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e_expf.S revision 1.2 
      1 /*
      2  * Written by J.T. Conklin <jtc (at) netbsd.org>.
      3  * Public domain.
      4  */
      5 
      6 #include <machine/asm.h>
      7 
      8 RCSID("$NetBSD: e_expf.S,v 1.2 1999/07/02 15:37:34 simonb Exp $")
      9 
     10 /* e^x = 2^(x * log2(e)) */
     11 ENTRY(__ieee754_expf)
     12 	flds	4(%esp)
     13 	fldl2e
     14 	fmulp				/* x * log2(e) */
     15 	fstl	%st(1)
     16 	frndint				/* int(x * log2(e)) */
     17 	fstl	%st(2)
     18 	fsubrp				/* fract(x * log2(e)) */
     19 	f2xm1				/* 2^(fract(x * log2(e))) - 1 */
     20 	fld1
     21 	faddp				/* 2^(fract(x * log2(e))) */
     22 	fscale				/* e^x */
     23 	fstpl	%st(1)
     24 	ret
     25