newlib-2.4.0

git-svn-id: svn://kolibrios.org@6536 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/newlib/libc/stdlib/ecvtbuf.c

@@ -0,0 +1,471 @@
+/*
+FUNCTION
+<<ecvtbuf>>, <<fcvtbuf>>---double or float to string
+
+INDEX
+	ecvtbuf
+INDEX
+	fcvtbuf
+
+ANSI_SYNOPSIS
+	#include <stdio.h>
+
+	char *ecvtbuf(double <[val]>, int <[chars]>, int *<[decpt]>,
+                       int *<[sgn]>, char *<[buf]>);
+
+	char *fcvtbuf(double <[val]>, int <[decimals]>, int *<[decpt]>,
+                       int *<[sgn]>, char *<[buf]>);
+
+TRAD_SYNOPSIS
+	#include <stdio.h>
+
+	char *ecvtbuf(<[val]>, <[chars]>, <[decpt]>, <[sgn]>, <[buf]>);
+	double <[val]>;
+	int <[chars]>;
+	int *<[decpt]>;
+	int *<[sgn]>;
+	char *<[buf]>;
+
+	char *fcvtbuf(<[val]>, <[decimals]>, <[decpt]>, <[sgn]>, <[buf]>);
+	double <[val]>;
+	int <[decimals]>;
+	int *<[decpt]>;
+	int *<[sgn]>;
+	char *<[buf]>;
+
+DESCRIPTION
+	<<ecvtbuf>> and <<fcvtbuf>> produce (null-terminated) strings
+	of digits representating the <<double>> number <[val]>.
+
+	The only difference between <<ecvtbuf>> and <<fcvtbuf>> is the
+	interpretation of the second argument (<[chars]> or
+	<[decimals]>). For <<ecvtbuf>>, the second argument <[chars]>
+	specifies the total number of characters to write (which is
+	also the number of significant digits in the formatted string,
+	since these two functions write only digits). For <<fcvtbuf>>,
+	the second argument <[decimals]> specifies the number of
+	characters to write after the decimal point; all digits for
+	the integer part of <[val]> are always included.
+
+	Since <<ecvtbuf>> and <<fcvtbuf>> write only digits in the
+	output string, they record the location of the decimal point
+	in <<*<[decpt]>>>, and the sign of the number in <<*<[sgn]>>>.
+	After formatting a number, <<*<[decpt]>>> contains the number
+	of digits to the left of the decimal point.  <<*<[sgn]>>>
+	contains <<0>> if the number is positive, and <<1>> if it is
+	negative.  For both functions, you supply a pointer <[buf]> to
+	an area of memory to hold the converted string.
+
+RETURNS
+	Both functions return a pointer to <[buf]>, the string
+	containing a character representation of <[val]>.
+
+PORTABILITY
+	Neither function is ANSI C.
+
+Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
+<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
+*/
+
+#include <_ansi.h>
+#include <stdlib.h>
+#include <string.h>
+#include <reent.h>
+#include "mprec.h"
+#include "local.h"
+
+static void
+_DEFUN (print_f, (ptr, buf, invalue, ndigit, type, dot, mode),
+	struct _reent *ptr _AND
+	char *buf _AND
+	double invalue _AND
+	int ndigit _AND
+	char type _AND
+	int dot _AND
+	int mode)
+{
+  int decpt;
+  int sign;
+  char *p, *start, *end;
+
+  start = p = _dtoa_r (ptr, invalue, mode, ndigit, &decpt, &sign, &end);
+
+  if (decpt == 9999)
+    {
+      strcpy (buf, p);
+      return;
+    }
+  while (*p && decpt > 0)
+    {
+      *buf++ = *p++;
+      decpt--;
+    }
+  /* Even if not in buffer */
+  while (decpt > 0)
+    {
+      *buf++ = '0';
+      decpt--;
+    }
+
+  if (dot || *p)
+    {
+      if (p == start)
+	*buf++ = '0';
+      *buf++ = '.';
+      while (decpt < 0 && ndigit > 0)
+	{
+	  *buf++ = '0';
+	  decpt++;
+	  ndigit--;
+	}
+
+      /* Print rest of stuff */
+      while (*p && ndigit > 0)
+	{
+	  *buf++ = *p++;
+	  ndigit--;
+	}
+      /* And trailing zeros */
+      while (ndigit > 0)
+	{
+	  *buf++ = '0';
+	  ndigit--;
+	}
+    }
+  *buf++ = 0;
+}
+
+/* Print number in e format with width chars after.
