https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95113
Bug ID: 95113
Summary: [10/11 Regression] Wrong code w/ -O2 -fexceptions
-fnon-call-exceptions
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: asolokha at gmx dot com
Target Milestone: ---
Target: x86_64-unknown-linux-gnu
The following program compiled w/ gcc-11.0.0-alpha20200510 snapshot
(g:13a46321516e2efd3bbb1f1899c539c6724240a9) w/ -O2 -fexceptions
-fnon-call-exceptions:
int p4, cd;
static long int
sg (long int kl, int mp)
{
if (mp == 0)
return 0;
if (kl == -1 && mp == -1)
return 0;
return kl / mp;
}
static int
eo (int *yg)
{
int du;
du = sg (p4, 1) + *yg;
(void) du;
return cd;
}
int
main (void)
{
int um = 0;
cd = sg (1, 1);
eo (&um);
return 0;
}
% x86_64-unknown-linux-gnu-gcc-11.0.0 -O2 -fexceptions -Wuninitialized -o good
li6hfrrz.c
% ./good
% echo $?
0
% objdump --section=.text --disassemble=main good | tail -n6
00000000000004e0 <main>:
4e0: c7 05 32 1b 00 00 01 movl $0x1,0x1b32(%rip) # 201c <cd>
4e7: 00 00 00
4ea: 31 c0 xor %eax,%eax
4ec: c3 retq
% x86_64-unknown-linux-gnu-gcc-11.0.0 -O2 -fexceptions -fnon-call-exceptions
-Wuninitialized -o bad li6hfrrz.c
% ./bad
zsh: segmentation fault (core dumped) ./bad
% objdump --section=.text --disassemble=main bad | tail -n6
00000000000004e0 <main>:
4e0: c7 05 32 1b 00 00 01 movl $0x1,0x1b32(%rip) # 201c <cd>
4e7: 00 00 00
4ea: 8b 04 25 00 00 00 00 mov 0x0,%eax
4f1: 31 c0 xor %eax,%eax
4f3: c3 retq
https://gcc.godbolt.org/z/V4a-K7
