Gentoo Archives: gentoo-user

From: Jarry <mr.jarry@×××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] "universal" CFLAGS/CXXFLAGS/CHOST for 64bit (AMD64 & EMT64T)?
Date: Sat, 11 Jun 2011 16:04:43
1 Hi,
2 how should I change/set CFLAGS/CXXFLAGS/CHOST if I want to have
3 system which can be easily migrated between AMD64 and Intel/Core
4 without recompilation? I have a few virtual servers which I can
5 not move from one arch to the other, as they have hw-specific
6 CFLAGS (different host-server hardware, both AMD64 and EM64T):
8 I have systems with Athlon64/X2 and Core2Quad, with settings:
9 CFLAGS="-march=athlon64 -O2 -pipe"
10 CFLAGS="-march=core2 -O2 -pipe"
11 CHOST is always "x86_64-pc-linux-gnu".
13 I'm not sure "-mtune=generic" is the right solution, because
14 it would generate code for IA32/AMD64/EM64T (if I understand
15 gcc manual correctly, for both 32bit as well as 64bit HW).
17 What I'm looking for are some generic 64bit settings only for
18 AMD64/EM64T (not 32bit/IA32) similar as for distros with binary
19 distributions (i.e. I can download Ubuntu either 32bit or 64bit
20 version, no other hardware-specific difference). I know with
21 "universal" 64bit binaries I'm going to loose some pefrormance,
22 but for me flexibility with migration would overweight this
23 disadvantage...
25 Jarry
27 --
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Subject Author
Re: [gentoo-user] "universal" CFLAGS/CXXFLAGS/CHOST for 64bit (AMD64 & EMT64T)? Florian Philipp <lists@×××××××××××.net>