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Altera_Forum
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8 years ago

[Kernel vectorization] Loads/Stores cannot be vectorized

Hi guys! The compiler says this on the above code: Compiler Warning: Vectorized kernel contains loads/stores that cannot be vectorized. This might reduce performance. What loads/st...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
8 years ago

The likely case is the following part: 

if(local_id == 0)
    group_counters = local_counter;

SIMD vectorizes operations at work-item level, and coalesces accesses that are consecutive at this level. For this particular access, since the write is done only by one work-item per work-group, it cannot be vectorized/coalesced.