From: Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
To: gcc Patches <gcc-patches@gcc.gnu.org>,
James Greenhalgh <james.greenhalgh@arm.com>
Cc: Richard Sandiford <richard.sandiford@arm.com>
Subject: Re: PR90724 - ICE with __sync_bool_compare_and_swap with -march=armv8.2-a
Date: Wed, 17 Jul 2019 07:19:00 -0000 [thread overview]
Message-ID: <CAAgBjMkfrdDtXS0nEz-a2bA_shjxd2euCtDyz+t0=CrOM1fh6w@mail.gmail.com> (raw)
In-Reply-To: <CAAgBjMnMqXAnbtnTT4Q_0GDFw9X3mRfbActR1bMkU73Cg_x6Yg@mail.gmail.com>
On Wed, 10 Jul 2019 at 16:54, Prathamesh Kulkarni
<prathamesh.kulkarni@linaro.org> 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.
ping https://gcc.gnu.org/ml/gcc-patches/2019-07/msg00793.html
Thanks,
Prathamesh
>
> PS: The issue has nothing to do with SVE, which I incorrectly
> mentioned in bug report.
>
> Thanks,
> Prathamesh
next prev parent reply other threads:[~2019-07-17 7:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-10 11:28 Prathamesh Kulkarni
2019-07-17 7:19 ` Prathamesh Kulkarni [this message]
2019-07-17 8:18 ` Kyrill Tkachov
2019-07-17 13:40 ` Prathamesh Kulkarni
2019-07-25 7:50 ` Prathamesh Kulkarni
2019-08-01 10:04 ` Prathamesh Kulkarni
2019-08-08 6:31 ` Prathamesh Kulkarni
2019-08-15 13:30 ` Prathamesh Kulkarni
2019-08-19 18:34 ` James Greenhalgh
2019-08-21 20:48 ` Prathamesh Kulkarni
2019-08-22 3:18 ` JiangNing OS
2019-08-22 3:36 ` JiangNing OS
2019-09-09 19:07 ` Prathamesh Kulkarni
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