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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/float/floorf.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/float/floorf.c')
-rw-r--r--libm/float/floorf.c526
1 files changed, 0 insertions, 526 deletions
diff --git a/libm/float/floorf.c b/libm/float/floorf.c
deleted file mode 100644
index 7a2f3530d..000000000
--- a/libm/float/floorf.c
+++ /dev/null
@@ -1,526 +0,0 @@
-/* ceilf()
- * floorf()
- * frexpf()
- * ldexpf()
- * signbitf()
- * isnanf()
- * isfinitef()
- *
- * Single precision floating point numeric utilities
- *
- *
- *
- * SYNOPSIS:
- *
- * float x, y;
- * float ceilf(), floorf(), frexpf(), ldexpf();
- * int signbit(), isnan(), isfinite();
- * int expnt, n;
- *
- * y = floorf(x);
- * y = ceilf(x);
- * y = frexpf( x, &expnt );
- * y = ldexpf( x, n );
- * n = signbit(x);
- * n = isnan(x);
- * n = isfinite(x);
- *
- *
- *
- * DESCRIPTION:
- *
- * All four routines return a single precision floating point
- * result.
- *
- * sfloor() returns the largest integer less than or equal to x.
- * It truncates toward minus infinity.
- *
- * sceil() returns the smallest integer greater than or equal
- * to x. It truncates toward plus infinity.
- *
- * sfrexp() 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.
- *
- * ldexpf() 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 2.1: December, 1988
-Copyright 1984, 1987, 1988 by Stephen L. Moshier
-Direct inquiries to 30 Frost Street, Cambridge, MA 02140
-*/
-
-
-#include <math.h>
-#ifdef DEC
-#undef DENORMAL
-#define DENORMAL 0
-#endif
-
-#ifdef UNK
-#undef UNK
-#if BIGENDIAN
-#define MIEEE 1
-#else
-#define IBMPC 1
-#endif
-/*
-char *unkmsg = "ceil(), floor(), frexp(), ldexp() must be rewritten!\n";
-*/
-#endif
-
-#define EXPMSK 0x807f
-#define MEXP 255
-#define NBITS 24
-
-
-extern float MAXNUMF; /* (2^24 - 1) * 2^103 */
-#ifdef ANSIC
-float floorf(float);
-#else
-float floorf();
-#endif
-
-float ceilf( float x )
-{
-float y;
-
-#ifdef UNK
-printf( "%s\n", unkmsg );
-return(0.0);
-#endif
-
-y = floorf( (float )x );
-if( y < x )
- y += 1.0;
-return(y);
-}
-
-
-
-
-/* Bit clearing masks: */
-
-static unsigned short bmask[] = {
-0xffff,
-0xfffe,
-0xfffc,
-0xfff8,
-0xfff0,
-0xffe0,
-0xffc0,
-0xff80,
-0xff00,
-0xfe00,
-0xfc00,
-0xf800,
-0xf000,
-0xe000,
-0xc000,
-0x8000,
-0x0000,
-};
-
-
-
-float floorf( float x )
-{
-unsigned short *p;
-union
- {
- float y;
- unsigned short i[2];
- } u;
-int e;
-
-#ifdef UNK
-printf( "%s\n", unkmsg );
-return(0.0);
-#endif
-
-u.y = x;
-/* find the exponent (power of 2) */
-#ifdef DEC
-p = &u.i[0];
-e = (( *p >> 7) & 0377) - 0201;
-p += 3;
-#endif
-
-#ifdef IBMPC
-p = &u.i[1];
-e = (( *p >> 7) & 0xff) - 0x7f;
-p -= 1;
-#endif
-
-#ifdef MIEEE
-p = &u.i[0];
-e = (( *p >> 7) & 0xff) - 0x7f;
-p += 1;
-#endif
-
-if( e < 0 )
- {
- if( u.y < 0 )
- return( -1.0 );
- else
- return( 0.0 );
- }
-
-e = (NBITS -1) - e;
-/* clean out 16 bits at a time */
-while( e >= 16 )
- {
-#ifdef IBMPC
- *p++ = 0;
-#endif
-
-#ifdef DEC
- *p-- = 0;
-#endif
-
-#ifdef MIEEE
- *p-- = 0;
-#endif
- e -= 16;
- }
-
-/* clear the remaining bits */
-if( e > 0 )
- *p &= bmask[e];
-
-if( (x < 0) && (u.y != x) )
- u.y -= 1.0;
-
-return(u.y);
-}
-
-
-
-float frexpf( float x, int *pw2 )
-{
-union
- {
- float y;
- unsigned short i[2];
- } u;
-int i, k;
-short *q;
-
-u.y = x;
-
-#ifdef UNK
-printf( "%s\n", unkmsg );
-return(0.0);
-#endif
-
-#ifdef IBMPC
-q = &u.i[1];
-#endif
-
-#ifdef DEC
-q = &u.i[0];
-#endif
-
-#ifdef MIEEE
-q = &u.i[0];
-#endif
-
-/* find the exponent (power of 2) */
-
-i = ( *q >> 7) & 0xff;
-if( i == 0 )
- {
