[X86] Tests for unsigned saturation downconvert detection.

One more test for smax(smin(x, C2), C1) pattern.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330090 91177308-0d34-0410-b5e6-96231b3b80d8

Author: againull

test/CodeGen/X86/avx512-trunc.ll

@@ -775,9 +775,8 @@ define <16 x i8> @usat_trunc_db_256(<8 x i32> %x) {
 ; %res = trunc %d
 
 
-
-define void @smax_usat_trunc_wb_256_mem(<16 x i16> %i, <16 x i8>* %res) {
-; KNL-LABEL: smax_usat_trunc_wb_256_mem:
+define void @smax_usat_trunc_wb_256_mem1(<16 x i16> %i, <16 x i8>* %res) {
+; KNL-LABEL: smax_usat_trunc_wb_256_mem1:
 ; KNL:       ## %bb.0:
 ; KNL-NEXT:    vpxor %xmm1, %xmm1, %xmm1
 ; KNL-NEXT:    vpmaxsw %ymm1, %ymm0, %ymm0
@@ -787,7 +786,7 @@ define void @smax_usat_trunc_wb_256_mem(<16 x i16> %i, <16 x i8>* %res) {
 ; KNL-NEXT:    vzeroupper
 ; KNL-NEXT:    retq
 ;
-; SKX-LABEL: smax_usat_trunc_wb_256_mem:
+; SKX-LABEL: smax_usat_trunc_wb_256_mem1:
 ; SKX:       ## %bb.0:
 ; SKX-NEXT:    vpxor %xmm1, %xmm1, %xmm1
 ; SKX-NEXT:    vpmaxsw %ymm1, %ymm0, %ymm0
@@ -804,6 +803,35 @@ define void @smax_usat_trunc_wb_256_mem(<16 x i16> %i, <16 x i8>* %res) {
   ret void
 }
 
+; Test for smax(smin(x, C2), C1).
+define void @smax_usat_trunc_wb_256_mem2(<16 x i16> %i, <16 x i8>* %res) {
+; KNL-LABEL: smax_usat_trunc_wb_256_mem2:
+; KNL:       ## %bb.0:
+; KNL-NEXT:    vpminsw {{.*}}(%rip), %ymm0, %ymm0
+; KNL-NEXT:    vpxor %xmm1, %xmm1, %xmm1
+; KNL-NEXT:    vpmaxsw %ymm1, %ymm0, %ymm0
+; KNL-NEXT:    vpmovsxwd %ymm0, %zmm0
+; KNL-NEXT:    vpmovdb %zmm0, (%rdi)
+; KNL-NEXT:    vzeroupper
+; KNL-NEXT:    retq
+;
+; SKX-LABEL: smax_usat_trunc_wb_256_mem2:
+; SKX:       ## %bb.0:
+; SKX-NEXT:    vpminsw {{.*}}(%rip), %ymm0, %ymm0
+; SKX-NEXT:    vpxor %xmm1, %xmm1, %xmm1
+; SKX-NEXT:    vpmaxsw %ymm1, %ymm0, %ymm0
+; SKX-NEXT:    vpmovwb %ymm0, (%rdi)
+; SKX-NEXT:    vzeroupper
+; SKX-NEXT:    retq
+  %x1 = icmp slt <16 x i16> %i, <i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255>
+  %x2 = select <16 x i1> %x1, <16 x i16> %i, <16 x i16> <i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255>
+  %x3 = icmp sgt <16 x i16> %x2, <i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0>
+  %x5 = select <16 x i1> %x3, <16 x i16> %x2, <16 x i16> <i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0>
+  %x6 = trunc <16 x i16> %x5 to <16 x i8>
+  store <16 x i8> %x6, <16 x i8>* %res, align 1
+  ret void
+}
+
 define <16 x i8> @smax_usat_trunc_wb_256(<16 x i16> %i) {
 ; KNL-LABEL: smax_usat_trunc_wb_256:
 ; KNL:       ## %bb.0: