MC/AsmMatcher: Add support for custom conversion functions.

llvm-svn: 124870

2 files changed, 27 insertions, 1 deletions

diff --git a/llvm/include/llvm/Target/Target.td b/llvm/include/llvm/Target/Target.td
index 1bc00b610e5..82628a148b0 100644
--- a/llvm/include/llvm/Target/Target.td
+++ b/llvm/include/llvm/Target/Target.td
@@ -248,6 +248,13 @@ class Instruction {
 
   /// Target-specific flags. This becomes the TSFlags field in TargetInstrDesc.
   bits<64> TSFlags = 0;
+
+  ///@name Assembler Parser Support
+  ///@{
+
+  string AsmMatchConverter = "";
+
+  ///@}
 }
 
 /// Predicates - These are extra conditionals which are turned into instruction
diff --git a/llvm/utils/TableGen/AsmMatcherEmitter.cpp b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
index 76904de7513..806f5d22246 100644
--- a/llvm/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
@@ -1388,6 +1388,26 @@ static void EmitConvertToMCInst(CodeGenTarget &Target,
          ie = Infos.end(); it != ie; ++it) {
     MatchableInfo &II = **it;
 
+    // Check if we have a custom match function.
+    StringRef AsmMatchConverter = II.getResultInst()->TheDef->getValueAsString(
+      "AsmMatchConverter");
+    if (!AsmMatchConverter.empty()) {
+      std::string Signature = "ConvertCustom_" + AsmMatchConverter.str();
+      II.ConversionFnKind = Signature;
+
+      // Check if we have already generated this signature.
+      if (!GeneratedFns.insert(Signature).second)
+        continue;
+
+      // If not, emit it now.  Add to the enum list.
+      OS << "  " << Signature << ",\n";
+
+      CvtOS << "  case " << Signature << ":\n";
+      CvtOS << "    " << AsmMatchConverter << "(Inst, Opcode, Operands);\n";
+      CvtOS << "    return;\n";
+      continue;
+    }
+
     // Build the conversion function signature.
     std::string Signature = "Convert";
     std::string CaseBody;
@@ -1988,7 +2008,6 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
        it != ie; ++it) {
     MatchableInfo &II = **it;
 
-
     OS << "  { " << Target.getName() << "::"
        << II.getResultInst()->TheDef->getName() << ", \"" << II.Mnemonic << "\""
        << ", " << II.ConversionFnKind << ", { ";