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Introduction to Intel Advanced Vector Extensions

bronxzv
New Contributor II
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I just read this article:

http://software.intel.com/en-us/articles/introduction-to-intel-advanced-vector-extensions/

it's a fairly good introduction to AVX though in the "Instruction Set Overview"the author states that "As a result, the VEX instructions can only be used when running in 64-bit mode." I know from first hand experience that this is wrong since my own AVX coderunfine in32-bit mode on a Sandy Bridge CPU. I'll suggest to fix this error in the article since newcomers to AVX may be misled by this.
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Max_L
Employee
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nice catch, wrong statement for sure, we will fix it, thanks! ... author was close in understanding of LDS/LES opcodes re-use for VEX prefix, but what happens in 32-bit is that VEX prefix, although still using LDS/LES opcodes, always ends up in unsupported forms of these instructions (those with memory operands), thanks to bit-complement encoding of some fields, hence everything is backwards compatible in 32-bit mode too

-Max


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