1994-02-11 21:20:17 +03:00
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/*
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1995-04-29 02:43:31 +04:00
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* Written by J.T. Conklin <jtc@netbsd.org>.
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* Public domain.
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1994-02-11 21:20:17 +03:00
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*/
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#include <machine/asm.h>
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2001-06-19 04:26:29 +04:00
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#include "abi.h"
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RCSID("$NetBSD: e_exp.S,v 1.10 2001/06/19 00:26:30 fvdl Exp $")
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1994-03-12 04:30:22 +03:00
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1994-02-11 21:20:17 +03:00
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/* e^x = 2^(x * log2(e)) */
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ENTRY(__ieee754_exp)
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2001-06-19 04:26:29 +04:00
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#ifdef __i386__
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1996-07-03 21:27:34 +04:00
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pushl %ebp
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movl %esp,%ebp
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subl $8,%esp
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fstcw -12(%ebp) /* store fpu control word */
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movw -12(%ebp),%dx
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orw $0x0180,%dx
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movw %dx,-16(%ebp)
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fldcw -16(%ebp) /* load modfied control word */
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fldl 8(%ebp)
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2001-06-19 04:26:29 +04:00
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#else
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fstcw -12(%rsp)
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movw -12(%rsp),%dx
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orw $0x0180,%dx
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movw %dx,-16(%rsp)
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fldcw -16(%rsp)
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movsd %xmm0,-8(%rsp)
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fldl -8(%rsp)
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#endif
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1994-02-11 21:20:17 +03:00
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fldl2e
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fmulp /* x * log2(e) */
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2001-06-19 04:26:29 +04:00
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fld %st(0)
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1994-02-11 21:20:17 +03:00
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frndint /* int(x * log2(e)) */
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1996-07-03 21:31:28 +04:00
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fxch %st(1)
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fsub %st(1),%st /* fract(x * log2(e)) */
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1999-07-02 19:37:33 +04:00
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f2xm1 /* 2^(fract(x * log2(e))) - 1 */
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1994-02-11 21:20:17 +03:00
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fld1
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faddp /* 2^(fract(x * log2(e))) */
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fscale /* e^x */
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2001-06-19 04:26:29 +04:00
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fstp %st(1)
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1996-07-03 21:27:34 +04:00
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2001-06-19 04:26:29 +04:00
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#ifdef __i386__
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1996-07-03 21:27:34 +04:00
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fldcw -12(%ebp) /* restore original control word */
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leave
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2001-06-19 04:26:29 +04:00
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#else
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fstpl -8(%rsp)
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movsd -8(%rsp),%xmm0
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fldcw -12(%rbp)
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#endif
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1994-02-11 21:20:17 +03:00
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ret
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