boost/math
2
0
Fork 0
mirror of https://github.com/boostorg/math.git synced 2026-01-20 16:52:09 +00:00
Code Issues Projects Releases Wiki Activity

Removed example/quadmath_snprintf.c

Browse Source
This commit is contained in:
pabristow
2016-08-12 15:16:17 +01:00
parent 7786c7d5a8
commit 62aa43b044
1 changed files with 0 additions and 93 deletions
Download Patch File Download Diff File Expand all files Collapse all files

93
example/quadmath_snprintf.c
View File

@@ -1,93 +0,0 @@
// Original source file copyright gcc.gnu.org, GNU Free Documentation License, Version 1.3.
// Notes for Boost.Math, (contains Quickbook snippets as C/C++ comments - do not remove!)
// Copyright Paul Bristow 2016.
// Distributed under the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
//[quadmath_snprintf_1
/*`Example of using GCC Quad-Precision Math Library quadmath `__float128` type,
taking a square root with sqrtq, and output using quadmath_snprintf.
From GCC Quad-Precision Math Library,
[@https://gcc.gnu.org/onlinedocs/libquadmath.pdf 3.2 quadmath_snprintf, Convert to string]
(pages 9 and 10).
Requires GCC linker option `-lquadmath`.
If this linker option is missing then you will get errors like:
``
/Cpp/float128/quadmath_snprintf/quadmath_snprintf.c:44: undefined reference to 'sqrtq'.
/Cpp/float128/quadmath_snprintf/quadmath_snprintf.c:45: undefined reference to 'quadmath_snprintf'.
``
On one system, the header file (that contains all the `extern` declarations), included, for example:
``
extern __float128 sqrtq (__float128) __quadmath_throw;
extern __float128 strtoflt128 (const char *, char **) __quadmath_throw;
extern int quadmath_snprintf (char *str, size_t size, const char *format, ...) __quadmath_throw;
``
An example of a location of `quadmath.h` is
``
C:\program files\gcc-6-win64\lib\gcc\x86_64-w64-mingw32\6.1.1\include\quadmath.h
``
and library at
``
C:\Program Files\gcc-6-win64\bin\libquadmath-0.dll
``
Command lines used (using [@http://www.codeblocks.org CodeBLocks]:
``
gcc.exe -Wall -g -c J:\Cpp\float128\quadmath_snprintf\main.c -o obj\Debug\main.o
g++.exe -o bin\Debug\quadmath_snprintf.exe obj\Debug\main.o -lquadmath
``
*/
//] [/quadmath_snprintf_1]
#include <quadmath.h>
#include <stdlib.h>
#include <stdio.h>
int main ()
{
__float128 r;
int prec = 20;
int width = 46;
char buf[128];
r = 2.0q;
r = sqrtq (r);
int n = quadmath_snprintf (buf, sizeof buf, "%+-#*.20Qe", width, r);
if ((size_t) n < sizeof buf)
printf ("%s\n", buf);
/* Prints: +1.41421356237309504880e+00 */
quadmath_snprintf (buf, sizeof buf, "%Qa", r);
if ((size_t) n < sizeof buf)
printf ("%s\n", buf);
/* Prints: 0x1.6a09e667f3bcc908b2fb1366ea96p+0 */
n = quadmath_snprintf (NULL, 0, "%+-#46.*Qe", prec, r);
if (n > -1)
{
char *str = malloc (n + 1);
if (str)
{
quadmath_snprintf (str, n + 1, "%+-#46.*Qe", prec, r);
printf ("%s\n", str);
/* Prints: +1.41421356237309504880e+00 */
}
free (str);
}
return 0;
}
/*
Output:
+1.41421356237309504880e+00
0x1.6a09e667f3bcc908b2fb1366ea96p+0
+1.41421356237309504880e+00
*/