[llvm] [AMDGPU] misched: avoid subregister dependencies (PR #140255)

[Robert Imschweiler via llvm-commits]

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@@ -535,6 +535,138 @@ unsigned GCNSubtarget::getMaxNumVGPRs(const MachineFunction &MF) const {
   return getBaseMaxNumVGPRs(F, MFI.getWavesPerEU());
 }
 
+// Check to which source operand UseOpIdx points to and return a pointer to the
+// operand of the corresponding source modifier.
+// Return nullptr if UseOpIdx either doesn't point to src0/1/2 or if there is no
+// operand for the corresponding source modifier.
+static MachineOperand *
+getVOP3PSourceModifierFromOpIdx(MachineInstr *UseI, int UseOpIdx,
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ro-i wrote:

https://github.com/llvm/llvm-project/pull/154944

https://github.com/llvm/llvm-project/pull/140255