[llvm-commits] [llvm] r158829 - in /llvm/trunk/lib/Transforms/InstCombine: InstCombineCasts.cpp InstructionCombining.cpp

[Nuno Lopes]

Author: nlopes
Date: Wed Jun 20 12:30:51 2012
New Revision: 158829

URL: http://llvm.org/viewvc/llvm-project?rev=158829&view=rev
Log:
replace usage of EmitGEPOffset() with TargetData::getIndexedOffset() when the GEP offset is known to be constant.
With this change, we avoid relying on the IR Builder to constant fold the operations.

No functionality change intended.

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
    llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp?rev=158829&r1=158828&r2=158829&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp Wed Jun 20 12:30:51 2012
@@ -1341,10 +1341,9 @@
     // non-type-safe code.
     if (TD && GEP->hasOneUse() && isa<BitCastInst>(GEP->getOperand(0)) &&
         GEP->hasAllConstantIndices()) {
-      // We are guaranteed to get a constant from EmitGEPOffset.
-      ConstantInt *OffsetV = cast<ConstantInt>(EmitGEPOffset(GEP));
-      int64_t Offset = OffsetV->getSExtValue();
-      
+      SmallVector<Value*, 8> Ops(GEP->idx_begin(), GEP->idx_end());
+      int64_t Offset = TD->getIndexedOffset(GEP->getPointerOperandType(), Ops);
+
       // Get the base pointer input of the bitcast, and the type it points to.
       Value *OrigBase = cast<BitCastInst>(GEP->getOperand(0))->getOperand(0);
       Type *GEPIdxTy =

Modified: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp?rev=158829&r1=158828&r2=158829&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp Wed Jun 20 12:30:51 2012
@@ -1058,10 +1058,9 @@
         !isa<BitCastInst>(BCI->getOperand(0)) && GEP.hasAllConstantIndices() &&
         StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace()) {
 
-      // Determine how much the GEP moves the pointer.  We are guaranteed to get
-      // a constant back from EmitGEPOffset.
-      ConstantInt *OffsetV = cast<ConstantInt>(EmitGEPOffset(&GEP));
-      int64_t Offset = OffsetV->getSExtValue();
+      // Determine how much the GEP moves the pointer.
+      SmallVector<Value*, 8> Ops(GEP.idx_begin(), GEP.idx_end());
+      int64_t Offset = TD->getIndexedOffset(GEP.getPointerOperandType(), Ops);
 
       // If this GEP instruction doesn't move the pointer, just replace the GEP
       // with a bitcast of the real input to the dest type.