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

[Matt Arsenault via llvm-commits]

Juan Manuel Martinez =?utf-8?q?Caama=C3=B1o?= <juamarti at amd.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/110284 at github.com>


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@@ -0,0 +1,307 @@
+#include <llvm/CodeGen/MachineFunctionPass.h>
+
+#include "AMDGPU.h"
+#include "AMDGPUDemoteSCCBranchToExecz.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) {
+    switch (Opc) {
+    case AMDGPU::S_CMP_EQ_I32:
+      Opc = AMDGPU::S_CMP_LG_I32;
+      break;
+    case AMDGPU::S_CMP_LG_I32:
+      Opc = AMDGPU::S_CMP_EQ_I32;
+      break;
+    case AMDGPU::S_CMP_GT_I32:
+      Opc = AMDGPU::S_CMP_LE_I32;
+      break;
+    case AMDGPU::S_CMP_GE_I32:
+      Opc = AMDGPU::S_CMP_LT_I32;
+      break;
+    case AMDGPU::S_CMP_LT_I32:
+      Opc = AMDGPU::S_CMP_GE_I32;
+      break;
+    case AMDGPU::S_CMP_LE_I32:
+      Opc = AMDGPU::S_CMP_GT_I32;
+      break;
+    case AMDGPU::S_CMP_EQ_U32:
+      Opc = AMDGPU::S_CMP_LG_U32;
+      break;
+    case AMDGPU::S_CMP_LG_U32:
+      Opc = AMDGPU::S_CMP_EQ_U32;
+      break;
+    case AMDGPU::S_CMP_GT_U32:
+      Opc = AMDGPU::S_CMP_LE_U32;
+      break;
+    case AMDGPU::S_CMP_GE_U32:
+      Opc = AMDGPU::S_CMP_LT_U32;
+      break;
+    case AMDGPU::S_CMP_LT_U32:
+      Opc = AMDGPU::S_CMP_GE_U32;
+      break;
+    case AMDGPU::S_CMP_LE_U32:
+      Opc = AMDGPU::S_CMP_GT_U32;
+      break;
+    case AMDGPU::S_CMP_EQ_U64:
+      Opc = AMDGPU::S_CMP_LG_U64;
+      break;
+    case AMDGPU::S_CMP_LG_U64:
+      Opc = AMDGPU::S_CMP_EQ_U64;
+      break;
+    default:
+      return std::nullopt;
+    }
+  }
+
+  switch (Opc) {
+  case AMDGPU::S_CMP_EQ_I32:
+    return AMDGPU::V_CMP_EQ_I32_e64;
+  case AMDGPU::S_CMP_LG_I32:
+    return AMDGPU::V_CMP_LT_I32_e64;
+  case AMDGPU::S_CMP_GT_I32:
+    return AMDGPU::V_CMP_GT_I32_e64;
+  case AMDGPU::S_CMP_GE_I32:
+    return AMDGPU::V_CMP_GE_I32_e64;
+  case AMDGPU::S_CMP_LT_I32:
+    return AMDGPU::V_CMP_LT_I32_e64;
+  case AMDGPU::S_CMP_LE_I32:
+    return AMDGPU::V_CMP_LE_I32_e64;
+  case AMDGPU::S_CMP_EQ_U32:
+    return AMDGPU::V_CMP_EQ_U32_e64;
+  case AMDGPU::S_CMP_LG_U32:
+    return AMDGPU::V_CMP_NE_U32_e64;
+  case AMDGPU::S_CMP_GT_U32:
+    return AMDGPU::V_CMP_GT_U32_e64;
+  case AMDGPU::S_CMP_GE_U32:
+    return AMDGPU::V_CMP_GE_U32_e64;
+  case AMDGPU::S_CMP_LT_U32:
+    return AMDGPU::V_CMP_LT_U32_e64;
+  case AMDGPU::S_CMP_LE_U32:
+    return AMDGPU::V_CMP_LE_U32_e64;
+  case AMDGPU::S_CMP_EQ_U64:
+    return AMDGPU::V_CMP_EQ_U64_e64;
+  case AMDGPU::S_CMP_LG_U64:
+    return AMDGPU::V_CMP_NE_U64_e64;
+  default:
+    return std::nullopt;
+  }
+}
+
+bool isSCmpPromotableToVCmp(const MachineInstr &MI) {
----------------
arsenm wrote:

llvm style is to prefer static to anonymous namespace 

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