target/4959: gcc/s390 fails with more than 1024 function pointers

[edward dot connell at sas dot com]

>Number:         4959
>Category:       target
>Synopsis:       gcc/s390 fails with more than 1024 function pointers
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Nov 27 10:16:01 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     edward.connell@sas.com
>Release:        gcc version 2.95.3 20010315 (release)
>Organization:
>Environment:
Linux/s390 native and cross-build
>Description:
gcc fails to compile a file with more than 1024 function pointers with "/var/tmp/cc6ojHFY.s:2073: Error: operand out of range (4096 not between 0 and 4095)".  Gcc is trying to use a relative offset but the distance gets too large.  Imagine the following with N=1025.

****************
int i0();
int i1();
int i2();

int main() {
 int (*funcs[3])();

 funcs[0]=i0;
 funcs[1]=i1;
 funcs[2]=i2;
 return 0;
}
**************

This program will generate a .c file which fails to compile on s390.

**************
#define NUM 1025

int main()
{
 int i;

 for (i=0; i<NUM; i++) {
   printf("int i%d();\n", i);
 }

 printf("\nint main() {\n int (*funcs[%d])();\n\n", NUM);

 for (i=0; i<NUM; i++) {
   printf(" funcs[%d]=i%d;\n", i, i);
 }

 printf(" return 0;\n}\n");

 return 0;
}
**************
>How-To-Repeat:
#define NUM 1025

int main()
{
 int i;

 for (i=0; i<NUM; i++) {
   printf("int i%d();\n", i);
 }

 printf("\nint main() {\n int (*funcs[%d])();\n\n", NUM);

 for (i=0; i<NUM; i++) {
   printf(" funcs[%d]=i%d;\n", i, i);
 }

 printf(" return 0;\n}\n");

 return 0;
}
>Fix:

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