58 lines
1.7 KiB
C
58 lines
1.7 KiB
C
/*---------------------------------------------------------------------------+
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| reg_convert.c |
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| Convert register representation. |
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| Copyright (C) 1992,1993,1994,1996,1997 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
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| E-mail billm@suburbia.net |
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+---------------------------------------------------------------------------*/
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#include "exception.h"
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#include "fpu_emu.h"
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int FPU_to_exp16(FPU_REG const *a, FPU_REG *x)
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{
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int sign = getsign(a);
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#ifndef EMU_BIG_ENDIAN
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*(s64 *)&(x->sigl) = *(const s64 *)&(a->sigl);
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#else
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*(s64 *)&(x->sigh) = *(const s64 *)&(a->sigh);
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#endif
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/* Set up the exponent as a 16 bit quantity. */
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setexponent16(x, exponent(a));
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if ( exponent16(x) == EXP_UNDER )
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{
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/* The number is a de-normal or pseudodenormal. */
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/* We only deal with the significand and exponent. */
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if (x->sigh & 0x80000000)
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{
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/* Is a pseudodenormal. */
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/* This is non-80486 behaviour because the number
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loses its 'denormal' identity. */
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addexponent(x, 1);
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}
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else
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{
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/* Is a denormal. */
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addexponent(x, 1);
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FPU_normalize_nuo(x, 0);
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}
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}
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if ( !(x->sigh & 0x80000000) )
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{
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EXCEPTION(EX_INTERNAL | 0x180);
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}
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return sign;
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}
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