Implement support for printing register and immediate operands,

add support for darwin vs aix syntax.  We now can print instructions
like this:

	add r3, r3, r4
	blr 

and (in aix mode):
	add 3, 3, 4
	blr 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119062 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp

@@ -13,9 +13,9 @@
 
 #define DEBUG_TYPE "asm-printer"
 #include "PPCInstPrinter.h"
+#include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
 //#include "llvm/MC/MCAsmInfo.h"
-//#include "llvm/MC/MCExpr.h"
 //#include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/raw_ostream.h"
 
@@ -39,3 +39,38 @@ void PPCInstPrinter::printInst(const MCInst *MI, raw_ostream &O) {
   printInstruction(MI, O);
 }
 
+/// stripRegisterPrefix - This method strips the character prefix from a
+/// register name so that only the number is left.  Used by for linux asm.
+const char *stripRegisterPrefix(const char *RegName) {
+  switch (RegName[0]) {
+  case 'r':
+  case 'f':
+  case 'v': return RegName + 1;
+  case 'c': if (RegName[1] == 'r') return RegName + 2;
+  }
+  
+  return RegName;
+}
+
+void PPCInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
+                                  raw_ostream &O) {
+  const MCOperand &Op = MI->getOperand(OpNo);
+  if (Op.isReg()) {
+    const char *RegName = getRegisterName(Op.getReg());
+    // The linux and AIX assembler does not take register prefixes.
+    if (!isDarwinSyntax())
+      RegName = stripRegisterPrefix(RegName);
+    
+    O << RegName;
+    return;
+  }
+  
+  if (Op.isImm()) {
+    O << Op.getImm();
+    return;
+  }
+  
+  assert(Op.isExpr() && "unknown operand kind in printOperand");
+  O << *Op.getExpr();
+}
+  

lib/Target/PowerPC/InstPrinter/PPCInstPrinter.h

@@ -20,8 +20,15 @@ namespace llvm {
   class MCOperand;
 
 class PPCInstPrinter : public MCInstPrinter {
+  // 0 -> AIX, 1 -> Darwin.
+  unsigned SyntaxVariant;
 public:
-  PPCInstPrinter(const MCAsmInfo &MAI) : MCInstPrinter(MAI) {}
+  PPCInstPrinter(const MCAsmInfo &MAI, unsigned syntaxVariant)
+    : MCInstPrinter(MAI), SyntaxVariant(syntaxVariant) {}
+  
+  bool isDarwinSyntax() const {
+    return SyntaxVariant == 1;
+  }
   
   virtual void printInst(const MCInst *MI, raw_ostream &O);
   virtual StringRef getOpcodeName(unsigned Opcode) const;
@@ -33,7 +40,7 @@ public:
   static const char *getRegisterName(unsigned RegNo);
   
 
-  void printOperand(const MCInst *MI, unsigned OpNo, raw_ostream &O) {}
+  void printOperand(const MCInst *MI, unsigned OpNo, raw_ostream &O);
   void printPredicateOperand(const MCInst *MI, unsigned OpNo,
                              raw_ostream &O, const char *Modifier) {}
 

lib/Target/PowerPC/PPCAsmPrinter.cpp

@@ -939,9 +939,7 @@ static AsmPrinter *createPPCAsmPrinterPass(TargetMachine &tm,
 static MCInstPrinter *createPPCMCInstPrinter(const Target &T,
                                              unsigned SyntaxVariant,
                                              const MCAsmInfo &MAI) {
-  if (SyntaxVariant == 0)
-    return new PPCInstPrinter(MAI);
-  return 0;
+  return new PPCInstPrinter(MAI, SyntaxVariant);
 }