| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /*---------------------------------------------------------------------------+ |
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| 3 | | reg_convert.c | |
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| 4 | | | |
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| 5 | | Convert register representation. | |
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| 6 | | | |
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| 7 | | Copyright (C) 1992,1993,1994,1996,1997 | |
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| 8 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia | |
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| 9 | | E-mail billm@suburbia.net | |
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| 10 | | | |
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| 11 | | | |
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| 12 | +---------------------------------------------------------------------------*/ |
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| 13 | |
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| 14 | #include "exception.h" |
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| 15 | #include "fpu_emu.h" |
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| 16 | |
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| 17 | int FPU_to_exp16(FPU_REG const *a, FPU_REG *x) |
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| 18 | { |
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| 19 | int sign = getsign(a); |
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| 20 | |
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| 21 | *(long long *)&(x->sigl) = *(const long long *)&(a->sigl); |
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| 22 | |
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| 23 | /* Set up the exponent as a 16 bit quantity. */ |
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| 24 | setexponent16(x, exponent(a)); |
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| 25 | |
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| 26 | if (exponent16(x) == EXP_UNDER) { |
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| 27 | /* The number is a de-normal or pseudodenormal. */ |
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| 28 | /* We only deal with the significand and exponent. */ |
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| 29 | |
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| 30 | if (x->sigh & 0x80000000) { |
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| 31 | /* Is a pseudodenormal. */ |
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| 32 | /* This is non-80486 behaviour because the number |
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| 33 | loses its 'denormal' identity. */ |
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| 34 | addexponent(x, 1); |
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| 35 | } else { |
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| 36 | /* Is a denormal. */ |
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| 37 | addexponent(x, 1); |
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| 38 | FPU_normalize_nuo(x); |
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| 39 | } |
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| 40 | } |
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| 41 | |
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| 42 | if (!(x->sigh & 0x80000000)) { |
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| 43 | EXCEPTION(EX_INTERNAL | 0x180); |
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| 44 | } |
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| 45 | |
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| 46 | return sign; |
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| 47 | } |
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| 48 | |
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