On Fri, 14 Mar 2008 11:41:35 +0200, Severi Salminen wrote:
> 2. What does "ucomisd %xmm0, %xmm0" effectively do? It compares the same
> register.

Checks whether the low double precision floating point value
in the register is (non-)zero.

In the SSE architecture, an instruction such as "por" does not affect
the flags, so the familiar x86 way of "or eax, eax" to set flags would
not work on SSE.

-- 
Joel Yliluoma - http://iki.fi/bisqwit/

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