From: Tamar Christina <Tamar.Christina@arm.com>
To: Richard Sandiford <richard.sandiford@linaro.org>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>, nd <nd@arm.com>,
James Greenhalgh <James.Greenhalgh@arm.com>,
Marcus Shawcroft <Marcus.Shawcroft@arm.com>,
Richard Earnshaw <Richard.Earnshaw@arm.com>
Subject: RE: [PATCH][GCC][AArch64] optimize float immediate moves (2 /4) - HF/DF/SF mode.
Date: Thu, 15 Jun 2017 13:25:00 -0000 [thread overview]
Message-ID: <VI1PR0801MB2031B9D822E987A87E7EB218FFC00@VI1PR0801MB2031.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <87mv9adgtb.fsf@linaro.org>
Hi Richard,
> > + rtx tmp = gen_reg_rtx (SImode);
> > + aarch64_expand_mov_immediate (tmp, gen_int_mode (ival, SImode));
> > + tmp = simplify_gen_subreg (HImode, tmp, SImode, 0);
>
> This looks wrong for big-endian, and...
>
> > + emit_move_insn (operands[0], gen_lowpart (HFmode, tmp));
>
> ...either it should be OK to go directly from tmp to the HFmode lowpart, or
> we should move the HImode temporary into a fresh REG. Current
> validate_subreg seems to suggest that we need the latter.
>
> Isn't it possible to use a HImode move immediate instead of an SImode one?
We don't really have a movehi pattern, currently a movhi would end up in the general
mov<mode>_aarch64 pattern which would then use end up using a w register as well.
I'll take a look at big-endian.
>
> Thanks,
> Richard
next prev parent reply other threads:[~2017-06-15 13:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-07 11:38 Tamar Christina
2017-06-12 7:31 ` Tamar Christina
2017-06-14 10:06 ` Richard Sandiford
2017-06-15 13:25 ` Tamar Christina [this message]
2017-06-15 14:28 ` Tamar Christina
2017-06-16 7:53 ` Richard Sandiford
2017-06-16 8:42 ` Tamar Christina
2017-06-14 8:43 ` James Greenhalgh
2017-06-21 10:48 ` Tamar Christina
2017-06-26 10:50 ` Tamar Christina
2017-07-03 6:12 ` Tamar Christina
2017-07-10 7:35 ` Tamar Christina
2017-07-27 16:09 ` James Greenhalgh
2017-08-01 11:47 ` Bin.Cheng
2017-08-01 11:51 ` Tamar Christina
2017-08-01 12:04 ` Bin.Cheng
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