forked from OSchip/llvm-project
105 lines
4.0 KiB
C++
105 lines
4.0 KiB
C++
//===-- 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;
|
|
bool addPreSched2() override;
|
|
bool addPreEmitPass() override;
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
void SystemZPassConfig::addIRPasses() {
|
|
TargetPassConfig::addIRPasses();
|
|
}
|
|
|
|
bool SystemZPassConfig::addInstSelector() {
|
|
addPass(createSystemZISelDag(getSystemZTargetMachine(), getOptLevel()));
|
|
return false;
|
|
}
|
|
|
|
bool SystemZPassConfig::addPreSched2() {
|
|
if (getOptLevel() != CodeGenOpt::None &&
|
|
getSystemZTargetMachine().getSubtargetImpl()->hasLoadStoreOnCond())
|
|
addPass(&IfConverterID);
|
|
return true;
|
|
}
|
|
|
|
bool 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()));
|
|
if (getOptLevel() != CodeGenOpt::None)
|
|
addPass(createSystemZShortenInstPass(getSystemZTargetMachine()));
|
|
addPass(createSystemZLongBranchPass(getSystemZTargetMachine()));
|
|
return true;
|
|
}
|
|
|
|
TargetPassConfig *SystemZTargetMachine::createPassConfig(PassManagerBase &PM) {
|
|
return new SystemZPassConfig(this, PM);
|
|
}
|