[Bug c/13028] New: ia64 gcc with -O2 does not store value in register into local varible

["czang at panasas dot com" <gcc-bugzilla at gcc dot gnu dot org>]

This can be demonstrated with the following sample program:

/*
 * program starts
 */

#define ntoh64(_src_, _dest_) { \
  unsigned int *src_p = (unsigned int *) _src_;   \
  unsigned int *dest_p = (unsigned int *) _dest_; \
    *dest_p++ = *src_p++; \
    *dest_p++ = *src_p++; \
}

void
call(unsigned long *number_p)
{
  unsigned long seqno;

  ntoh64(number_p, &seqno);

  printf("in reply_received: seqno is %lu\n", seqno);

  printf("in reply_received: seqno is %lu\n", seqno);
}

main() {
  unsigned long number = 1010101;
  call(&number);
}

/*
 * program ends
 */

The following is the compile command line:

[build-hp1] gcc -v -save-temps -O2 compiler.c 
Reading specs from /usr/lib/gcc-lib/ia64-redhat-linux/2.96/specs
gcc version 2.96 20000731 (Red Hat Linux 7.2 2.96-112.7.2)
 /usr/lib/gcc-lib/ia64-redhat-linux/2.96/cpp0 -lang-c -v -D__GNUC__=2
-D__GNUC_MINOR__=96 -D__GNUC_PATCHLEVEL__=0 -D__ia64 -D__ia64__ -D__linux
-D__linux__ -D_LONGLONG -Dlinux -Dunix -D__LP64__ -D__ELF__ -D__ia64 -D__ia64__
-D__linux -D__linux__ -D_LONGLONG -D__linux__ -D__unix__ -D__LP64__ -D__ELF__
-D__linux -D__unix -Asystem(linux) -Acpu(ia64) -Amachine(ia64) -D__OPTIMIZE__
-D__LONG_MAX__=9223372036854775807L compiler.c compiler.i
GNU CPP version 2.96 20000731 (Red Hat Linux 7.2 2.96-112.7.2) (cpplib) (IA-64)
ignoring nonexistent directory "/usr/ia64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc-lib/ia64-redhat-linux/2.96/include
 /usr/include
End of search list.
 /usr/lib/gcc-lib/ia64-redhat-linux/2.96/cc1 compiler.i -mb-step -quiet
-dumpbase compiler.c -O2 -version -o compiler.s
GNU C version 2.96 20000731 (Red Hat Linux 7.2 2.96-112.7.2) (ia64-redhat-linux)
compiled by GNU C version 2.96 20000731 (Red Hat Linux 7.2 2.96-112.7.2).
 as -x -o compiler.o compiler.s
 /usr/lib/gcc-lib/ia64-redhat-linux/2.96/collect2 -dynamic-linker
/lib/ld-linux-ia64.so.2 /usr/lib/gcc-lib/ia64-redhat-linux/2.96/../../../crt1.o
/usr/lib/gcc-lib/ia64-redhat-linux/2.96/../../../crti.o
/usr/lib/gcc-lib/ia64-redhat-linux/2.96/crtbegin.o
-L/usr/lib/gcc-lib/ia64-redhat-linux/2.96
-L/usr/lib/gcc-lib/ia64-redhat-linux/2.96/../../.. compiler.o -lgcc -lc -lgcc
/usr/lib/gcc-lib/ia64-redhat-linux/2.96/crtend.o
/usr/lib/gcc-lib/ia64-redhat-linux/2.96/../../../crtn.o

The following is the run of the generated program:

[build-hp1] a.out
in reply_received: seqno is 0
in reply_received: seqno is 1010101

-- 
           Summary: ia64 gcc with -O2 does not store value in register into
                    local varible
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: czang at panasas dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13028