search for: costly

Sorry if double posted... might have sent this to old mailing list address... ---------- Forwarded message ---------- From: Stephen Thomas <stephen.warner.thomas at gmail.com> Date: Wed, Aug 5, 2015 at 10:39 AM Subject: How to use CostModel? To: LLVM Dev <llvmdev at cs.uiuc.edu> Hi, I'm trying to use the built-in CostModel class to estimate the number of machine instructions

Hello! I am trying to get a logic estatement in R using the if function, but it is all the time comming and error, I have tryied different methods but nothing is working the sentence is the following: dispersal[1] <- if (any (relativenes[1] < cost)) ((relativenes[1]- cost)/(relativenes[1]- cost*cost)) else 0 for (i in 2: time){ dispersal[i] <- if (any

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,

Comments and suggestions for improving the specifications are welcome. Thanks, Alvin One example comparing context/specify (CS) with given/when/then (GWT) with a strategy pattern follows: Consider a pipeline transporting oil supplied by multiple partners. The amounts transported on behalf of each partner are recorded as transactions in a general ledger. There are multiple approaches to

On 4 February 2013 18:25, Arnold Schwaighofer <aschwaighofer at apple.com>wrote: > For cases where this approach breaks really badly we could consider adding > a specialized api or parameters (like the type of a user/use). But we > should do so only as a last resort and backed by actual code that would > benefit from doing so. > Very sensible, more or less what I had in

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

The loop vectorized does not estimate the cost of vectorization by looking at the IR you list below. It does not vectorize and then run the CostAnalysis pass. It estimates the cost itself before it even performs the vectorization. The way it works is that it looks at all the scalar instructions and asks: What is the cost if I execute the scalar instruction as a vector instruction. Therefore, it

Hi all, I have a query regarding Cost Table for AVX2 in TargetTransformInfo. The table consist of entries for shift and div operations only. There are no entries for ADD, SUB and MUL for AVX2 cost table. Those entries are present in Cost Table for AVX. The reason for query is - when my sub target feature is AVX2, in SLP Vectorization, while calculating scalar cost of ADD, it doesn't see

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<Copied Cong> Thanks Elena. Mostly I was interested in why such a high cost 30 kept for TRUNCATE v16i32 to v16i8 in SSE41. Looking at the code it appears like TRUNCATE v16i32 to v16i8 in SSE41 is very expensive vs SSE2. I feel this number should be same/close to the cost mentioned for same operation in SSE2ConversionTbl. Below patch from Cong Hou reduce cost for same operation in SSE2

Makes sense. I personally greatly prefer having a type rather than a `static constexpr int CostUnfathomable = 10000`. I think the type should have arithmetic operators defined such that an "invalid cost" on either side results in an invalid cost (similar to how NaN infects floats), and an implicit conversion that constructs a valid cost. Then I could just do: ``` Cost c = 7; // c is a

I try to track down an error that causes that Astcc just reports the time, but not the costs. I could narrow the problem down into this sub routine: sub calccost() { my ($adjconn, $adjcost, $answeredtime, $increment) = @_; eval { my $adjtime = int(($answeredtime + $increment - 1) / $increment) * $increment }; my $cost; print STDERR "Adjusted time is $adjtime, cost is $adjcost with

All, I have a question regarding colors in bar plots. I want to stack a total of 18 cost values in each bar. Basically, it is six cost types and each cost type has three components- direct, indirect, and induced costs. I would like to use both solid color bars and bars with the slanted lines (using the density parameter). The colors would distinguish cost types and the lines would

Hi Chris, Thanks for the reply. My email was really to just ask if people were ok with the idea in principle and I kind of deliberately avoided getting into too many details at this point. If people are happy with the idea in principle I can push a patch up soon that shows what such a class could like so that people can comment on it? Regards, David Sherwood. From: Chris Tetreault <ctetreau

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 Sebastian, It boils down to this: The previous heuristic solver could return infinite cost solutions in some rare cases (despite finite-cost solutions existing). The new solver is still heuristic, but it should always return a finite cost solution if one exists. It does this by avoiding early reduction of infinite spill cost nodes via R1 or R2. To illustrate why the early reductions can be a

Hi, I have been working in the TargetTransformInfo layer for the last few weeks with several ongoing goals: > Remove ambiguity. > Improve cost modelling performance, accuracy and utility. > Help empower the backends. > Reduce the surface area of the API. > Reduce the dependencies between the layers - of which there are many! My latest patch is an NFC to help address the issue of

On 2017-01-20 14:31, Hal Finkel wrote: > > On 01/20/2017 06:11 AM, Jonas Paulsson via llvm-dev wrote: >> Hi, >> >> I wonder why getScalarizationOverhead() does not take into account >> the number of operands of the instruction? This should influence the >> number of extracts needed, so instead of >> >> Scalarization cost = NumEls * (insert +

On Wed, Jan 15, 2014 at 5:30 PM, Nadav Rotem <nrotem at apple.com> wrote: > Was the vectorizer successful in unrolling the loop in quantum_sigma_x? I > wonder if 'size’ is typically high or low. No. The vectorizer stated that it wasn't going to bother with the loop because it wasn't profitable. Specifically: LV: Checking a loop in "quantum_sigma_x" LV: Found a

Hi, I was going through the X86TTIImpl::getCastInstrCost, and got a doubt on cost calculation for TRUNCATE instruction in AVX mode. In AVX2ConversionTbl & AVXConversionTbl table there is no cost defined for TRUNCATE v16i32 to v16i8, as a fallback it goes to SSE41ConversionTbl table and there it finds cost as 30 for this operation. 30 cost for this operation looks very high. Wondering why