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-mtune is specific to scheduling the code for a particular CPU architecture -march specifies the instruction set and implies -mtune. -m32 and -m64 generate code for 32-bit and 64-bit x86 architectures.=20 There are ways to run 32-bit drivers on 64-bit systems, but I don't have that info at my fingertips right now. On Thu, 17 May 2007 15:54:25 -0400 Kristian Hermansen <kristian.hermansen-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org> wrote: > Matthew Gillen wrote: > >>From the gcc man page: > >> While picking a specific cpu-type will schedule things appropriately f= or > >> that particular chip, the compiler will not generate any code that doe= s not > >> run on the i386 without the -march=3Dcpu-type option being used. > >=20 > > Check the "-mtune=3Dcpu-type" and "march=3Dcpu-type" command line switc= hes. >=20 > This is not entirely correct. I generate code from gcc (amd64)=20 > targeting i386 all the time using only the -m32 option. For instance: >=20 > administrator at khermans-um64:/tmp$ uname -a > Linux khermans-um64 2.6.20-15-generic #2 SMP Sun Apr 15 06:17:24 UTC=20 > 2007 x86_64 GNU/Linux > administrator at khermans-um64:/tmp$ cat hello.c > #include <stdio.h> >=20 > int main() { > printf("Hello World!\n"); > } > administrator at khermans-um64:/tmp$ gcc -o hello64 hello.c > administrator at khermans-um64:/tmp$ file hello64 > hello64: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), for=20 > GNU/Linux 2.6.0, dynamically linked (uses shared libs), not stripped > administrator at khermans-um64:/tmp$ ./hello64 > Hello World! > administrator at khermans-um64:/tmp$ gcc -m32 -o hello32 hello.c > administrator at khermans-um64:/tmp$ file hello32 > hello32: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for=20 > GNU/Linux 2.6.0, dynamically linked (uses shared libs), not stripped > administrator at khermans-um64:/tmp$ ./hello32 > Hello World! >=20 > Any questions? > --=20 > Kristian Hermansen >=20 > --=20 > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed to be clean. >=20 > _______________________________________________ > Discuss mailing list > Discuss-mNDKBlG2WHs at public.gmane.org > http://lists.blu.org/mailman/listinfo/discuss >=20 --=20 Jerry Feldman <gaf-mNDKBlG2WHs at public.gmane.org> Boston Linux and Unix user group http://www.blu.org PGP key id:C5061EA9 PGP Key fingerprint:053C 73EC 3AC1 5C44 3E14 9245 FB00 3ED5 C506 1EA9
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