70 lines
1.7 KiB
C
70 lines
1.7 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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<<lrint>>, <<lrintf>>, <<lrintl>>---round and convert to long integer
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INDEX
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lrint
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INDEX
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lrintf
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INDEX
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lrintl
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ANSI_SYNOPSIS
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#include <math.h>
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long int lrint(double x);
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long int lrintf(float x);
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long int lrintl(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 <<lrint>>, <<lrintf>> and <<lrintl>> functions round <[x]> to the nearest integer value,
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according to the current rounding direction. If the rounded value is outside the
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range of the return type, the numeric result is unspecified. A range error may
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occur if the magnitude of <[x]> is too large.
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RETURNS
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These functions return the rounded integer value of <[x]>.
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<<lrint>>, <<lrintf>> and <<lrintl>> return the result as a long integer.
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PORTABILITY
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<<lrint>>, <<lrintf>>, and <<lrintl>> are ANSI.
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<<lrint>> and <<lrintf>> are available on all platforms.
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<<lrintl>> 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 lrint(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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long int _f_lrint (double x)
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{
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long int _result;
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asm ("fistpl %0" : "=m" (_result) : "t" (x) : "st");
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return _result;
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}
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#endif /* !__GNUC__ || _SOFT_FLOAT */
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