[llvm] [KnownFPClass] Add tests for FTPZ|DAPZ and dynamic denormal modes (PR #227943)

[Eric Ross via llvm-commits]

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@@ -107,7 +187,67 @@ define float @ret_tanh_nonneg(float nofpclass(ninf nzero nsub nnorm) %arg) {
 define float @ret_tanh_nonan(float nofpclass(nan) %arg) {
 ; CHECK-LABEL: define nofpclass(nan inf) float @ret_tanh_nonan
 ; CHECK-SAME: (float nofpclass(nan) [[ARG:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan inf) float @llvm.tanh.f32(float nofpclass(nan) [[ARG]]) #[[ATTR2]]
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan inf) float @llvm.tanh.f32(float nofpclass(nan) [[ARG]]) #[[ATTR4]]
+; CHECK-NEXT:    ret float [[CALL]]
+;
+  %call = call float @llvm.tanh.f32(float %arg)
+  ret float %call
+}
+
+define float @ret_tanh_negnormal_negsubnormal_mode_dynamic_dynamic(float nofpclass(nan inf zero psub pnorm) %arg) #0 {
+; CHECK-LABEL: define nofpclass(nan inf) float @ret_tanh_negnormal_negsubnormal_mode_dynamic_dynamic
+; CHECK-SAME: (float nofpclass(nan inf zero psub pnorm) [[ARG:%.*]]) #[[ATTR2]] {
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan inf) float @llvm.tanh.f32(float nofpclass(nan inf zero psub pnorm) [[ARG]]) #[[ATTR4]]
+; CHECK-NEXT:    ret float [[CALL]]
+;
+  %call = call float @llvm.tanh.f32(float %arg)
+  ret float %call
+}
+
+define float @ret_tanh_negnormal_negsubnormal_mode_ftpz_dapz(float nofpclass(nan inf zero psub pnorm) %arg) #1 {
+; CHECK-LABEL: define nofpclass(nan inf) float @ret_tanh_negnormal_negsubnormal_mode_ftpz_dapz
+; CHECK-SAME: (float nofpclass(nan inf zero psub pnorm) [[ARG:%.*]]) #[[ATTR3]] {
+; CHECK-NEXT:    [[CALL:%.*]] = call nofpclass(nan inf) float @llvm.tanh.f32(float nofpclass(nan inf zero psub pnorm) [[ARG]]) #[[ATTR4]]
+; CHECK-NEXT:    ret float [[CALL]]
+;
+  %call = call float @llvm.tanh.f32(float %arg)
+  ret float %call
+}
+
+define float @ret_tanh_negnormal_mode_dynamic_dynamic(float nofpclass(nan inf zero sub pnorm) %arg) #0 {
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ZERICO2005 wrote:

`tanh(fcNegNormal)` may be `fcNegSubnormal`, meaning that the result could flush to `fcPosZero`.

https://github.com/llvm/llvm-project/pull/227943