[llvm] [AMDGPU] Filter candidates of LiveRegOptimizer for profitable cases (PR #124624)

[Jeffrey Byrnes via llvm-commits]

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@@ -125,6 +127,117 @@ class LiveRegOptimizer {
     return LK.first != TargetLoweringBase::TypeLegal;
   }
 
+  /// Check if intrinsic natively operates on 8-bit or 16-bit
+  bool isNativeIntrinsic(Intrinsic::ID ID) {
+    switch (ID) {
+    case Intrinsic::amdgcn_dot4_f32_fp8_bf8:
+    case Intrinsic::amdgcn_dot4_f32_bf8_fp8:
+    case Intrinsic::amdgcn_dot4_f32_fp8_fp8:
+    case Intrinsic::amdgcn_dot4_f32_bf8_bf8:
+    case Intrinsic::amdgcn_mfma_i32_4x4x4i8:
+    case Intrinsic::amdgcn_mfma_i32_16x16x4i8:
+    case Intrinsic::amdgcn_mfma_i32_32x32x4i8:
+    case Intrinsic::amdgcn_mfma_i32_16x16x16i8:
+    case Intrinsic::amdgcn_mfma_i32_32x32x8i8:
+    case Intrinsic::amdgcn_mfma_i32_16x16x64_i8:
+    case Intrinsic::amdgcn_mfma_i32_32x32x32_i8:
+    case Intrinsic::amdgcn_mfma_i32_32x32x16_i8:
+    case Intrinsic::amdgcn_mfma_i32_16x16x32_i8:
+    case Intrinsic::amdgcn_mfma_f32_16x16x32_bf8_bf8:
+    case Intrinsic::amdgcn_mfma_f32_16x16x32_bf8_fp8:
+    case Intrinsic::amdgcn_mfma_f32_16x16x32_fp8_bf8:
+    case Intrinsic::amdgcn_mfma_f32_16x16x32_fp8_fp8:
+    case Intrinsic::amdgcn_mfma_f32_32x32x16_bf8_bf8:
+    case Intrinsic::amdgcn_mfma_f32_32x32x16_bf8_fp8:
+    case Intrinsic::amdgcn_mfma_f32_32x32x16_fp8_bf8:
+    case Intrinsic::amdgcn_mfma_f32_32x32x16_fp8_fp8:
+    case Intrinsic::amdgcn_smfmac_i32_16x16x64_i8:
+    case Intrinsic::amdgcn_smfmac_i32_32x32x32_i8:
+    case Intrinsic::amdgcn_smfmac_f32_16x16x64_bf8_bf8:
+    case Intrinsic::amdgcn_smfmac_f32_16x16x64_bf8_fp8:
+    case Intrinsic::amdgcn_smfmac_f32_16x16x64_fp8_bf8:
+    case Intrinsic::amdgcn_smfmac_f32_16x16x64_fp8_fp8:
+    case Intrinsic::amdgcn_smfmac_f32_32x32x32_bf8_bf8:
+    case Intrinsic::amdgcn_smfmac_f32_32x32x32_bf8_fp8:
+    case Intrinsic::amdgcn_smfmac_f32_32x32x32_fp8_bf8:
+    case Intrinsic::amdgcn_smfmac_f32_32x32x32_fp8_fp8:
+    case Intrinsic::amdgcn_smfmac_i32_16x16x128_i8:
+    case Intrinsic::amdgcn_smfmac_i32_32x32x64_i8:
+    case Intrinsic::amdgcn_smfmac_f32_16x16x128_bf8_bf8:
+    case Intrinsic::amdgcn_smfmac_f32_16x16x128_bf8_fp8:
+    case Intrinsic::amdgcn_smfmac_f32_16x16x128_fp8_bf8:
+    case Intrinsic::amdgcn_smfmac_f32_16x16x128_fp8_fp8:
+    case Intrinsic::amdgcn_smfmac_f32_32x32x64_bf8_bf8:
+    case Intrinsic::amdgcn_smfmac_f32_32x32x64_bf8_fp8:
+    case Intrinsic::amdgcn_smfmac_f32_32x32x64_fp8_bf8:
+    case Intrinsic::amdgcn_smfmac_f32_32x32x64_fp8_fp8:
+    case Intrinsic::amdgcn_wmma_f32_16x16x16_fp8_fp8:
+    case Intrinsic::amdgcn_wmma_f32_16x16x16_fp8_bf8:
+    case Intrinsic::amdgcn_wmma_f32_16x16x16_bf8_fp8:
+    case Intrinsic::amdgcn_wmma_f32_16x16x16_bf8_bf8:
+    case Intrinsic::amdgcn_swmmac_f32_16x16x32_fp8_fp8:
+    case Intrinsic::amdgcn_swmmac_f32_16x16x32_fp8_bf8:
+    case Intrinsic::amdgcn_swmmac_f32_16x16x32_bf8_fp8:
+    case Intrinsic::amdgcn_swmmac_f32_16x16x32_bf8_bf8:
+    case Intrinsic::amdgcn_wmma_i32_16x16x16_iu8:
+    case Intrinsic::amdgcn_wmma_i32_16x16x16_iu4:
+    case Intrinsic::amdgcn_wmma_i32_16x16x32_iu4:
+    case Intrinsic::amdgcn_swmmac_i32_16x16x32_iu8:
+    case Intrinsic::amdgcn_swmmac_i32_16x16x32_iu4:
+    case Intrinsic::amdgcn_swmmac_i32_16x16x64_iu4:
+      return true;
+    default:
+      return false;
+    }
+  }
+
+  bool isOpLegal(Instruction *I) {
+    if (const auto Intr = dyn_cast<IntrinsicInst>(I)) {
+      Intrinsic::ID ID = Intr->getIntrinsicID();
+      if (isNativeIntrinsic(ID))
+        return true;
+    }
+    // Stores
+    if (isa<StoreInst>(I))
+      return true;
+    return false;
+  }
+
+  bool isCoercionProfitable(Instruction *II) {
+    SmallPtrSet<Instruction *, 4> CVisited;
+    SmallVector<Instruction *, 4> UserList;
+
+    // Check users for profitable conditions (across block user which can
+    // natively handle the illegal vector).
+    for (User *V : II->users())
+      if (auto *UseInst = dyn_cast<Instruction>(V))
+        UserList.push_back(UseInst);
+
+    auto IsLookThru = [](Instruction *II) {
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jrbyrnes wrote:

Can we also look thru v_perm intrinsic

https://github.com/llvm/llvm-project/pull/124624