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Re: Being more careful with FP on gcc:

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From:
Greg Lindahl
Date:
January 22, 2011 22:32
Subject:
Re: Being more careful with FP on gcc:
Message ID:
20110123063221.GG22485@bx9.net
On Sun, Jan 23, 2011 at 11:36:43AM +0530, Philip Potter wrote:

> Investigating i386 further, it seems only a few i386 processors have
> double-precision SSE instructions; the gcc docs suggest most intel and
> all AMD i386 processors only support single-precision SSE, which
> doesn't solve the problem completely. This pretty much knocks the
> -mfparch=sse option out for most i386 situations.

I would bet that most i386 machines today are x86-64 machines being
run in 32-bit mode, which all do support SSE2. Still, distros do build
very conservatively for 32-bits, the perl rpm in CentOS 5.5 is '.386'
and not '.686', and I don't recall off the top of my head if 686 is
actually using SSE2, but I think not. 386, definitely not.

-- greg
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