[Nasm-devel] problem with vcvtph2pd

[Lukasz Marek]

On Fri, 22 Mar 2024 at 19:30, Henrik Gramner <henrik at gramner.com> wrote:

> On Fri, Mar 22, 2024 at 6:30 PM Henrik Gramner <henrik at gramner.com> wrote:
> >
> > From what I can tell the root cause seems to be at
> >
> https://github.com/netwide-assembler/nasm/blob/master/asm/assemble.c#L2508
> > where opsize == 4 and BITS64 >> SIZE_SHIFT == 8, so the result of the
> > division becomes 0.
> >
> > I don't really understand the logic in this function though so I'm not
> > sure what the correct fix would be.
>
> Fwiw the following seems to fix the issue, but I don't know if there
> are side effects that ends up breaking something else:
>
> --- a/asm/assemble.c
> +++ b/asm/assemble.c
> @@ -2505,7 +2505,7 @@ static uint8_t get_broadcast_num(opflags_t
> opflags, opflags_t brsize)
>       * The shift term is to take care of the extra BITS80 inserted
>       * between BITS64 and BITS128.
>       */
> -    brcast_num = ((opsize / (BITS64 >> SIZE_SHIFT)) * (BITS64 / brsize))
> +    brcast_num = ((opsize / (BITS32 >> SIZE_SHIFT)) * (BITS32 / brsize))
>          >> (opsize > (BITS64 >> SIZE_SHIFT));
>
>      return brcast_num;
>

Thanks for the help. I will test it tomorrow.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.nasm.us/archives/nasm-devel/attachments/20240322/f6b30931/attachment.htm>