[TableGen] Fix wrong codegen of BothFusionPredicateWithMCInstPredicate (#83990)

We should generate the `MCInstPredicate` twice, one with `FirstMI`
and another with `SecondMI`.

Author: wangpc-pp

llvm/include/llvm/Target/TargetSchedule.td

@@ -617,7 +617,7 @@ class SecondFusionPredicateWithMCInstPredicate<MCInstPredicate pred>
   : FusionPredicateWithMCInstPredicate<second_fusion_target, pred>;
 // The pred will be applied on both firstMI and secondMI.
 class BothFusionPredicateWithMCInstPredicate<MCInstPredicate pred>
-  : FusionPredicateWithMCInstPredicate<second_fusion_target, pred>;
+  : FusionPredicateWithMCInstPredicate<both_fusion_target, pred>;
 
 // Tie firstOpIdx and secondOpIdx. The operand of `FirstMI` at position
 // `firstOpIdx` should be the same as the operand of `SecondMI` at position

llvm/test/TableGen/MacroFusion.td

@@ -34,6 +34,11 @@ let Namespace = "Test" in {
 def Inst0 : TestInst<0>;
 def Inst1 : TestInst<1>;
 
+def BothFusionPredicate: BothFusionPredicateWithMCInstPredicate<CheckRegOperand<0, X0>>;
+def TestBothFusionPredicate: Fusion<"test-both-fusion-predicate", "HasBothFusionPredicate",
+                                    "Test BothFusionPredicate",
+                                    [BothFusionPredicate]>;
+
 def TestFusion: SimpleFusion<"test-fusion", "HasTestFusion", "Test Fusion",
                              CheckOpcode<[Inst0]>,
                              CheckAll<[
@@ -45,6 +50,7 @@ def TestFusion: SimpleFusion<"test-fusion", "HasTestFusion", "Test Fusion",
 // CHECK-PREDICATOR-NEXT:  #undef GET_Test_MACRO_FUSION_PRED_DECL
 // CHECK-PREDICATOR-EMPTY:
 // CHECK-PREDICATOR-NEXT:  namespace llvm {
+// CHECK-PREDICATOR-NEXT:  bool isTestBothFusionPredicate(const TargetInstrInfo &, const TargetSubtargetInfo &, const MachineInstr *, const MachineInstr &);
 // CHECK-PREDICATOR-NEXT:  bool isTestFusion(const TargetInstrInfo &, const TargetSubtargetInfo &, const MachineInstr *, const MachineInstr &);
 // CHECK-PREDICATOR-NEXT:  } // end namespace llvm
 // CHECK-PREDICATOR-EMPTY:
@@ -54,6 +60,24 @@ def TestFusion: SimpleFusion<"test-fusion", "HasTestFusion", "Test Fusion",
 // CHECK-PREDICATOR-NEXT:  #undef GET_Test_MACRO_FUSION_PRED_IMPL
 // CHECK-PREDICATOR-EMPTY:
 // CHECK-PREDICATOR-NEXT:  namespace llvm {
+// CHECK-PREDICATOR-NEXT:  bool isTestBothFusionPredicate(
+// CHECK-PREDICATOR-NEXT:      const TargetInstrInfo &TII,
+// CHECK-PREDICATOR-NEXT:      const TargetSubtargetInfo &STI,
+// CHECK-PREDICATOR-NEXT:      const MachineInstr *FirstMI,
+// CHECK-PREDICATOR-NEXT:      const MachineInstr &SecondMI) {
+// CHECK-PREDICATOR-NEXT:    auto &MRI = SecondMI.getMF()->getRegInfo();
+// CHECK-PREDICATOR-NEXT:    {
+// CHECK-PREDICATOR-NEXT:      const MachineInstr *MI = FirstMI;
+// CHECK-PREDICATOR-NEXT:      if (MI->getOperand(0).getReg() != Test::X0)
+// CHECK-PREDICATOR-NEXT:        return false;
+// CHECK-PREDICATOR-NEXT:    }
+// CHECK-PREDICATOR-NEXT:    {
+// CHECK-PREDICATOR-NEXT:      const MachineInstr *MI = &SecondMI;
+// CHECK-PREDICATOR-NEXT:      if (MI->getOperand(0).getReg() != Test::X0)
+// CHECK-PREDICATOR-NEXT:        return false;
+// CHECK-PREDICATOR-NEXT:    }
+// CHECK-PREDICATOR-NEXT:    return true;
+// CHECK-PREDICATOR-NEXT:  }
 // CHECK-PREDICATOR-NEXT:  bool isTestFusion(
 // CHECK-PREDICATOR-NEXT:      const TargetInstrInfo &TII,
 // CHECK-PREDICATOR-NEXT:      const TargetSubtargetInfo &STI,
@@ -106,6 +130,7 @@ def TestFusion: SimpleFusion<"test-fusion", "HasTestFusion", "Test Fusion",
 
