https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90131
Bug ID: 90131
Summary: wrong debug info at -O3
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: qrzhang at gatech dot edu
Target Milestone: ---
This issue is similar to bug 90074 --- same flag, same gcc versions. The
bisection also points to r255267. It appears that the issue remains after the
patch.
$ gcc-trunk -v
gcc version 9.0.1 20190417 (experimental) [trunk revision 270407] (GCC)
$ gdb -v
GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.5) 7.11.1
#Wrong result#
$ gcc-trunk -g abc.c outer.c -O3
$ gdb -x cmds -batch a.out
Breakpoint 1 at 0x40040f: file abc.c, line 16.
Breakpoint 1, main () at abc.c:16
16 optimize_me_not();
$1 = 9
#Correct result#
$ gcc-trunk -g abc.c outer.c
$ gdb -x cmds -batch a.out
Breakpoint 1 at 0x4004c8: file abc.c, line 16.
Breakpoint 1, main () at abc.c:16
16 optimize_me_not();
$1 = 0
$ cat abc.c
volatile long a;
int b[9][1];
static short c[2][1] = {3};
int main() {
int i, d, e;
i = 0;
for (; i < 9; i++)
a = b[i][0];
i = 0;
for (; i < 2; i++) {
d = 0;
for (; d < 1; d++) {
e = 0;
for (; e < 1; e++)
a = c[i][e];
optimize_me_not();
}
}
}
$ cat outer.c
void optimize_me_not() {}
$ cat cmds
b 16
r
p i
kill
q
