[llvm] [AMDGPU][CodeGen] Fold immediates in src1 operands of V_MAD/MAC/FMA/FMAC. (PR #68002)

[Joe Nash via llvm-commits]

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@@ -3250,9 +3250,12 @@ bool SIInstrInfo::FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
     MachineOperand *Src2 = getNamedOperand(UseMI, AMDGPU::OpName::src2);
 
     // Multiplied part is the constant: Use v_madmk_{f16, f32}.
-    // We should only expect these to be on src0 due to canonicalization.
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Sisyph wrote:

Thanks for checking. The compiler appears to have not been emitting madmk for a while. I'm fine with this approach but can't comment on whether some other approach using canonicalization is possible or desirable. 

https://github.com/llvm/llvm-project/pull/68002