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41 lines
928 B
ArmAsm
41 lines
928 B
ArmAsm
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/*
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* Written by J.T. Conklin <jtc@netbsd.org>.
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* Public domain.
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*
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* Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
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*/
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#include <machine/asm.h>
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RCSID("$NetBSD: $")
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/* e^x = 2^(x * log2l(e)) */
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ENTRY(__ieee754_expl)
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fldt 4(%esp)
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/* I added the following ugly construct because expl(+-Inf) resulted
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in NaN. The ugliness results from the bright minds at Intel.
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-- drepper@cygnus.com. */
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fxam /* Is NaN or +-Inf? */
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fstsw %ax
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sahf
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jnc .LnoInfNaN /* No, jump. */
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jp .LisInf /* Is +-Inf, jump. */
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.LnoInfNaN:
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fldl2e
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fmulp /* x * log2(e) */
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fstl %st(1)
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frndint /* int(x * log2(e)) */
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fstl %st(2)
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fsubrp /* fract(x * log2(e)) */
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f2xm1 /* 2^(fract(x * log2(e))) - 1 */
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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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ret
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.LisInf:
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andb $2, %ah /* Test sign. */
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jz .LpInf /* If positive, jump. */
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fldz /* Set result to 0. */
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.LpInf: ret
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