aboutsummaryrefslogtreecommitdiff
path: root/nuttx/libc/stdio/lib_libdtoa.c
diff options
context:
space:
mode:
Diffstat (limited to 'nuttx/libc/stdio/lib_libdtoa.c')
-rw-r--r--nuttx/libc/stdio/lib_libdtoa.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/nuttx/libc/stdio/lib_libdtoa.c b/nuttx/libc/stdio/lib_libdtoa.c
new file mode 100644
index 000000000..29f61fd76
--- /dev/null
+++ b/nuttx/libc/stdio/lib_libdtoa.c
@@ -0,0 +1,304 @@
+/****************************************************************************
+ * libc/unistd/lib_libdtoa.c
+ *
+ * This file was ported to NuttX by Yolande Cates.
+ *
+ * Copyright (c) 1990, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX_PREC 16
+
+#ifndef MIN
+# define MIN(a,b) (a < b ? a : b)
+#endif
+
+#ifndef MAX
+# define MAX(a,b) (a > b ? a : b)
+#endif
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: zeroes
+ *
+ * Description:
+ * Print the specified number of zeres
+ *
+ ****************************************************************************/
+
+static void zeroes(FAR struct lib_outstream_s *obj, int nzeroes)
+{
+ int i;
+
+ for (i = nzeroes; i > 0; i--)
+ {
+ obj->put(obj, '0');
+ }
+}
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: lib_dtoa
+ *
+ * Description:
+ * This is part of lib_vsprintf(). It handles the floating point formats.
+ * This version supports only the %f (with precision). If no precision
+ * was provided in the format, this will use precision == 0 which is
+ * probably not what you want.
+ *
+ * Input Parameters:
+ * obj - The output stream object
+ * fmt - The format character. Not used 'f' is always assumed
+ * prec - The number of digits to the right of the decimal point. If no
+ * precision is provided in the format, this will be zero. And,
+ * unfortunately in this case, it will be treated literally as
+ * a precision of zero.
+ * flags - Only ALTFORM and SHOWPLUS flags are supported. ALTFORM only
+ * applies if prec == 0 which is not supported anyway.
+ * value - The floating point value to convert.
+ *
+ ****************************************************************************/
+
+static void lib_dtoa(FAR struct lib_outstream_s *obj, int fmt, int prec,
+ uint8_t flags, double value)
+{
+ FAR char *digits; /* String returned by __dtoa */
+ FAR char *digalloc; /* Copy of digits to be freed after usage */
+ FAR char *rve; /* Points to the end of the return value */
+ int expt; /* Integer value of exponent */
+ int numlen; /* Actual number of digits returned by cvt */
+ int nchars; /* Number of characters to print */
+ int dsgn; /* Unused sign indicator */
+ int i;
+
+ /* Non-zero... positive or negative */
+
+ if (value < 0)
+ {
+ value = -value;
+ SET_NEGATE(flags);
+ }
+
+ /* Perform the conversion */
+
+ digits = __dtoa(value, 3, prec, &expt, &dsgn, &rve);
+ digalloc = digits;
+ numlen = rve - digits;
+
+ if (IS_NEGATE(flags))
+ {
+ obj->put(obj, '-');
+ }
+ else if (IS_SHOWPLUS(flags))
+ {
+ obj->put(obj, '+');
+ }
+
+ /* Special case exact zero or the case where the number is smaller than
+ * the print precision.
+ */
+
+ if (value == 0 || expt < -prec)
+ {
+ /* kludge for __dtoa irregularity */
+
+ obj->put(obj, '0');
+
+ /* A decimal point is printed only in the alternate form or if a
+ * particular precision is requested.
+ */
+
+ if (prec > 0 || IS_ALTFORM(flags))
+ {
+ obj->put(obj, '.');
+
+ /* Always print at least one digit to the right of the decimal point. */
+
+ prec = MAX(1, prec);
+ }
+ }
+
+ /* A non-zero value will be printed */
+
+ else
+ {
+
+ /* Handle the case where the value is less than 1.0 (in magnitude) and
+ * will need a leading zero.
+ */
+
+ if (expt <= 0)
+ {
+ /* Print a single zero to the left of the decimal point */
+
+ obj->put(obj, '0');
+
+ /* Print the decimal point */
+
+ obj->put(obj, '.');
+
+ /* Print any leading zeros to the right of the decimal point */
+
+ if (expt < 0)
+ {
+ nchars = MIN(-expt, prec);
+ zeroes(obj, nchars);
+ prec -= nchars;
+ }
+ }
+
+ /* Handle the general case where the value is greater than 1.0 (in
+ * magnitude).
+ */
+
+ else
+ {
+ /* Print the integer part to the left of the decimal point */
+
+ for (i = expt; i > 0; i--)
+ {
+ if (*digits != '\0')
+ {
+ obj->put(obj, *digits);
+ digits++;
+ }
+ else
+ {
+ obj->put(obj, '0');
+ }
+ }
+
+ /* Get the length of the fractional part */
+
+ numlen -= expt;
+
+ /* If there is no fractional part, then a decimal point is printed
+ * only in the alternate form or if a particular precision is
+ * requested.
+ */
+
+ if (numlen > 0 || prec > 0 || IS_ALTFORM(flags))
+ {
+ /* Print the decimal point */
+
+ obj->put(obj, '.');
+
+ /* Always print at least one digit to the right of the decimal
+ * point.
+ */
+
+ prec = MAX(1, prec);
+ }
+ }
+
+ /* If a precision was specified, then limit the number digits to the
+ * right of the decimal point.
+ */
+
+ if (prec > 0)
+ {
+ nchars = MIN(numlen, prec);
+ }
+ else
+ {
+ nchars = numlen;
+ }
+
+ /* Print the fractional part to the right of the decimal point */
+
+ for (i = nchars; i > 0; i--)
+ {
+ obj->put(obj, *digits);
+ digits++;
+ }
+
+ /* Decremnt to get the number of trailing zeroes to print */
+
+ prec -= nchars;
+ }
+
+ /* Finally, print any trailing zeroes */
+
+ zeroes(obj, prec);
+
+ /* Is this memory supposed to be freed or not? */
+
+#if 0
+ if (digalloc)
+ {
+ free(digalloc);
+ }
+#endif
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-13 07:50:46 +0000