[llvm] 7e12325 - [X86] Add test showing failure to remove vector rotate of allsignbits

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-01-24T10:12:51Z
New Revision: 7e123255861a3d74306ed1b0ceebd9d1725c84f0

URL: https://github.com/llvm/llvm-project/commit/7e123255861a3d74306ed1b0ceebd9d1725c84f0
DIFF: https://github.com/llvm/llvm-project/commit/7e123255861a3d74306ed1b0ceebd9d1725c84f0.diff

LOG: [X86] Add test showing failure to remove vector rotate of allsignbits

Rotating an 0/-1 value by any amount will always result in the same 0/-1 value

Added: 
    

Modified: 
    llvm/test/CodeGen/X86/rotate_vec.ll

Removed: 
    


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diff  --git a/llvm/test/CodeGen/X86/rotate_vec.ll b/llvm/test/CodeGen/X86/rotate_vec.ll
index 36594aaeb875..cf1a90ae5de7 100644
--- a/llvm/test/CodeGen/X86/rotate_vec.ll
+++ b/llvm/test/CodeGen/X86/rotate_vec.ll
@@ -85,4 +85,22 @@ define <4 x i32> @rot_v4i32_zero_non_splat(<4 x i32> %x) {
   %2 = shufflevector <4 x i32> %1, <4 x i32> undef, <4 x i32> zeroinitializer
   ret <4 x i32> %2
 }
+
+define <4 x i32> @rot_v4i32_allsignbits(<4 x i32> %x, <4 x i32> %y) {
+; XOP-LABEL: rot_v4i32_allsignbits:
+; XOP:       # %bb.0:
+; XOP-NEXT:    vpsrad $31, %xmm0, %xmm0
+; XOP-NEXT:    vprotd %xmm1, %xmm0, %xmm0
+; XOP-NEXT:    retq
+;
+; AVX512-LABEL: rot_v4i32_allsignbits:
+; AVX512:       # %bb.0:
+; AVX512-NEXT:    vpsrad $31, %xmm0, %xmm0
+; AVX512-NEXT:    vprolvd %xmm1, %xmm0, %xmm0
+; AVX512-NEXT:    retq
+  %1 = ashr <4 x i32> %x, <i32 31, i32 31, i32 31, i32 31>
+  %2 = call <4 x i32> @llvm.fshl.v4i32(<4 x i32> %1, <4 x i32> %1, <4 x i32> %y)
+  ret <4 x i32> %2
+}
+
 declare <4 x i32> @llvm.fshl.v4i32(<4 x i32>, <4 x i32>, <4 x i32>)