[llvm-dev] PR36144: X86 Intel syntax and masm flavor

[Francis Visoiu Mistrih via llvm-dev]

Hi,

We have a significant regression since llvm 5.0.0 in the x86 assembler.

The following snippets fail:

1)

.intel_syntax
0:
  jmp 0b

2)

.intel_syntax
  and edi, 0b010101

when running through `llvm-mc -arch x86-64`.

This regression was introduced in r301390, which was driven by PR27884.

I think https://llvm.org/PR36144 describes this very well, and I think we should
get this fixed, since it's a pretty basic thing to support in the assembler.

Here are a few solutions to this:

1) Introduce a new asm dialect/flavor/style to assemble masm files.

2) Only set the flags based on the target triple. Also suggested in PR27884.

3) Only set the flags based on a new command line flag.

Let me know if any other solution comes to mind.

While we get this issue fixed, is it reasonable to revert r301390?

Thanks,

-- 
Francis