Initial commit

2025-08-20 18:25:46 +08:00
commit 92a1d4d3c7
3987 changed files with 1181678 additions and 0 deletions
--- a/libc/math/modf.c
+++ b/libc/math/modf.c
@@ -0,0 +1,112 @@
+/* modf.c - separate floating-point number into integer and fraction parts */
+
+/* Copyright 1992-1993 Wind River Systems, Inc. */
+
+/*
+modification history
+--------------------
+01j,19mar95,dvs  removed TRON ifdef - no longer supported.
+01i,05feb93,jdi  doc changes based on kdl review.
+01h,02dec92,jdi  doc tweaks.
+01g,28oct92,jdi  documentation cleanup.
+01f,20sep92,smb  documentation additions
+01e,10sep92,wmd  changed dummy function for i960KB from printf to bcopy.
+01d,04sep92,wmd  restored to rev 1b, instead modified mathP.h using  _BYTE_ORDER 
+		 conditionals to flip the contents of struct DOUBLE.  Added a dummy
+		 printf() in order to force compiler to compile code correctly for i960kb.
+01c,03sep92,wmd  modified modf() for the i960, word order for DOUBLE is reversed.
+01b,25jul92,kdl	 replaced modf() routine contents with version from floatLib.c;
+		 deleted isnan(), iszero(), isinf(), _d_type().
+01a,08jul92,smb  documentation.
+*/
+
+/*
+DESCRIPTION
+
+SEE ALSO: American National Standard X3.159-1989
+
+NOMANUAL
+*/
+
+#include "vxWorks.h"
+#include "math.h"
+#include "stddef.h"
+#include "errno.h"
+#include "private/mathP.h"
+
+
+
+/*******************************************************************************
+*
+* modf - separate a floating-point number into integer and fraction parts (ANSI)
+*
+* This routine stores the integer portion of <value>
+* in <pIntPart> and returns the fractional portion.
+* Both parts are double precision and will have the same sign as <value>.
+*
+* INCLUDE FILES: math.h
+*
+* RETURNS: The double-precision fractional portion of <value>.
+*
+* SEE ALSO: frexp(), ldexp()
+*/
+
+double modf
+    (
+    double value,               /* value to split                  */
+    double *pIntPart            /* where integer portion is stored */
+    )
+    {
+    DOUBLE 	dat;
+    FAST int 	exp;
+    FAST double fracPart;
+    FAST double intPart;
+    int 	negflag = (value < 0);
+
+    if (negflag)
+        value = -value;		/* make it positive */
+
+    dat.ddat = value;
+
+    /* Separate the exponent, and change it from biased to 2's comp. */
+    exp = ((dat.ldat.l1 & 0x7ff00000) >> 20) - 1023;
+
+#if CPU==I960KB
+    bcopy ((char *)&negflag, (char *)&negflag, 0);
+#endif  /* CPU==I960KB - to force gcc960 to compile correct code for the i960kb */
+    
+    if (exp <= -1)
+        {
+	/* If exponent is negative, fracPart == |value|, and intPart == 0. */
+
+        fracPart = value;
+        intPart = 0.;
+        }
+
+    /* clear the fractional part in dat */
+
+    else if (exp <= 20)
+        {
+        dat.ldat.l1 &= (-1 << (20 - exp));
+        dat.ldat.l2 = 0;
+        intPart = dat.ddat;
+        fracPart = value - intPart;
+        }
+
+    else if (exp <= 52)
+        {
+        dat.ldat.l2 &= (-1 << (52 - exp));
+        intPart = dat.ddat;
+        fracPart = value - intPart;
+	}
+
+    else
+        {
+        fracPart = 0.;
+        intPart = value;
+        }
+
+    *pIntPart = (negflag ? -intPart : intPart);
+    return (negflag ? -fracPart : fracPart);
+    }
+