search for: maxvfs

...nt for this VF to participate in VPlan and VF selection. As the (scalar) types can be collected once for all VFs, I guess it is cheap enough. As both collectUniformsAndScalars() and collectInstsToScalarize() don't look cheap, doing such check can speed up vectorization, in particular, for large MaxVFs. Another minor thing is when force vectorization is enabled and MaxVF > 1, expected cost of VF=2 is computed twice at the moment. bool ForceVectorization = Hints->getForce() == LoopVectorizeHints::FK_Enabled; // Ignore scalar width, because the user explicitly wants vectorization. if...

Hi Hal, I am not familiar with Blue Gene at all but I will do my best to answer. > is going to assume that the vectors can hold 256/32 == 8 single-precision values even though the real maximum is 4 values. How should we handle this? The loop vectorizer uses TTI to find the size of the vector register. It uses this number to calculate the maximum vectorization factor. The formula is MaxVF =

Nadav, et al., On the BG/Q, the vectors hold 4 double-precision values. For vectorizing single-precision code, there are single-precision-rounded instructions, and special load/store instructions, which allow the double-precision numbers to be treated as single-precision numbers. The problem is that the current vectorization code (in the BBVectorizer and, as far as I can tell, also in the

----- Original Message ----- > From: "Nadav Rotem" <nrotem at apple.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Sunday, January 27, 2013 9:16:42 PM > Subject: Re: Floats as Doubles in Vectors > > Hi Hal, > > I am not familiar with Blue Gene at all but

It might also make sense to have functions that return costs for vector ops return some sort of `LinearPolyBase` with `ScalarTy` being `InstructionCost`. From: llvm-dev <llvm-dev-bounces at lists.llvm.org> On Behalf Of Vineet Kumar via llvm-dev Sent: Monday, November 16, 2020 11:24 PM To: David Sherwood <David.Sherwood at arm.com>; llvm-dev at lists.llvm.org Subject: [EXT] Re:

Hi, I'd like to propose a change to our cost interfaces so that instead of returning an unsigned value from functions like getInstructionCost, getUserCost, etc., we instead return a wrapper class that encodes an integer cost along with extra state. The extra state can be used to express: 1. A cost as infinitely expensive in order to prevent certain optimisations taking place. For example,

Thanks for looking into this. 1) Issues with re running vectorizer: Vectorizer might generate redundant alias checks while vectorizing epilog loop. Redundant alias checks are expensive, we like to reuse the results of already computed alias checks. With metadata we can limit the width of epilog loop, but not sure about reusing alias check result. Any thoughts on rerunning vectorizer with reusing