RE: Quick question about "print EXPR"

["Brian Desany" <brian@desany.com>]

 
> Brian Desany wrote:
> >>Did you include <math.h> in your program? 
> > 
> > 
> > Yep, I did (the program itself works properly).
> > 
> > FWIW the only lines of the program that aren't listed in my 
> original post are:
> > #include <stdio.h>
> > #include <math.h>
> > 
> > And just in case it matters, I compiled using the command 
> "cc -lm -g test.c".
> > If I compile with "gcc -lm -g test.c", "p floor(whatever)" 
> is always 
> > 16 (rather than 1 as in the original post).
> 
> Wonder if GDB can see this.  What does:
> 
> (gdb) ptype floor
> 
> print?

type = int ()

I was wrong about "p floor(whatever)" always returning a constant value. It
returns a different value depending apparently on what line of the program
I'm currently stopped on:

Breakpoint 1, main (argc=1, argv=0xbfffcf54) at test.c:9
9                        yada = 2.5;
(gdb) p floor(123.456)
$1 = 0
(gdb) n
10                       haha = floor(yada);
(gdb) p floor(123.456)
$2 = 0
(gdb) n
11                       printf("%0.1f %0.1f\n",yada, haha);
(gdb) p floor(123.456)
$3 = 3199
(gdb) n
2.5 -0.0
12                       return 0;
(gdb) p floor(123.456)
$4 = 9
(gdb) 

> 
> Andrew
> 
> > [bdesany]$ cc -v
> > Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/2.96/specs
> > gcc version 2.96 20000731 (Red Hat Linux 7.1 2.96-81) 
> [bdesany]$ gcc 
> > -v Reading specs from 
> > /home/bdesany/sys/lib/gcc/i686-pc-linux-gnu/3.4.2/specs
> > Configured with: ./configure --prefix=/home/bdesany/sys 
> Thread model: 
> > posix gcc version 3.4.2
> > 
> > Thanks-
> > -Brian.