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authorEric Andersen <andersen@codepoet.org>2001-11-22 14:04:29 +0000
committerEric Andersen <andersen@codepoet.org>2001-11-22 14:04:29 +0000
commit7ce331c01ce6eb7b3f5c715a38a24359da9c6ee2 (patch)
tree3a7e8476e868ae15f4da1b7ce26b2db6f434468c /libm/double/isnan.c
parentc117dd5fb183afb1a4790a6f6110d88704be6bf8 (diff)
Totally rework the math library, this time based on the MacOs X
math library (which is itself based on the math lib from FreeBSD). -Erik
Diffstat (limited to 'libm/double/isnan.c')
-rw-r--r--libm/double/isnan.c237
1 files changed, 0 insertions, 237 deletions
diff --git a/libm/double/isnan.c b/libm/double/isnan.c
deleted file mode 100644
index 8ae83bcba..000000000
--- a/libm/double/isnan.c
+++ /dev/null
@@ -1,237 +0,0 @@
-/* isnan()
- * signbit()
- * isfinite()
- *
- * Floating point numeric utilities
- *
- *
- *
- * SYNOPSIS:
- *
- * double ceil(), floor(), frexp(), ldexp();
- * int signbit(), isnan(), isfinite();
- * double x, y;
- * int expnt, n;
- *
- * y = floor(x);
- * y = ceil(x);
- * y = frexp( x, &expnt );
- * y = ldexp( x, n );
- * n = signbit(x);
- * n = isnan(x);
- * n = isfinite(x);
- *
- *
- *
- * DESCRIPTION:
- *
- * All four routines return a double precision floating point
- * result.
- *
- * floor() returns the largest integer less than or equal to x.
- * It truncates toward minus infinity.
- *
- * ceil() returns the smallest integer greater than or equal
- * to x. It truncates toward plus infinity.
- *
- * frexp() extracts the exponent from x. It returns an integer
- * power of two to expnt and the significand between 0.5 and 1
- * to y. Thus x = y * 2**expn.
- *
- * ldexp() multiplies x by 2**n.
- *
- * signbit(x) returns 1 if the sign bit of x is 1, else 0.
- *
- * These functions are part of the standard C run time library
- * for many but not all C compilers. The ones supplied are
- * written in C for either DEC or IEEE arithmetic. They should
- * be used only if your compiler library does not already have
- * them.
- *
- * The IEEE versions assume that denormal numbers are implemented
- * in the arithmetic. Some modifications will be required if
- * the arithmetic has abrupt rather than gradual underflow.
- */
-
-
-/*
-Cephes Math Library Release 2.3: March, 1995
-Copyright 1984, 1995 by Stephen L. Moshier
-*/
-
-
-#include <math.h>
-
-#ifdef UNK
-/* ceil(), floor(), frexp(), ldexp() may need to be rewritten. */
-#undef UNK
-#if BIGENDIAN
-#define MIEEE 1
-#else
-#define IBMPC 1
-#endif
-#endif
-
-
-/* Return 1 if the sign bit of x is 1, else 0. */
-
-int signbit(x)
-double x;
-{
-union
- {
- double d;
- short s[4];
- int i[2];
- } u;
-
-u.d = x;
-
-if( sizeof(int) == 4 )
- {
-#ifdef IBMPC
- return( u.i[1] < 0 );
-#endif
-#ifdef DEC
- return( u.s[3] < 0 );
-#endif
-#ifdef MIEEE
- return( u.i[0] < 0 );
-#endif
- }
-else
- {
-#ifdef IBMPC
- return( u.s[3] < 0 );
-#endif
-#ifdef DEC
- return( u.s[3] < 0 );
-#endif
-#ifdef MIEEE
- return( u.s[0] < 0 );
-#endif
- }
-}
-
-
-/* Return 1 if x is a number that is Not a Number, else return 0. */
-
-int isnan(x)
-double x;
-{
-#ifdef NANS
-union
- {
- double d;
- unsigned short s[4];
- unsigned int i[2];
- } u;
-
-u.d = x;
-
-if( sizeof(int) == 4 )
- {
-#ifdef IBMPC
- if( ((u.i[1] & 0x7ff00000) == 0x7ff00000)
- && (((u.i[1] & 0x000fffff) != 0) || (u.i[0] != 0)))
- return 1;
-#endif
-#ifdef DEC
- if( (u.s[1] & 0x7fff) == 0)
- {
- if( (u.s[2] | u.s[1] | u.s[0]) != 0 )
- return(1);
- }
-#endif
-#ifdef MIEEE
- if( ((u.i[0] & 0x7ff00000) == 0x7ff00000)
- && (((u.i[0] & 0x000fffff) != 0) || (u.i[1] != 0)))
- return 1;
-#endif
- return(0);
- }
-else
- { /* size int not 4 */
-#ifdef IBMPC
- if( (u.s[3] & 0x7ff0) == 0x7ff0)
- {
- if( ((u.s[3] & 0x000f) | u.s[2] | u.s[1] | u.s[0]) != 0 )
- return(1);
- }
-#endif
-#ifdef DEC
- if( (u.s[3] & 0x7fff) == 0)
- {
- if( (u.s[2] | u.s[1] | u.s[0]) != 0 )
- return(1);
- }
-#endif
-#ifdef MIEEE
- if( (u.s[0] & 0x7ff0) == 0x7ff0)
- {
- if( ((u.s[0] & 0x000f) | u.s[1] | u.s[2] | u.s[3]) != 0 )
- return(1);
- }
-#endif
- return(0);
- } /* size int not 4 */
-
-#else
-/* No NANS. */
-return(0);
-#endif
-}
-
-
-/* Return 1 if x is not infinite and is not a NaN. */
-
-int isfinite(x)
-double x;
-{
-#ifdef INFINITIES
-union
- {
- double d;
- unsigned short s[4];
- unsigned int i[2];
- } u;
-
-u.d = x;
-
-if( sizeof(int) == 4 )
- {
-#ifdef IBMPC
- if( (u.i[1] & 0x7ff00000) != 0x7ff00000)
- return 1;
-#endif
-#ifdef DEC
- if( (u.s[3] & 0x7fff) != 0)
- return 1;
-#endif
-#ifdef MIEEE
- if( (u.i[0] & 0x7ff00000) != 0x7ff00000)
- return 1;
-#endif
- return(0);
- }
-else
- {
-#ifdef IBMPC
- if( (u.s[3] & 0x7ff0) != 0x7ff0)
- return 1;
-#endif
-#ifdef DEC
- if( (u.s[3] & 0x7fff) != 0)
- return 1;
-#endif
-#ifdef MIEEE
- if( (u.s[0] & 0x7ff0) != 0x7ff0)
- return 1;
-#endif
- return(0);
- }
-#else
-/* No INFINITY. */
-return(1);
-#endif
-}