[llvm] r286452 - [DAGCombiner] Show missed opportunity to UNDEF out-of-range SHL

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Thu Nov 10 08:19:45 2016
New Revision: 286452

URL: http://llvm.org/viewvc/llvm-project?rev=286452&view=rev
Log:
[DAGCombiner] Show missed opportunity to UNDEF out-of-range SHL

Fails to match constant shift value due to presence of AND mask.

Modified:
    llvm/trunk/test/CodeGen/X86/combine-shl.ll

Modified: llvm/trunk/test/CodeGen/X86/combine-shl.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/combine-shl.ll?rev=286452&r1=286451&r2=286452&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/combine-shl.ll (original)
+++ llvm/trunk/test/CodeGen/X86/combine-shl.ll Thu Nov 10 08:19:45 2016
@@ -44,6 +44,21 @@ define <4 x i32> @combine_vec_shl_outofr
   ret <4 x i32> %1
 }
 
+define <4 x i32> @combine_vec_shl_outofrange2(<4 x i32> %a0) {
+; SSE-LABEL: combine_vec_shl_outofrange2:
+; SSE:       # BB#0:
+; SSE-NEXT:    xorps %xmm0, %xmm0
+; SSE-NEXT:    retq
+;
+; AVX-LABEL: combine_vec_shl_outofrange2:
+; AVX:       # BB#0:
+; AVX-NEXT:    vxorps %xmm0, %xmm0, %xmm0
+; AVX-NEXT:    retq
+  %1 = and <4 x i32> %a0, <i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647>
+  %2 = shl <4 x i32> %1, <i32 33, i32 33, i32 33, i32 33>
+  ret <4 x i32> %2
+}
+
 ; fold (shl x, 0) -> x
 define <4 x i32> @combine_vec_shl_by_zero(<4 x i32> %x) {
 ; SSE-LABEL: combine_vec_shl_by_zero: