Re: PATCH: Enable TFmode for x86

["Uros Bizjak" <ubizjak at gmail dot com>]

On Mon, Jun 30, 2008 at 2:09 AM, H.J. Lu <hjl.tools@gmail.com> wrote:

> Here is the updated patch.

> +#define __FP_FRAC_ADD_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0)           \
> +  do {                                                                         \
> +    __asm__ volatile("addl %5,%1; adcl %3,%0"                          \
> +                    : "=r"(r1), "=r"(r0)                               \
> +                    : "%0"(x1), "g"(y1), "%1"(x0), "g"(y0)             \
> +                    : "cc");                                           \
> +    __asm__ volatile("adcl %5,%1; adcl %3,%0"                          \
> +                    : "=r"(r3), "=r"(r2)                               \
> +                    : "%0"(x3), "g"(y3), "%1"(x2), "g"(y2)             \
> +                    : "cc");                                           \
> +  } while (0)

This is wrong, carry flag propagation is broken between these two asm
insns. Also, clobbers should be added (please look at attached
source).

> +#define _i386_div_64_32(q, r, nh, nl, d)                               \
> +  __asm__ ("divl %4" : "=a"(q), "=d"(r) : "0"(nl), "1"(nh), "g"(d) : "cc")

The definition above is also unused and should be removed. udiv_qrnnd
from longlong.h is used by default through soft-fp sources.

Attached to this message, please find definitions of
__FP_FRAC_{ADD,SUB}_{3,4} macros, together with a test application.

Uros.

Attachment: frac.c
Description: Binary data