4e1f5e0734
Revision 320791 introduced a pass that transforms reg+reg instructions to reg+imm if they're fed by "load immediate". However, it didn't handle out-of-range shifts correctly as reported in PR35688. This patch fixes that and therefore the PR. Furthermore, there was undefined behaviour in the patch where the RHS of an initialization expression was 32 bits and constant `1` was shifted left 32 bits. This was fixed by ensuring the RHS is 64 bits just like the LHS. Differential Revision: https://reviews.llvm.org/D41369 llvm-svn: 321551
96 lines
3.1 KiB
C++
96 lines
3.1 KiB
C++
//===--------- PPCPreEmitPeephole.cpp - Late peephole optimizations -------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// A pre-emit peephole for catching opportunities introduced by late passes such
|
|
// as MachineBlockPlacement.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "PPC.h"
|
|
#include "PPCInstrInfo.h"
|
|
#include "PPCSubtarget.h"
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/Statistic.h"
|
|
#include "llvm/CodeGen/LivePhysRegs.h"
|
|
#include "llvm/CodeGen/MachineFunctionPass.h"
|
|
#include "llvm/CodeGen/MachineInstrBuilder.h"
|
|
#include "llvm/CodeGen/MachineRegisterInfo.h"
|
|
#include "llvm/Support/CommandLine.h"
|
|
#include "llvm/ADT/Statistic.h"
|
|
#include "llvm/Support/Debug.h"
|
|
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "ppc-pre-emit-peephole"
|
|
|
|
STATISTIC(NumRRConvertedInPreEmit,
|
|
"Number of r+r instructions converted to r+i in pre-emit peephole");
|
|
STATISTIC(NumRemovedInPreEmit,
|
|
"Number of instructions deleted in pre-emit peephole");
|
|
|
|
static cl::opt<bool>
|
|
RunPreEmitPeephole("ppc-late-peephole", cl::Hidden, cl::init(true),
|
|
cl::desc("Run pre-emit peephole optimizations."));
|
|
|
|
namespace {
|
|
class PPCPreEmitPeephole : public MachineFunctionPass {
|
|
public:
|
|
static char ID;
|
|
PPCPreEmitPeephole() : MachineFunctionPass(ID) {
|
|
initializePPCPreEmitPeepholePass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
MachineFunctionPass::getAnalysisUsage(AU);
|
|
}
|
|
|
|
MachineFunctionProperties getRequiredProperties() const override {
|
|
return MachineFunctionProperties().set(
|
|
MachineFunctionProperties::Property::NoVRegs);
|
|
}
|
|
|
|
bool runOnMachineFunction(MachineFunction &MF) override {
|
|
if (skipFunction(MF.getFunction()) || !RunPreEmitPeephole)
|
|
return false;
|
|
bool Changed = false;
|
|
const PPCInstrInfo *TII = MF.getSubtarget<PPCSubtarget>().getInstrInfo();
|
|
SmallVector<MachineInstr *, 4> InstrsToErase;
|
|
for (MachineBasicBlock &MBB : MF) {
|
|
for (MachineInstr &MI : MBB) {
|
|
MachineInstr *DefMIToErase = nullptr;
|
|
if (TII->convertToImmediateForm(MI, &DefMIToErase)) {
|
|
Changed = true;
|
|
NumRRConvertedInPreEmit++;
|
|
DEBUG(dbgs() << "Converted instruction to imm form: ");
|
|
DEBUG(MI.dump());
|
|
if (DefMIToErase) {
|
|
InstrsToErase.push_back(DefMIToErase);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
for (MachineInstr *MI : InstrsToErase) {
|
|
DEBUG(dbgs() << "PPC pre-emit peephole: erasing instruction: ");
|
|
DEBUG(MI->dump());
|
|
MI->eraseFromParent();
|
|
NumRemovedInPreEmit++;
|
|
}
|
|
return Changed;
|
|
}
|
|
};
|
|
}
|
|
|
|
INITIALIZE_PASS(PPCPreEmitPeephole, DEBUG_TYPE, "PowerPC Pre-Emit Peephole",
|
|
false, false)
|
|
char PPCPreEmitPeephole::ID = 0;
|
|
|
|
FunctionPass *llvm::createPPCPreEmitPeepholePass() {
|
|
return new PPCPreEmitPeephole();
|
|
}
|