[llvm] [InstCombine] Handle isnormal idiom (PR #125454)

[Matt Arsenault via llvm-commits]

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@@ -877,6 +877,162 @@ define i1 @isnan_idiom_ppc_fp128(ppc_fp128 %x) {
   ret i1 %ret
 }
 
+define i1 @fpclass_test_normal(float %num) {
+; CHECK-LABEL: define i1 @fpclass_test_normal(
+; CHECK-SAME: float [[NUM:%.*]]) {
+; CHECK-NEXT:    [[RES:%.*]] = call i1 @llvm.is.fpclass.f32(float [[NUM]], i32 264)
+; CHECK-NEXT:    ret i1 [[RES]]
+;
+  %cast = bitcast float %num to i32
+  %masked = and i32 %cast, 2139095040
+  %test1 = icmp ne i32 %masked, 2139095040
+  %test2 = icmp ne i32 %masked, 0
+  %res = and i1 %test1, %test2
+  ret i1 %res
+}
+
+define i1 @fpclass_test_normal_half(half %num) {
+; CHECK-LABEL: define i1 @fpclass_test_normal_half(
+; CHECK-SAME: half [[NUM:%.*]]) {
+; CHECK-NEXT:    [[RES:%.*]] = call i1 @llvm.is.fpclass.f16(half [[NUM]], i32 264)
+; CHECK-NEXT:    ret i1 [[RES]]
+;
+  %cast = bitcast half %num to i16
+  %masked = and i16 %cast, 31744
+  %test1 = icmp ne i16 %masked, 31744
+  %test2 = icmp ne i16 %masked, 0
+  %res = and i1 %test1, %test2
+  ret i1 %res
+}
+
+define <2 x i1> @fpclass_test_normal_half_vec(<2 x half> %num) {
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arsenm wrote:

Missing test for negated form for vector? 

https://github.com/llvm/llvm-project/pull/125454