diff options
Diffstat (limited to 'sysdeps/x86_64/fpu/s_log1pl.S')
| -rw-r--r-- | sysdeps/x86_64/fpu/s_log1pl.S | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/sysdeps/x86_64/fpu/s_log1pl.S b/sysdeps/x86_64/fpu/s_log1pl.S new file mode 100644 index 0000000000..7fbd0e5aaa --- /dev/null +++ b/sysdeps/x86_64/fpu/s_log1pl.S @@ -0,0 +1,71 @@ +/* + * Written by J.T. Conklin <jtc@netbsd.org>. + * Public domain. + * + * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>. + * Adapted for x86-64 by Andreas Jaeger <aj@suse.de>. + */ + +#include <machine/asm.h> + +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 + +/* + * Use the fyl2xp1 function when the argument is in the range -0.29 to 0.29, + * otherwise fyl2x with the needed extra computation. + */ +#ifdef PIC +#define MO(op) op##(%rip) +#else +#define MO(op) op +#endif + + .text +ENTRY(__log1pl) + fldln2 + + fldt 8(%rsp) + + fxam + fnstsw + fld %st + andb $1,%ah + jnz 3f // in case x is NaN or ħInf +4: + fabs + fldt MO(limit) + fcompp + fnstsw + andb $1,%ah + jz 2f + + faddl MO(one) + fyl2x + ret + +2: fyl2xp1 + ret + +3: jp 4b // in case x is ħInf + fstp %st(1) + fstp %st(1) + ret + +END (__log1pl) +weak_alias (__log1pl, log1pl) |