[X86] Use addAliasForDirective to support the .word directive (reland)

The X86 asm parser currently has custom parsing logic for .word. Rather than
use this custom logic, we can just use addAliasForDirective to enable the
reuse of AsmParser::parseDirectiveValue.

See also similar changes to Sparc (rL333078), AArch64 (rL333077), and Hexagon
(rL332607) backends.

Differential Revision: https://reviews.llvm.org/D47004

This is a fixed reland of rL336100. This should have been caught in 
pre-commit testing so apologies for the noise.

llvm-svn: 336104

1 files changed, 3 insertions, 25 deletions

diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 86d8ae1fc9b..6a675f96e1c 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -846,7 +846,6 @@ private:
                         const InlineAsmIdentifierInfo &Info);
 
   bool parseDirectiveEven(SMLoc L);
-  bool ParseDirectiveWord(unsigned Size, SMLoc L);
   bool ParseDirectiveCode(StringRef IDVal, SMLoc L);
 
   /// CodeView FPO data directives.
@@ -945,6 +944,8 @@ public:
       : MCTargetAsmParser(Options, sti, mii),  InstInfo(nullptr),
         Code16GCC(false) {
 
+    Parser.addAliasForDirective(".word", ".2byte");
+
     // Initialize the set of available features.
     setAvailableFeatures(ComputeAvailableFeatures(getSTI().getFeatureBits()));
     Instrumentation.reset(
@@ -3264,9 +3265,7 @@ bool X86AsmParser::OmitRegisterFromClobberLists(unsigned RegNo) {
 bool X86AsmParser::ParseDirective(AsmToken DirectiveID) {
   MCAsmParser &Parser = getParser();
   StringRef IDVal = DirectiveID.getIdentifier();
-  if (IDVal == ".word")
-    return ParseDirectiveWord(2, DirectiveID.getLoc());
-  else if (IDVal.startswith(".code"))
+  if (IDVal.startswith(".code"))
     return ParseDirectiveCode(IDVal, DirectiveID.getLoc());
   else if (IDVal.startswith(".att_syntax")) {
     getParser().setParsingInlineAsm(false);
@@ -3327,27 +3326,6 @@ bool X86AsmParser::parseDirectiveEven(SMLoc L) {
     getStreamer().EmitValueToAlignment(2, 0, 1, 0);
   return false;
 }
-/// ParseDirectiveWord
-///  ::= .word [ expression (, expression)* ]
-bool X86AsmParser::ParseDirectiveWord(unsigned Size, SMLoc L) {
-  auto parseOp = [&]() -> bool {
-    const MCExpr *Value;
-    SMLoc ExprLoc = getLexer().getLoc();
-    if (getParser().parseExpression(Value))
-      return true;
-    if (const auto *MCE = dyn_cast<MCConstantExpr>(Value)) {
-      assert(Size <= 8 && "Invalid size");
-      uint64_t IntValue = MCE->getValue();
-      if (!isUIntN(8 * Size, IntValue) && !isIntN(8 * Size, IntValue))
-        return Error(ExprLoc, "literal value out of range for directive");
-      getStreamer().EmitIntValue(IntValue, Size);
-    } else
-      getStreamer().EmitValue(Value, Size, ExprLoc);
-    return false;
-  };
-  parseMany(parseOp);
-  return false;
-}
 
 /// ParseDirectiveCode
 ///  ::= .code16 | .code32 | .code64