Fix PR17764

- When selecting BLEND from vselect, the operands need swapping as due to the difference between vselect and SSE/AVX's BLEND insn git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193900 91177308-0d34-0410-b5e6-96231b3b80d8
hzou35 · Nov 2, 2013 · 9d293f1 · 9d293f1
1 parent daaa8b7
commit 9d293f1
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diff --git a/lib/Target/X86/X86InstrSSE.td b/lib/Target/X86/X86InstrSSE.td
@@ -6965,7 +6965,7 @@ let Predicates = [HasAVX] in {
 let Predicates = [HasAVX2] in {
   def : Pat<(v32i8 (vselect (v32i8 VR256:$mask), (v32i8 VR256:$src1),
                             (v32i8 VR256:$src2))),
-            (VPBLENDVBYrr VR256:$src1, VR256:$src2, VR256:$mask)>;
+            (VPBLENDVBYrr VR256:$src2, VR256:$src1, VR256:$mask)>;
   def : Pat<(v16i16 (X86Blendi (v16i16 VR256:$src1), (v16i16 VR256:$src2),
                                (imm:$mask))),
             (VPBLENDWYrri VR256:$src1, VR256:$src2, imm:$mask)>;

diff --git a/test/CodeGen/X86/pr17764.ll b/test/CodeGen/X86/pr17764.ll
@@ -0,0 +1,10 @@
+; RUN: llc < %s -mtriple=x86_64-linux -mcpu=core-avx2 | FileCheck %s
+
+define <16 x i16> @foo(<16 x i1> %mask, <16 x i16> %x, <16 x i16> %y) {
+  %ret = select <16 x i1> %mask, <16 x i16> %x, <16 x i16> %y
+  ret <16 x i16> %ret
+}
+
+; CHECK: foo
+; CHECK: vpblendvb %ymm0, %ymm1, %ymm2, %ymm0
+; CHECK: ret