similar to: Saving Compile Time in InstCombine

On 03/17/2017 04:30 PM, Mehdi Amini via llvm-dev wrote: > >> On Mar 17, 2017, at 11:50 AM, Mikhail Zolotukhin via llvm-dev >> <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> >> Hi, >> >> One of the most time-consuming passes in LLVM middle-end is >> InstCombine (see e.g. [1]). It is a very powerful pass capable

> On Mar 17, 2017, at 6:12 PM, David Majnemer via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Honestly, I'm not a huge fan of this change as-is. The set of transforms that were added behind ExpensiveChecks seems awfully strange and many would not lead the reader to believe that they are expensive at all (the SimplifyDemandedInstructionBits and foldICmpUsingKnownBits calls

> To (hopefully) make it easier to answer this question, I've posted my (work-in-progress) patch which adds a known-bits cache to InstCombine. > I rebased it yesterday, so it should be fairly easy to apply: https://reviews.llvm.org/D31239 - Seeing what this does to the performance of the > benchmarks mentioned in this thread (among others) would certainly be interesting. Thanks! I

> On Mar 17, 2017, at 6:12 PM, David Majnemer <david.majnemer at gmail.com> wrote: > > Honestly, I'm not a huge fan of this change as-is. The set of transforms that were added behind ExpensiveChecks seems awfully strange and many would not lead the reader to believe that they are expensive at all (the SimplifyDemandedInstructionBits and foldICmpUsingKnownBits calls being the

In my testing results are not that impressive, but that's because I'm now focusing on Os. For me even complete disabling of all KnownBits-related patterns in InstCombine places the results very close to the noise level. In my original patch I also had some extra patterns moved under ExpensiveCombines - and that seems to make a difference too (without this part, or without the KnownBits

Hi Bob, are these performance regressions real? They look pretty serious. Ciao, Duncan. On 10/12/11 09:40, llvm-testresults at cs.uiuc.edu wrote: > > bwilson__llvm-gcc_PROD__i386 nightly tester results > > URL http://llvm.org/perf/db_default/simple/nts/332/ > Nickname bwilson__llvm-gcc_PROD__i386:4 > Name curlew.apple.com > > Run ID Order Start Time End Time >

Yes, they are real. I re-ran the two tests with the biggest execution time regressions, and the results were completely reproducible. On Oct 12, 2011, at 1:24 AM, Duncan Sands wrote: > Hi Bob, are these performance regressions real? They look pretty serious. > > Ciao, Duncan. > > On 10/12/11 09:40, llvm-testresults at cs.uiuc.edu wrote: >> >>

A big compile time regression. Any ideas? Ciao, Duncan. On 22/07/11 19:13, llvm-testresults at cs.uiuc.edu wrote: > > bwilson__llvm-gcc_PROD__i386 nightly tester results > > URL http://llvm.org/perf/db_default/simple/nts/253/ > Nickname bwilson__llvm-gcc_PROD__i386:4 > Name curlew.apple.com > > Run ID Order Start Time End Time > Current 253 0 2011-07-22 16:22:04

Did something change with exception handling recently? A bunch of lit bots are showing slower compile times for many tests. Ciao, Duncan. On 20/06/12 07:53, llvm-testresults at cs.uiuc.edu wrote: > > lab-mini-03__O0-g__clang_DEV__x86_64 test results > <http://llvm.org/perf/db_default/v4/nts/1283?compare_to=1278&baseline=999> > > Run Order Start Time Duration >

Nothing that I'm aware of has changed with EH. Is it possible to bisect the problem? -bw On Jun 20, 2012, at 12:38 AM, Duncan Sands <baldrick at free.fr> wrote: > Did something change with exception handling recently? A bunch of lit bots are > showing slower compile times for many tests. > > Ciao, Duncan. > > On 20/06/12 07:53, llvm-testresults at cs.uiuc.edu

Hi Bill, > Nothing that I'm aware of has changed with EH. Is it possible to bisect the problem? I don't see any relevant LLVM changes, so I guess clang C++ compilation slowed down due to some clang changes. I'm not going to investigate this. Ciao, Duncan. > > -bw > > On Jun 20, 2012, at 12:38 AM, Duncan Sands <baldrick at free.fr> wrote: > >> Did

Are these 225 compile time regressions real? It sure looks bad! Ciao, Duncan. On 01/12/11 09:39, llvm-testresults at cs.uiuc.edu wrote: > > bwilson__llvm-gcc_PROD__i386 nightly tester results > > URL http://llvm.org/perf/db_default/simple/nts/380/ > Nickname bwilson__llvm-gcc_PROD__i386:4 > Name curlew.apple.com > > Run ID Order Start Time End Time > Current 380

Hi, I have just tagged 3.7.1-rc1, so it is ready for testing. As a reminder, when doing regression testing, use the 3.7.0 release as your baseline. Thanks, Tom

On Jul 24, 2011, at 3:02 AM, Duncan Sands wrote: > A big compile time regression. Any ideas? > > Ciao, Duncan. False alarm. For some reason that I have not yet been able to figure out, these tests run significantly more slowly when I run them during the daytime, which I did for that run. I checked a few of the worst regressions reported here and they all recovered in subsequent

Most of libc++ doesn't have explicit template instantiations, which leads to a pretty significant build time and code size cost when using libc++, since a large number of common templates will be emitted by the compiler and coalesced by the linker. Notably, in include/__config, we have: #ifndef _LIBCPP_EXTERN_TEMPLATE #define _LIBCPP_EXTERN_TEMPLATE(...) #endif whereas before

On Jul 5, 2012, at 1:33 AM, Duncan Sands wrote: > Hi Bill, > >> Nothing that I'm aware of has changed with EH. Is it possible to bisect the problem? > > I don't see any relevant LLVM changes, so I guess clang C++ compilation slowed > down due to some clang changes. I'm not going to investigate this. > Crumbs. John, Do you know of anything that went into

Hi, Below you can see the updated benchmark results for the new SLP-vectorizer. As you can see, there is a small number of compile time regressions, a single major runtime *regression, and many performance gains. There is a tiny increase in code size: 30k for the whole test-suite. Based on the numbers below I would like to enable the SLP-vectorizer by default for -O3. Please let me know if you

Hi, Does the LLVM project perform any kind of tracking for commit-by-commit compile-time changes? It looks like LNT only tracks run-time performance (and to be honest I wasn't able to make heads or tails of the results even for that -- the interface was pretty unintuitive to me.) While it is "normal" that each new LLVM release regresses compile-time by 2-3%, LLVM 10 seems to be

Hi all, I've started looking at the GlobalMerge pass, enabled by default on ARM and AArch64. I think we should reconsider that, at least for AArch64. As is, the pass just merges all globals together, in groups of 4KB (AArch64, 128B on ARM). At the time it was enabled, the general thinking was "it's almost free, it doesn't affect performance much, we might as well use it".

Hi, Over the past six months, a MemorySSA-backed DSE implementation has been added to LLVM and it now covers almost all cases the existing DSE implementation does, plus adding a major new capability: eliminating stores across basic blocks. Thanks everyone involved with reviews, testing & patches! I think now would be a good time to start working towards switching to use MemorySSA-backed DSE