On 6/4/14, Mark Kettenis <mark.kette...@xs4all.nl> wrote:
>> Date: Mon, 2 Jun 2014 21:18:26 -0400
>> From: Daniel Dickman <didick...@gmail.com>
>>
>> >
>> > Another bug. Intel chose an extended precision format with an
>> > explicit integer bit, and the code doesn't handle that. Assuming we
>> > don't support machines with extended precision format that have an
>> > implicit integer bit, the following diff (an adaptation of the code in
>> > glibc) should fix things. Not entirely happy with the fix though, so
>> > I'm still thinking about improvements.
>>
>> confirming that this patch fixes the failing numpy regress test on i386.
>>
>> let me know if you want me to test a different diff.
>
> Here's a better diff, inspired by what FreeBSD has.
>
> ok?
I like it better than the other diff; OK martynas@.
> Index: s_nextafterl.c
> ===================================================================
> RCS file: /cvs/src/lib/libm/src/ld80/s_nextafterl.c,v
> retrieving revision 1.4
> diff -u -p -r1.4 s_nextafterl.c
> --- s_nextafterl.c 12 Nov 2013 21:07:28 -0000 1.4
> +++ s_nextafterl.c 4 Jun 2014 10:05:17 -0000
> @@ -32,8 +32,8 @@ nextafterl(long double x, long double y)
> ix = esx&0x7fff; /* |x| */
> iy = esy&0x7fff; /* |y| */
>
> - if (((ix==0x7fff)&&((hx|lx)!=0)) || /* x is nan */
> - ((iy==0x7fff)&&((hy|ly)!=0))) /* y is nan */
> + if (((ix==0x7fff)&&((hx&0x7fffffff|lx)!=0)) || /* x is nan */
> + ((iy==0x7fff)&&((hy&0x7fffffff|ly)!=0))) /* y is nan */
> return x+y;
> if(x==y) return y; /* x=y, return y */
> if((ix|hx|lx)==0) { /* x == 0 */
> @@ -47,31 +47,30 @@ nextafterl(long double x, long double y)
> if(ix>iy||((ix==iy) && (hx>hy||((hx==hy)&&(lx>ly))))) {
> /* x > y, x -= ulp */
> if(lx==0) {
> - if (hx==0) esx -= 1;
> - hx -= 1;
> + if ((hx&0x7fffffff)==0) esx -= 1;
> + hx = (hx - 1) | (hx & 0x80000000);
> }
> lx -= 1;
> } else { /* x < y, x += ulp */
> lx += 1;
> if(lx==0) {
> - hx += 1;
> - if (hx==0)
> - esx += 1;
> + hx = (hx + 1) | (hx & 0x80000000);
> + if ((hx&0x7fffffff)==0) esx += 1;
> }
> }
> } else { /* x < 0 */
> if(esy>=0||(ix>iy||((ix==iy)&&(hx>hy||((hx==hy)&&(lx>ly)))))){
> /* x < y, x -= ulp */
> if(lx==0) {
> - if (hx==0) esx -= 1;
> - hx -= 1;
> + if ((hx&0x7fffffff)==0) esx -= 1;
> + hx = (hx - 1) | (hx & 0x80000000);
> }
> lx -= 1;
> } else { /* x > y, x += ulp */
> lx += 1;
> if(lx==0) {
> - hx += 1;
> - if (hx==0) esx += 1;
> + hx = (hx + 1) | (hx & 0x80000000);
> + if ((hx&0x7fffffff)==0) esx += 1;
> }
> }
> }
>
