Re: [Tinycc-devel] tccasm mov instruction

[Michael Matz]

Hi,

On Mon, 20 Feb 2017, grischka wrote:

> The good news:  we got debug line output with asm to create
> mixed output as below.

Yeah, noticed that.  Nice :)

> p0:
>    movslq %eax, %rcx
>   0:    48                      rex.W
>   1:    48 63 c8                movslq %eax,%rcx
>    mov $0x12345678,%eax
>   4:    b8 78 56 34 12          mov    $0x12345678,%eax
>    mov $0x12345678,%rax
>   9:    48 b8 78 56 34 12 48    movabs $0xffffb84812345678,%rax
>  10:    b8 ff ff
>    mov $0x123456789abcdef0,%rax
>  13:    ff                      (bad)
>  14:    ff 90 90 90 90 90       callq  *-0x6f6f6f70(%rax)
>
> Could you look at this?

Whoops!  Avoidance of mov im32->reg64 didn't work for rax and hardcoding 
REX in the opcode directly defeats an generated REX prefix from operands.
This (and some other similar opcodes) fixed in mob.  Thanks for noticing.
(Interestingly the linux kernel at least doesn't trip over this, always 
got lucky with either not using rax or the instructions in question).


Ciao,
Michael.