Re: [Tinycc-devel] lcall invalid hex code

[Michael Matz]

Hi,
On Tue, 3 May 2016, Sergey Korshunoff wrote:

> > Fixed in mob, plus some more asm bugs (32 and 64 bit).
>
> ALT(DEF_ASM_OP1(lcall, 0xff, 3, OPC_MODRM, OPT_EA))        1) or
> ALT(DEF_ASM_OP1(lcall, 0xff, 3, OPC_MODRM, OPT_INDIR))    2) ?

The first one.  Look at the handling of OPT_INDIR, it's a no-op in tccs 
sources.  Note that OPT_INDIR can be or-ed with anything else, so 
OPT_EA|OPT_INDIR is also okay, though it won't change much.

> A test code:
> static unsigned long bios32_service(unsigned long service)
> {
>    int return_code;
>    __asm__("lcall *(%%edi); cld"
>        : "=a" (return_code)
>        : "0" (service),
>          "D" (&bios32_indirect));
>    __asm__("lcall (%%edi); cld"
>        : "=a" (return_code)
>        : "0" (service),
>          "D" (&bios32_indirect));
> }
>
> gcc/as prints warning for second case (indirect call w/o *). tcc with
> 1) accept all cases 2) don't accept second case (error:).
>
> I looked at the "call" opcode 0xff modifiers
> ALT(DEF_ASM_OP1(call, 0xff, 2, OPC_MODRM, OPT_INDIR))

That should be |OPT_EA as well I think.


Ciao,
Michael.