Twines: Don't allow implicit conversion from integers, this is too tricky.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77605 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/AsmMatcherEmitter.cpp

@@ -17,6 +17,32 @@
 #include "Record.h"
 using namespace llvm;
 
+static std::string FlattenVariants(const std::string &AsmString,
+                                   unsigned Index) {
+  StringRef Cur = AsmString;
+  std::string Res = "";
+  
+  for (;;) {
+    std::pair<StringRef, StringRef> Split = Cur.split('{');
+
+    Res += Split.first;
+    if (Split.second.empty())
+      break;
+
+    std::pair<StringRef, StringRef> Inner = Cur.split('}');
+    StringRef Selection = Inner.first;
+    for (unsigned i = 0; i != Index; ++i)
+      Selection = Selection.split('|').second;
+    Selection = Selection.split('|').first;
+
+    Res += Selection;
+
+    Cur = Inner.second;
+  } 
+
+  return Res;
+}
+
 void AsmMatcherEmitter::run(raw_ostream &OS) {
   CodeGenTarget Target;
   const std::vector<CodeGenRegister> &Registers = Target.getRegisters();
@@ -44,4 +70,29 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
   }
   OS << "  return true;\n";
   OS << "}\n";
+
+  // Emit the function to match instructions.  
+  std::vector<const CodeGenInstruction*> NumberedInstructions;
+  Target.getInstructionsByEnumValue(NumberedInstructions);
+
+  const std::map<std::string, CodeGenInstruction> &Instructions =
+    Target.getInstructions();
+  for (std::map<std::string, CodeGenInstruction>::const_iterator 
+         it = Instructions.begin(), ie = Instructions.end(); it != ie; ++it) {
+    const CodeGenInstruction &CGI = it->second;
+
+    if (it->first != "SUB8rr")
+      continue;
+
+    /*
+def SUB8rr  : I<0x28, MRMDestReg, (outs GR8:$dst), (ins GR8:$src1, GR8:$src2),
+                "sub{b}\t{$src2, $dst|$dst, $src2}",
+                [(set GR8:$dst, (sub GR8:$src1, GR8:$src2)),
+                 (implicit EFLAGS)]>;
+    */
+
+    outs() << it->first << " "
+           << FlattenVariants(CGI.AsmString, 0)
+           << "\n";
+  }
 }