| 1 | /* |
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| 2 | * ==================================================== |
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| 3 | * x87 FP implementation contributed to Newlib by |
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| 4 | * Dave Korn, November 2007. This file is placed in the |
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| 5 | * public domain. Permission to use, copy, modify, and |
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| 6 | * distribute this software is freely granted. |
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| 7 | * ==================================================== |
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| 8 | */ |
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| 9 | |
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| 10 | #if defined(__GNUC__) && !defined(_SOFT_FLOAT) |
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| 11 | |
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| 12 | #include <math.h> |
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| 13 | |
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| 14 | /* |
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| 15 | FUNCTION |
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| 16 | <<rint>>, <<rintf>>, <<rintl>>---round to integer |
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| 17 | INDEX |
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| 18 | rint |
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| 19 | INDEX |
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| 20 | rintf |
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| 21 | INDEX |
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| 22 | rintl |
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| 23 | |
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| 24 | SYNOPSIS |
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| 25 | #include <math.h> |
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| 26 | double rint(double x); |
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| 27 | float rintf(float x); |
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| 28 | long double rintl(long double x); |
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| 29 | |
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| 30 | DESCRIPTION |
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| 31 | The <<rint>>, <<rintf>> and <<rintl>> functions round <[x]> to an integer value |
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| 32 | in floating-point format, using the current rounding direction. They may |
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| 33 | raise the inexact exception if the result differs in value from the argument. |
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| 34 | |
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| 35 | RETURNS |
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| 36 | These functions return the rounded integer value of <[x]>. |
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| 37 | |
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| 38 | PORTABILITY |
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| 39 | <<rint>>, <<rintf>> and <<rintl>> are ANSI. |
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| 40 | <<rint>> and <<rintf>> are available on all platforms. |
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| 41 | <<rintl>> is only available on i386 platforms when hardware |
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| 42 | floating point support is available and when compiling with GCC. |
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| 43 | |
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| 44 | */ |
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| 45 | |
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| 46 | /* |
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| 47 | * Fast math version of rint(x) |
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| 48 | * Return x rounded to integral value according to the prevailing |
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| 49 | * rounding mode. |
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| 50 | * Method: |
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| 51 | * Using inline x87 asms. |
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| 52 | * Exception: |
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| 53 | * Governed by x87 FPCR. |
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| 54 | */ |
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| 55 | |
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| 56 | double _f_rint (double x) |
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| 57 | { |
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| 58 | double _result; |
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| 59 | asm ("frndint" : "=t" (_result) : "0" (x)); |
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| 60 | return _result; |
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| 61 | } |
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| 62 | |
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| 63 | #endif /* !__GNUC__ || _SOFT_FLOAT */ |
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| 64 | |
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