core dump using pow and structures with egcs

[Andy Loening]

Hello People,

I might have a bug for you guys to chew on here.  From what I can tell,
this is the simplest case I could come up with.  I did need three elements
in the structure and two pows to produce this bug.


test.c
------------------------------------------------------------------
#include <math.h> 

typedef struct {
  double x;
  double y;
  double z; 
} RealPoint; 

int main (void) {
  
  RealPoint p1 = {25.0, 25.0, 25.0};
  double a;

  a = (pow(3,2)+pow(4,2));

  return; 
}
---------------------------------------------------------------


When I compile and run this, I get a core dump.  I'm compiling with:
"egcs -lm -Ox -o test test.c"
where x is 2 or 3.

This is a redhat 6.0 gnu/linux box and "egcs -v" gives me
gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)           

I also get the same thing on a mandrake 5.3 gnu/linux box where
"egcs -v" gives me: gcc version egcs-2.90.29 980515 (egcs-1.0.3 release) 
In this case, any optimization level will cause the crash.  Note that gcc
version 2.7.2.3 on this box does not give this behaviour.

So, I compiled with -ggdb (this is back on the redhat 6.0 based system,
egcs version 1.1.2) did a bt in gdb, and this is what I get:

------------------------------------------------------------------
Core was generated by `./test'. Program terminated with signal 11,
Segmentation fault. Reading symbols from
/opt/rsi/idl_5.2/bin/bin.linux/__setfpucw.so...done. 
Reading symbols from /lib/libm.so.6...done. 
Reading symbols from /lib/libc.so.6...done. 
Reading symbols from /lib/ld-linux.so.2...done. 
#0 0x8048515 in main () at /usr/include/bits/mathinline.h:376 376
__inline_mathcode2 (pow, __x, __y, \ 
(gdb) bt 
#0 0x8048515 in main () at /usr/include/bits/mathinline.h:376
#1 0x4004fcb3 in __libc_start_main (main=0x8048440 <main>, argc=1,
    argv=0xbffffb84, init=0x8048310 <_init>, fini=0x80485bc <_fini>,
    rtld_fini=0x4000a350 <_dl_fini>, stack_end=0xbffffb7c)
    at ../sysdeps/generic/libc-start.c:78                                   
----------------------------------------------------------------



If you guys want any more information, please feel free to get in touch
with me (loening@ucla.edu). Oh, and I'm not on this list, so replying to
the list won't send anything to me.

Thanks,
	Andy