diff options
| -rw-r--r-- | lib/Analysis/InstructionSimplify.cpp | 12 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/2010-11-21-SizeZeroTypeGEP.ll | 8 |
2 files changed, 18 insertions, 2 deletions
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 97612f46d3..6b51b222e2 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -18,6 +18,7 @@ #include "llvm/Analysis/Dominators.h" #include "llvm/Support/PatternMatch.h" #include "llvm/Support/ValueHandle.h" +#include "llvm/Target/TargetData.h" using namespace llvm; using namespace llvm::PatternMatch; @@ -698,11 +699,18 @@ Value *llvm::SimplifyGEPInst(Value *const *Ops, unsigned NumOps, //if (isa<UndefValue>(Ops[0])) // return UndefValue::get(GEP.getType()); - // getelementptr P, 0 -> P. - if (NumOps == 2) + if (NumOps == 2) { + // getelementptr P, 0 -> P. if (ConstantInt *C = dyn_cast<ConstantInt>(Ops[1])) if (C->isZero()) return Ops[0]; + // getelementptr P, N -> P if P points to a type of zero size. + if (TD) { + const Type *Ty = cast<PointerType>(Ops[0]->getType())->getElementType(); + if (Ty->isSized() && !TD->getTypeAllocSize(Ty)) + return Ops[0]; + } + } // Check to see if this is constant foldable. for (unsigned i = 0; i != NumOps; ++i) diff --git a/test/Transforms/InstCombine/2010-11-21-SizeZeroTypeGEP.ll b/test/Transforms/InstCombine/2010-11-21-SizeZeroTypeGEP.ll new file mode 100644 index 0000000000..24da5bb3df --- /dev/null +++ b/test/Transforms/InstCombine/2010-11-21-SizeZeroTypeGEP.ll @@ -0,0 +1,8 @@ +; RUN: opt < %s -instcombine -S | not grep getelementptr + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128" + +define {}* @foo({}* %x, i32 %n) { + %p = getelementptr {}* %x, i32 %n + ret {}* %p +} |