[Bug c/79728] New: ice in setup_pressure_classes, at ira.c:912

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79728

            Bug ID: 79728
           Summary: ice in setup_pressure_classes, at ira.c:912
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

The following two lines of code:

$ more bug340.c
register a __asm__("xmm0");
fn1() {}
$ 

does this with a build of gcc trunk from revision 245750.

bug340.c:2:1: internal compiler error: in setup_pressure_classes, at ira.c:912
 fn1() {}
 ^~~
0x9ed9e8 setup_pressure_classes
        ../../trunk/gcc/ira.c:912
0x9ed9e8 setup_allocno_and_important_classes
        ../../trunk/gcc/ira.c:1068
0x9ed9e8 find_reg_classes
        ../../trunk/gcc/ira.c:1428
0x9ed9e8 ira_init()
        ../../trunk/gcc/ira.c:1727

This seems to have been going wrong since sometime before revision 236961.