From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: Paul Eggert <eggert@cs.ucla.edu>
Cc: bug-gnulib@gnu.org, libc-alpha@sourceware.org
Subject: Re: [PATCH 2/3] posix: Remove alloca usage on regex build_trtable
Date: Mon, 11 Jan 2021 09:31:51 -0300 [thread overview]
Message-ID: <1546c8d0-fd22-0e10-8f0d-2b6f1791f1c1@linaro.org> (raw)
In-Reply-To: <831a8e3b-7a4a-0c9a-418e-0656fc137765@cs.ucla.edu>
On 08/01/2021 19:30, Paul Eggert wrote:
> On 1/6/21 10:17 AM, Adhemerval Zanella wrote:
>> __libc_use_alloca/alloca is replaced with malloc regardless.
>
> These allocations are so small that they should be put on the stack instead of using malloc. I did that in Gnulib by installing the attached patch. The idea is that the resulting regexec.c file should be copyable unchanged into glibc.
>
> From a Gnulib point of view this code uses a 20 KiB frame (on a 64-bit host) which goes past the usual 4032-byte limit for stack frames, but I think we can stretch the point here. In glibc the limit is 64 KiB so there's no problem.
Right, I think we can maybe use scratch_buffer for these or even a dynamic array
with a more proper initial size as an improvement.
next prev parent reply other threads:[~2021-01-11 12:36 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 18:17 [PATCH 1/3] posix: Remove alloca usage on regex set_regs Adhemerval Zanella
2021-01-06 18:17 ` [PATCH 2/3] posix: Remove alloca usage on regex build_trtable Adhemerval Zanella
2021-01-08 22:30 ` Paul Eggert
2021-01-11 12:31 ` Adhemerval Zanella [this message]
2021-01-06 18:17 ` [PATCH 3/3] posix: Remove alloca definition from regex Adhemerval Zanella
2021-01-09 1:20 ` Paul Eggert
2021-01-11 12:33 ` Adhemerval Zanella
2021-01-08 20:14 ` [PATCH 1/3] posix: Remove alloca usage on regex set_regs Paul Eggert
2021-01-11 12:35 ` Adhemerval Zanella
2021-01-09 1:24 ` Darshit Shah
2021-01-09 3:54 ` Paul Eggert
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