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From: Laurynas Biveinis <laurynas.biveinis@gmail.com>
Date: Tue, 16 Aug 2011 05:52:00 -0000
Message-ID: <CAHkCEVcXfdkrE8QvAauqUWQ0hAXdBJYGC0fcRcVeeC5MwPeK0Q@mail.gmail.com>
Subject: Re: ggc_alloc_rtvec_sized allocates spaces more than necessary?
To: Richard Guenther <richard.guenther@gmail.com>
Cc: =?UTF-8?B?546L5Lqu?= <netcasper@gmail.com>, gcc@gcc.gnu.org
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> On Mon, Aug 15, 2011 at 2:16 PM, =E7=8E=8B=E4=BA=AE <netcasper@gmail.com>=
 wrote:
>> The size it allocates is
>>
>> =C2=A0(sizeof (struct rtvec_def) + ((NELT) - 1)) * sizeof (rtx)

>> Originally, the allocated size is
>>
>> =C2=A0sizeof (struct rtvec_def) + ((NELT) - 1) * sizeof (rtx)

Yes, this is correct, good catch.

>> =C2=A0(sizeof (struct rtvec_def) + sizeof (rtx) - 1) / sizeof (rtx) +
>> ((NELT) - 1) =C2=A0 // (3)

Due to the way those macros expand, right now replacing the first arg
with "1" and the second one with straightforward "sizeof (struct
rtvec_def) + ((NELT) - 1) * sizeof (rtx)" will work and will be easier
to read than division. Liang, would you submit such patch?

Thanks again,
--=20
Laurynas