[x86] add smin/smax with zero tests

These are vector tests corresponding to the discussion at:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/106868.html

Apart from the lack of min/max matching, the and/andn difference
shows a lack of DAG-level canonicalization.

llvm-svn: 286737

diff --git a/llvm/test/CodeGen/X86/vec_minmax_match.ll b/llvm/test/CodeGen/X86/vec_minmax_match.ll
index d6860c0e846127fc5121469f44987b4faef39075..6293a61516139e6c3ccd3c6e7e919959aaa33627 100644 (file)
--- a/llvm/test/CodeGen/X86/vec_minmax_match.ll
+++ b/llvm/test/CodeGen/X86/vec_minmax_match.ll
@@ -32,6 +32,38 @@ define <4 x i32> @smin_vec2(<4 x i32> %x) {
   ret <4 x i32> %sel
 }
 
+; Z = X -nsw Y
+; (X >s Y) ? 0 : Z ==> (Z >s 0) ? 0 : Z ==> SMIN(Z, 0)
+define <4 x i32> @smin_vec3(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: smin_vec3:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    vpsubd %xmm1, %xmm0, %xmm2
+; CHECK-NEXT:    vpcmpgtd %xmm1, %xmm0, %xmm0
+; CHECK-NEXT:    vpandn %xmm2, %xmm0, %xmm0
+; CHECK-NEXT:    retq
+;
+  %sub = sub nsw <4 x i32> %x, %y
+  %cmp = icmp sgt <4 x i32> %x, %y
+  %sel = select <4 x i1> %cmp, <4 x i32> zeroinitializer, <4 x i32> %sub
+  ret <4 x i32> %sel
+}
+
+; Z = X -nsw Y
+; (X <s Y) ? Z : 0 ==> (Z <s 0) ? Z : 0 ==> SMIN(Z, 0)
+define <4 x i32> @smin_vec4(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: smin_vec4:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    vpsubd %xmm1, %xmm0, %xmm2
+; CHECK-NEXT:    vpcmpgtd %xmm0, %xmm1, %xmm0
+; CHECK-NEXT:    vpand %xmm2, %xmm0, %xmm0
+; CHECK-NEXT:    retq
+;
+  %sub = sub nsw <4 x i32> %x, %y
+  %cmp = icmp slt <4 x i32> %x, %y
+  %sel = select <4 x i1> %cmp, <4 x i32> %sub, <4 x i32> zeroinitializer
+  ret <4 x i32> %sel
+}
+
 define <4 x i32> @smax_vec1(<4 x i32> %x) {
 ; CHECK-LABEL: smax_vec1:
 ; CHECK:       # BB#0:
@@ -60,6 +92,38 @@ define <4 x i32> @smax_vec2(<4 x i32> %x) {
   ret <4 x i32> %sel
 }
 
+; Z = X -nsw Y
+; (X <s Y) ? 0 : Z ==> (Z <s 0) ? 0 : Z ==> SMAX(Z, 0)
+define <4 x i32> @smax_vec3(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: smax_vec3:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    vpsubd %xmm1, %xmm0, %xmm2
+; CHECK-NEXT:    vpcmpgtd %xmm0, %xmm1, %xmm0
+; CHECK-NEXT:    vpandn %xmm2, %xmm0, %xmm0
+; CHECK-NEXT:    retq
+;
+  %sub = sub nsw <4 x i32> %x, %y
+  %cmp = icmp slt <4 x i32> %x, %y
+  %sel = select <4 x i1> %cmp, <4 x i32> zeroinitializer, <4 x i32> %sub
+  ret <4 x i32> %sel
+}
+
+; Z = X -nsw Y
+; (X >s Y) ? Z : 0 ==> (Z >s 0) ? Z : 0 ==> SMAX(Z, 0)
+define <4 x i32> @smax_vec4(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: smax_vec4:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    vpsubd %xmm1, %xmm0, %xmm2
+; CHECK-NEXT:    vpcmpgtd %xmm1, %xmm0, %xmm0
+; CHECK-NEXT:    vpand %xmm2, %xmm0, %xmm0
+; CHECK-NEXT:    retq
+;
+  %sub = sub nsw <4 x i32> %x, %y
+  %cmp = icmp sgt <4 x i32> %x, %y
+  %sel = select <4 x i1> %cmp, <4 x i32> %sub, <4 x i32> zeroinitializer
+  ret <4 x i32> %sel
+}
+
 define <4 x i32> @umax_vec1(<4 x i32> %x) {
 ; CHECK-LABEL: umax_vec1:
 ; CHECK:       # BB#0: