[ms-inline asm] Have the TargetParser callback to Sema to determine the size of

a memory operand.  Retain this information and then add the sizing directives
to the IR.  This allows the backend to do proper instruction selection.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166316 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCParser/MCParsedAsmOperand.h

@@ -57,12 +57,17 @@ public:
 
   /// isMem - Is this a memory operand?
   virtual bool isMem() const = 0;
+  virtual unsigned getMemSize() const { return 0; }
 
   /// getStartLoc - Get the location of the first token of this operand.
   virtual SMLoc getStartLoc() const = 0;
   /// getEndLoc - Get the location of the last token of this operand.
   virtual SMLoc getEndLoc() const = 0;
 
+  /// needSizeDirective - Do we need to emit a sizing directive for this
+  /// operand?  Only valid when parsing MS-style inline assembly.
+  virtual bool needSizeDirective() const { return false; }
+
   /// print - Print a debug representation of the operand to the given stream.
   virtual void print(raw_ostream &OS) const = 0;
   /// dump - Print to the debug stream.

lib/MC/MCParser/AsmParser.cpp

@@ -3577,17 +3577,18 @@ namespace {
 enum AsmOpRewriteKind {
    AOK_Imm,
    AOK_Input,
-   AOK_Output
+   AOK_Output,
+   AOK_SizeDirective
 };
 
 struct AsmOpRewrite {
   AsmOpRewriteKind Kind;
   SMLoc Loc;
   unsigned Len;
-
+  unsigned Size;
 public:
-  AsmOpRewrite(AsmOpRewriteKind kind, SMLoc loc, unsigned len)
-    : Kind(kind), Loc(loc), Len(len) { }
+  AsmOpRewrite(AsmOpRewriteKind kind, SMLoc loc, unsigned len, unsigned size = 0)
+    : Kind(kind), Loc(loc), Len(len), Size(size) { }
 };
 }
 
@@ -3650,6 +3651,11 @@ bool AsmParser::ParseMSInlineAsm(void *AsmLoc, std::string &AsmString,
                                                     Size);
         if (OpDecl) {
           bool isOutput = (i == 1) && Desc.mayStore();
+          if (Operand->needSizeDirective())
+            AsmStrRewrites.push_back(AsmOpRewrite(AOK_SizeDirective,
+                                                  Operand->getStartLoc(), 0,
+                                                  Operand->getMemSize()));
+          
           if (isOutput) {
             std::string Constraint = "=";
             ++InputIdx;
@@ -3701,17 +3707,23 @@ bool AsmParser::ParseMSInlineAsm(void *AsmLoc, std::string &AsmString,
 
   // Build the IR assembly string.
   std::string AsmStringIR;
+  AsmOpRewriteKind PrevKind = AOK_Imm;
   raw_string_ostream OS(AsmStringIR);
   const char *Start = SrcMgr.getMemoryBuffer(0)->getBufferStart();
   for (SmallVectorImpl<struct AsmOpRewrite>::iterator
          I = AsmStrRewrites.begin(), E = AsmStrRewrites.end(); I != E; ++I) {
     const char *Loc = (*I).Loc.getPointer();
-    
-    // Emit everything up to the immediate/expression.
-    OS << StringRef(Start, Loc - Start);
-    
+
+    AsmOpRewriteKind Kind = (*I).Kind;
+
+    // Emit everything up to the immediate/expression.  If the previous rewrite
+    // was a size directive, then this has already been done.
+    if (PrevKind != AOK_SizeDirective)
+      OS << StringRef(Start, Loc - Start);
+    PrevKind = Kind;
+
     // Rewrite expressions in $N notation.
-    switch ((*I).Kind) {
+    switch (Kind) {
     case AOK_Imm:
       OS << Twine("$$") + StringRef(Loc, (*I).Len);
       break;
@@ -3723,10 +3735,22 @@ bool AsmParser::ParseMSInlineAsm(void *AsmLoc, std::string &AsmString,
       OS << '$';
       OS << OutputIdx++;
       break;
+    case AOK_SizeDirective:
+      switch((*I).Size) {
+      default: break;
+      case 8:  OS << "byte ptr "; break;
+      case 16: OS << "word ptr "; break;
+      case 32: OS << "dword ptr "; break;
+      case 64: OS << "qword ptr "; break;
+      case 80: OS << "xword ptr "; break;
+      case 128: OS << "xmmword ptr "; break;
+      case 256: OS << "ymmword ptr "; break;
+      }
     }
-    
+
     // Skip the original expression.
-    Start = Loc + (*I).Len;
+    if (Kind != AOK_SizeDirective)
+      Start = Loc + (*I).Len;
   }
 
   // Emit the remainder of the asm string.

lib/Target/X86/AsmParser/X86AsmParser.cpp

@@ -11,6 +11,7 @@
 #include "llvm/MC/MCTargetAsmParser.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSubtargetInfo.h"
@@ -180,6 +181,7 @@ struct X86Operand : public MCParsedAsmOperand {
       unsigned IndexReg;
       unsigned Scale;
       unsigned Size;
+      bool NeedSizeDir;
     } Mem;
   };
 
@@ -312,6 +314,16 @@ struct X86Operand : public MCParsedAsmOperand {
     return isImmSExti64i32Value(CE->getValue());
   }
 
+  unsigned getMemSize() const {
+    assert(Kind == Memory && "Invalid access!");
+    return Mem.Size;
+  }
+
+  bool needSizeDirective() const {
+    assert(Kind == Memory && "Invalid access!");
+    return Mem.NeedSizeDir;
+  }
+
   bool isMem() const { return Kind == Memory; }
   bool isMem8() const {
     return Kind == Memory && (!Mem.Size || Mem.Size == 8);
@@ -451,7 +463,8 @@ struct X86Operand : public MCParsedAsmOperand {
 
   /// Create an absolute memory operand.
   static X86Operand *CreateMem(const MCExpr *Disp, SMLoc StartLoc,
-                               SMLoc EndLoc, unsigned Size = 0) {
+                               SMLoc EndLoc, unsigned Size = 0,
+                               bool NeedSizeDir = false) {
     X86Operand *Res = new X86Operand(Memory, StartLoc, EndLoc);
     Res->Mem.SegReg   = 0;
     Res->Mem.Disp     = Disp;
@@ -459,6 +472,7 @@ struct X86Operand : public MCParsedAsmOperand {
     Res->Mem.IndexReg = 0;
     Res->Mem.Scale    = 1;
     Res->Mem.Size     = Size;
+    Res->Mem.NeedSizeDir = NeedSizeDir;
     return Res;
   }
 
@@ -466,7 +480,7 @@ struct X86Operand : public MCParsedAsmOperand {
   static X86Operand *CreateMem(unsigned SegReg, const MCExpr *Disp,
                                unsigned BaseReg, unsigned IndexReg,
                                unsigned Scale, SMLoc StartLoc, SMLoc EndLoc,
-                               unsigned Size = 0) {
+                               unsigned Size = 0, bool NeedSizeDir = false) {
     // We should never just have a displacement, that should be parsed as an
     // absolute memory operand.
     assert((SegReg || BaseReg || IndexReg) && "Invalid memory operand!");
@@ -481,6 +495,7 @@ struct X86Operand : public MCParsedAsmOperand {
     Res->Mem.IndexReg = IndexReg;
     Res->Mem.Scale    = Scale;
     Res->Mem.Size     = Size;
+    Res->Mem.NeedSizeDir = NeedSizeDir;
     return Res;
   }
 };
@@ -753,7 +768,19 @@ X86Operand *X86AsmParser::ParseIntelMemOperand(unsigned SegReg, SMLoc Start) {
   const MCExpr *Disp = MCConstantExpr::Create(0, getParser().getContext());
   if (getParser().ParseExpression(Disp, End)) return 0;
   End = Parser.getTok().getLoc();
-  return X86Operand::CreateMem(Disp, Start, End, Size);
+
+  bool NeedSizeDir = false;
+  if (!Size && isParsingInlineAsm()) {
+    if (const MCSymbolRefExpr *SymRef = dyn_cast<MCSymbolRefExpr>(Disp)) {
+      const MCSymbol &Sym = SymRef->getSymbol();
+      // FIXME: The SemaLookup will fail if the name is anything other then an
+      // identifier.
+      // FIXME: Pass a valid SMLoc.
+      SemaCallback->LookupInlineAsmIdentifier(Sym.getName(), NULL, Size);
+      NeedSizeDir = Size > 0;
+    }
+  }
+  return X86Operand::CreateMem(Disp, Start, End, Size, NeedSizeDir);
 }
 
 X86Operand *X86AsmParser::ParseIntelOperand() {