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authorEli Bendersky <eliben@chromium.org>2013-07-15 16:09:15 -0700
committerEli Bendersky <eliben@chromium.org>2013-07-15 16:09:15 -0700
commitc6cf05cb5108f356dde97c01ee4188b0671d4542 (patch)
tree436fdc2a55296d3c202e7ef11f31be3be53efb5f /lib/CodeGen/IfConversion.cpp
parentc75199c649c739aade160289d93f257edc798cde (diff)
parent7dfcb84fc16b3bf6b2379713b53090757f0a45f9 (diff)
Merge commit '7dfcb84fc16b3bf6b2379713b53090757f0a45f9'
Conflicts: docs/LangRef.rst include/llvm/CodeGen/CallingConvLower.h include/llvm/IRReader/IRReader.h include/llvm/Target/TargetMachine.h lib/CodeGen/CallingConvLower.cpp lib/IRReader/IRReader.cpp lib/IRReader/LLVMBuild.txt lib/IRReader/Makefile lib/LLVMBuild.txt lib/Makefile lib/Support/MemoryBuffer.cpp lib/Support/Unix/PathV2.inc lib/Target/ARM/ARMBaseInstrInfo.cpp lib/Target/ARM/ARMISelLowering.cpp lib/Target/ARM/ARMInstrInfo.td lib/Target/ARM/ARMSubtarget.cpp lib/Target/ARM/ARMTargetMachine.cpp lib/Target/Mips/CMakeLists.txt lib/Target/Mips/MipsDelaySlotFiller.cpp lib/Target/Mips/MipsISelLowering.cpp lib/Target/Mips/MipsInstrInfo.td lib/Target/Mips/MipsSubtarget.cpp lib/Target/Mips/MipsSubtarget.h lib/Target/X86/X86FastISel.cpp lib/Target/X86/X86ISelDAGToDAG.cpp lib/Target/X86/X86ISelLowering.cpp lib/Target/X86/X86InstrControl.td lib/Target/X86/X86InstrFormats.td lib/Transforms/IPO/ExtractGV.cpp lib/Transforms/InstCombine/InstCombineCompares.cpp lib/Transforms/Utils/SimplifyLibCalls.cpp test/CodeGen/X86/fast-isel-divrem.ll test/MC/ARM/data-in-code.ll tools/Makefile tools/llvm-extract/llvm-extract.cpp tools/llvm-link/CMakeLists.txt tools/opt/CMakeLists.txt tools/opt/LLVMBuild.txt tools/opt/Makefile tools/opt/opt.cpp
Diffstat (limited to 'lib/CodeGen/IfConversion.cpp')
-rw-r--r--lib/CodeGen/IfConversion.cpp29
1 files changed, 27 insertions, 2 deletions
diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp
index 9958d7daad..8264d6dbab 100644
--- a/lib/CodeGen/IfConversion.cpp
+++ b/lib/CodeGen/IfConversion.cpp
@@ -1039,6 +1039,10 @@ bool IfConverter::IfConvertSimple(BBInfo &BBI, IfcvtKind Kind) {
return false;
}
+ if (CvtBBI->BB->hasAddressTaken())
+ // Conservatively abort if-conversion if BB's address is taken.
+ return false;
+
if (Kind == ICSimpleFalse)
if (TII->ReverseBranchCondition(Cond))
llvm_unreachable("Unable to reverse branch condition!");
@@ -1054,6 +1058,10 @@ bool IfConverter::IfConvertSimple(BBInfo &BBI, IfcvtKind Kind) {
// Copy instructions in the true block, predicate them, and add them to
// the entry block.
CopyAndPredicateBlock(BBI, *CvtBBI, Cond, Redefs);
+
+ // RemoveExtraEdges won't work if the block has an unanalyzable branch, so
+ // explicitly remove CvtBBI as a successor.
+ BBI.BB->removeSuccessor(CvtBBI->BB);
} else {
PredicateBlock(*CvtBBI, CvtBBI->BB->end(), Cond, Redefs);
@@ -1112,6 +1120,10 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) {
return false;
}
+ if (CvtBBI->BB->hasAddressTaken())
+ // Conservatively abort if-conversion if BB's address is taken.
+ return false;
+
if (Kind == ICTriangleFalse || Kind == ICTriangleFRev)
if (TII->ReverseBranchCondition(Cond))
llvm_unreachable("Unable to reverse branch condition!");
@@ -1146,6 +1158,10 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) {
// Copy instructions in the true block, predicate them, and add them to
// the entry block.
CopyAndPredicateBlock(BBI, *CvtBBI, Cond, Redefs, true);
+
+ // RemoveExtraEdges won't work if the block has an unanalyzable branch, so
+ // explicitly remove CvtBBI as a successor.
+ BBI.BB->removeSuccessor(CvtBBI->BB);
} else {
// Predicate the 'true' block after removing its branch.
CvtBBI->NonPredSize -= TII->RemoveBranch(*CvtBBI->BB);
@@ -1176,7 +1192,8 @@ bool IfConverter::IfConvertTriangle(BBInfo &BBI, IfcvtKind Kind) {
// block. By not merging them, we make it possible to iteratively
// ifcvt the blocks.
if (!HasEarlyExit &&
- NextBBI->BB->pred_size() == 1 && !NextBBI->HasFallThrough) {
+ NextBBI->BB->pred_size() == 1 && !NextBBI->HasFallThrough &&
+ !NextBBI->BB->hasAddressTaken()) {
MergeBlocks(BBI, *NextBBI);
FalseBBDead = true;
} else {
@@ -1226,6 +1243,10 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind,
return false;
}
+ if (TrueBBI.BB->hasAddressTaken() || FalseBBI.BB->hasAddressTaken())
+ // Conservatively abort if-conversion if either BB has its address taken.
+ return false;
+
// Put the predicated instructions from the 'true' block before the
// instructions from the 'false' block, unless the true block would clobber
// the predicate, in which case, do the opposite.
@@ -1374,7 +1395,8 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind,
// tail, add a unconditional branch to it.
if (TailBB) {
BBInfo &TailBBI = BBAnalysis[TailBB->getNumber()];
- bool CanMergeTail = !TailBBI.HasFallThrough;
+ bool CanMergeTail = !TailBBI.HasFallThrough &&
+ !TailBBI.BB->hasAddressTaken();
// There may still be a fall-through edge from BBI1 or BBI2 to TailBB;
// check if there are any other predecessors besides those.
unsigned NumPreds = TailBB->pred_size();
@@ -1543,6 +1565,9 @@ void IfConverter::CopyAndPredicateBlock(BBInfo &ToBBI, BBInfo &FromBBI,
/// i.e., when FromBBI's branch is being moved, add those successor edges to
/// ToBBI.
void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) {
+ assert(!FromBBI.BB->hasAddressTaken() &&
+ "Removing a BB whose address is taken!");
+
ToBBI.BB->splice(ToBBI.BB->end(),
FromBBI.BB, FromBBI.BB->begin(), FromBBI.BB->end());