[InstCombine] Add tests for signed saturating always overflow; NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361864 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/saturating-add-sub.ll b/test/Transforms/InstCombine/saturating-add-sub.ll
index 8b50eb642627118fcc6499fa6ee9fb7834d1ceaf..26374a501e7445dbd11a3b9ce09c242c58be543a 100644 (file)
--- a/test/Transforms/InstCombine/saturating-add-sub.ll
+++ b/test/Transforms/InstCombine/saturating-add-sub.ll
@@ -339,6 +339,32 @@ define <2 x i8> @test_vector_sadd_neg_neg(<2 x i8> %a) {
   ret <2 x i8> %r
 }
 
+define i8 @test_scalar_sadd_always_overflows_low(i8 %a) {
+; CHECK-LABEL: @test_scalar_sadd_always_overflows_low(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[A:%.*]], -120
+; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP]], i8 [[A]], i8 -120
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.sadd.sat.i8(i8 [[MIN]], i8 -10)
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %cmp = icmp slt i8 %a, -120
+  %min = select i1 %cmp, i8 %a, i8 -120
+  %r = call i8 @llvm.sadd.sat.i8(i8 %min, i8 -10)
+  ret i8 %r
+}
+
+define i8 @test_scalar_sadd_always_overflows_high(i8 %a) {
+; CHECK-LABEL: @test_scalar_sadd_always_overflows_high(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[A:%.*]], 120
+; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP]], i8 [[A]], i8 120
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.sadd.sat.i8(i8 [[MAX]], i8 10)
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %cmp = icmp sgt i8 %a, 120
+  %max = select i1 %cmp, i8 %a, i8 120
+  %r = call i8 @llvm.sadd.sat.i8(i8 %max, i8 10)
+  ret i8 %r
+}
+
 ; While this is a no-overflow condition, the nuw flag gets lost due to
 ; canonicalization and we can no longer determine this
 define i8 @test_scalar_uadd_sub_nuw_lost_no_ov(i8 %a) {
@@ -801,6 +827,32 @@ define <2 x i8> @test_vector_ssub_neg_nneg(<2 x i8> %a) {
   ret <2 x i8> %r
 }
 
+define i8 @test_scalar_ssub_always_overflows_low(i8 %a) {
+; CHECK-LABEL: @test_scalar_ssub_always_overflows_low(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[A:%.*]], 120
+; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP]], i8 [[A]], i8 120
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 -10, i8 [[MAX]])
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %cmp = icmp sgt i8 %a, 120
+  %max = select i1 %cmp, i8 %a, i8 120
+  %r = call i8 @llvm.ssub.sat.i8(i8 -10, i8 %max)
+  ret i8 %r
+}
+
+define i8 @test_scalar_ssub_always_overflows_high(i8 %a) {
+; CHECK-LABEL: @test_scalar_ssub_always_overflows_high(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[A:%.*]], -120
+; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP]], i8 [[A]], i8 -120
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 10, i8 [[MIN]])
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %cmp = icmp slt i8 %a, -120
+  %min = select i1 %cmp, i8 %a, i8 -120
+  %r = call i8 @llvm.ssub.sat.i8(i8 10, i8 %min)
+  ret i8 %r
+}
+
 define i8 @test_scalar_usub_add_nuw_no_ov(i8 %a) {
 ; CHECK-LABEL: @test_scalar_usub_add_nuw_no_ov(
 ; CHECK-NEXT:    [[R:%.*]] = add i8 [[A:%.*]], 1