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retroman Apprentice
Joined: 18 Nov 2004 Posts: 207 Location: Stuttgart
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Posted: Wed May 16, 2007 12:04 pm Post subject: Optimum make.conf values |
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Ive been working on some benchmarks to find the best compile flags for some of my systems. Here is the results for my Ultra60 2x 450mhz processors 512mb ram
Each test was condicted multiple times
"time emerge nano"
CFLAGS="-O3 -mcpu=ultrasparc -mtune=ultrasparc"
2m9.138
1m59.214
1m59.600
1m58.137
CFLAGS="-O3 -mcpu=ultrasparc -mtune=ultrasparc"
MAKEOPTS="-j3"
1m44.968
1m51.632
1m42.577
1m45.114
CFLAGS="-O3 -mcpu=ultrasparc -mtune=ultrasparc"
MAKEOPTS="-j4"
1m43.481
1m43.053
1m43.425
1m43.069
CFLAGS="-O2 -mcpu=ultrasparc -mtune=ultrasparc"
MAKEOPTS="-j4"
1m39.974
1m42.018
1m40.040
1m41.804
CFLAGS="-O2 -mcpu=ultrasparc -mtune=ultrasparc"
MAKEOPTS="-j3"
1m35.294
1m39.816
1m40.409
1m42.369
CFLAGS="-O2 -mcpu=ultrasparc -mtune=ultrasparc -fomit-frame-pointer"
MAKEOPTS="-j3"
1m35.151
1m39.411
1m39.271
1m40.966
CFLAGS="-O2 -mcpu=ultrasparc -mtune=ultrasparc -pipe -fomit-frame-pointer"
MAKEOPTS="-j3"
1m39.887
1m38.091
1m39.875
1m37.561
the -pipe flag would probably further spped up the compile time if I had more memory, Im also not sure if fomit-frame-pointer has any great benefit on a sparc64 processor |
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Ferris Retired Dev
Joined: 13 Jan 2003 Posts: 426 Location: N. Virginia (USA)
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Posted: Wed May 16, 2007 12:16 pm Post subject: |
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Neither -O3 nor -fomit-frame-pointer is generally a good idea on sparc.
Regards, |
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gust4voz Retired Dev
Joined: 09 Sep 2003 Posts: 373 Location: Buenos Aires, Argentina
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Posted: Wed May 16, 2007 1:09 pm Post subject: |
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Also "time emerge nano" is only measuring how fast it builds - not how fast it works.
I assume you want the fastest binaries, not the fastest build times.
Usually the job option for MAKEOPTS is cpu+1, so -j3 for 2 processors and so on.
As Ferris says, -O3 and -fomit-frame-pointer are really not good ideas on sparc, if you trigger some build/run issue with those we'll just close the bug with "lower your settings to a sane value".
I'm using CFLAGS="-mcpu=ultrasparc -mtune=ultrasparc -mvis -Wa,-Av8plusa -O2 -pipe" and didn't hit issues on stable, though some people seemed to have hit some from what i've read - the ones i've seen in the past are usually related to the linker flags being pass to the wrong places. _________________ Gustavo Zacarias
Gentoo/SPARC monkey |
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retroman Apprentice
Joined: 18 Nov 2004 Posts: 207 Location: Stuttgart
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Posted: Wed May 16, 2007 2:21 pm Post subject: |
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Im not familiar with these flags what do they do?
-mvis -Wa,-Av8plusa
thanx
jordan |
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gust4voz Retired Dev
Joined: 09 Sep 2003 Posts: 373 Location: Buenos Aires, Argentina
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Posted: Wed May 16, 2007 4:28 pm Post subject: |
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-mvis enables the VIS instruction set.
-Wa,-Av8plusa is a linker directive since sometimes, with -mvis, things get confused and build 64-bit userland stuff (which won't work) - basically it forces 32-bit. _________________ Gustavo Zacarias
Gentoo/SPARC monkey |
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retroman Apprentice
Joined: 18 Nov 2004 Posts: 207 Location: Stuttgart
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Posted: Wed May 16, 2007 8:58 pm Post subject: |
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are there any notable performance gains with these? It doesnt matter if it breaks compatibility with other computers. This is the only ultra 60 I have. |
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