glibc/sysdeps/i386/fpu/s_log1pl.S
2012-02-07 00:41:11 +01:00

74 lines
1.2 KiB
ArmAsm

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*
* Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
*/
#include <machine/asm.h>
RCSID("$NetBSD: s_log1p.S,v 1.7 1995/05/09 00:10:58 jtc Exp $")
.section .rodata
.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
/*
* 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)
#ifdef PIC
LOAD_PIC_REG (dx)
#endif
fxam
fnstsw
fld %st
sahf
jc 3f // in case x is NaN or ±Inf
4:
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
2: fyl2xp1
ret
3: jp 4b // in case x is ±Inf
fstp %st(1)
fstp %st(1)
ret
END (__log1pl)
weak_alias (__log1pl, log1pl)