU, StringRef FS, + const TargetOptions &Options, + Reloc::Model RM, CodeModel::Model CM, + CodeGenOpt::Level OL) + : LLVMTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL), + TLOF(make_unique<TargetLoweringObjectFileELF>()), + Subtarget(TT, CPU, FS, *this) { + initAsmInfo(); +} + +SystemZTargetMachine::~SystemZTargetMachine() {} + +namespace { +/// SystemZ Code Generator Pass Configuration Options. +class SystemZPassConfig : public TargetPassConfig { +public: + SystemZPassConfig(SystemZTargetMachine *TM, PassManagerBase &PM) + : TargetPassConfig(TM, PM) {} + + SystemZTargetMachine &getSystemZTargetMachine() const { + return getTM<SystemZTargetMachine>(); + } + + void addIRPasses() override; + bool addInstSelector() override; + void addPreSched2() override; + void addPreEmitPass() override; +}; +} // end anonymous namespace + +void SystemZPassConfig::addIRPasses() { + TargetPassConfig::addIRPasses(); +} + +bool SystemZPassConfig::addInstSelector() { + addPass(createSystemZISelDag(getSystemZTargetMachine(), getOptLevel())); + return false; +} + +void SystemZPassConfig::addPreSched2() { + if (getOptLevel() != CodeGenOpt::None && + getSystemZTargetMachine().getSubtargetImpl()->hasLoadStoreOnCond()) + addPass(&IfConverterID); +} + +void SystemZPassConfig::addPreEmitPass() { + // We eliminate comparisons here rather than earlier because some + // transformations can change the set of available CC values and we + // generally want those transformations to have priority. This is + // especially true in the commonest case where the result of the comparison + // is used by a single in-range branch instruction, since we will then + // be able to fuse the compare and the branch instead. + // + // For example, two-address NILF can sometimes be converted into + // three-address RISBLG. NILF produces a CC value that indicates whether + // the low word is zero, but RISBLG does not modify CC at all. On the + // other hand, 64-bit ANDs like NILL can sometimes be converted to RISBG. + // The CC value produced by NILL isn't useful for our purposes, but the + // value produced by RISBG can be used for any comparison with zero + // (not just equality). So there are some transformations that lose + // CC values (while still being worthwhile) and others that happen to make + // the CC result more useful than it was originally. + // + // Another reason is that we only want to use BRANCH ON COUNT in cases + // where we know that the count register is not going to be spilled. + // + // Doing it so late makes it more likely that a register will be reused + // between the comparison and the branch, but it isn't clear whether + // preventing that would be a win or not. + if (getOptLevel() != CodeGenOpt::None) + addPass(createSystemZElimComparePass(getSystemZTargetMachine()), false); + if (getOptLevel() != CodeGenOpt::None) + addPass(createSystemZShortenInstPass(getSystemZTargetMachine()), false); + addPass(createSystemZLongBranchPass(getSystemZTargetMachine())); +} + +TargetPassConfig *SystemZTargetMachine::createPassConfig(PassManagerBase &PM) { + return new SystemZPassConfig(this, PM); +} |