X-Git-Url: https://git.hcoop.net/bpt/emacs.git/blobdiff_plain/4f9d7df139695e97cd1772d41940500480585df7..d2aa42f8be4756cf4efc96b975bb6db9c0bdff94:/src/floatfns.c
diff --git a/src/floatfns.c b/src/floatfns.c
index 8ee28210e4..96a89337c7 100644
--- a/src/floatfns.c
+++ b/src/floatfns.c
@@ -1,6 +1,9 @@
/* Primitive operations on floating point for GNU Emacs Lisp interpreter.
Copyright (C) 1988, 1993, 1994, 1999, 2001, 2002, 2003, 2004,
- 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+
+Author: Wolfgang Rupprecht
+(according to ack.texi)
This file is part of GNU Emacs.
@@ -45,6 +48,7 @@ along with GNU Emacs. If not, see . */
#include
#include
+#include
#include "lisp.h"
#include "syssignal.h"
@@ -66,7 +70,7 @@ along with GNU Emacs. If not, see . */
/* This declaration is omitted on some systems, like Ultrix. */
#if !defined (HPUX) && defined (HAVE_LOGB) && !defined (logb)
-extern double logb ();
+extern double logb (double);
#endif /* not HPUX and HAVE_LOGB and no logb macro */
#if defined(DOMAIN) && defined(SING) && defined(OVERFLOW)
@@ -95,21 +99,7 @@ extern double logb ();
#ifdef FLOAT_CHECK_ERRNO
# include
-
-#ifndef USE_CRT_DLL
-extern int errno;
#endif
-#endif
-
-/* Avoid traps on VMS from sinh and cosh.
- All the other functions set errno instead. */
-
-#ifdef VMS
-#undef cosh
-#undef sinh
-#define cosh(x) ((exp(x)+exp(-x))*0.5)
-#define sinh(x) ((exp(x)-exp(-x))*0.5)
-#endif /* VMS */
#ifdef FLOAT_CATCH_SIGILL
static SIGTYPE float_error ();
@@ -298,6 +288,70 @@ DEFUN ("tan", Ftan, Stan, 1, 1, 0,
IN_FLOAT (d = sin (d) / c, "tan", arg);
return make_float (d);
}
+
+#if defined HAVE_ISNAN && defined HAVE_COPYSIGN
+DEFUN ("isnan", Fisnan, Sisnan, 1, 1, 0,
+ doc: /* Return non nil iff argument X is a NaN. */)
+ (x)
+ Lisp_Object x;
+{
+ CHECK_FLOAT (x);
+ return isnan (XFLOAT_DATA (x)) ? Qt : Qnil;
+}
+
+DEFUN ("copysign", Fcopysign, Scopysign, 1, 2, 0,
+ doc: /* Copy sign of X2 to value of X1, and return the result.
+Cause an error if X1 or X2 is not a float. */)
+ (x1, x2)
+ Lisp_Object x1, x2;
+{
+ double f1, f2;
+
+ CHECK_FLOAT (x1);
+ CHECK_FLOAT (x2);
+
+ f1 = XFLOAT_DATA (x1);
+ f2 = XFLOAT_DATA (x2);
+
+ return make_float (copysign (f1, f2));
+}
+
+DEFUN ("frexp", Ffrexp, Sfrexp, 1, 1, 0,
+ doc: /* Get significand and exponent of a floating point number.
+Breaks the floating point number X into its binary significand SGNFCAND
+\(a floating point value between 0.5 (included) and 1.0 (excluded))
+and an integral exponent EXP for 2, such that:
+
+ X = SGNFCAND * 2^EXP
+
+The function returns the cons cell (SGNFCAND . EXP).
