search for: 8xi8

Hi Nadav/Devs I am exploring Loop Vectorizer to vectorize i8 scalar operations into 8xi8 vector operation. I was expecting the Loop Vectorizer to analyze the profitability for vectorization factor(VF) of 8, However it is not doing so due to the widest type calculation done for the blocks inside the loop. May be I am missing something, however, I am curious to know why Loop Vectorizer...

...LVMdev] Vectorization factor limitation in Loop Vectorizer Hi Shahid, On Dec 10, 2014, at 10:48 PM, Shahid, Asghar-ahmad <Asghar-ahmad.Shahid at amd.com<mailto:Asghar-ahmad.Shahid at amd.com>> wrote: Hi Nadav/Devs I am exploring Loop Vectorizer to vectorize i8 scalar operations into 8xi8 vector operation. I was expecting the Loop Vectorizer to analyze the profitability for vectorization factor(VF) of 8, However it is not doing so due to the widest type calculation done for the blocks inside the loop. May be I am missing something, however, I am curious to know why Loop Vectorizer...

...BasicTTI attempts to handle all of the target independent logic. It uses the TargetLowering interface to check if the types are legal and how many times large vectors need to be split. Different targets need to implement the cases that the BasicTTI does not catch. For example, the cost of zext <8xi8> to <8 x i32> which is custom lowered on some targets. > Do you think that updating ARMTTI would be the best course of action now, and inspect the differences in the CostModel later? > We should update TTI and inspect the cost model as we go. > I also haven't seen anything...

Hi Nadav, I'm interested in knowing how you'll work up the ARM cost model and how easy it'd be to split the work. As far as I can see, LoopVectorizationCostModel is the class that does all the work, with assistance from the target transform info. Do you think that updating ARMTTI would be the best course of action now, and inspect the differences in the CostModel later? I also

...o handle all of the target > independent logic. It uses the TargetLowering interface to check if the > types are legal and how many times large vectors need to be split. > Different targets need to implement the cases that the BasicTTI does not > catch. For example, the cost of zext <8xi8> to <8 x i32> which is custom > lowered on some targets. > I'm also thinking about the individual instructions cost (getArithmeticInstrCost, getShuffleCost, etc). That can be a simple and easily parallelized task. I got the A9 manual that has the cost of all instructions (includ...