[llvm-branch-commits] [llvm] [AMDGPU][SILoadStoreOptimizer] Merge constrained sloads (PR #96162)

[Jay Foad via llvm-branch-commits]

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@@ -1212,8 +1228,14 @@ void SILoadStoreOptimizer::copyToDestRegs(
 
   // Copy to the old destination registers.
   const MCInstrDesc &CopyDesc = TII->get(TargetOpcode::COPY);
-  const auto *Dest0 = TII->getNamedOperand(*CI.I, OpName);
-  const auto *Dest1 = TII->getNamedOperand(*Paired.I, OpName);
+  auto *Dest0 = TII->getNamedOperand(*CI.I, OpName);
+  auto *Dest1 = TII->getNamedOperand(*Paired.I, OpName);
+
+  // The constrained sload instructions in S_LOAD_IMM class will have
+  // `early-clobber` flag in the dst operand. Remove the flag before using the
+  // MOs in copies.
+  Dest0->setIsEarlyClobber(false);
+  Dest1->setIsEarlyClobber(false);
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jayfoad wrote:

It's a bit ugly to modify in-place the operands of `CI.I` and `Paired.I`. But I guess it is harmless since they will be erased soon, when the merged load instruction is created.

https://github.com/llvm/llvm-project/pull/96162