[PATCH] D34739: [X86][InlineAsm][Ms Compatibility]Prefer variable name over a register when the two collides

[coby via Phabricator via llvm-commits]

coby created this revision.

On MS-style, the following snippet:

//int eax;
__asm mov eax, ebx//

should yield loading of //ebx//, into the location pointed by the variable //eax//

This patch sees to it.

Currently, a reg-to-reg move would have been invoked.

Clang-side:


Repository:
  rL LLVM

https://reviews.llvm.org/D34739

Files:
  lib/Target/X86/AsmParser/X86AsmParser.cpp


Index: lib/Target/X86/AsmParser/X86AsmParser.cpp
===================================================================
--- lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -944,7 +944,8 @@
   EndLoc = Tok.getEndLoc();
 
   if (Tok.isNot(AsmToken::Identifier)) {
-    if (isParsingIntelSyntax()) return true;
+    if (isParsingIntelSyntax())
+      return true;
     return Error(StartLoc, "invalid register name",
                  SMRange(StartLoc, EndLoc));
   }
@@ -955,6 +956,16 @@
   if (RegNo == 0)
     RegNo = MatchRegisterName(Tok.getString().lower());
 
+  // In MS inline-asm we allow variables to be named as registers, and
+  // give them precedence over actual registers
+  // However - we require the match to be case sensitive
+  if (isParsingInlineAsm() && isParsingIntelSyntax() && RegNo) {
+    StringRef LineBuf(Tok.getIdentifier().data());
+    InlineAsmIdentifierInfo Info;
+    if (SemaCallback->LookupInlineAsmIdentifier(LineBuf, Info, false))
+      return true;
+  }
+
   // The "flags" register cannot be referenced directly.
   // Treat it as an identifier instead.
   if (isParsingInlineAsm() && isParsingIntelSyntax() && RegNo == X86::EFLAGS)


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