"--emit asm" uses different syntax than `asm!` on x86

[RalfJung]

Rust inline assembly expects to be written like this:

    crate::arch::asm!(
        "movntps [{mem_addr}], {a}",
        mem_addr = in(reg) mem_addr,
        a = in(xmm_reg) a,
    );

However, when dumping the output assembly via --emit asm, it looks like this:

	movntps	%xmm0, (%rdi)

Operand order is swapped, and it's using (%name) instead of [name]. I guess one is AT&T syntax and one is Intel syntax.

Would be good if Rust could be consistent with its own inline asm syntax. :)

[clubby789]

cc #48011

[shepmaster]

Presumably this is an x86-only issue. To the best of my knowledge, only that architecture has both formats.

Additionally, there's a att_syntax flag you can pass, so theoretically the issue is "just" that the defaults of the two differ.

[RalfJung]

Presumably this is an x86-only issue. To the best of my knowledge, only that architecture has both formats.

I sure hope so, this is rather idiotic after all.^^

Additionally, there's a att_syntax flag you can pass, so theoretically the issue is "just" that the defaults of the two differ.

That also requires (a) knowing that there are two syntaxes, and (b) knowing the flag to switch between them.