[Bug target/71763] New: powerpc64: ICE due to need for output reload on jump

["anton at samba dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71763

            Bug ID: 71763
           Summary: powerpc64: ICE due to need for output reload on jump
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anton at samba dot org
  Target Milestone: ---

The following test case:

int a, b;
float c;

void fn2(void);

void fn1(void)
{
        long d;

        for (d = 3; d; d--) {
                for (a = 0; a <= 1; a++) {
                        b &= 1;
                        if (b) {
                                for (;;) {
                                        fn2();
                                        c = d;
                                }
                        }
                }
        }
}

built with -O1 hits an ICE:

crash1b.c:21:1: error: unable to generate reloads for:
 }
 ^
(jump_insn 43 42 62 7 (parallel [
            (set (pc)
                (if_then_else (ne (reg/v:DI 108 31 [orig:157 d ] [157])
                        (const_int 1 [0x1]))
                    (label_ref:DI 41)
                    (pc)))
            (set (reg/v:DI 108 31 [orig:157 d ] [157])
                (plus:DI (reg/v:DI 108 31 [orig:157 d ] [157])
                    (const_int -1 [0xffffffffffffffff])))
            (clobber (scratch:CC))
            (clobber (scratch:DI))
        ]) crash1b.c:10 797 {*ctrdi_internal1}
     (int_list:REG_BR_PROB 7500 (nil))
 -> 41)
crash1b.c:21:1: internal compiler error: in find_reloads, at reload.c:3830
0x10836413 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        ../../gcc/gcc/rtl-error.c:108
0x1081c173 find_reloads(rtx_insn*, int, int, int, short*)
        ../../gcc/gcc/reload.c:3830
0x1083178f calculate_needs_all_insns
        ../../gcc/gcc/reload1.c:1483
0x1083178f reload(rtx_insn*, int)
        ../../gcc/gcc/reload1.c:995
0x1068c84b do_reload
        ../../gcc/gcc/ira.c:5396
0x1068c84b execute
        ../../gcc/gcc/ira.c:5568