[llvm] [AMDGPU] Implement llvm.fptosi.sat and llvm.fptoui.sat (PR #174726)

[Carl Ritson via llvm-commits]

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@@ -3762,6 +3767,52 @@ SDValue AMDGPUTargetLowering::LowerFP_TO_INT(const SDValue Op,
   return SDValue();
 }
 
+SDValue AMDGPUTargetLowering::LowerFP_TO_INT_SAT(const SDValue Op,
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perlfu wrote:

I don't think this belongs in the generic legalizer.
Each target that implements the saturated conversions has their own logic already.
AMDGPU logic is subtly different again from other targets (X86, AArch, etc).

https://github.com/llvm/llvm-project/pull/174726