[ms] [llvm-ml] Restrict implicit RIP-relative addressing to named-variable references

[epastor]

Summary

ML64.EXE applies implicit RIP-relative addressing only to memory references that include a named-variable reference.

[mstorsjo]

LGTM, the test output seems reasonable to me.

With this, plus D104964 and D104965 I'm able to build the OpenMP assembly file for both i386 and x86_64. (I don't really have a big functional test setup for it though, but it compiles at least, so how wrong could it be?) ;-)

[epastor]

Restrict further to only named-variable references

[epastor]

Rebase on parent

llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp

if ((BaseReg || IndexReg) &&
       CheckBaseRegAndIndexRegAndScale(BaseReg, IndexReg, Scale, is64BitMode(),
                                       ErrMsg))
     return Error(Start, ErrMsg);
   if (isParsingMSInlineAsm())
     return CreateMemForMSInlineAsm(RegNo, Disp, BaseReg, IndexReg, Scale, Start,
                                    End, Size, SM.getSymName(),
                                    SM.getIdentifierInfo(), Operands);
 
-  // When parsing x64 MS-style assembly, all memory operands default to
-  // RIP-relative when interpreted as non-absolute references.
-  if (Parser.isParsingMasm() && is64BitMode()) {
+  // When parsing x64 MS-style assembly, all non-absolute references to a symbol
+  // default to RIP-relative.
+  if (Parser.isParsingMasm() && is64BitMode() && !SM.getSymName().empty()) {
     Operands.push_back(X86Operand::CreateMem(getPointerWidth(), RegNo, Disp,
                                              BaseReg, IndexReg, Scale, Start,
                                              End, Size,
                                              /*DefaultBaseReg=*/X86::RIP));
     return false;
   }
 
   if ((BaseReg || IndexReg || RegNo))

llvm/test/tools/llvm-ml/rip-relative-addressing.asm

-; RUN: llvm-ml -m32 -filetype=s %s /Fo - | FileCheck %s --check-prefix=CHECK-32
-; RUN: llvm-ml -m64 -filetype=s %s /Fo - | FileCheck %s --check-prefix=CHECK-64
+; RUN: llvm-ml -m32 -filetype=s %s /Fo - | FileCheck %s --check-prefixes=CHECK,CHECK-32
+; RUN: llvm-ml -m64 -filetype=s %s /Fo - | FileCheck %s --check-prefixes=CHECK,CHECK-64
+
+.data
+foo DWORD 28
 
 .code
+
+t1:
+mov eax, foo
+; CHECK-LABEL: t1:
+; CHECK-32: mov eax, dword ptr [foo]
+; CHECK-64: mov eax, dword ptr [rip + foo]
+
+t2:
+mov eax, [foo]
+; CHECK-LABEL: t2:
+; CHECK-32: mov eax, dword ptr [foo]
+; CHECK-64: mov eax, dword ptr [rip + foo]
+
+t3:
+mov eax, [foo+2]
+; CHECK-LABEL: t3:
+; CHECK-32: mov eax, dword ptr [foo+2]
+; CHECK-64: mov eax, dword ptr [rip + foo+2]
+
+t4:
+mov eax, [2+foo]
+; CHECK-LABEL: t4:
+; CHECK-32: mov eax, dword ptr [foo+2]
+; CHECK-64: mov eax, dword ptr [rip + foo+2]
+
+t5:
 mov eax, [4]
-; CHECK-32: mov eax, dword ptr [4]
-; CHECK-64: mov eax, dword ptr [rip + 4]
+; CHECK-LABEL: t5:
+; CHECK: mov eax, dword ptr [4]
+
 END
 No newline at end of file