diff options
Diffstat (limited to 'sysdeps/libm-i387/s_log1pl.S')
| -rw-r--r-- | sysdeps/libm-i387/s_log1pl.S | 60 |
1 files changed, 51 insertions, 9 deletions
diff --git a/sysdeps/libm-i387/s_log1pl.S b/sysdeps/libm-i387/s_log1pl.S index 647e136413..05a17b2831 100644 --- a/sysdeps/libm-i387/s_log1pl.S +++ b/sysdeps/libm-i387/s_log1pl.S @@ -7,20 +7,62 @@ #include <machine/asm.h> -RCSID("$NetBSD: $") +RCSID("$NetBSD: s_log1p.S,v 1.7 1995/05/09 00:10:58 jtc Exp $") + +#ifdef __ELF__ + .section .rodata +#else + .text +#endif + .align ALIGNARG(4) + /* The fyl2xp1 can only be used for values in + -1 + sqrt(2) / 2 <= x <= 1 - sqrt(2) / 2 + 0.29 is a safe value. + */ +limit: .tfloat 0.29 + /* Please note: we use a double value here. Since 1.0 has + an exact representation this does not effect the accuracy + but it helps to optimize the code. */ +one: .double 1.0 /* - * Since the fyl2xp1 instruction has such a limited range: - * -(1 - (sqrt(2) / 2)) <= x <= sqrt(2) - 1 - * it's not worth trying to use it. + * Use the fyl2xp1 function when the argument is in the range -0.29 to 0.29, + * otherwise fyl2x with the needed extra computation. */ - + .text ENTRY(__log1pl) fldln2 - fldt 4(%esp) - fld1 - faddp + + fldt 4(%esp) + +#ifdef PIC + call 1f +1: popl %edx + addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %edx +#endif + + fld %st + fabs +#ifdef PIC + fldt limit@GOTOFF(%edx) +#else + fldt limit +#endif + fcompp + fnstsw + sahf + jnc 2f + +#ifdef PIC + faddl one@GOTOFF(%edx) +#else + faddl one +#endif fyl2x ret -PSEUDO_END (__log1pl) + +2: fyl2xp1 + ret + +END (__log1pl) weak_alias (__log1pl, log1pl) |