Back out r130862; it appears to be breaking bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130867 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eli Friedman 2011-05-04 20:48:42 +00:00
parent 49cec1d818
commit 24d4c9911e
3 changed files with 30 additions and 68 deletions

View File

@ -82,8 +82,7 @@ namespace {
MachineBasicBlock::const_iterator E) const ;
bool hasLivePhysRegDefUses(const MachineInstr *MI,
const MachineBasicBlock *MBB,
SmallSet<unsigned,8> &PhysRefs,
SmallVector<unsigned,8> &PhysDefs) const;
SmallSet<unsigned,8> &PhysRefs) const;
bool PhysRegDefsReach(MachineInstr *CSMI, MachineInstr *MI,
SmallSet<unsigned,8> &PhysRefs) const;
bool isCSECandidate(MachineInstr *MI);
@ -190,8 +189,7 @@ MachineCSE::isPhysDefTriviallyDead(unsigned Reg,
/// instruction does not uses a physical register.
bool MachineCSE::hasLivePhysRegDefUses(const MachineInstr *MI,
const MachineBasicBlock *MBB,
SmallSet<unsigned,8> &PhysRefs,
SmallVector<unsigned,8> &PhysDefs) const{
SmallSet<unsigned,8> &PhysRefs) const {
MachineBasicBlock::const_iterator I = MI; I = llvm::next(I);
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
@ -208,7 +206,6 @@ bool MachineCSE::hasLivePhysRegDefUses(const MachineInstr *MI,
if (MO.isDef() &&
(MO.isDead() || isPhysDefTriviallyDead(Reg, I, MBB->end())))
continue;
PhysDefs.push_back(Reg);
PhysRefs.insert(Reg);
for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias)
PhysRefs.insert(*Alias);
@ -219,40 +216,35 @@ bool MachineCSE::hasLivePhysRegDefUses(const MachineInstr *MI,
bool MachineCSE::PhysRegDefsReach(MachineInstr *CSMI, MachineInstr *MI,
SmallSet<unsigned,8> &PhysRefs) const {
// Look backward from MI to find CSMI.
// For now conservatively returns false if the common subexpression is
// not in the same basic block as the given instruction.
MachineBasicBlock *MBB = MI->getParent();
if (CSMI->getParent() != MBB)
return false;
MachineBasicBlock::const_iterator I = CSMI; I = llvm::next(I);
MachineBasicBlock::const_iterator E = MI;
unsigned LookAheadLeft = LookAheadLimit;
MachineBasicBlock::const_reverse_iterator I(MI);
MachineBasicBlock::const_reverse_iterator E(MI->getParent()->rend());
while (LookAheadLeft) {
while (LookAheadLeft && I != E) {
// Skip over dbg_value's.
while (I != E && I->isDebugValue())
++I;
if (&*I == CSMI)
return true;
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = I->getOperand(i);
if (!MO.isReg() || !MO.isDef())
continue;
unsigned MOReg = MO.getReg();
if (TargetRegisterInfo::isVirtualRegister(MOReg))
continue;
if (PhysRefs.count(MOReg))
return false;
}
--LookAheadLeft;
// Skip over dbg_value's.
while (I != E && I->isDebugValue())
++I;
if (I == E)
return true;
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = I->getOperand(i);
if (!MO.isReg() || !MO.isDef())
continue;
unsigned MOReg = MO.getReg();
if (TargetRegisterInfo::isVirtualRegister(MOReg))
continue;
if (PhysRefs.count(MOReg))
return false;
}
// Go back another BB; for now, only go back at most one BB.
MachineBasicBlock *CSBB = CSMI->getParent();
MachineBasicBlock *BB = MI->getParent();
if (!CSBB->isSuccessor(BB) || BB->pred_size() != 1)
return false;
I = CSBB->rbegin();
E = CSBB->rend();
--LookAheadLeft;
++I;
}
return false;
@ -403,8 +395,7 @@ bool MachineCSE::ProcessBlock(MachineBasicBlock *MBB) {
// used, then it's not safe to replace it with a common subexpression.
// It's also not safe if the instruction uses physical registers.
SmallSet<unsigned,8> PhysRefs;
SmallVector<unsigned,8> DirectPhysRefs;
if (FoundCSE && hasLivePhysRegDefUses(MI, MBB, PhysRefs, DirectPhysRefs)) {
if (FoundCSE && hasLivePhysRegDefUses(MI, MBB, PhysRefs)) {
FoundCSE = false;
// ... Unless the CS is local and it also defines the physical register
@ -457,13 +448,6 @@ bool MachineCSE::ProcessBlock(MachineBasicBlock *MBB) {
MRI->clearKillFlags(CSEPairs[i].second);
}
MI->eraseFromParent();
if (!DirectPhysRefs.empty() && CSMI->getParent() != MBB) {
assert(CSMI->getParent()->isSuccessor(MBB));
SmallVector<unsigned,8>::iterator PI = DirectPhysRefs.begin(),
PE = DirectPhysRefs.end();
for (; PI != PE; ++PI)
MBB->addLiveIn(*PI);
}
++NumCSEs;
if (!PhysRefs.empty())
++NumPhysCSEs;

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@ -21,8 +21,8 @@ bb7: ; preds = %bb3
bb9: ; preds = %bb7
; CHECK: cmp r0, #0
; CHECK-NOT: cmp
; CHECK: cbnz
; CHECK: cmp r0, #0
; CHECK-NEXT: cbnz
%0 = tail call double @floor(double %b) nounwind readnone ; <double> [#uses=0]
br label %bb11

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@ -1,22 +0,0 @@
; RUN: llc < %s -mtriple=x86_64-apple-darwin10 | FileCheck %s
define i32 @cmp(i32* %aa, i32* %bb) nounwind readnone ssp {
entry:
%a = load i32* %aa
%b = load i32* %bb
%cmp = icmp sgt i32 %a, %b
br i1 %cmp, label %return, label %if.end
; CHECK: cmp:
; CHECK: cmpl
; CHECK: jg
if.end: ; preds = %entry
; CHECK-NOT: cmpl
; CHECK: cmov
%cmp4 = icmp slt i32 %a, %b
%. = select i1 %cmp4, i32 2, i32 111
br label %return
return: ; preds = %if.end, %entry
%retval.0 = phi i32 [ 1, %entry ], [ %., %if.end ]
ret i32 %retval.0
}