[PATCH 4/8] aarch64: Use memcpy to copy vector tables in vtbx4 intrinsics

[Jonathan Wright]

Same explanation as for patch 3/8:

I haven't added test cases here because these intrinsics don't map to
a single instruction (they're legacy from Armv7) and would trip the
"scan-assembler not mov" that we're using for the other tests.

Thanks,
Jonathan
________________________________
From: Richard Sandiford <richard.sandiford@arm.com>
Sent: 23 July 2021 10:31
To: Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>
Cc: Jonathan Wright <Jonathan.Wright@arm.com>; gcc-patches@gcc.gnu.org <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH 4/8] aarch64: Use memcpy to copy vector tables in vtbx4 intrinsics

Kyrylo Tkachov <Kyrylo.Tkachov@arm.com> writes:
>> -----Original Message-----
>> From: Jonathan Wright <Jonathan.Wright@arm.com>
>> Sent: 23 July 2021 10:15
>> To: gcc-patches@gcc.gnu.org
>> Cc: Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>; Richard Sandiford
>> <Richard.Sandiford@arm.com>
>> Subject: [PATCH 4/8] aarch64: Use memcpy to copy vector tables in vtbx4
>> intrinsics
>>
>> Hi,
>>
>> This patch uses __builtin_memcpy to copy vector structures instead of
>> building a new opaque structure one vector at a time in each of the
>> vtbx4 Neon intrinsics in arm_neon.h. This simplifies the header file
>> and also improves code generation - superfluous move instructions
>> were emitted for every register extraction/set in this additional
>> structure.
>>
>> Regression tested and bootstrapped on aarch64-none-linux-gnu - no
>> issues.
>>
>> Ok for master?
>
> Ok.

Here too I think we want some testcases…

Thanks,
Richard