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Move StrongPHIElimination after live interval analysis. This will make things happier down the road. 

llvm-svn: 48138
This commit is contained in:
Owen Anderson 2008-03-10 07:22:36 +00:00
parent 5f4b355f20
commit 75d04819a6
1 changed files with 27 additions and 36 deletions
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63
llvm/lib/CodeGen/StrongPHIElimination.cpp
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@ -21,7 +21,7 @@
#define DEBUG_TYPE "strongphielim"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
@ -65,7 +65,10 @@ namespace {
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<MachineDominatorTree>();
AU.addRequired<LiveVariables>();
AU.addRequired<LiveIntervals>();
// TODO: Actually make this true.
AU.addPreserved<LiveIntervals>();
MachineFunctionPass::getAnalysisUsage(AU);
}
@ -269,34 +272,23 @@ StrongPHIElimination::computeDomForest(std::set<unsigned>& regs,
return ret;
}
/// isLiveIn - helper method that determines, from a VarInfo, if a register
/// isLiveIn - helper method that determines, from a regno, if a register
/// is live into a block
static bool isLiveIn(unsigned r, MachineBasicBlock* MBB,
MachineRegisterInfo& MRI, LiveVariables& LV) {
LiveVariables::VarInfo V = LV.getVarInfo(r);
if (V.AliveBlocks.test(MBB->getNumber()))
return true;
if (MRI.getVRegDef(r)->getParent() != MBB &&
V.UsedBlocks.test(MBB->getNumber()))
return true;
return false;
LiveIntervals& LI) {
LiveInterval& I = LI.getOrCreateInterval(r);
unsigned idx = LI.getMBBStartIdx(MBB);
return I.liveBeforeAndAt(idx);
}
/// isLiveOut - help method that determines, from a VarInfo, if a register is
/// isLiveOut - help method that determines, from a regno, if a register is
/// live out of a block.
static bool isLiveOut(unsigned r, MachineBasicBlock* MBB,
MachineRegisterInfo& MRI, LiveVariables& LV) {
LiveVariables::VarInfo& V = LV.getVarInfo(r);
if (MBB == MRI.getVRegDef(r)->getParent() ||
V.UsedBlocks.test(MBB->getNumber())) {
for (std::vector<MachineInstr*>::iterator I = V.Kills.begin(),
E = V.Kills.end(); I != E; ++I)
if ((*I)->getParent() == MBB)
return false;
return true;
LiveIntervals& LI) {
for (MachineBasicBlock::succ_iterator PI = MBB->succ_begin(),
E = MBB->succ_end(); PI != E; ++PI) {
if (isLiveIn(r, *PI, LI))
return true;
}
return false;
@ -307,7 +299,7 @@ static bool isLiveOut(unsigned r, MachineBasicBlock* MBB,
/// registers. 0 - defined in the same block, 1 - first properly dominates
/// second, 2 - second properly dominates first
static bool interferes(unsigned a, unsigned b, MachineBasicBlock* scan,
LiveVariables& LV, unsigned mode) {
LiveIntervals& LV, unsigned mode) {
MachineInstr* def = 0;
MachineInstr* kill = 0;
@ -400,7 +392,7 @@ static bool interferes(unsigned a, unsigned b, MachineBasicBlock* scan,
/// copies. This method is responsible for determining which operands receive
/// which treatment.
void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
LiveVariables& LV = getAnalysis<LiveVariables>();
LiveIntervals& LI = getAnalysis<LiveIntervals>();
MachineRegisterInfo& MRI = MBB->getParent()->getRegInfo();
// Holds names that have been added to a set in any PHI within this block
@ -435,12 +427,12 @@ void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
// in this block OR
// 5) if any two operands are defined in the same block, insert copies
// for one of them
if (isLiveIn(SrcReg, P->getParent(), MRI, LV) ||
if (isLiveIn(SrcReg, P->getParent(), LI) ||
isLiveOut(P->getOperand(0).getReg(),
MRI.getVRegDef(SrcReg)->getParent(), MRI, LV) ||
MRI.getVRegDef(SrcReg)->getParent(), LI) ||
( MRI.getVRegDef(SrcReg)->getOpcode() == TargetInstrInfo::PHI &&
isLiveIn(P->getOperand(0).getReg(),
MRI.getVRegDef(SrcReg)->getParent(), MRI, LV) ) ||
MRI.getVRegDef(SrcReg)->getParent(), LI) ) ||
ProcessedNames.count(SrcReg) ||
UnionedBlocks.count(MRI.getVRegDef(SrcReg)->getParent())) {
@ -494,7 +486,7 @@ void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
}
// If there's an interference, we need to insert copies
if (interferes(p.first, p.second, scan, LV, mode)) {
if (interferes(p.first, p.second, scan, LI, mode)) {
// Insert copies for First
for (int i = P->getNumOperands() - 1; i >= 2; i-=2) {
if (P->getOperand(i-1).getReg() == p.first) {
@ -537,7 +529,7 @@ void StrongPHIElimination::processPHIUnion(MachineInstr* Inst,
// Code is still in SSA form, so we can use MRI::getVRegDef()
MachineRegisterInfo& MRI = Inst->getParent()->getParent()->getRegInfo();
LiveVariables& LV = getAnalysis<LiveVariables>();
LiveIntervals& LI = getAnalysis<LiveIntervals>();
unsigned DestReg = Inst->getOperand(0).getReg();
// DF walk on the DomForest
@ -557,7 +549,7 @@ void StrongPHIElimination::processPHIUnion(MachineInstr* Inst,
// for the child or the parent. In the interest of simplicity, we're
// just always choosing the parent.
if (isLiveOut(DFNode->getReg(),
MRI.getVRegDef(child->getReg())->getParent(), MRI, LV)) {
MRI.getVRegDef(child->getReg())->getParent(), LI)) {
// Insert copies for parent
for (int i = Inst->getNumOperands() - 1; i >= 2; i-=2) {
if (Inst->getOperand(i-1).getReg() == DFNode->getReg()) {
@ -574,8 +566,7 @@ void StrongPHIElimination::processPHIUnion(MachineInstr* Inst,
// If a node is live-in to the defining block of one of its children, but
// not live-out, then we need to scan that block for local interferences.
} else if (isLiveIn(DFNode->getReg(),
MRI.getVRegDef(child->getReg())->getParent(),
MRI, LV) ||
MRI.getVRegDef(child->getReg())->getParent(), LI) ||
MRI.getVRegDef(DFNode->getReg())->getParent() ==
MRI.getVRegDef(child->getReg())->getParent()) {
// Add (p, c) to possible local interferences
@ -624,7 +615,7 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
}
}
LiveVariables& LV = getAnalysis<LiveVariables>();
LiveIntervals& LI = getAnalysis<LiveIntervals>();
MachineFunction* MF = MBB->getParent();
MachineRegisterInfo& MRI = MF->getRegInfo();
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
@ -637,7 +628,7 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(curr.first);
if (isLiveOut(curr.second, MBB, MRI, LV)) {
if (isLiveOut(curr.second, MBB, LI)) {
// Create a temporary
unsigned t = MF->getRegInfo().createVirtualRegister(RC);