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Programming-Guides/Porting_Vector_Intrinsics/sec_differences.xml

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XML

<?xml version="1.0" encoding="UTF-8"?>
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<section xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink"
version="5.0"
xml:id="sec_differences">
<title>Profound differences</title>
<para>We have already mentioned above a number of architectural differences
that affect porting of codes containing Intel intrinsics to POWER. The fact
that Intel supports multiple vector extensions with different vector widths
(64, 128, 256, and 512 bits) while the PowerISA only supports vectors of
128 bits is one issue. Another is the difference in how the respective ISAs
support scalars in vector registers.  In the text above we propose
workable alternatives for the PowerPC port. There are also differences in the
handling of floating point exceptions and rounding modes that may impact the
application's performance or behavior.</para>
<xi:include href="sec_floatingpoint_exceptions.xml"/>
<xi:include href="sec_floatingpoint_rounding.xml"/>
<xi:include href="sec_performance.xml"/>
</section>