[PATCH] D73227: [ms] [llvm-ml] Use default RIP-relative addressing for x64 MASM.

Wed Apr 1 12:57:21 PDT 2020

thakis added inline comments.

================
Comment at: llvm/lib/Target/X86/AsmParser/X86Operand.h:63
     unsigned BaseReg;
+    unsigned DefaultBaseReg;
     unsigned IndexReg;
----------------
epastor wrote:
> rnk wrote:
> > I'd really like to get by without adding more operand members that don't correspond to parts of the x86 addressing mode.
> Agreed. Unfortunately, the only obvious way to do that would be to match the x64 addressing mode more closely, and assume that all non-absolute memory references lacking a BaseReg are RIP-relative... which would break GNU-style assembly, since they made the decision to enforce explicit RIP-relative referencing.
It sounds like ms-style 64-bit assembly with a msvc triple will already be incompatible with gnu-style assembly, due to the rip-relative differences. Is that incorrect?

If not, I think we should have the GNU mode and the msvc mode here, and not a third kinda-hybrid mode. It sounds like this is currently some hybrid mode.

If needed, we could have the full commandline flag / pragma dance for picking a mode for inline asm and only setting the default mode off the triple if use cases for that emerge, but that can happen later.

(Maybe I misunderstood what you're saying, though.)

Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73227/new/

https://reviews.llvm.org/D73227