[Bug c/27413] New: compiling with -ansi puts in broken version of atanh

[Bug c/27413] New: compiling with -ansi puts in broken version of atanh

[anonymous at mailinator dot com]

If you use -ansi to compile a program that uses the atanh function, the
compiler somehow replaces atanh with a function that just returns 0.  I think
the compiler should either put in the correct atanh function or refuses to
link/compile.  The following shows how to reproduce the bug:


$ cat > bug.c

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

int main() { printf("atanh(%f) returns %f!\n",.32,atanh(.32)); return 0;}

$ gcc bug.c -o bug.exe -lm && bug.exe
atanh(0.320000) returns 0.331647!
$ gcc -ansi bug.c -o bug.exe -lm && bug.exe
atanh(0.320000) returns 0.000000!


-- 
           Summary: compiling with -ansi puts in broken version of atanh
           Product: gcc
           Version: 3.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: anonymous at mailinator dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27413

[Bug c/27413] compiling with -ansi puts in broken version of atanh

[anonymous at mailinator dot com]

------- Comment #1 from anonymous at mailinator dot com  2006-05-04 01:25 -------
Created an attachment (id=11370)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11370&action=view)
.i file created with -save-temps flag


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27413

[Bug c/27413] compiling with -ansi puts in broken version of atanh

[anonymous at mailinator dot com]

------- Comment #2 from anonymous at mailinator dot com  2006-05-04 01:27 -------
Created an attachment (id=11371)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11371&action=view)
.s file created with -save-temps


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27413

[Bug c/27413] compiling with -ansi puts in broken version of atanh

[anonymous at mailinator dot com]

------- Comment #3 from anonymous at mailinator dot com  2006-05-04 01:28 -------
Created an attachment (id=11372)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11372&action=view)
output of compiler with --save-temps


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27413

[Bug c/27413] compiling with -ansi puts in broken version of atanh

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2006-05-04 01:52 -------
t1.c: In function 'main':
t1.c:5: warning: implicit declaration of function 'atanh'
t1.c:5: warning: format '%f' expects type 'double', but argument 3 has type
'int'


You need either -std=c99 or not use -ansi as atanh is a C99 math function and
not part of C90.  Also this is more of a glibc issue than a GCC one.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27413