similar to: [LLVMdev] ARM vectorizer cost model

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

On 9 January 2013 17:10, Nadav Rotem <nrotem at apple.com> wrote: > For example: > "opt -cost-model -analyze dumper.ll -mtriple=thumbv7 > -mcpu=cortex-a15" > > I also run the vectorizer with -debug-only=loop-vectorize because it dumps > the costs of all of the instructions with different vectorization factors, > and it also detects the different kinds

Hi all, I'm looking for a place where to put the costs of vector (and scalar) cast operations for ARM, but I noticed the TargetTransform methods call the TargetLowering ones when unsure. Now, I'm not sure... Many casts on ARM are free, and I could build a list of cases where it is true, but should I put this on the lowering or the transform? My main motivation is to get the costs right

Hi Renato, I think that we need to improve ::isTruncateFree, ::isZextFree, etc to include all of the free conversions. Vector and Scalar. Non-free conversions are marked with setOperationAction so the generic parts of TTI should be able to give a reasonable cost estimation. The cost tables should contain cases that are not handled by TTI. So, if we have a clever DAGCombine optimization (that

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

On 10 January 2013 23:00, Nadav Rotem <nrotem at apple.com> wrote: > Some of the costs for the arithmetic operations should be handled > automatically by the BasicTTI (which asks TartetLowering if the type and > operations are legal). We need to have cost tables for things like "trunk > <4 x i64> to <4 x i8>" because even TLI does not know how custom

Hi, I noticed many functions in the TargetTransformInfo interface are duplicates of those already in TargetLowering (e.g. isTruncateFree). Is the expectation really that targets will reimplement the same functions twice? AArch64’s TTI uses some TLI calls in some of its implementations, but why doesn’t the base TargetTransformInfo call the TargetLowering versions by default? - Matt

Just realized that BasicTransformInfoClass is an immutable pass. Not sure how to reconcile this with fact that there will be different answers needed depending on the subtarget. Seems like BasicTansformInfoClass should become a function pass that does not modify anything. On 03/22/2013 09:43 AM, Reed Kotler wrote: > Another way to do this would to be to have a reset virtual function >

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

Hi Reed, We will need to reconstruct the target machine and the TTI chain when the function attributes change. We currently don't have code for doing that but I suggest that you talk with Bill Wendling about the best way to implement this. Thanks, Nadav On Mar 22, 2013, at 11:30 AM, Reed Kotler <rkotler at mips.com> wrote: > Just realized that BasicTransformInfoClass is an

CostModule::getInstructionCost also consults TTI ( http://llvm.org/docs/doxygen/html/CostModel_8cpp_source.html#l00380). No? Jingyue On Wed, Jan 14, 2015 at 4:05 PM, Chandler Carruth <chandlerc at google.com> wrote: > > On Wed, Jan 14, 2015 at 3:54 PM, Jingyue Wu <jingyue at google.com> wrote: > >> I'm looking for APIs that compute instruction costs, and noticed

Amara, >I support this direction Thanks for the support. >but are there actually any real world workloads where gather/scatter scalarisation would be worth it, on any micro-architecture? If we don’t have examples and the compile time cost is non-negligible then I think we’d still like to keep the early >bailouts in some form.’ It's not like I have specific application code in

On 01/05/2018 06:28 PM, Saito, Hideki wrote: > Amara, > >> I support this direction > Thanks for the support. > >> but are there actually any real world workloads where gather/scatter scalarisation would be worth it, on any micro-architecture? If we don’t have examples and the compile time cost is non-negligible then I think we’d still like to keep the early >bailouts in

Thanks, Hal. I plan to post a patch w/o HW Legality early bailout first. That should enable further discussion on where the initial very high cost for "illegal masked load/store/gather/scatter" should be coming from --- like should LoopVectorize provide it? Or should it be provided by TTI? I prefer the latter (TTI) but the first revision of the patch will intentionally do the former

Hi all, While tinkering with saturation instructions, I hit problems with the cost model calculations. The loop vectorizer cost model accumulates the individual TTI cost model of each instruction. For saturating arithmetic, this is a gross overestimate, since you have 2 sexts (inputs), 2 icmps + 2 selects (for the saturation), and a truncate (output); these all fold alway. With an intrinsic,

add -basicaa to your command line :) On Mon, May 11, 2015 at 7:15 AM, Willy WOLFF <willy.mh.wolff at gmail.com> wrote: > I play a bit more with MemoryDependenceAnalysis by wrapping my pass, and > call explicitely BasicAliasAnalysis. Its still using No Alias Analysis. > > How can I let MemoryDependenceAnalysis use BasicAliasAnalysis? > > Please, find attached my pass. >

On Jan 11, 2013, at 7:36 AM, Renato Golin Linaro <renato.golin at linaro.org> wrote: > On 10 January 2013 23:00, Nadav Rotem <nrotem at apple.com> wrote: > Some of the costs for the arithmetic operations should be handled automatically by the BasicTTI (which asks TartetLowering if the type and operations are legal). We need to have cost tables for things like "trunk <4 x

For being able to change subtargets within a compilation unit, among other things, I need to be able to change the target lowering class that is used by BasicTTI For example we have a mips16 and non mips16 version. On the original call that creates this class, I'd like to pass the address of the address of the TargetLoweringBase class. That way I can insert a function pass before this

----- Original Message ----- > From: "Jingyue Wu" <jingyue at google.com> > To: "songlh" <songlh at cs.wisc.edu>, llvmdev at cs.uiuc.edu > Sent: Wednesday, October 15, 2014 2:50:12 PM > Subject: Re: [LLVMdev] how to choose which alias analysis used in my pass? > > > Isn't -basicaa the default alias analysis already? No, -basicaa is added

Does LLVM have loop multiversioning ? it seems it does not with clang++ -O3 -mllvm -debug-pass=Arguments program.c -c bash-4.1$ clang++ -O3 -mllvm -debug-pass=Arguments fast_algorithms.c -c clang-3.6: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated Pass Arguments: -datalayout -notti -basictti -x86tti -targetlibinfo -no-aa -tbaa -scoped-noalias