generalize my previous operand loc info hack.  If the same operand
is busted for all variants, report it as the location.  This allows
us to get the operand right for bugs like:

t.s:3:12: error: invalid operand for instruction
	outb %al, %gs
	          ^

Even though there are reg/imm and reg/reg forms of this instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113183 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/AsmMatcherEmitter.cpp b/utils/TableGen/AsmMatcherEmitter.cpp
index 238cdd9..7079013 100644
--- a/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/utils/TableGen/AsmMatcherEmitter.cpp
@@ -1684,7 +1684,6 @@
   // Emit code to get the available features.
   OS << "  // Get the current feature set.\n";
   OS << "  unsigned AvailableFeatures = getAvailableFeatures();\n\n";
-  OS << "  ErrorInfo = 0;\n";
 
   // Emit code to compute the class list for this operand vector.
   OS << "  // Eliminate obvious mismatches.\n";
@@ -1714,7 +1713,11 @@
   OS << "  StringRef Mnemonic = ((" << Target.getName()
      << "Operand*)Operands[0])->getToken();\n\n";
 
+  OS << "  // Some state to try to produce better error messages.\n";
   OS << "  bool HadMatchOtherThanFeatures = false;\n\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";
 
   // Emit code to search the table.
   OS << "  // Search the table.\n";
@@ -1738,12 +1741,12 @@
   OS << "    for (unsigned i = 0; i != " << MaxNumOperands << "; ++i) {\n";
   OS << "      if (IsSubclass(Classes[i], it->Classes[i]))\n";
   OS << "        continue;\n";
-  OS << "      // If there is only one instruction with this opcode, report\n";
-  OS << "      // this as an operand error with location info.\n";
-  OS << "      if (MnemonicRange.first+1 == ie) {\n";
+  OS << "      // If this operand is broken for all of the instances of this\n";
+  OS << "      // mnemonic, keep track of it so we can report loc info.\n";
+  OS << "      if (it == MnemonicRange.first || ErrorInfo == i+1)\n";
   OS << "        ErrorInfo = i+1;\n";
-  OS << "        return Match_InvalidOperand;\n";
-  OS << "      }\n";
+  OS << "      else\n";
+  OS << "        ErrorInfo = ~0U;";
   OS << "      // Otherwise, just reject this instance of the mnemonic.\n";
   OS << "      OperandsValid = false;\n";
   OS << "      break;\n";
@@ -1772,7 +1775,6 @@
 
   OS << "  // Okay, we had no match.  Try to return a useful error code.\n";
   OS << "  if (HadMatchOtherThanFeatures) return Match_MissingFeature;\n";
-  OS << "  ErrorInfo = ~0U;\n";
   OS << "  return Match_InvalidOperand;\n";
   OS << "}\n\n";