[debbugs-tracker] bug#23474: closed (Gzip and CFLAGS)

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Your message dated Fri, 6 May 2016 19:52:26 -0700
with message-id <address@hidden>
and subject line Re: bug#23474: Gzip and CFLAGS
has caused the debbugs.gnu.org bug report #23474,
regarding Gzip and CFLAGS
to be marked as done.

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23474: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=23474
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--- Begin Message --- Subject: Gzip and CFLAGS Date: Fri, 6 May 2016 21:15:15 -0400

Hello there,

            After having compiled gzip, I had looked at the Makefile “./configure” generated.

            Looking at CFLAGS=”” (system configuration section), not many compiler flags are specified for optimization. 

            The “Specific Targets” section sets different flags for different systems, which are set accordingly.

            Currently, I am looking at “CFLAGS= -O”.

            I noticed that some optimization flags were not set (curious as to why):

-         -march=native (pentium3, athlon64, etc) (produces code for the specific architecture specified)

-         -O2 (recommended level to use to increase code performance )

-         -pipe (makes compilation process faster)

-         -fomit-frame-pointer (reduces generated code size)

Also, I found this article http://lists.gnu.org/archive/html/bug-gzip/2013-02/msg00000.html and it mentions setting –O2 and encountering an issue (it has since been fixed).

After running some tests after I recompiled (Linux), sometimes I noticed it to be a little bit faster (at times) on x86_64.

Note: There are many different conditions that cause the numbers to fluctuate, such as: # of processes running, ram usage, CPU power etc.

 

Thank You

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> Subject: 
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> Re: bug#23474: Gzip and CFLAGS
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> Date: 
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> Fri, 6 May 2016 19:52:26 -0700
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> User-agent: 
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> Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2
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> Tom Smith wrote:
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> >             Currently, I am looking at “CFLAGS= -O”.
>
> You don't mention which gzip version. If you haven't already, please try the
> current version, gzip 1.8. Its 'configure' script should default to -O2
> optimization for GCC, and to no optimization for other compilers. To some extent
> this is arbitrary. Tweaking this further is up to you. For example,
> -march=native is better for some usages but not for others, which is why it is
> not the default.
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>
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> --- End Message ---