Hi Prathamesh
On 7/10/19 12:24 PM, Prathamesh Kulkarni wrote:
Hi,
For following test-case,
static long long AL[24];
int
check_ok (void)
{
return (__sync_bool_compare_and_swap (AL+1, 0x200000003ll,
0x1234567890ll));
}
Compiling with -O2 -march=armv8.2-a results in:
pr90724.c: In function ‘check_ok’:
pr90724.c:7:1: error: unrecognizable insn:
7 | }
| ^
(insn 11 10 12 2 (set (reg:CC 66 cc)
(compare:CC (reg:DI 95)
(const_int 8589934595 [0x200000003]))) "pr90724.c":6:11 -1
(nil))
IIUC, the issue is that 0x200000003 falls outside the range of
allowable immediate in cmp ? If it's replaced by a small constant then
it works.
The ICE results with -march=armv8.2-a because, we enter if
(TARGET_LSE) { ... } condition
in aarch64_expand_compare_and_swap, while with -march=armv8.a it goes
into else,
which forces oldval into register if the predicate fails to match.
The attached patch checks if y (oldval) satisfies aarch64_plus_operand
predicate and if not, forces it to be in register, which resolves ICE.
Does it look OK ?
Bootstrap+testing in progress on aarch64-linux-gnu.
PS: The issue has nothing to do with SVE, which I incorrectly
mentioned in bug report.
This looks ok to me (but you'll need maintainer approval).
Does this fail on the branches as well?
Thanks,
Kyrill
Thanks,
Prathamesh
