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authorChris Lattner <sabre@nondot.org>2009-08-30 20:36:46 +0000
committerChris Lattner <sabre@nondot.org>2009-08-30 20:36:46 +0000
commitc2f2cf896e3c5ca269eaf0621965d6e3378cc625 (patch)
tree9fc79365dd20ed318b5f6cdb142c80032a9c05d5
parenta3e620caba93746e47c7dd29b24f63fd6c96294e (diff)
downloadbcm5719-llvm-c2f2cf896e3c5ca269eaf0621965d6e3378cc625.tar.gz
bcm5719-llvm-c2f2cf896e3c5ca269eaf0621965d6e3378cc625.zip
misc cleanup
llvm-svn: 80507
-rw-r--r--llvm/lib/Transforms/Scalar/InstructionCombining.cpp26
1 files changed, 13 insertions, 13 deletions
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
index 478068c95b5..a02aa5dff8b 100644
--- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -10784,8 +10784,7 @@ Instruction *InstCombiner::visitPHINode(PHINode &PN) {
Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
Value *PtrOp = GEP.getOperand(0);
- // Is it 'getelementptr %P, i32 0' or 'getelementptr %P'
- // If so, eliminate the noop.
+ // Eliminate 'getelementptr %P, i32 0' and 'getelementptr %P', they are noops.
if (GEP.getNumOperands() == 1)
return ReplaceInstUsesWith(GEP, PtrOp);
@@ -10896,15 +10895,15 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
// Handle gep(bitcast x) and gep(gep x, 0, 0, 0).
if (Value *X = getBitCastOperand(PtrOp)) {
assert(isa<PointerType>(X->getType()) && "Must be cast from pointer");
-
+
+ // Transform: GEP (bitcast [10 x i8]* X to [0 x i8]*), i32 0, ...
+ // into : GEP [10 x i8]* X, i32 0, ...
+ //
+ // Likewise, transform: GEP (bitcast i8* X to [0 x i8]*), i32 0, ...
+ // into : GEP i8* X, ...
+ //
+ // This occurs when the program declares an array extern like "int X[];"
if (HasZeroPointerIndex) {
- // transform: GEP (bitcast [10 x i8]* X to [0 x i8]*), i32 0, ...
- // into : GEP [10 x i8]* X, i32 0, ...
- //
- // Likewise, transform: GEP (bitcast i8* X to [0 x i8]*), i32 0, ...
- // into : GEP i8* X, ...
- //
- // This occurs when the program declares an array extern like "int X[];"
const PointerType *CPTy = cast<PointerType>(PtrOp->getType());
const PointerType *XTy = cast<PointerType>(X->getType());
if (const ArrayType *CATy =
@@ -10919,8 +10918,9 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
if (cast<GEPOperator>(&GEP)->isInBounds())
cast<GEPOperator>(NewGEP)->setIsInBounds(true);
return NewGEP;
- } else if (const ArrayType *XATy =
- dyn_cast<ArrayType>(XTy->getElementType())) {
+ }
+
+ if (const ArrayType *XATy = dyn_cast<ArrayType>(XTy->getElementType())){
// GEP (bitcast [10 x i8]* X to [0 x i8]*), i32 0, ... ?
if (CATy->getElementType() == XATy->getElementType()) {
// -> GEP [10 x i8]* X, i32 0, ...
@@ -11271,7 +11271,7 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
LI.setAlignment(KnownAlign);
}
- // load (cast X) --> cast (load X) iff safe
+ // load (cast X) --> cast (load X) iff safe.
if (isa<CastInst>(Op))
if (Instruction *Res = InstCombineLoadCast(*this, LI, TD))
return Res;
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