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authorEric Andersen <andersen@codepoet.org>2001-05-10 00:40:28 +0000
committerEric Andersen <andersen@codepoet.org>2001-05-10 00:40:28 +0000
commit1077fa4d772832f77a677ce7fb7c2d513b959e3f (patch)
tree579bee13fb0b58d2800206366ec2caecbb15f3fc /libm/ldouble/isnanl.c
parent22358dd7ce7bb49792204b698f01a6f69b9c8e08 (diff)
uClibc now has a math library. muahahahaha!
-Erik
Diffstat (limited to 'libm/ldouble/isnanl.c')
-rw-r--r--libm/ldouble/isnanl.c186
1 files changed, 186 insertions, 0 deletions
diff --git a/libm/ldouble/isnanl.c b/libm/ldouble/isnanl.c
new file mode 100644
index 000000000..44158ecc7
--- /dev/null
+++ b/libm/ldouble/isnanl.c
@@ -0,0 +1,186 @@
+/* isnanl()
+ * isfinitel()
+ * signbitl()
+ *
+ * Floating point IEEE special number tests
+ *
+ *
+ *
+ * SYNOPSIS:
+ *
+ * int signbitl(), isnanl(), isfinitel();
+ * long double x, y;
+ *
+ * n = signbitl(x);
+ * n = isnanl(x);
+ * n = isfinitel(x);
+ *
+ *
+ *
+ * DESCRIPTION:
+ *
+ * These functions are part of the standard C run time library
+ * for some but not all C compilers. The ones supplied are
+ * written in C for IEEE arithmetic. They should
+ * be used only if your compiler library does not already have
+ * them.
+ *
+ */
+
+
+/*
+Cephes Math Library Release 2.7: June, 1998
+Copyright 1992, 1998 by Stephen L. Moshier
+*/
+
+
+#include <math.h>
+
+/* This is defined in mconf.h. */
+/* #define DENORMAL 1 */
+
+#ifdef UNK
+/* Change UNK into something else. */
+#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 signbitl(x)
+long double x;
+{
+union
+ {
+ long double d;
+ short s[6];
+ int i[3];
+ } u;
+
+u.d = x;
+
+if( sizeof(int) == 4 )
+ {
+#ifdef IBMPC
+ return( u.s[4] < 0 );
+#endif
+#ifdef MIEEE
+ return( u.i[0] < 0 );
+#endif
+ }
+else
+ {
+#ifdef IBMPC
+ return( u.s[4] < 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 isnanl(x)
+long double x;
+{
+#ifdef NANS
+union
+ {
+ long double d;
+ unsigned short s[6];
+ unsigned int i[3];
+ } u;
+
+u.d = x;
+
+if( sizeof(int) == 4 )
+ {
+#ifdef IBMPC
+ if( ((u.s[4] & 0x7fff) == 0x7fff)
+ && (((u.i[1] & 0x7fffffff)!= 0) || (u.i[0] != 0)))
+ return 1;
+#endif
+#ifdef MIEEE
+ if( ((u.i[0] & 0x7fff0000) == 0x7fff0000)
+ && (((u.i[1] & 0x7fffffff) != 0) || (u.i[2] != 0)))
+ return 1;
+#endif
+ return(0);
+ }
+else
+ { /* size int not 4 */
+#ifdef IBMPC
+ if( (u.s[4] & 0x7fff) == 0x7fff)
+ {
+ if((u.s[3] & 0x7fff) | u.s[2] | u.s[1] | u.s[0])
+ return(1);
+ }
+#endif
+#ifdef MIEEE
+ if( (u.s[0] & 0x7fff) == 0x7fff)
+ {
+ if((u.s[2] & 0x7fff) | u.s[3] | u.s[4] | u.s[5])
+ 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 isfinitel(x)
+long double x;
+{
+#ifdef INFINITIES
+union
+ {
+ long double d;
+ unsigned short s[6];
+ unsigned int i[3];
+ } u;
+
+u.d = x;
+
+if( sizeof(int) == 4 )
+ {
+#ifdef IBMPC
+ if( (u.s[4] & 0x7fff) != 0x7fff)
+ return 1;
+#endif
+#ifdef MIEEE
+ if( (u.i[0] & 0x7fff0000) != 0x7fff0000)
+ return 1;
+#endif
+ return(0);
+ }
+else
+ {
+#ifdef IBMPC
+ if( (u.s[4] & 0x7fff) != 0x7fff)
+ return 1;
+#endif
+#ifdef MIEEE
+ if( (u.s[0] & 0x7fff) != 0x7fff)
+ return 1;
+#endif
+ return(0);
+ }
+#else
+/* No INFINITY. */
+return(1);
+#endif
+}