[444] | 1 | /* |
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| 2 | * ==================================================== |
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| 3 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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| 4 | * |
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| 5 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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| 6 | * Permission to use, copy, modify, and distribute this |
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| 7 | * software is freely granted, provided that this notice |
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| 8 | * is preserved. |
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| 9 | * ==================================================== |
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| 10 | */ |
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| 11 | |
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| 12 | #include "fdlibm.h" |
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| 13 | |
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| 14 | #ifdef __STDC__ |
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| 15 | float truncf(float x) |
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| 16 | #else |
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| 17 | float truncf(x) |
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| 18 | float x; |
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| 19 | #endif |
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| 20 | { |
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| 21 | __int32_t signbit, w, exponent_less_127; |
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| 22 | |
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| 23 | GET_FLOAT_WORD(w,x); |
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| 24 | |
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| 25 | /* Extract sign bit. */ |
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| 26 | signbit = w & 0x80000000; |
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| 27 | |
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| 28 | /* Extract exponent field. */ |
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| 29 | exponent_less_127 = ((w & 0x7f800000) >> 23) - 127; |
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| 30 | |
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| 31 | if (exponent_less_127 < 23) |
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| 32 | { |
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| 33 | if (exponent_less_127 < 0) |
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| 34 | { |
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| 35 | /* -1 < x < 1, so result is +0 or -0. */ |
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| 36 | SET_FLOAT_WORD(x, signbit); |
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| 37 | } |
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| 38 | else |
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| 39 | { |
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| 40 | SET_FLOAT_WORD(x, signbit | (w & ~(0x007fffff >> exponent_less_127))); |
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| 41 | } |
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| 42 | } |
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| 43 | else |
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| 44 | { |
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| 45 | if (exponent_less_127 == 255) |
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| 46 | /* x is NaN or infinite. */ |
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| 47 | return x + x; |
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| 48 | |
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| 49 | /* All bits in the fraction field are relevant. */ |
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| 50 | } |
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| 51 | return x; |
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| 52 | } |
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| 53 | |
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| 54 | #ifdef _DOUBLE_IS_32BITS |
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| 55 | |
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| 56 | #ifdef __STDC__ |
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| 57 | double trunc(double x) |
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| 58 | #else |
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| 59 | double trunc(x) |
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| 60 | double x; |
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| 61 | #endif |
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| 62 | { |
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| 63 | return (double) truncf((float) x); |
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| 64 | } |
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| 65 | |
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| 66 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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