Last change
on this file since 559 was
444,
checked in by satin@…, 6 years ago
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add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
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File size:
1.1 KB
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Rev | Line | |
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[444] | 1 | |
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| 2 | /* @(#)z_frexpf.c 1.0 98/08/13 */ |
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| 3 | /****************************************************************** |
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| 4 | * frexp |
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| 5 | * |
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| 6 | * Input: |
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| 7 | * d - floating point value |
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| 8 | * exp - exponent value |
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| 9 | * |
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| 10 | * Output: |
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| 11 | * A floating point value in the range [0.5, 1). |
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| 12 | * |
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| 13 | * Description: |
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| 14 | * This routine breaks a floating point value into a number f and |
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| 15 | * an exponent exp such that d = f * 2 ^ exp. |
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| 16 | * |
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| 17 | *****************************************************************/ |
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| 18 | |
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| 19 | #include "fdlibm.h" |
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| 20 | #include "zmath.h" |
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| 21 | |
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| 22 | float frexpf (float d, int *exp) |
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| 23 | { |
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| 24 | float f; |
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| 25 | __int32_t wf, wd; |
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| 26 | |
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| 27 | /* Check for special values. */ |
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| 28 | switch (numtestf (d)) |
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| 29 | { |
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| 30 | case NAN: |
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| 31 | case INF: |
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| 32 | errno = EDOM; |
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| 33 | case 0: |
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| 34 | *exp = 0; |
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| 35 | return (d); |
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| 36 | } |
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| 37 | |
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| 38 | GET_FLOAT_WORD (wd, d); |
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| 39 | |
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| 40 | /* Get the exponent. */ |
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| 41 | *exp = ((wd & 0x7f800000) >> 23) - 126; |
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| 42 | |
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| 43 | /* Get the mantissa. */ |
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| 44 | wf = wd & 0x7fffff; |
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| 45 | wf |= 0x3f000000; |
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| 46 | |
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| 47 | SET_FLOAT_WORD (f, wf); |
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| 48 | |
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| 49 | return (f); |
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| 50 | } |
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| 51 | |
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| 52 | #ifdef _DOUBLE_IS_32BITS |
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| 53 | |
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| 54 | double frexp (double x, int *exp) |
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| 55 | { |
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| 56 | return (double) frexpf ((float) x, exp); |
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| 57 | } |
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| 58 | |
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| 59 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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