https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83241
Bug ID: 83241
Summary: [8 regression] segmentation fault in dce
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: arnd at linaro dot org
Target Milestone: ---
I ran into this internal compiler error with today's gcc checkout (r255300),
both x86 and arm.
x86_64-linux-gcc-8.0.0 -xc -c -O2 - <<EOF
typedef struct {
int in_mb;
short mb[32];
} mbx_cmd_t;
struct qla_hw_data {
volatile int flags;
int md_tmplt_hdr_dma;
} a;
mbx_cmd_t b;
void fn1() {
struct qla_hw_data c = a;
b.mb[0] = b.mb[1] = 6;
b.mb[4] = c.md_tmplt_hdr_dma;
b.mb[5] = c.md_tmplt_hdr_dma >> 16;
b.in_mb = 1;
}
EOF
during GIMPLE pass: dce
<stdin>: In function 'fn1':
<stdin>:10:6: internal compiler error: Segmentation fault
0xab19cf crash_signal
/home/arnd/git/gcc/gcc/toplev.c:325
0xb8a220 gimple_code
/home/arnd/git/gcc/gcc/gimple.h:1677
0xb8a220 gimple_nop_p
/home/arnd/git/gcc/gcc/gimple.h:6294
0xb8a220 walk_aliased_vdefs_1
/home/arnd/git/gcc/gcc/tree-ssa-alias.c:2897
0xb8a3e1 walk_aliased_vdefs(ao_ref*, tree_node*, bool (*)(ao_ref*, tree_node*,
void*), void*, bitmap_head**, bool*, unsigned int)
/home/arnd/git/gcc/gcc/tree-ssa-alias.c:2951
0xb9e2a4 mark_aliased_reaching_defs_necessary
/home/arnd/git/gcc/gcc/tree-ssa-dce.c:526
0xb9fa82 propagate_necessity
/home/arnd/git/gcc/gcc/tree-ssa-dce.c:892
0xba27b8 perform_tree_ssa_dce
/home/arnd/git/gcc/gcc/tree-ssa-dce.c:1606
