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path: root/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
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2016-12-01Object: Extract a ModuleSymbolTable class from IRObjectFile.Peter Collingbourne1-3/+1
This class represents a symbol table built from in-memory IR. It provides access to GlobalValues and should only be used if such access is required (e.g. in the LTO implementation). We will eventually change IRObjectFile to read from a bitcode symbol table rather than using ModuleSymbolTable, so it would not be able to expose the module. Differential Revision: https://reviews.llvm.org/D27073 llvm-svn: 288319
2016-11-23[PM] Change the static object whose address is used to uniquely identifyChandler Carruth1-1/+1
analyses to have a common type which is enforced rather than using a char object and a `void *` type when used as an identifier. This has a number of advantages. First, it at least helps some of the confusion raised in Justin Lebar's code review of why `void *` was being used everywhere by having a stronger type that connects to documentation about this. However, perhaps more importantly, it addresses a serious issue where the alignment of these pointer-like identifiers was unknown. This made it hard to use them in pointer-like data structures. We were already dodging this in dangerous ways to create the "all analyses" entry. In a subsequent patch I attempted to use these with TinyPtrVector and things fell apart in a very bad way. And it isn't just a compile time or type system issue. Worse than that, the actual alignment of these pointer-like opaque identifiers wasn't guaranteed to be a useful alignment as they were just characters. This change introduces a type to use as the "key" object whose address forms the opaque identifier. This both forces the objects to have proper alignment, and provides type checking that we get it right everywhere. It also makes the types somewhat less mysterious than `void *`. We could go one step further and introduce a truly opaque pointer-like type to return from the `ID()` static function rather than returning `AnalysisKey *`, but that didn't seem to be a clear win so this is just the initial change to get to a reliably typed and aligned object serving is a key for all the analyses. Thanks to Richard Smith and Justin Lebar for helping pick plausible names and avoid making this refactoring many times. =] And thanks to Sean for the super fast review! While here, I've tried to move away from the "PassID" nomenclature entirely as it wasn't really helping and is overloaded with old pass manager constructs. Now we have IDs for analyses, and key objects whose address can be used as IDs. Where possible and clear I've shortened this to just "ID". In a few places I kept "AnalysisID" to make it clear what was being identified. Differential Revision: https://reviews.llvm.org/D27031 llvm-svn: 287783
2016-11-14Restore "[ThinLTO] Prevent exporting of locals used/defined in module level asm"Teresa Johnson1-0/+45
This restores the rest of r286297 (part was restored in r286475). Specifically, it restores the part requiring adding a dependency from the Analysis to Object library (downstream use changed to correctly model split BitReader vs BitWriter libraries). Original description of this part of patch follows: Module level asm may also contain defs of values. We need to prevent export of any refs to local values defined in module level asm (e.g. a ref in normal IR), since that also requires renaming/promotion of the local. To do that, the summary index builder looks at all values in the module level asm string that are not marked Weak or Global, which is exactly the set of locals that are defined. A summary is created for each of these local defs and flagged as NoRename. This required adding handling to the BitcodeWriter to look at GV declarations to see if they have a summary (rather than skipping them all). Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to ensure that an MCAsmParser is available, otherwise the module asm parse would silently fail. Initialized the asm parser in the opt tool for use in testing this fix. Fixes PR30610. llvm-svn: 286844
2016-11-14[ThinLTO] Make inline assembly handling more efficient in summaryTeresa Johnson1-7/+10
Summary: The change in r285513 to prevent exporting of locals used in inline asm added all locals in the llvm.used set to the reference set of functions containing inline asm. Since these locals were marked NoRename, this automatically prevented importing of the function. Unfortunately, this caused an explosion in the summary reference lists in some cases. In my particular example, it happened for a large protocol buffer generated C++ file, where many of the generated functions contained an inline asm call. It was exacerbated when doing a ThinLTO PGO instrumentation build, where the PGO instrumentation included thousands of private __profd_* values that were added to llvm.used. We really only need to include a single llvm.used local (NoRename) value in the reference list of a function containing inline asm to block it being imported. However, it seems cleaner to add a flag to the summary that explicitly describes this situation, which is what this patch does. Reviewers: mehdi_amini Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D26402 llvm-svn: 286840
