diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineVectorOps.cpp | 7 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/obfuscated_splat.ll | 11 |
2 files changed, 16 insertions, 2 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp index cf60f0f426..dd7ea14e8a 100644 --- a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp +++ b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp @@ -636,8 +636,11 @@ Instruction *InstCombiner::visitShuffleVectorInst(ShuffleVectorInst &SVI) { // If LHS's width is changed, shift the mask value accordingly. // If newRHS == NULL, i.e. LHSOp0 == RHSOp0, we want to remap any - // references to RHSOp0 to LHSOp0, so we don't need to shift the mask. - if (eltMask >= 0 && newRHS != NULL) + // references from RHSOp0 to LHSOp0, so we don't need to shift the mask. + // If newRHS == newLHS, we want to remap any references from newRHS to + // newLHS so that we can properly identify splats that may occur due to + // obfuscation accross the two vectors. + if (eltMask >= 0 && newRHS != NULL && newLHS != newRHS) eltMask += newLHSWidth; } diff --git a/test/Transforms/InstCombine/obfuscated_splat.ll b/test/Transforms/InstCombine/obfuscated_splat.ll new file mode 100644 index 0000000000..c25dade168 --- /dev/null +++ b/test/Transforms/InstCombine/obfuscated_splat.ll @@ -0,0 +1,11 @@ +; RUN: opt -instcombine -S %s | FileCheck %s + +define void @test(<4 x float> *%in_ptr, <4 x float> *%out_ptr) { + %A = load <4 x float>* %in_ptr, align 16 + %B = shufflevector <4 x float> %A, <4 x float> undef, <4 x i32> <i32 0, i32 0, i32 undef, i32 undef> + %C = shufflevector <4 x float> %B, <4 x float> %A, <4 x i32> <i32 0, i32 1, i32 4, i32 undef> + %D = shufflevector <4 x float> %C, <4 x float> %A, <4 x i32> <i32 0, i32 1, i32 2, i32 4> +; CHECK: %D = shufflevector <4 x float> %A, <4 x float> undef, <4 x i32> zeroinitializer + store <4 x float> %D, <4 x float> *%out_ptr + ret void +} |