NetBSD/lib/libm/arch/i387/e_expf.S

25 lines
493 B
ArmAsm

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*/
#include <machine/asm.h>
RCSID("$NetBSD: e_expf.S,v 1.3 2000/09/26 07:28:24 kleink Exp $")
/* e^x = 2^(x * log2(e)) */
ENTRY(__ieee754_expf)
flds 4(%esp)
fldl2e
fmulp /* x * log2(e) */
fldl %st(0)
frndint /* int(x * log2(e)) */
fsubr %st(0),%st(1) /* fract(x * log2(e)) */
fxch
f2xm1 /* 2^(fract(x * log2(e))) - 1 */
fld1
faddp /* 2^(fract(x * log2(e))) */
fscale /* e^x */
fstpl %st(1)
ret