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On 07/21/2010 03:22 AM, Dale wrote: |
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> Alan McKinnon wrote: |
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>> On Wednesday 21 July 2010 10:53:19 fajfusio@××.pl wrote: |
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>> |
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>>> Hi |
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>>> |
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>>> I've just switched to gcc 4.3.4 from 4.1.2 using gcc-config tool. I |
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>>> don't |
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>>> want to rebuild any package now. As time goes on my packages will be |
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>>> compiled with new version. I hope that after a few month there will be |
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>>> only a number of packages not compiled with a new gcc. Then I want to |
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>>> recompile them on demand including libtool if necessary. |
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>>> |
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>>> Do you think my plan have a chance to succeed. |
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>>> |
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>> Yes. |
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>> |
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>> Why do you think you would even need to get into a long compile? Have |
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>> you been |
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>> reading that GCC Upgrade Guide at gentoo.org? You know, the one that |
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>> is so |
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>> flat out wrong on so many levels? |
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>> |
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>> |
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> |
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> I recently upgraded my gcc and I must confess, I did do a emerge -e |
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> system. Is it needed, nope. |
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> |
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> OP, Alan is correct on this. You don't really need to re-emerge |
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> everything. If, like me, you want to be on the safe side, just do a |
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> emerge -e system and let the rest recompile as you update. |
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> |
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> Another good thing about this way, if this version of gcc causes you |
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> trouble, you can downgrade and only have to re-emerge system. ;-) I |
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> did upgrade gcc once and had serious issues with it. Wouldn't compile a |
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> kernel, programs crashing and other weird things. After a downgrade, |
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> all went back to normal. The only thing worse than a emerge -e world is |
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> having to do it twice. LOL |
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|
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And to play devil's advocate, I'll chime in with my experience. The 4.4 |
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GCC, at least on AMD CPUs, creates noticeably faster code. I recompiled |
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all my packages after I upgraded to 4.4 and it was a *noticeable* |
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difference. |
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|
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But, to make perfectly clear what Alan and Dale have stated previously, |
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it is not a requirement to recompile anything. The binaries that are |
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created still call the same system calls as they did before. The kernel |
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still publishes them in the same locations. And to prove to yourself |
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this is true, grab a statically linked binary, compiled for a stock |
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standard i686, and run it on your machine. |
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