search for: cost

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 for each IR Instruction. To get a feel for what kind of output the CostModel pass gives, I ran it on the command line like so: $ cat test.c int...

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 (relativenes[i] < cost)) ((relativenes[i]- cost)/(relativenes[i]- cost*cost)) else 0 } dispersal[1] <- if (relativenes[1] < cost) dispersal[1] <- (...

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...

...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 allocating the pipeline operational costs to each partner: - fixed amount - equal split - fixed percentage - gross override with subsidiary cost allocation - proportional cost allocation - tiered cost allocation The fixed amount, equal split, and fixed percentage methods were easy to specify since all logic is contained withi...

...arithmetic operation? It won't be perfect, but it adds a bit more information at very reduced price. Though, this would require us to pass the Instruction, not the Opcode. Do you have an example where this happening? The example below is not stopping the vectorizer, but it does add a lot of costs where there are none... ** C code: int direct (int k) { int i; int a[256], b[256], c[256]; for (i=0; i<256; i++){ a[i] = b[i] * c[i]; } return a[k]; } ** ASM vectorized result: adr r5, .LCPI0_0 vdup.32 q9, r1 vld1.64 {d16, d17}, [r5, :128]...

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 generic). IMO, it will make things more clea...

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 scala...

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...

...es 4 3.3 Proposed Service Commencement Date 4 4.0 IMPUTATION TEST 4 5.0 DEMAND AND REVENUE INFORMATION 5 5.1 Forecast Assumptions and Methodology 5 5.2 Number of Customers 5 5.3 Number of 0-ECRS Calls 5 5.4 Bell Canada Average 0-ECRS Call Duration 5 5.5 Estimates of Demand Quantities 5 6.0 PHASE II COSTS 6 6.1 Study Assumptions 6 6.2 Study Period 7 6.3 Financial Parameters and Tax Rates 7 6.4 Cost Inclusions 7 6.4.1 Expenses Causal to the Service 7 6.4.2 Capital Causal to the Service 8 6.4.3 Capital Causal to Demand 8 6.4.4 Expenses Causal to Demand 8 6.4.5 Phase II Cost Summary 9 7.0 3RD PARTY AC...

<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 oper...

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...

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...

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 di...

...le can comment on it? Regards, David Sherwood. From: Chris Tetreault <ctetreau at quicinc.com> Sent: 05 November 2020 19:23 To: David Sherwood <David.Sherwood at arm.com>; LLVM Dev <llvm-dev at lists.llvm.org> Subject: RE: [llvm-dev] [Proposal] Introducing the concept of invalid costs to the IR cost model You're being quite vague about what the extra state is. Is this because you haven't yet settled on what it should be, or do you actually intend to let it be a template parameter: template <typename T> struct Cost { unsigned Val; T State; } Thanks, Chris...

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...

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...

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 ambiguity, I have uploaded the patch here: https:/...

...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 + extract) >> >> it would be better to do >> >> Scalarization cost = NumEls * (insert + (extract * numOperands)) > > I suspect this is an oversight (although we need to be a bit careful > here because if two operands are the same, which is not un...

...ecifically: LV: Checking a loop in "quantum_sigma_x" LV: Found a loop: for.body LV: Found an induction variable. LV: Found a write-only loop! LV: We can vectorize this loop! LV: Found trip count: 0 LV: The Widest type: 64 bits. LV: The Widest register is: 128 bits. LV: Found an estimated cost of 0 for VF 1 For instruction: %indvars.iv = phi i64 [ 0, %for.body.lr.ph ], [ %indvars.iv.next, %for.body ] LV: Found an estimated cost of 0 for VF 1 For instruction: %state = getelementptr inbounds %struct.quantum_reg_node_struct* %2, i64 %indvars.iv, i32 1, !dbg !58 LV: Found an estimated cost...

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 o...