https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97404
Bug ID: 97404
Summary: [9/10/11 Regression] aarch64: Wrong code since
r9-3666-g74ca1c01d
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ipa
Assignee: unassigned at gcc dot gnu.org
Reporter: acoplan at gcc dot gnu.org
CC: marxin at gcc dot gnu.org
Target Milestone: ---
AArch64 GCC miscompiles the following testcase:
char a, b;
long c;
short d, e;
long *f = &c;
int g;
char h(signed char i) { return 0; }
static short j(short i, int k) { return i < 0 ? 0 : i >> k; }
void l(void);
void m(void)
{
e = j(d | 9766, 11);
*f = e;
}
void l(void)
{
a = 5 | g;
b = h(a);
}
int main()
{
m();
if (c != 4)
__builtin_abort();
}
when built with -O2 -fno-inline since
r9-3666-g74ca1c01d02e548f32aa26f9a887dcc0730703fb. Immediately prior to this
revision we have:
j.constprop.0:
.LFB5:
.cfi_startproc
tst w0, 32768
sbfx w0, w0, 11, 5
csel w0, w0, wzr, eq
ret
and afterwards we have:
j.constprop.0:
.LFB5:
.cfi_startproc
mov w0, 0
ret
which would suggest that GCC has determined that j is always called with
arguments such that it returns 0, but this is not the case.
