[X86] Add test case for trunc_packus_v16i32_v16i8 with avx512vl+avx512bw and prefer-vector-width=256 and min-legal-vector-width=256. NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@374283 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/X86/min-legal-vector-width.ll

@@ -1079,3 +1079,23 @@ define void @vselect_split_v16i16_setcc(<16 x i16> %s, <16 x i16> %t, <16 x i32>
   store <16 x i32> %b, <16 x i32>* %r
   ret void
 }
+
+define <16 x i8> @trunc_packus_v16i32_v16i8(<16 x i32>* %p, <16 x i8>* %q) "min-legal-vector-width"="256" {
+; CHECK-LABEL: trunc_packus_v16i32_v16i8:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vpxor %xmm0, %xmm0, %xmm0
+; CHECK-NEXT:    vpmaxsd 32(%rdi), %ymm0, %ymm1
+; CHECK-NEXT:    vpmovusdb %ymm1, %xmm1
+; CHECK-NEXT:    vpmaxsd (%rdi), %ymm0, %ymm0
+; CHECK-NEXT:    vpmovusdb %ymm0, %xmm0
+; CHECK-NEXT:    vpunpcklqdq {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; CHECK-NEXT:    vzeroupper
+; CHECK-NEXT:    retq
+  %a = load <16 x i32>, <16 x i32>* %p
+  %b = icmp slt <16 x i32> %a, <i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255>
+  %c = select <16 x i1> %b, <16 x i32> %a, <16 x i32> <i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255, i32 255>
+  %d = icmp sgt <16 x i32> %c, zeroinitializer
+  %e = select <16 x i1> %d, <16 x i32> %c, <16 x i32> zeroinitializer
+  %f = trunc <16 x i32> %e to <16 x i8>
+  ret <16 x i8> %f
+}