https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79636
Bug ID: 79636
Summary: ICE in assign_by_spills, at lra-assigns.c:1457
Product: gcc
Version: 7.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: gerhard.steinmetz.fort...@t-online.de
Target Milestone: ---
With -O0 for versions down to at least 4.8 (on x86_64 GNU/Linux)
and file ./gcc/testsuite/gcc.target/i386/pr65693.c
$ cat pr65693.c
int a;
void
foo (int (*fn) (int, int, int), unsigned int b)
{
unsigned long *c = (unsigned long *) __builtin_alloca (b);
a = *c;
register int d asm ("edx") = fn (0, 0, d);
}
$ gcc-7-20170219 -O1 -c pr65693.c
$ gcc-7-20170219 -O0 -c pr65693.c
pr65693.c: In function 'foo':
pr65693.c:9:1: error: unable to find a register to spill
}
^
pr65693.c:9:1: error: this is the insn:
(insn 11 35 12 2 (parallel [
(set (reg:DI 96)
(udiv:DI (reg:DI 94)
(reg:DI 106)))
(set (reg:DI 107 [97])
(umod:DI (reg:DI 94)
(reg:DI 106)))
(clobber (reg:CC 17 flags))
]) "pr65693.c":6 368 {*udivmoddi4}
(expr_list:REG_UNUSED (reg:DI 107 [97])
(expr_list:REG_DEAD (reg:DI 106)
(expr_list:REG_DEAD (reg:DI 94)
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil))))))
pr65693.c:9:1: internal compiler error: in assign_by_spills, at
lra-assigns.c:1457
0xb8a8a8 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
../../gcc/rtl-error.c:108
0xa79431 assign_by_spills
../../gcc/lra-assigns.c:1457
0xa79b4e lra_assign()
../../gcc/lra-assigns.c:1643
0xa751a6 lra(_IO_FILE*)
../../gcc/lra.c:2451
0xa2b339 do_reload
../../gcc/ira.c:5452
0xa2b339 execute
../../gcc/ira.c:5636
