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Avoid adding PHI arguments for a predecessor that has gone away when a BRCOND was constant folded. 

This fixes PR5980.

llvm-svn: 93184
This commit is contained in:
Jakob Stoklund Olesen 2010-01-11 21:02:33 +00:00
parent 93ad708a46
commit d2a1bee2d4
2 changed files with 116 additions and 14 deletions
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33
llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
View File

@ -1017,8 +1017,7 @@ SelectionDAGISel::FinishBasicBlock() {
for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size();
j != ej; ++j) { j != ej; ++j) {
MachineBasicBlock* cBB = SDB->BitTestCases[i].Cases[j].ThisBB; MachineBasicBlock* cBB = SDB->BitTestCases[i].Cases[j].ThisBB;
if (cBB->succ_end() != if (cBB->isSuccessor(PHIBB)) {
std::find(cBB->succ_begin(),cBB->succ_end(), PHIBB)) {
PHI->addOperand(MachineOperand::CreateReg(SDB->PHINodesToUpdate[pi].second, PHI->addOperand(MachineOperand::CreateReg(SDB->PHINodesToUpdate[pi].second,
false)); false));
PHI->addOperand(MachineOperand::CreateMBB(cBB)); PHI->addOperand(MachineOperand::CreateMBB(cBB));
@ -1067,7 +1066,7 @@ SelectionDAGISel::FinishBasicBlock() {
(MachineOperand::CreateMBB(SDB->JTCases[i].first.HeaderBB)); (MachineOperand::CreateMBB(SDB->JTCases[i].first.HeaderBB));
} }
// JT BB. Just iterate over successors here // JT BB. Just iterate over successors here
if (BB->succ_end() != std::find(BB->succ_begin(),BB->succ_end(), PHIBB)) { if (BB->isSuccessor(PHIBB)) {
PHI->addOperand PHI->addOperand
(MachineOperand::CreateReg(SDB->PHINodesToUpdate[pi].second, false)); (MachineOperand::CreateReg(SDB->PHINodesToUpdate[pi].second, false));
PHI->addOperand(MachineOperand::CreateMBB(BB)); PHI->addOperand(MachineOperand::CreateMBB(BB));
@ -1113,17 +1112,23 @@ SelectionDAGISel::FinishBasicBlock() {
SDB->EdgeMapping.find(BB); SDB->EdgeMapping.find(BB);
if (EI != SDB->EdgeMapping.end()) if (EI != SDB->EdgeMapping.end())
ThisBB = EI->second; ThisBB = EI->second;
for (MachineBasicBlock::iterator Phi = BB->begin();
Phi != BB->end() && Phi->getOpcode() == TargetInstrInfo::PHI; ++Phi){ // BB may have been removed from the CFG if a branch was constant folded.
// This value for this PHI node is recorded in PHINodesToUpdate, get it. if (ThisBB->isSuccessor(BB)) {
for (unsigned pn = 0; ; ++pn) { for (MachineBasicBlock::iterator Phi = BB->begin();
assert(pn != SDB->PHINodesToUpdate.size() && Phi != BB->end() && Phi->getOpcode() == TargetInstrInfo::PHI;
"Didn't find PHI entry!"); ++Phi) {
if (SDB->PHINodesToUpdate[pn].first == Phi) { // This value for this PHI node is recorded in PHINodesToUpdate.
Phi->addOperand(MachineOperand::CreateReg(SDB->PHINodesToUpdate[pn]. for (unsigned pn = 0; ; ++pn) {
second, false)); assert(pn != SDB->PHINodesToUpdate.size() &&
Phi->addOperand(MachineOperand::CreateMBB(ThisBB)); "Didn't find PHI entry!");
break; if (SDB->PHINodesToUpdate[pn].first == Phi) {
Phi->addOperand(MachineOperand::
CreateReg(SDB->PHINodesToUpdate[pn].second,
false));
Phi->addOperand(MachineOperand::CreateMBB(ThisBB));
break;
}
} }
} }
} }

97
llvm/test/CodeGen/X86/2010-01-11-ExtraPHIArg.ll Normal file
View File

@ -0,0 +1,97 @@
; RUN: llc -verify-machineinstrs < %s
;
; The lowering of a switch combined with constand folding would leave spurious extra arguments on a PHI instruction.
;
target triple = "x86_64-apple-darwin10"
define void @foo() {
br label %cond_true813.i
cond_true813.i: ; preds = %0
br i1 false, label %cond_true818.i, label %cond_next1146.i
cond_true818.i: ; preds = %cond_true813.i
br i1 false, label %recog_memoized.exit52, label %cond_next1146.i
recog_memoized.exit52: ; preds = %cond_true818.i
switch i32 0, label %bb886.i.preheader [
i32 0, label %bb907.i
i32 44, label %bb866.i
i32 103, label %bb874.i
i32 114, label %bb874.i
]
bb857.i: ; preds = %bb886.i, %bb866.i
%tmp862.i494.24 = phi i8* [ null, %bb866.i ], [ %tmp862.i494.26, %bb886.i ] ; <i8*> [#uses=1]
switch i32 0, label %bb886.i.preheader [
i32 0, label %bb907.i
i32 44, label %bb866.i
i32 103, label %bb874.i
i32 114, label %bb874.i
]
bb866.i.loopexit: ; preds = %bb874.i
br label %bb866.i
bb866.i.loopexit31: ; preds = %cond_true903.i
br label %bb866.i
bb866.i: ; preds = %bb866.i.loopexit31, %bb866.i.loopexit, %bb857.i, %recog_memoized.exit52
br i1 false, label %bb907.i, label %bb857.i
bb874.i.preheader.loopexit: ; preds = %cond_true903.i, %cond_true903.i
ret void
bb874.i: ; preds = %bb857.i, %bb857.i, %recog_memoized.exit52, %recog_memoized.exit52
switch i32 0, label %bb886.i.preheader.loopexit [
i32 0, label %bb907.i
i32 44, label %bb866.i.loopexit
i32 103, label %bb874.i.backedge
i32 114, label %bb874.i.backedge
]
bb874.i.backedge: ; preds = %bb874.i, %bb874.i
ret void
bb886.i.preheader.loopexit: ; preds = %bb874.i
ret void
bb886.i.preheader: ; preds = %bb857.i, %recog_memoized.exit52
%tmp862.i494.26 = phi i8* [ undef, %recog_memoized.exit52 ], [ %tmp862.i494.24, %bb857.i ] ; <i8*> [#uses=1]
br label %bb886.i
bb886.i: ; preds = %cond_true903.i, %bb886.i.preheader
br i1 false, label %bb857.i, label %cond_true903.i
cond_true903.i: ; preds = %bb886.i
switch i32 0, label %bb886.i [
i32 0, label %bb907.i
i32 44, label %bb866.i.loopexit31
i32 103, label %bb874.i.preheader.loopexit
i32 114, label %bb874.i.preheader.loopexit
]
bb907.i: ; preds = %cond_true903.i, %bb874.i, %bb866.i, %bb857.i, %recog_memoized.exit52
br i1 false, label %cond_next1146.i, label %cond_true910.i
cond_true910.i: ; preds = %bb907.i
ret void
cond_next1146.i: ; preds = %bb907.i, %cond_true818.i, %cond_true813.i
ret void
bb2060.i: ; No predecessors!
br i1 false, label %cond_true2064.i, label %bb2067.i
cond_true2064.i: ; preds = %bb2060.i
unreachable
bb2067.i: ; preds = %bb2060.i
ret void
cond_next3473: ; No predecessors!
ret void
cond_next3521: ; No predecessors!
ret void
}