1998-06-09 18:24:13 +00:00
|
|
|
/*
|
|
|
|
|
* Written by Ulrich Drepper.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#include <machine/asm.h>
|
|
|
|
|
|
2011-10-12 15:27:51 +00:00
|
|
|
/* 10^x = 2^(x * log2(10)) */
|
1998-06-09 18:24:13 +00:00
|
|
|
ENTRY(__ieee754_exp10f)
|
|
|
|
|
flds 4(%esp)
|
|
|
|
|
/* I added the following ugly construct because exp(+-Inf) resulted
|
|
|
|
|
in NaN. The ugliness results from the bright minds at Intel.
|
|
|
|
|
For the i686 the code can be written better.
|
|
|
|
|
-- drepper@cygnus.com. */
|
|
|
|
|
fxam /* Is NaN or +-Inf? */
|
|
|
|
|
fstsw %ax
|
|
|
|
|
movb $0x45, %dh
|
|
|
|
|
andb %ah, %dh
|
|
|
|
|
cmpb $0x05, %dh
|
|
|
|
|
je 1f /* Is +-Inf, jump. */
|
|
|
|
|
fldl2t
|
|
|
|
|
fmulp /* x * log2(10) */
|
|
|
|
|
fld %st
|
|
|
|
|
frndint /* int(x * log2(10)) */
|
|
|
|
|
fsubr %st,%st(1) /* fract(x * log2(10)) */
|
|
|
|
|
fxch
|
|
|
|
|
f2xm1 /* 2^(fract(x * log2(10))) - 1 */
|
|
|
|
|
fld1
|
|
|
|
|
faddp /* 2^(fract(x * log2(10))) */
|
|
|
|
|
fscale /* e^x */
|
|
|
|
|
fstp %st(1)
|
|
|
|
|
ret
|
|
|
|
|
|
|
|
|
|
1: testl $0x200, %eax /* Test sign. */
|
|
|
|
|
jz 2f /* If positive, jump. */
|
|
|
|
|
fstp %st
|
|
|
|
|
fldz /* Set result to 0. */
|
|
|
|
|
2: ret
|
|
|
|
|
END (__ieee754_exp10f)
|
2011-10-12 15:27:51 +00:00
|
|
|
strong_alias (__ieee754_exp10f, __exp10f_finite)
|