- if( u.y == 0.0 )
- {
- *pw2 = 0;
- return(0.0);
- }
-/* Number is denormal or zero */
-#if DENORMAL
-/* Handle denormal number. */
- do
- {
- u.y *= 2.0;
- i -= 1;
- k = ( *q >> 7) & 0xff;
- }
- while( k == 0 );
- i = i + k;
-#else
- *pw2 = 0;
- return( 0.0 );
-#endif /* DENORMAL */
- }
-i -= 0x7e;
-*pw2 = i;
-*q &= 0x807f; /* strip all exponent bits */
-*q |= 0x3f00; /* mantissa between 0.5 and 1 */
-return( u.y );
-}
-
-
-
-
-
-float ldexpf( float x, int pw2 )
-{
-union
- {
- float y;
- unsigned short i[2];
- } u;
-short *q;
-int e;
-
-#ifdef UNK
-printf( "%s\n", unkmsg );
-return(0.0);
-#endif
-
-u.y = x;
-#ifdef DEC
-q = &u.i[0];
-#endif
-
-#ifdef IBMPC
-q = &u.i[1];
-#endif
-#ifdef MIEEE
-q = &u.i[0];
-#endif
-while( (e = ( *q >> 7) & 0xff) == 0 )
- {
- if( u.y == (float )0.0 )
- {
- return( 0.0 );
- }
-/* Input is denormal. */
- if( pw2 > 0 )
- {
- u.y *= 2.0;
- pw2 -= 1;
- }
- if( pw2 < 0 )
- {
- if( pw2 < -24 )
- return( 0.0 );
- u.y *= 0.5;
- pw2 += 1;
- }
- if( pw2 == 0 )
- return(u.y);
- }
-
-e += pw2;
-
-/* Handle overflow */
-if( e > MEXP )
- {
- return( MAXNUMF );
- }
-
-*q &= 0x807f;
-
-/* Handle denormalized results */
-if( e < 1 )
- {
-#if DENORMAL
- if( e < -24 )
- return( 0.0 );
- *q |= 0x80; /* Set LSB of exponent. */
- /* For denormals, significant bits may be lost even
- when dividing by 2. Construct 2^-(1-e) so the result
- is obtained with only one multiplication. */
- u.y *= ldexpf(1.0f, e - 1);
- return(u.y);
-#else
- return( 0.0 );
-#endif
- }
-*q |= (e & 0xff) << 7;
-return(u.y);
-}
-
-
-/* Return 1 if the sign bit of x is 1, else 0. */
-
-int signbitf(x)
-float x;
-{
-union
- {
- float f;
- short s[4];
- int i;
- } u;
-
-u.f = x;
-
-if( sizeof(int) == 4 )
- {
-#ifdef IBMPC
- return( u.i < 0 );
-#endif
-#ifdef DEC
- return( u.s[1] < 0 );
-#endif
-#ifdef MIEEE
- return( u.i < 0 );
-#endif
- }
-else
- {
-#ifdef IBMPC
- return( u.s[1] < 0 );
-#endif
-#ifdef DEC
- return( u.s[1] < 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 isnanf(x)
-float x;
-{
-#ifdef NANS
-union
- {
- float f;
- unsigned short s[2];
- unsigned int i;
- } u;
-
-u.f = x;
-
-if( sizeof(int) == 4 )
- {
-#ifdef IBMPC
- if( ((u.i & 0x7f800000) == 0x7f800000)
- && ((u.i & 0x007fffff) != 0) )
- return 1;
-#endif
-#ifdef DEC
- if( (u.s[1] & 0x7f80) == 0)
- {
- if( (u.s[1] | u.s[0]) != 0 )
- return(1);
- }
-#endif
-#ifdef MIEEE
- if( ((u.i & 0x7f800000) == 0x7f800000)
- && ((u.i & 0x007fffff) != 0) )
- return 1;
-#endif
- return(0);
- }
-else
- { /* size int not 4 */
-#ifdef IBMPC
- if( (u.s[1] & 0x7f80) == 0x7f80)
- {
- if( ((u.s[1] & 0x007f) | u.s[0]) != 0 )
- return(1);
- }
-#endif
-#ifdef DEC
- if( (u.s[1] & 0x7f80) == 0)
- {
- if( (u.s[1] | u.s[0]) != 0 )
- return(1);
- }
-#endif
-#ifdef MIEEE
- if( (u.s[0] & 0x7f80) == 0x7f80)
- {
- if( ((u.s[0] & 0x000f) | u.s[1]) != 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 isfinitef(x)
-float x;
-{
-#ifdef INFINITIES
-union
- {
- float f;
- unsigned short s[2];
- unsigned int i;
- } u;
-
-u.f = x;
-
-if( sizeof(int) == 4 )
- {
-#ifdef IBMPC
- if( (u.i & 0x7f800000) != 0x7f800000)
- return 1;
-#endif
-#ifdef DEC
- if( (u.s[1] & 0x7f80) == 0)
- {
- if( (u.s[1] | u.s[0]) != 0 )
- return(1);
- }
-#endif
-#ifdef MIEEE
- if( (u.i & 0x7f800000) != 0x7f800000)
- return 1;
-#endif
- return(0);
- }
-else
- {
-#ifdef IBMPC
- if( (u.s[1] & 0x7f80) != 0x7f80)
- return 1;
-#endif
-#ifdef DEC
- if( (u.s[1] & 0x7f80) == 0)
- {
- if( (u.s[1] | u.s[0]) != 0 )
- return(1);
- }
-#endif
-#ifdef MIEEE
- if( (u.s[0] & 0x7f80) != 0x7f80)
- return 1;
-#endif
- return(0);
- }
-#else
-/* No INFINITY. */
-return(1);
-#endif
-}