target/6265: arm-elf toolchain wrong reference to varibles or stack address when using -O2 option

[davidwu at arcturusnetworks dot com]

>Number:         6265
>Category:       target
>Synopsis:       arm-elf toolchain wrong reference to varibles or stack address when using -O2 option
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Apr 11 13:36:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     davidwu@arcturusnetworks.com
>Release:        gcc 2.95.3/ gcc 3.1
>Organization:
>Environment:
Linux version 2.4.4-4GB (gcc version 2.95.3 20010315 (SuSE)) #1 Sat Jun 23 05:26:59 GMT 2001
>Description:
the following codes(file1) compile and execute correctly without using -O2
option. But when using -O2 option, the struct P3 is wrong(gcc 2.95) or 
Struct P2(gcc 3.1) is wrong. 
when using one "printf"( or just unuse bar()),it will be correct. 
 
//======================
typedef struct {
  long int p_x, p_y;
} Point;
 
void
bar ()
{
}
 
void
f (p0, p1, p2, p3, p4, p5)
Point p0, p1, p2, p3, p4, p5;
{
printf("p0x=%d\n",p0.p_x);
printf("p0y=%d\n",p0.p_y);
printf("%d\n",p1.p_x);
printf("%d\n",p1.p_y);
printf("%d\n",p2.p_x);
printf("%d\n",p2.p_y);
printf("%d\n",p1.p_x);
printf("%d\n",p1.p_y);
printf("%d\n",p2.p_x);
printf("%d\n",p2.p_y);
printf("%d\n",p3.p_x);
printf("%d\n",p3.p_y);
printf("%d\n",p4.p_x);
printf("%d\n",p4.p_y);
printf("%d\n",p5.p_x);
printf("%d\n",p5.p_y);
}
 
void
foo ()
{
  Point p0, p1, p2, p3, p4, p5;
  bar();
 
  p0.p_x = 0;
//printf("%d\n",p0.p_x);
  p0.p_y = 1;
  p1.p_x = -1;
  p1.p_y = 0;
  p2.p_x = 1;
  p2.p_y = -1;
  p3.p_x = -1;
  p3.p_y = 1;
  p4.p_x = 0;
  p4.p_y = -1;
  p5.p_x = 1;
  p5.p_y = 0;
f(p0,p1,p2,p3,p4,p5); 
}
 
int
main()
{
  foo ();
  exit(0);
}
//========= end =======
>How-To-Repeat:
configure arm-elf cross gcc with simulator(gdb has a simulator)
compile above file with -O2 and execute.  
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: