Changes in directory llvm/lib/CodeGen:
IfConversion.cpp updated: 1.23 -> 1.24
---
Log message:
Fix some subtle bugs: bug during succeessor copying; incorrectly updating
states of ifcvted blocks.
---
Diffs of the changes: (+19 -20)
IfConversion.cpp | 39 +++++++++++++++++++--------------------
1 files changed, 19 insertions(+), 20 deletions(-)
Index: llvm/lib/CodeGen/IfConversion.cpp
diff -u llvm/lib/CodeGen/IfConversion.cpp:1.23
llvm/lib/CodeGen/IfConversion.cpp:1.24
--- llvm/lib/CodeGen/IfConversion.cpp:1.23 Mon Jun 4 15:33:36 2007
+++ llvm/lib/CodeGen/IfConversion.cpp Mon Jun 4 19:07:37 2007
@@ -153,7 +153,9 @@
default: assert(false && "Unexpected!");
break;
case ICReAnalyze:
- // One or more of 'childrean' have been modified, abort!
+ // One or more of 'children' have been modified, abort!
+ case ICDead:
+ // Block has been already been if-converted, abort!
break;
case ICSimple:
case ICSimpleFalse:
@@ -219,9 +221,10 @@
void IfConverter::StructuralAnalysis(MachineBasicBlock *BB) {
BBInfo &BBI = BBAnalysis[BB->getNumber()];
- if (BBI.Kind == ICReAnalyze)
+ if (BBI.Kind == ICReAnalyze) {
BBI.BrCond.clear();
- else {
+ BBI.TrueBB = BBI.FalseBB = NULL;
+ } else {
if (BBI.Kind != ICNotAnalyzed)
return; // Already analyzed.
BBI.BB = BB;
@@ -504,10 +507,7 @@
std::copy(Cond.begin(), Cond.end(), std::back_inserter(BBI.Predicate));
// Update block info. BB can be iteratively if-converted.
- BBI.Kind = ICNotAnalyzed;
- BBI.TrueBB = BBI.FalseBB = NULL;
- BBI.BrCond.clear();
- TII->AnalyzeBranch(*BBI.BB, BBI.TrueBB, BBI.FalseBB, BBI.BrCond);
+ BBI.Kind = ICReAnalyze;
ReTryPreds(BBI.BB);
CvtBBI->Kind = ICDead;
@@ -537,9 +537,11 @@
// Join the 'true' and 'false' blocks if the 'false' block has no other
// predecessors. Otherwise, add a unconditional branch from 'true' to
'false'.
BBInfo &FalseBBI = BBAnalysis[BBI.FalseBB->getNumber()];
- if (FalseBBI.BB->pred_size() == 2)
+ bool FalseBBDead = false;
+ if (FalseBBI.BB->pred_size() == 2) {
MergeBlocks(TrueBBI, FalseBBI);
- else if (!isNextBlock(TrueBBI.BB, FalseBBI.BB))
+ FalseBBDead = true;
+ } else if (!isNextBlock(TrueBBI.BB, FalseBBI.BB))
InsertUncondBranch(TrueBBI.BB, FalseBBI.BB, TII);
// Now merge the entry of the triangle with the true block.
@@ -549,12 +551,11 @@
std::back_inserter(BBI.Predicate));
// Update block info. BB can be iteratively if-converted.
- BBI.Kind = ICNotClassfied;
- BBI.TrueBB = BBI.FalseBB = NULL;
- BBI.BrCond.clear();
- TII->AnalyzeBranch(*BBI.BB, BBI.TrueBB, BBI.FalseBB, BBI.BrCond);
+ BBI.Kind = ICReAnalyze;
ReTryPreds(BBI.BB);
TrueBBI.Kind = ICDead;
+ if (FalseBBDead)
+ FalseBBI.Kind = ICDead;
// FIXME: Must maintain LiveIns.
return true;
@@ -683,10 +684,7 @@
// Update block info. BB may be iteratively if-converted.
if (OkToIfcvt) {
- BBI.Kind = ICNotClassfied;
- BBI.TrueBB = BBI.FalseBB = NULL;
- BBI.BrCond.clear();
- TII->AnalyzeBranch(*BBI.BB, BBI.TrueBB, BBI.FalseBB, BBI.BrCond);
+ BBI.Kind = ICReAnalyze;
ReTryPreds(BBI.BB);
}
TrueBBI.Kind = ICDead;
@@ -734,9 +732,10 @@
static void TransferSuccs(MachineBasicBlock *ToBB, MachineBasicBlock *FromBB) {
for (MachineBasicBlock::succ_iterator I = FromBB->succ_begin(),
E = FromBB->succ_end(); I != E; ++I) {
- FromBB->removeSuccessor(*I);
- if (!ToBB->isSuccessor(*I))
- ToBB->addSuccessor(*I);
+ MachineBasicBlock *Succ = *I;
+ FromBB->removeSuccessor(Succ);
+ if (!ToBB->isSuccessor(Succ))
+ ToBB->addSuccessor(Succ);
}
}
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