[X86] Add a temporary testcase for PR21876/r223996.

llvm-svn: 224074

1 files changed, 29 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/avx2-pmovx-256-old-shuffle.ll b/llvm/test/CodeGen/X86/avx2-pmovx-256-old-shuffle.ll
new file mode 100644
index 00000000000..44eb42adb9f
--- /dev/null
+++ b/llvm/test/CodeGen/X86/avx2-pmovx-256-old-shuffle.ll
@@ -0,0 +1,29 @@
+; RUN: llc < %s -x86-experimental-vector-shuffle-lowering=false -mattr=+avx2 | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-darwin"
+
+; PR21876
+; The old shuffle lowering sometimes generates VZEXT nodes with both input
+; and output same-sized types, here 256-bits.  For instance, a v8i8 to v8i32
+; zero-extend would become a (v8i32 (VZEXT v32i8)) node, which can't happen
+; otherwise.  The companion commit r223996 added those patterns temporarily.
+; This test, along with the VR256 for AVX2 PMOVXrr instructions, should be
+; removed once the old vector shuffle lowering goes away.
+
+define void @test_avx2_pmovx_256(<8 x i8>* %tmp64, <8 x float>* %tmp75) {
+; CHECK-LABEL: test_avx2_pmovx_256
+; We really don't care about the generated code.
+; CHECK: vpmovzxbd
+; CHECK: vpbroadcastd
+; CHECK: vpand
+; CHECK: vcvtdq2ps
+; CHECK: vmovups
+; CHECK: vzeroupper
+; CHECK: retq
+
+  %wide.load458 = load <8 x i8>* %tmp64, align 1
+  %tmp68 = uitofp <8 x i8> %wide.load458 to <8 x float>
+  store <8 x float> %tmp68, <8 x float>* %tmp75, align 4
+  ret void
+}