[llvm] [AMDGPU][AMDGPUDemoteSCCBranchToExecz] demote s_cbranch_scc0/1 branches into vcmp + s_cbranch_execz branches (PR #110284)

[Juan Manuel Martinez Caamaño via llvm-commits]

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@@ -0,0 +1,306 @@
+#include <llvm/CodeGen/MachineFunctionPass.h>
+
+#include "AMDGPU.h"
+#include "GCNSubtarget.h"
+#include "SIInstrInfo.h"
+#include "SIRegisterInfo.h"
+
+using namespace llvm;
+
+namespace {
+#define DEBUG_TYPE "amdgpu-demote-scc-to-execz"
+const char PassName[] = "AMDGPU s_cbranch_scc to s_cbranch_execz conversion";
+
+std::optional<unsigned> getVALUOpc(const MachineInstr &MI,
+                                   bool Reverse = false) {
+  unsigned Opc = MI.getOpcode();
+  if (Reverse) {
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jmmartinez wrote:

There has to be a better way to do this.

https://github.com/llvm/llvm-project/pull/110284