Re: Compiling for newer Intel CPUs with an older Intel build system?

[Mike Frysinger]

On 04 Mar 2016 19:16, Sean Byland wrote:
> Thanks. Targeting the least common denominator ISA to get portable code
> works well for many things but in this case I’m curious about getting
> better performance than portability.

that's not what you said.  you said you wanted to build on a newer cpu
and execute on an older one.  you really can't have it both ways: you
must pick a lowest common denominator (via the -march flag).  there is
the -mtune flag to allow you to select insn scheduling and such, but
gcc won't generate incompatible code.

if you want to know more about what gcc offers with insn/isa selection,
you should ask on the gcc mailing lists:
        https://gcc.gnu.org/ml/gcc-help/

this question isn't really relevant to autoconf/autotools
-mike

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