68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
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/*
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* ====================================================
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* x87 FP implementation contributed to Newlib by
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* Dave Korn, November 2007. This file is placed in the
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* public domain. Permission to use, copy, modify, and
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* distribute this software is freely granted.
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* ====================================================
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*/
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#if defined(__GNUC__) && !defined(_SOFT_FLOAT)
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#include <math.h>
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/*
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FUNCTION
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<<rint>>, <<rintf>>, <<rintl>>---round to integer
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INDEX
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rint
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INDEX
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rintf
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INDEX
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rintl
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ANSI_SYNOPSIS
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#include <math.h>
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double rint(double x);
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float rintf(float x);
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long double rintl(long double x);
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TRAD_SYNOPSIS
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ANSI-only.
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DESCRIPTION
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The <<rint>>, <<rintf>> and <<rintl>> functions round <[x]> to an integer value
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in floating-point format, using the current rounding direction. They may
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raise the inexact exception if the result differs in value from the argument.
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RETURNS
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These functions return the rounded integer value of <[x]>.
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PORTABILITY
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<<rint>>, <<rintf>> and <<rintl>> are ANSI.
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<<rint>> and <<rintf>> are available on all platforms.
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<<rintl>> is only available on i386 platforms when hardware
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floating point support is available and when compiling with GCC.
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*/
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/*
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* Fast math version of rint(x)
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* Return x rounded to integral value according to the prevailing
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* rounding mode.
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* Method:
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* Using inline x87 asms.
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* Exception:
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* Governed by x87 FPCR.
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*/
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double _f_rint (double x)
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{
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double _result;
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asm ("frndint" : "=t" (_result) : "0" (x));
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return _result;
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}
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#endif /* !__GNUC__ || _SOFT_FLOAT */
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