[llvm] [AMDGPU] Add flag to force emit s_nop (PR #117839)

[Jay Foad via llvm-commits]

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@@ -325,7 +330,9 @@ unsigned GCNHazardRecognizer::PreEmitNoops(MachineInstr *MI) {
   unsigned W = PreEmitNoopsCommon(MI);
   fixHazards(MI);
   CurrCycleInstr = nullptr;
-  return W;
+  unsigned NopPad =
+      NopPadding.getNumOccurrences() && !MI->isTerminator() ? NopPadding : 0;
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jayfoad wrote:

Why don't you want nop before a terminator?

https://github.com/llvm/llvm-project/pull/117839