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how to use 2 SIMD in EU

Fu_J_Intel
Employee
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Gen8/9 has 2 SIMD in each EU.  How can i specify to use 2 SIMD in openCL?

thanks,

Jeffrey

 

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Tamer_Assad
Innovator
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Hi Jeffrey,

 

First, your kernel's NDRange should be  wide enough to utilize multiple SIMD.

Then, in order to motivate the compiler to use 2 SIMD lanes, make sure you have:

 1- simultaneous Kernel instances executing the same target instruction

 2- target instruction applied to elements of a data type fitting half the target SIMD. (data type length <= Target SIMD Width/2)

 3- explicit declaration of target data type.

 

Best regards,

Tamer

 

 

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