[llvm] [LLVM] Slay undead copysign code (PR #111269)

[Matt Arsenault via llvm-commits]

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@@ -1649,12 +1649,13 @@ void DAGTypeLegalizer::ExpandFloatRes_FCEIL(SDNode *N,
 
 void DAGTypeLegalizer::ExpandFloatRes_FCOPYSIGN(SDNode *N,
                                                 SDValue &Lo, SDValue &Hi) {
-  ExpandFloatRes_Binary(N, GetFPLibCall(N->getValueType(0),
-                                        RTLIB::COPYSIGN_F32,
-                                        RTLIB::COPYSIGN_F64,
-                                        RTLIB::COPYSIGN_F80,
-                                        RTLIB::COPYSIGN_F128,
-                                        RTLIB::COPYSIGN_PPCF128), Lo, Hi);
+
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arsenm wrote:

llvm.copysign.f32(float %x, fptrunc double %y to float) can fold into one FCOPYSIGN operation with mismatched types during codegen. The IR intrinsic does not directly support this 

https://github.com/llvm/llvm-project/pull/111269