diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp index fe544c2f065..bd79a2697c1 100644 --- a/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -1450,42 +1450,6 @@ Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) { CI.setOperand(0, GEP->getOperand(0)); return &CI; } - - // If the GEP has a single use, and the base pointer is a bitcast, and the - // GEP computes a constant offset, see if we can convert these three - // instructions into fewer. This typically happens with unions and other - // non-type-safe code. - unsigned AS = GEP->getPointerAddressSpace(); - unsigned OffsetBits = DL.getPointerSizeInBits(AS); - APInt Offset(OffsetBits, 0); - BitCastInst *BCI = dyn_cast(GEP->getOperand(0)); - if (GEP->hasOneUse() && BCI && GEP->accumulateConstantOffset(DL, Offset)) { - // FIXME: This is insufficiently tested - just a no-crash test - // (test/Transforms/InstCombine/2007-05-14-Crash.ll) - // - // Get the base pointer input of the bitcast, and the type it points to. - Value *OrigBase = BCI->getOperand(0); - SmallVector NewIndices; - if (FindElementAtOffset(OrigBase->getType(), Offset.getSExtValue(), - NewIndices)) { - // FIXME: This codepath is completely untested - could be unreachable - // for all I know. - // If we were able to index down into an element, create the GEP - // and bitcast the result. This eliminates one bitcast, potentially - // two. - Value *NGEP = cast(GEP)->isInBounds() - ? Builder->CreateInBoundsGEP(OrigBase, NewIndices) - : Builder->CreateGEP( - OrigBase->getType()->getPointerElementType(), - OrigBase, NewIndices); - NGEP->takeName(GEP); - - if (isa(CI)) - return new BitCastInst(NGEP, CI.getType()); - assert(isa(CI)); - return new PtrToIntInst(NGEP, CI.getType()); - } - } } return commonCastTransforms(CI);