+If X is zero, both parts (SGNFCAND and EXP) are zero. */)
+ (x)
+ Lisp_Object x;
+{
+ double f = XFLOATINT (x);
+
+ if (f == 0.0)
+ return Fcons (make_float (0.0), make_number (0));
+ else
+ {
+ int exp;
+ double sgnfcand = frexp (f, &exp);
+ return Fcons (make_float (sgnfcand), make_number (exp));
+ }
+}
+
+DEFUN ("ldexp", Fldexp, Sldexp, 1, 2, 0,
+ doc: /* Construct number X from significand SGNFCAND and exponent EXP.
+Returns the floating point value resulting from multiplying SGNFCAND
+(the significand) by 2 raised to the power of EXP (the exponent). */)
+ (sgnfcand, exp)
+ Lisp_Object sgnfcand, exp;
+{
+ CHECK_NUMBER (exp);
+ return make_float (ldexp (XFLOATINT (sgnfcand), XINT (exp)));
+}
+#endif
#if 0 /* Leave these out unless we find there's a reason for them. */
@@ -724,11 +778,10 @@ This is the same as the exponent of a float. */)
/* the rounding functions */
static Lisp_Object
-rounding_driver (arg, divisor, double_round, int_round2, name)
- register Lisp_Object arg, divisor;
- double (*double_round) ();
- EMACS_INT (*int_round2) ();
- char *name;
+rounding_driver (Lisp_Object arg, Lisp_Object divisor,
+ double (*double_round) (double),
+ EMACS_INT (*int_round2) (EMACS_INT, EMACS_INT),
+ char *name)
{
CHECK_NUMBER_OR_FLOAT (arg);
@@ -778,8 +831,7 @@ rounding_driver (arg, divisor, double_round, int_round2, name)
integer functions. */
static EMACS_INT
-ceiling2 (i1, i2)
- EMACS_INT i1, i2;
+ceiling2 (EMACS_INT i1, EMACS_INT i2)
{
return (i2 < 0
? (i1 < 0 ? ((-1 - i1) / -i2) + 1 : - (i1 / -i2))
@@ -787,8 +839,7 @@ ceiling2 (i1, i2)
}
static EMACS_INT
-floor2 (i1, i2)
- EMACS_INT i1, i2;
+floor2 (EMACS_INT i1, EMACS_INT i2)
{
return (i2 < 0
? (i1 <= 0 ? -i1 / -i2 : -1 - ((i1 - 1) / -i2))
@@ -796,8 +847,7 @@ floor2 (i1, i2)
}
static EMACS_INT
-truncate2 (i1, i2)
- EMACS_INT i1, i2;
+truncate2 (EMACS_INT i1, EMACS_INT i2)
{
return (i2 < 0
? (i1 < 0 ? -i1 / -i2 : - (i1 / -i2))
@@ -805,8 +855,7 @@ truncate2 (i1, i2)
}
static EMACS_INT
-round2 (i1, i2)
- EMACS_INT i1, i2;
+round2 (EMACS_INT i1, EMACS_INT i2)
{
/* The C language's division operator gives us one remainder R, but
we want the remainder R1 on the other side of 0 if R1 is closer
@@ -826,16 +875,14 @@ round2 (i1, i2)
#define emacs_rint rint
#else
static double
-emacs_rint (d)
- double d;
+emacs_rint (double d)
{
return floor (d + 0.5);
}
#endif
static double
-double_identity (d)
- double d;
+double_identity (double d)
{
return d;
}
@@ -887,8 +934,7 @@ With optional DIVISOR, truncate ARG/DIVISOR. */)
Lisp_Object
-fmod_float (x, y)
- register Lisp_Object x, y;
+fmod_float (Lisp_Object x, Lisp_Object y)
{
double f1, f2;
@@ -1027,6 +1073,12 @@ syms_of_floatfns ()
defsubr (&Scos);
defsubr (&Ssin);
defsubr (&Stan);
+#if defined HAVE_ISNAN && defined HAVE_COPYSIGN
+ defsubr (&Sisnan);
+ defsubr (&Scopysign);
+ defsubr (&Sfrexp);
+ defsubr (&Sldexp);
+#endif
#if 0
defsubr (&Sacosh);
defsubr (&Sasinh);