[clang] [llvm] [IR] Allow fast math flags on calls with homogeneous FP struct types (PR #110506)

[Matt Arsenault via cfe-commits]

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@@ -1122,6 +1122,26 @@ define void @fastMathFlagsForArrayCalls([2 x float] %f, [2 x double] %d1, [2 x <
   ret void
 }
 
+declare { float, float } @fmf_struct_f32()
+declare { double, double } @fmf_struct_f64()
+declare { <4 x double>, <4 x double> } @fmf_struct_v4f64()
+
+; CHECK-LABEL: fastMathFlagsForStructCalls(
+define void @fastMathFlagsForStructCalls({ float, float } %f, { double, double } %d1, { <4 x double>, <4 x double> } %d2) {
+  %call.fast = call fast { float, float } @fmf_struct_f32()
+  ; CHECK: %call.fast = call fast { float, float } @fmf_struct_f32()
+
+  ; Throw in some other attributes to make sure those stay in the right places.
+
+  %call.nsz.arcp = notail call nsz arcp { double, double } @fmf_struct_f64()
+  ; CHECK: %call.nsz.arcp = notail call nsz arcp { double, double } @fmf_struct_f64()
+
+  %call.nnan.ninf = tail call nnan ninf fastcc { <4 x double>, <4 x double> } @fmf_struct_v4f64()
+  ; CHECK: %call.nnan.ninf = tail call nnan ninf fastcc { <4 x double>, <4 x double> } @fmf_struct_v4f64()
+
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arsenm wrote:

Can you also add a test with nofpclass attributes on the return / argument? The intent was it would be allowed for the same types as FPMathOperator 

https://github.com/llvm/llvm-project/pull/110506