[llvm] [AMDGPU] Remove s_delay_alu for VALU->SGPR->SALU (PR #127212)

[Nicolai Hähnle via llvm-commits]

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@@ -331,6 +331,11 @@ class AMDGPUInsertDelayAlu {
     bool Changed = false;
     MachineInstr *LastDelayAlu = nullptr;
 
+    bool VALUSALUStall = false;
+    MCRegUnit lastSgprWrite = 0;
+    MCRegUnit longestWait = 0;
+    unsigned deletedCyclesNum = 0;
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nhaehnle wrote:

Reduce the scope of variables as much as possible.

For example, VALUSALUStall doesn't need to be defined outside the loop.

https://github.com/llvm/llvm-project/pull/127212