 // CHECK-SUBTARGET:      std::vector<MacroFusionPredTy> TestGenSubtargetInfo::getMacroFusions() const {
 // CHECK-SUBTARGET-NEXT:   std::vector<MacroFusionPredTy> Fusions;
+// CHECK-SUBTARGET-NEXT:   if (hasFeature(Test::TestBothFusionPredicate)) Fusions.push_back(llvm::isTestBothFusionPredicate); 
 // CHECK-SUBTARGET-NEXT:   if (hasFeature(Test::TestFusion)) Fusions.push_back(llvm::isTestFusion);
 // CHECK-SUBTARGET-NEXT:   return Fusions;
 // CHECK-SUBTARGET-NEXT: }

llvm/utils/TableGen/MacroFusionPredicatorEmitter.cpp

@@ -152,8 +152,7 @@ void MacroFusionPredicatorEmitter::emitFirstPredicate(Record *Predicate,
         << "if (FirstDest.isVirtual() && !MRI.hasOneNonDBGUse(FirstDest))\n";
     OS.indent(4) << "  return false;\n";
     OS.indent(2) << "}\n";
-  } else if (Predicate->isSubClassOf(
-                 "FirstFusionPredicateWithMCInstPredicate")) {
+  } else if (Predicate->isSubClassOf("FusionPredicateWithMCInstPredicate")) {
     OS.indent(2) << "{\n";
     OS.indent(4) << "const MachineInstr *MI = FirstMI;\n";
     OS.indent(4) << "if (";
@@ -173,7 +172,7 @@ void MacroFusionPredicatorEmitter::emitFirstPredicate(Record *Predicate,
 void MacroFusionPredicatorEmitter::emitSecondPredicate(Record *Predicate,
                                                        PredicateExpander &PE,
                                                        raw_ostream &OS) {
-  if (Predicate->isSubClassOf("SecondFusionPredicateWithMCInstPredicate")) {
+  if (Predicate->isSubClassOf("FusionPredicateWithMCInstPredicate")) {
     OS.indent(2) << "{\n";
     OS.indent(4) << "const MachineInstr *MI = &SecondMI;\n";
     OS.indent(4) << "if (";
@@ -185,7 +184,7 @@ void MacroFusionPredicatorEmitter::emitSecondPredicate(Record *Predicate,
     OS.indent(2) << "}\n";
   } else {
     PrintFatalError(Predicate->getLoc(),
-                    "Unsupported predicate for first instruction: " +
+                    "Unsupported predicate for second instruction: " +
                         Predicate->getType()->getAsString());
   }
 }
@@ -196,9 +195,8 @@ void MacroFusionPredicatorEmitter::emitBothPredicate(Record *Predicate,
   if (Predicate->isSubClassOf("FusionPredicateWithCode"))
     OS << Predicate->getValueAsString("Predicate");
   else if (Predicate->isSubClassOf("BothFusionPredicateWithMCInstPredicate")) {
-    Record *MCPred = Predicate->getValueAsDef("Predicate");
-    emitFirstPredicate(MCPred, PE, OS);
-    emitSecondPredicate(MCPred, PE, OS);
+    emitFirstPredicate(Predicate, PE, OS);
+    emitSecondPredicate(Predicate, PE, OS);
   } else if (Predicate->isSubClassOf("TieReg")) {
     int FirstOpIdx = Predicate->getValueAsInt("FirstOpIdx");
     int SecondOpIdx = Predicate->getValueAsInt("SecondOpIdx");