Add another interesting shufflevector test case for InstSimplify. NFC.

Test case shows opportunity to constant fold a shuffle with one variable
input vector operand.

llvm-svn: 299327

diff --git a/llvm/test/Transforms/InstSimplify/shufflevector.ll b/llvm/test/Transforms/InstSimplify/shufflevector.ll
index 1baecd2..4a9c0df 100644 (file)
--- a/llvm/test/Transforms/InstSimplify/shufflevector.ll
+++ b/llvm/test/Transforms/InstSimplify/shufflevector.ll
@@ -1,6 +1,15 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -instsimplify -S | FileCheck %s
 
+define <4 x i32> @const_folding(<4 x i32> %x) {
+; CHECK-LABEL: @const_folding(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> zeroinitializer, <4 x i32> <i32 5, i32 4, i32 5, i32 4>
+; CHECK-NEXT:    ret <4 x i32> [[SHUF]]
+;
+  %shuf = shufflevector <4 x i32> %x, <4 x i32> zeroinitializer, <4 x i32> <i32 5, i32 4, i32 5, i32 4>
+  ret <4 x i32> %shuf
+}
+
 define <4 x i32> @splat_operand(<4 x i32> %x) {
 ; CHECK-LABEL: @splat_operand(
 ; CHECK-NEXT:    [[SPLAT:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> zeroinitializer