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

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/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*/
#include <machine/asm.h>
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RCSID("$NetBSD: e_expf.S,v 1.2 1999/07/02 15:37:34 simonb Exp $")
/* e^x = 2^(x * log2(e)) */
ENTRY(__ieee754_expf)
flds 4(%esp)
fldl2e
fmulp /* x * log2(e) */
fstl %st(1)
frndint /* int(x * log2(e)) */
fstl %st(2)
fsubrp /* fract(x * log2(e)) */
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f2xm1 /* 2^(fract(x * log2(e))) - 1 */
fld1
faddp /* 2^(fract(x * log2(e))) */
fscale /* e^x */
fstpl %st(1)
ret