Description of problem:
If a C code is compiled with the -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
flag then the offset argument for  pread() is passed as 0 or some garbage
number. This happens only on a powerPC. The sample code to reproduce this is as
follows:
===================================================================
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

int main(void)
{
        int fdin, fdout, ret;
        char *buf;
        off_t off=73728;

        buf=(char *) malloc(131072);
        if (!buf) {printf ("Bad"); exit(0);}

        fdin = open("/oradata/BAN25/system01.dbf", O_RDONLY);
        if(fdin<0) printf("fdin error\n");
        fdout = open("/tmp/checksystem.dbf", O_WRONLY | O_CREAT);
        if(fdout<0) printf("fdout error\n");

        ret = pread(fdin, buf, 8192, off);
        if(ret!=8192){printf("error read\n");}
        ret = write(fdout, buf, 8192);
        if(ret!=8192){printf("error write\n");}

        close(fdin);
        close(fdout);
}

===================================================================

and was compiled as follows

#gcc -g -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 try.c
The strace output for the same is attached with this bug (strace.out).
strace was generated as:
#strace -f ./a.out >strace.out 2>&1

Now pread would work fine if these changes were done.
-> If  pread() is changed to pread64() in teh code, then things work fine.
-> also ifthe code is  compiled with -D_XOPEN_SOURCE=500 and things worked fine
   but unfortunately I cannot use the -D_XOPEN_SOURCE=500 flag as this flag   
   seems to uset the following type definations: uint, u_long etc, which are
   being used in the code base.

The same code was compliled on an Intel and AMD system and pread() worked fine
without the -D_XOPEN_SOURCE=500 compilation flag. That is the offset was passed
sucessfully.

Why does this happen? 

Version-Release number of selected component (if applicable): 
This fails on a powerpc with either of the gcc versions glibc-2.3.4-2.19 and 
glibc-2.3.4-2.25


How reproducible: 
Always reproducable (consistant)


Steps to Reproduce:
1. Write a C code with the pread() call
2. Set the debug flag -D_FILE_OFFSET_BITS=64 for gcc and compile.
3. strace output for the execution shows that pread64()is called internally and
the offset value is changed to some junk value or 0.

I am passing the offset as 73728.
Actual results:
pread64(3, "\0\242\0\0\377\300\0\0\0\0\0\0\0\0\0\0\341\304\0\0\0\0"..., 8192, 0) 

Expected results:
pread64(3, "\0\242\0\0\377\300\0\0\0\0\0\0\0\0\0\0\341\304\0\0\0\0"..., 8192, 73728)

Additional info:
If I directly call pread64() within the code, things work fine.