+
+   TYPE is one of 'e' or 'E'.  It may also be one of 'g' or 'G' indicating
+   that _gcvt is calling us and we should remove trailing zeroes.
+
+   WIDTH is the number of digits of precision after the decimal point.  */
+
+static void
+_DEFUN (print_e, (ptr, buf, invalue, width, type, dot),
+	struct _reent *ptr _AND
+	char *buf _AND
+	double invalue _AND
+	int width _AND
+	char type _AND
+	int dot)
+{
+  int sign;
+  char *end;
+  char *p;
+  int decpt;
+  int top;
+  int ndigit = width;
+
+  p = _dtoa_r (ptr, invalue, 2, width + 1, &decpt, &sign, &end);
+
+  if (decpt == 9999)
+    {
+      strcpy (buf, p);
+      return;
+    }
+
+  *buf++ = *p++;
+  if (dot || ndigit != 0)
+    *buf++ = '.';
+
+  while (*p && ndigit > 0)
+    {
+      *buf++ = *p++;
+      ndigit--;
+    }
+
+  /* Add trailing zeroes to fill out to ndigits unless this is 'g' format.
+     Also, convert g/G to e/E.  */
+
+  if (type == 'g')
+    type = 'e';
+  else if (type == 'G')
+    type = 'E';
+  else
+    {
+      while (ndigit > 0)
+	{
+	  *buf++ = '0';
+	  ndigit--;
+	}
+    }
+
+  /* Add the exponent.  */
+
+  *buf++ = type;
+  decpt--;
+  if (decpt < 0)
+    {
+      *buf++ = '-';
+      decpt = -decpt;
+    }
+  else
+    {
+      *buf++ = '+';
+    }
+  if (decpt > 99)
+    {
+      int top = decpt / 100;
+      *buf++ = top + '0';
+      decpt -= top * 100;
+    }
+  top = decpt / 10;
+  *buf++ = top + '0';
+  decpt -= top * 10;
+  *buf++ = decpt + '0';
+
+  *buf++ = 0;
+}
+
+#ifndef _REENT_ONLY
+
+/* Undocumented behaviour: when given NULL as a buffer, return a
+   pointer to static space in the rent structure.  This is only to
+   support ecvt and fcvt, which aren't ANSI anyway.  */
+
+char *
+_DEFUN (fcvtbuf, (invalue, ndigit, decpt, sign, fcvt_buf),
+	double invalue _AND
+	int ndigit _AND
+	int *decpt _AND
+	int *sign _AND
+	char *fcvt_buf)
+{
+  struct _reent *reent = _REENT;
+  char *save;
+  char *p;
+  char *end;
+  int done = 0;
+
+  if (fcvt_buf == NULL)
+    {
+      if (reent->_cvtlen <= ndigit + 35)
+	{
+	  if ((fcvt_buf = (char *) _realloc_r (reent, reent->_cvtbuf,
+					       ndigit + 36)) == NULL)
+	    return NULL;
+	  reent->_cvtlen = ndigit + 36;
+	  reent->_cvtbuf = fcvt_buf;
+	}
+
+      fcvt_buf = reent->_cvtbuf ;
+    }
+
+  save = fcvt_buf;
+
+  if (invalue < 1.0 && invalue > -1.0)
+    {
+      p = _dtoa_r (reent, invalue, 2, ndigit, decpt, sign, &end);
+    }
+  else
+    {
+      p = _dtoa_r (reent, invalue, 3, ndigit, decpt, sign, &end);
+    }
+
+  /* Now copy */
+
+  done = -*decpt;
+  while (p < end)
+    {
+      *fcvt_buf++ = *p++;
+      done++;
+    }
+  /* And unsuppress the trailing zeroes */
+  while (done < ndigit)
+    {
+      *fcvt_buf++ = '0';
+      done++;
+    }
+  *fcvt_buf++ = 0;
+  return save;
+}
+
+char *
+_DEFUN (ecvtbuf, (invalue, ndigit, decpt, sign, fcvt_buf),
+	double invalue _AND
+	int ndigit _AND
+	int *decpt _AND
+	int *sign _AND
+	char *fcvt_buf)
+{
+  struct _reent *reent = _REENT;
+  char *save;
+  char *p;
+  char *end;
+  int done = 0;
+
+  if (fcvt_buf == NULL)
+    {
+      if (reent->_cvtlen <= ndigit)
+	{
+	  if ((fcvt_buf = (char *) _realloc_r (reent, reent->_cvtbuf,
+					       ndigit + 1)) == NULL)
+	    return NULL;
