[llvm] [RISCV][GISel] Add FP calling convention support (PR #69138)

[Philip Reames via llvm-commits]

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@@ -94,11 +94,60 @@ struct RISCVOutgoingValueHandler : public CallLowering::OutgoingValueHandler {
 
   void assignValueToReg(Register ValVReg, Register PhysReg,
                         CCValAssign VA) override {
+    // If we're passing an f32 value into an i64, anyextend before copying.
+    if (VA.getLocVT() == MVT::i64 && VA.getValVT() == MVT::f32)
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preames wrote:

It looks like maybe this bit of code could be handled by setting LocInfo to  CCValAssign::AExt, and letting it fallthrough instead?  Not sure about what else that means though, so take with bucket of salt.  

https://github.com/llvm/llvm-project/pull/69138