| 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 roundf(float x) |
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| 16 | #else |
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| 17 | float roundf(x) |
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| 18 | float x; |
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| 19 | #endif |
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| 20 | { |
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| 21 | __uint32_t w; |
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| 22 | /* Most significant word, least significant word. */ |
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| 23 | int exponent_less_127; |
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| 24 | |
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| 25 | GET_FLOAT_WORD(w, x); |
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| 26 | |
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| 27 | /* Extract exponent field. */ |
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| 28 | exponent_less_127 = (int)((w & 0x7f800000) >> 23) - 127; |
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| 29 | |
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| 30 | if (exponent_less_127 < 23) |
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| 31 | { |
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| 32 | if (exponent_less_127 < 0) |
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| 33 | { |
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| 34 | w &= 0x80000000; |
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| 35 | if (exponent_less_127 == -1) |
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| 36 | /* Result is +1.0 or -1.0. */ |
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| 37 | w |= ((__uint32_t)127 << 23); |
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| 38 | } |
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| 39 | else |
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| 40 | { |
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| 41 | unsigned int exponent_mask = 0x007fffff >> exponent_less_127; |
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| 42 | if ((w & exponent_mask) == 0) |
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| 43 | /* x has an integral value. */ |
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| 44 | return x; |
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| 45 | |
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| 46 | w += 0x00400000 >> exponent_less_127; |
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| 47 | w &= ~exponent_mask; |
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| 48 | } |
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| 49 | } |
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| 50 | else |
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| 51 | { |
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| 52 | if (exponent_less_127 == 128) |
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| 53 | /* x is NaN or infinite. */ |
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| 54 | return x + x; |
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| 55 | else |
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| 56 | return x; |
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| 57 | } |
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| 58 | SET_FLOAT_WORD(x, w); |
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| 59 | return x; |
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| 60 | } |
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| 61 | |
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| 62 | #ifdef _DOUBLE_IS_32BITS |
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| 63 | |
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| 64 | #ifdef __STDC__ |
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| 65 | double round(double x) |
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| 66 | #else |
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| 67 | double round(x) |
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| 68 | double x; |
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| 69 | #endif |
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| 70 | { |
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| 71 | return (double) roundf((float) x); |
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| 72 | } |
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| 73 | |
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| 74 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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