search for: getarithmeticinstrcost

Hi, I'm looking for APIs that compute instruction costs, and noticed several of them. 1. A series of APIs of TargetTransformInfo that compute the cost of instructions of a particular type (e.g. getArithmeticInstrCost and getShuffleCost) 2. TargetTransformInfo::getOperationCost 3. CostModel::getInstructionCost::getInstructionCost in lib/Analysis/CostModel.cpp Only the first one is used extensively in LLVM's code base, but the second and third one seems more recently added and more general, making me think i...

Dear LLVM contributors, I work on the "Improvement of vectorization process in Polly". At the moment I'm trying to implement tiling, interchanging and unrolling of specific loops based on the following algorithm for the analytical modeling [1]. It requires information about the following parameters of a target architecture: 1. Size of double-precision floating-point number. 2.

...erationCost(), which returns various fixed values (4 for division (TCC_Expensive, but this isn't nearly expensive enough)). getOperationCost only uses the type and opcode to estimate, so it doesn't require a value. No target overrides this. The hooks that targets do really implement, like getArithmeticInstrCost, use some information about the operands so require a value. These don't appear to be used at all by the cost model, and instead in specific places in some passes. Why don't any targets override getOperationCost or why aren't there any other hooks that change its behavior? Having thes...

...:54 PM, Jingyue Wu <jingyue at google.com> wrote: > >> I'm looking for APIs that compute instruction costs, and noticed several >> of them. >> >> 1. A series of APIs of TargetTransformInfo that compute the cost of >> instructions of a particular type (e.g. getArithmeticInstrCost and >> getShuffleCost) >> 2. TargetTransformInfo::getOperationCost >> 3. CostModel::getInstructionCost::getInstructionCost in >> lib/Analysis/CostModel.cpp >> >> Only the first one is used extensively in LLVM's code base, but the >> second and third one...

...s 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 (including NEON and VFP), that should give us a head start. I'm guessing the cost you already have for Intel and the BasicTTI is in "ideal cycle count",...

I know, I said a bad word -- analysis group. But it works pretty much the way I think we want here. We *always* want a TargetTransformInfo, and we have reasonable (conservative) stubs in place. We would just like the option of providing one from the target that has very clever implementations. I would propose that we make TargetTransformInfo be an analysis group, and provide

On Jan 10, 2013, at 2:19 PM, Renato Golin Linaro <renato.golin at linaro.org> wrote: > 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 (including NEON and VFP), that should give us a head start. Renato, Thanks for working on this! Some of the costs for the arithmetic operations should be handled...

> I don't understand why you want to factor out the information, > exactly. It seems like what you need is a function like: > > unsigned getMinLeadingZeros(const SCEV *); > > then, if you want to get the non-extended expression, you can just > apply an appropriate truncation. I assume, however, that I'm missing > something. The problem is not about how to codegen

Hi Renato, > I'm interested in knowing how you'll work up the ARM cost model and how easy it'd be to split the work. Yes, I am starting to work on the ARM cost model and I would appreciate any help in the form of: advice, performance measurements, patches, etc. I tune the cost model by running the cost model analysis pass and I compare the output of the analysis to the output

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

Thanks Nadav for the info. It clears my query :) Yes its an integer ADD, and since AVX2 supports 256 bits integer arithmetic, so its cost is less than AVX1. One query though - shouldn't then the cost of integer ADD/SUB/MUL (which would be 1) be explicitly specified in AVX2 cost table? Because right now this entry is missing and cost of these operations are taken from BaseTTI (which is