[llvm] [TableGen] Add a backend to generate MacroFusion predicators (PR #72222)

[Craig Topper via llvm-commits]

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@@ -0,0 +1,177 @@
+//===--- MacroFusionPredicatorEmitter.cpp - Generator for MacroFusion ----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// MacroFusionPredicatorEmitter implements a TableGen-driven predicators
+// generator for MacroFusion.
+//
+//===---------------------------------------------------------------------===//
+
+#include "CodeGenTarget.h"
+#include "PredicateExpander.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/TableGen/Error.h"
+#include "llvm/TableGen/Record.h"
+#include "llvm/TableGen/TableGenBackend.h"
+#include <set>
+#include <vector>
+
+using namespace llvm;
+
+#define DEBUG_TYPE "macro-fusion-predicator"
+
+namespace {
+class MacroFusionPredicatorEmitter {
+  RecordKeeper &Records;
+  CodeGenTarget Target;
+
+  void emitMacroFusionDecl(std::vector<Record *> MacroFusions,
+                           PredicateExpander &PE, raw_ostream &OS);
+  void emitMacroFusionImpl(std::vector<Record *> MacroFusions,
+                           PredicateExpander &PE, raw_ostream &OS);
+  void emitFirstPredicate(Record *FirstPredicate, PredicateExpander &PE,
+                          raw_ostream &OS);
+  void emitSecondPredicate(Record *SecondPredicate, PredicateExpander &PE,
+                           raw_ostream &OS);
+  void emitPrologAndEpilog(std::vector<Record *> Predicates,
+                           PredicateExpander &PE, raw_ostream &OS);
+
+public:
+  MacroFusionPredicatorEmitter(RecordKeeper &R) : Records(R), Target(R) {}
+
+  void run(raw_ostream &OS);
+};
+} // End anonymous namespace.
+
+void MacroFusionPredicatorEmitter::emitMacroFusionDecl(
+    std::vector<Record *> MacroFusions, PredicateExpander &PE,
+    raw_ostream &OS) {
+  OS << "#ifdef GET_" << Target.getName() << "_MACRO_FUSION_PRED_DECL\n\n";
+
+  for (Record *MacroFusion : MacroFusions) {
+    OS << "bool is" << MacroFusion->getName() << "(const TargetInstrInfo &, "
+       << "const TargetSubtargetInfo &, "
+       << "const MachineInstr *, "
+       << "const MachineInstr &);\n";
+  }
+
+  OS << "\n#endif\n";
+  OS << "#undef GET_" << Target.getName() << "_MACRO_FUSION_PRED_DECL\n";
+}
+
+void MacroFusionPredicatorEmitter::emitMacroFusionImpl(
+    std::vector<Record *> MacroFusions, PredicateExpander &PE,
+    raw_ostream &OS) {
+  OS << "#ifdef GET_" << Target.getName() << "_MACRO_FUSION_PRED_IMPL\n\n";
+
+  for (Record *MacroFusion : MacroFusions) {
+    Record *First = MacroFusion->getValueAsDef("First");
+    Record *Second = MacroFusion->getValueAsDef("Second");
+    std::vector<Record *> Prolog = MacroFusion->getValueAsListOfDefs("Prolog");
+    std::vector<Record *> Epilog = MacroFusion->getValueAsListOfDefs("Epilog");
+
+    OS << "bool is" << MacroFusion->getName() << "(\n";
+    OS.indent(5) << "const TargetInstrInfo &TII,\n";
+    OS.indent(5) << "const TargetSubtargetInfo &STI,\n";
+    OS.indent(5) << "const MachineInstr *FirstMI,\n";
+    OS.indent(5) << "const MachineInstr &SecondMI) {\n";
+    OS.indent(2) << "auto &MRI = SecondMI.getMF()->getRegInfo();\n";
+
+    emitFirstPredicate(First, PE, OS);
+    emitSecondPredicate(Second, PE, OS);
+
+    if (!Prolog.empty())
+      emitPrologAndEpilog(Prolog, PE, OS);
+
+    OS.indent(2) << "if(!matchFirst(FirstMI))\n";
+    OS.indent(2) << "  return false;\n";
+    OS.indent(2) << "if(!matchSecond(&SecondMI))\n";
+    OS.indent(2) << "  return false;\n";
+
+    if (!Epilog.empty())
+      emitPrologAndEpilog(Epilog, PE, OS);
+
+    OS.indent(2) << "return true;\n";
+    OS << "}\n";
+  }
+
+  OS << "\n#endif\n";
+  OS << "#undef GET_" << Target.getName() << "_MACRO_FUSION_PRED_IMPL\n\n";
+}
+
+void MacroFusionPredicatorEmitter::emitFirstPredicate(Record *FirstPredicate,
+                                                      PredicateExpander &PE,
+                                                      raw_ostream &OS) {
+
+  OS.indent(2) << "auto matchFirst = [&](const MachineInstr* MI) {\n";
----------------
topperc wrote:

`const MachineInstr *MI`

https://github.com/llvm/llvm-project/pull/72222