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Diffstat (limited to 'newlib/libm/machine/i386/f_lrint.c')
-rw-r--r-- | newlib/libm/machine/i386/f_lrint.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/newlib/libm/machine/i386/f_lrint.c b/newlib/libm/machine/i386/f_lrint.c new file mode 100644 index 000000000..b8cdabb5d --- /dev/null +++ b/newlib/libm/machine/i386/f_lrint.c @@ -0,0 +1,69 @@ +/* + * ==================================================== + * x87 FP implementation contributed to Newlib by + * Dave Korn, November 2007. This file is placed in the + * public domain. Permission to use, copy, modify, and + * distribute this software is freely granted. + * ==================================================== + */ + +#if defined(__GNUC__) && !defined(_SOFT_FLOAT) + +#include <math.h> + +/* +FUNCTION +<<lrint>>, <<lrintf>>, <<lrintl>>---round and convert to long integer +INDEX + lrint +INDEX + lrintf +INDEX + lrintl + +ANSI_SYNOPSIS + #include <math.h> + long int lrint(double x); + long int lrintf(float x); + long int lrintl(long double x); + +TRAD_SYNOPSIS + ANSI-only. + +DESCRIPTION +The <<lrint>>, <<lrintf>> and <<lrintl>> functions round <[x]> to the nearest integer value, +according to the current rounding direction. If the rounded value is outside the +range of the return type, the numeric result is unspecified. A range error may +occur if the magnitude of <[x]> is too large. + +RETURNS +These functions return the rounded integer value of <[x]>. +<<lrint>>, <<lrintf>> and <<lrintl>> return the result as a long integer. + +PORTABILITY +<<lrint>>, <<lrintf>>, and <<lrintl>> are ANSI. +<<lrint>> and <<lrintf>> are available on all platforms. +<<lrintl>> is only available on i386 platforms when hardware +floating point support is available and when compiling with GCC. + +*/ + +/* + * Fast math version of lrint(x) + * Return x rounded to integral value according to the prevailing + * rounding mode. + * Method: + * Using inline x87 asms. + * Exception: + * Governed by x87 FPCR. + */ + +long int _f_lrint (double x) +{ + long int _result; + asm ("fistpl %0" : "=m" (_result) : "t" (x) : "st"); + return _result; +} + +#endif /* !__GNUC__ || _SOFT_FLOAT */ + |