OS << " bool HadMatchOtherThanFeatures = false;\n";
OS << " bool HadMatchOtherThanPredicate = false;\n";
OS << " unsigned RetCode = Match_InvalidOperand;\n";
+ OS << " unsigned MissingFeatures = ~0U;\n";
OS << " // Set ErrorInfo to the operand that mismatches if it is\n";
OS << " // wrong for all instances of the instruction.\n";
OS << " ErrorInfo = ~0U;\n";
OS << " if ((AvailableFeatures & it->RequiredFeatures) "
<< "!= it->RequiredFeatures) {\n";
OS << " HadMatchOtherThanFeatures = true;\n";
- OS << " ErrorInfo = it->RequiredFeatures & ~AvailableFeatures;\n";
+ OS << " unsigned NewMissingFeatures = it->RequiredFeatures & "
+ "~AvailableFeatures;\n";
+ OS << " if (CountPopulation_32(NewMissingFeatures) <= "
+ "CountPopulation_32(MissingFeatures))\n";
+ OS << " MissingFeatures = NewMissingFeatures;\n";
OS << " continue;\n";
OS << " }\n";
OS << "\n";
OS << " // Okay, we had no match. Try to return a useful error code.\n";
OS << " if (HadMatchOtherThanPredicate || !HadMatchOtherThanFeatures)";
- OS << " return RetCode;\n";
- OS << " assert(ErrorInfo && \"missing feature(s) but what?!\");";
+ OS << " return RetCode;\n";
+ OS << " // Missing feature matches return which features were missing\n";
+ OS << " ErrorInfo = MissingFeatures;\n";
OS << " return Match_MissingFeature;\n";
OS << "}\n\n";