+	  reent->_cvtlen = ndigit + 1;
+	  reent->_cvtbuf = fcvt_buf;
+	}
+
+      fcvt_buf = reent->_cvtbuf ;
+    }
+
+  save = fcvt_buf;
+
+  p = _dtoa_r (reent, invalue, 2, ndigit, decpt, sign, &end);
+
+  /* Now copy */
+
+  while (p < end)
+    {
+      *fcvt_buf++ = *p++;
+      done++;
+    }
+  /* And unsuppress the trailing zeroes */
+  while (done < ndigit)
+    {
+      *fcvt_buf++ = '0';
+      done++;
+    }
+  *fcvt_buf++ = 0;
+  return save;
+}
+
+#endif
+
+char *
+_DEFUN (_gcvt, (ptr, invalue, ndigit, buf, type, dot),
+	struct _reent *ptr _AND
+	double invalue _AND
+	int ndigit _AND
+	char *buf _AND
+	char type _AND
+	int dot)
+{
+  char *save = buf;
+
+  if (invalue < 0)
+    {
+      invalue = -invalue;
+    }
+
+  if (invalue == 0)
+    {
+      *buf++ = '0';
+      *buf = '\0';
+    }
+  else
+    /* Which one to print ?
+       ANSI says that anything with more that 4 zeros after the . or more
+       than precision digits before is printed in e with the qualification
+       that trailing zeroes are removed from the fraction portion.  */
+
+  if (0.0001 >= invalue || invalue >= _mprec_log10 (ndigit))
+    {
+      /* We subtract 1 from ndigit because in the 'e' format the precision is
+	 the number of digits after the . but in 'g' format it is the number
+	 of significant digits.
+
+	 We defer changing type to e/E so that print_e() can know it's us
+	 calling and thus should remove trailing zeroes.  */
+
+      print_e (ptr, buf, invalue, ndigit - 1, type, dot);
+    }
+  else
+    {
+      int decpt;
+      int sign;
+      char *end;
+      char *p;
+
+      if (invalue < 1.0)
+	{
+	  /* what we want is ndigits after the point */
+	  p = _dtoa_r (ptr, invalue, 3, ndigit, &decpt, &sign, &end);
+	}
+      else
+	{
+	  p = _dtoa_r (ptr, invalue, 2, ndigit, &decpt, &sign, &end);
+	}
+
+      if (decpt == 9999)
+	{
+	  strcpy (buf, p);
+	  return save;
+	}
+      while (*p && decpt > 0)
+	{
+	  *buf++ = *p++;
+	  decpt--;
+	  ndigit--;
+	}
+      /* Even if not in buffer */
+      while (decpt > 0 && ndigit > 0)
+	{
+	  *buf++ = '0';
+	  decpt--;
+	  ndigit--;
+	}
+
+      if (dot || *p)
+	{
+	  if (buf == save)
+	    *buf++ = '0';
+	  *buf++ = '.';
+	  while (decpt < 0 && ndigit > 0)
+	    {
+	      *buf++ = '0';
+	      decpt++;
+	      ndigit--;
+	    }
+
+	  /* Print rest of stuff */
+	  while (*p && ndigit > 0)
+	    {
+	      *buf++ = *p++;
+	      ndigit--;
+	    }
+	  /* And trailing zeros */
+	  if (dot)
+	    {
+	      while (ndigit > 0)
+		{
+		  *buf++ = '0';
+		  ndigit--;
+		}
+	    }
+	}
+      *buf++ = 0;
+    }
+
+  return save;
+}
+
+char *
+_DEFUN (_dcvt, (ptr, buffer, invalue, precision, width, type, dot),
+	struct _reent *ptr _AND
+	char *buffer _AND
+	double invalue _AND
+	int precision _AND
+	int width _AND
+	char type _AND
+	int dot)
+{
+  switch (type)
+    {
+    case 'f':
+    case 'F':
+      print_f (ptr, buffer, invalue, precision, type, precision == 0 ? dot : 1, 3);
+      break;
+    case 'g':
+    case 'G':
+      if (precision == 0)
+	precision = 1;
+      _gcvt (ptr, invalue, precision, buffer, type, dot);
+      break;
+    case 'e':
+    case 'E':
+      print_e (ptr, buffer, invalue, precision, type, dot);
+    }
+  return buffer;
+}