From 75dda50ebe5771b7129db2080e35c1d51d4f5e68 Mon Sep 17 00:00:00 2001 From: Simon Pilgrim Date: Tue, 14 Feb 2017 11:20:11 +0000 Subject: [X86][SSE] Test case showing missed PSHUFB target shuffle constant fold opportunity. It also shows an unnecessary pshufb/broadcast being used - the original pshufb mask only requested the lowest byte. llvm-svn: 295046 --- .../CodeGen/X86/vector-shuffle-combining-ssse3.ll | 35 ++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'llvm/test') diff --git a/llvm/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll b/llvm/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll index 792496e83f0..7b73bda48ce 100644 --- a/llvm/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll +++ b/llvm/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll @@ -586,3 +586,38 @@ define <16 x i8> @constant_fold_pshufb() { %1 = tail call <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8> , <16 x i8> ) ret <16 x i8> %1 } + +; FIXME - unnecessary pshufb/broadcast being used - pshufb mask only needs lowest byte. +define <16 x i8> @constant_fold_pshufb_2() { +; SSE-LABEL: constant_fold_pshufb_2: +; SSE: # BB#0: +; SSE-NEXT: movl $2, %eax +; SSE-NEXT: movd %eax, %xmm0 +; SSE-NEXT: pxor %xmm1, %xmm1 +; SSE-NEXT: pshufb %xmm1, %xmm0 +; SSE-NEXT: retq +; +; AVX1-LABEL: constant_fold_pshufb_2: +; AVX1: # BB#0: +; AVX1-NEXT: movl $2, %eax +; AVX1-NEXT: vmovd %eax, %xmm0 +; AVX1-NEXT: vpxor %xmm1, %xmm1, %xmm1 +; AVX1-NEXT: vpshufb %xmm1, %xmm0, %xmm0 +; AVX1-NEXT: retq +; +; AVX2-LABEL: constant_fold_pshufb_2: +; AVX2: # BB#0: +; AVX2-NEXT: movl $2, %eax +; AVX2-NEXT: vmovd %eax, %xmm0 +; AVX2-NEXT: vpbroadcastb %xmm0, %xmm0 +; AVX2-NEXT: retq +; +; AVX512F-LABEL: constant_fold_pshufb_2: +; AVX512F: # BB#0: +; AVX512F-NEXT: movl $2, %eax +; AVX512F-NEXT: vmovd %eax, %xmm0 +; AVX512F-NEXT: vpbroadcastb %xmm0, %xmm0 +; AVX512F-NEXT: retq + %1 = tail call <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8> , <16 x i8> ) + ret <16 x i8> %1 +} -- cgit v1.2.3