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On Friday 17 October 2008 20:11:21 ann kok wrote: |
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> hi all |
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> |
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> why we have to put the following flags in the make.conf |
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> |
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> what are the purpose? |
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> |
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> CFLAGS="-O2 -pipe" |
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> CXXFLAGS="-O2 -pipe" |
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> CHOST="x86_64-pc-linux-gnu" |
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It's so that the compiler knows how to build stuff.... |
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It doesn't know what you want if you don't tell it. CHOST for example tells |
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the compiler which machine architecture the output binaries must be built |
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for. There's nothing to stop you using an amd64 machine to build binaries |
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that will run on a Sun sparc, and relying on the current machine architecture |
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for the default is an especially stupid idea. A more sensible example is how |
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Ubuntu does it. Their master build machines are probably the latest fancy |
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Dual Cores, yet the code is built for i586 or i686 machines. CHOST controls |
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CFLAGS are actually optional. -O is the optimization level and it's pretty |
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normal and safe to use -O2. -pipe is an instruction to gcc on how to operate |
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when it's compiling stuff. It makes the build go faster and reduce disk |
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activity while doing it. |
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But all of this is in the Gentoo Handbook. Did you read it? |
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-- |
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alan dot mckinnon at gmail dot com |
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