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author | Pirama Arumuga Nainar <pirama@google.com> | 2016-03-03 15:48:50 -0800 |
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committer | Pirama Arumuga Nainar <pirama@google.com> | 2016-03-03 16:08:14 -0800 |
commit | f3ef5332fa3f4d5ec72c178a2b19dac363a19383 (patch) | |
tree | b335b029f55ecd8145638c9d723e3680f098d516 /lib/Target/WebAssembly/WebAssemblyPeephole.cpp | |
parent | 4310bcf018d080c679c61f59d2db434ccf06a412 (diff) | |
download | llvm-f3ef5332fa3f4d5ec72c178a2b19dac363a19383.tar.gz |
Update aosp/master LLVM for rebase to r256229
http://b/26987366
Change-Id: I1f29c4676a8abe633ab5707dded58d846c973d50
Diffstat (limited to 'lib/Target/WebAssembly/WebAssemblyPeephole.cpp')
-rw-r--r-- | lib/Target/WebAssembly/WebAssemblyPeephole.cpp | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/lib/Target/WebAssembly/WebAssemblyPeephole.cpp b/lib/Target/WebAssembly/WebAssemblyPeephole.cpp new file mode 100644 index 000000000000..4ad6eed7385b --- /dev/null +++ b/lib/Target/WebAssembly/WebAssemblyPeephole.cpp @@ -0,0 +1,86 @@ +//===-- WebAssemblyPeephole.cpp - WebAssembly Peephole Optimiztions -------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// \brief Late peephole optimizations for WebAssembly. +/// +//===----------------------------------------------------------------------===// + +#include "WebAssembly.h" +#include "MCTargetDesc/WebAssemblyMCTargetDesc.h" +#include "WebAssemblyMachineFunctionInfo.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +using namespace llvm; + +#define DEBUG_TYPE "wasm-peephole" + +namespace { +class WebAssemblyPeephole final : public MachineFunctionPass { + const char *getPassName() const override { + return "WebAssembly late peephole optimizer"; + } + + void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.setPreservesCFG(); + MachineFunctionPass::getAnalysisUsage(AU); + } + + bool runOnMachineFunction(MachineFunction &MF) override; + +public: + static char ID; + WebAssemblyPeephole() : MachineFunctionPass(ID) {} +}; +} // end anonymous namespace + +char WebAssemblyPeephole::ID = 0; +FunctionPass *llvm::createWebAssemblyPeephole() { + return new WebAssemblyPeephole(); +} + +bool WebAssemblyPeephole::runOnMachineFunction(MachineFunction &MF) { + bool Changed = false; + + MachineRegisterInfo &MRI = MF.getRegInfo(); + WebAssemblyFunctionInfo &MFI = *MF.getInfo<WebAssemblyFunctionInfo>(); + + for (auto &MBB : MF) + for (auto &MI : MBB) + switch (MI.getOpcode()) { + default: + break; + case WebAssembly::STORE8_I32: + case WebAssembly::STORE16_I32: + case WebAssembly::STORE8_I64: + case WebAssembly::STORE16_I64: + case WebAssembly::STORE32_I64: + case WebAssembly::STORE_F32: + case WebAssembly::STORE_F64: + case WebAssembly::STORE_I32: + case WebAssembly::STORE_I64: { + // Store instructions return their value operand. If we ended up using + // the same register for both, replace it with a dead def so that it + // can use $discard instead. + MachineOperand &MO = MI.getOperand(0); + unsigned OldReg = MO.getReg(); + // TODO: Handle SP/physregs + if (OldReg == MI.getOperand(3).getReg() + && TargetRegisterInfo::isVirtualRegister(MI.getOperand(3).getReg())) { + Changed = true; + unsigned NewReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg)); + MO.setReg(NewReg); + MO.setIsDead(); + MFI.stackifyVReg(NewReg); + MFI.addWAReg(NewReg, WebAssemblyFunctionInfo::UnusedReg); + } + } + } + + return Changed; +} |