2016-11-10Restore part of "[ThinLTO] Prevent exporting of locals used/defined in ↵Teresa Johnson1-4/+14
module level asm" This restores the part of r286297 that didn't require adding a dependency from the Analysis to Object library. There are two parts to the original fix, and this will address the handling for the case where locals are used in module level asm. The part that requires functionality in libObject handles local defs in module level asm, and was reverted because our downstream build of clang builds lib/Bitcode into a single library, and this new dependency introduced a cycle there. I am trying to get that fixed (see D26502), so for now that change isn't being restored llvm-svn: 286475
2016-11-09Revert "[ThinLTO] Prevent exporting of locals used/defined in module level asm"Mehdi Amini1-57/+4
This reverts commit r286297. Introduces a dependency from libAnalysis to libObject, which I missed during the review. llvm-svn: 286329
2016-11-08[ThinLTO] Prevent exporting of locals used/defined in module level asmTeresa Johnson1-4/+57
Summary: This patch uses the same approach added for inline asm in r285513 to similarly prevent promotion/renaming of locals used or defined in module level asm. All static global values defined in normal IR and used in module level asm should be included on either the llvm.used or llvm.compiler.used global. The former were already being flagged as NoRename in the summary, and I've simply added llvm.compiler.used values to this handling. Module level asm may also contain defs of values. We need to prevent export of any refs to local values defined in module level asm (e.g. a ref in normal IR), since that also requires renaming/promotion of the local. To do that, the summary index builder looks at all values in the module level asm string that are not marked Weak or Global, which is exactly the set of locals that are defined. A summary is created for each of these local defs and flagged as NoRename. This required adding handling to the BitcodeWriter to look at GV declarations to see if they have a summary (rather than skipping them all). Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to ensure that an MCAsmParser is available, otherwise the module asm parse would silently fail. Initialized the asm parser in the opt tool for use in testing this fix. Fixes PR30610. Reviewers: mehdi_amini Subscribers: johanengelen, krasin, llvm-commits Differential Revision: https://reviews.llvm.org/D26146 llvm-svn: 286297
2016-10-30[ThinLTO] Use per-summary flag to prevent exporting locals used in inline asmTeresa Johnson1-46/+30
Summary: Instead of using the workaround of suppressing the entire index for modules that call inline asm that may reference locals, use the NoRename flag on the summary for any locals in the llvm.used set, and add a reference edge from any functions containing inline asm. This avoids issues from having no summaries despite the module defining global values, which was preventing more aggressive index-based optimization. It will be followed by a subsequent patch to make a similar fix for local references in module level asm (to fix PR30610). Reviewers: mehdi_amini Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D26121 llvm-svn: 285513
2016-10-28[ThinLTO] Create AliasSummary when building indexTeresa Johnson1-6/+24
Summary: Previously we were creating the alias summary on the fly while writing the summary to bitcode. This moves the creation of these summaries to the module summary index builder where we build the rest of the summary index. This is going to be necessary for setting the NoRename flag for values possibly used in inline asm or module level asm. Reviewers: mehdi_amini Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D26049 llvm-svn: 285379
2016-10-08[ThinLTO] Record calls to aliasesTeresa Johnson1-1/+12
Summary: When there is a call to an alias in the same module, we were not adding a call edge. So we could incorrectly think that the alias was dead if it was inlined in that function, despite having a reference imported elsewhere. This resulted in unsats at link time. Add a call edge when the call is to an alias. Reviewers: davide, mehdi_amini Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D25384 llvm-svn: 283664
2016-09-28Refactor the ProfileSummaryInfo to use doInitialization and doFinalization ↵Dehao Chen1-1/+1
to handle Module update. Summary: This refactors the change in r282616 Reviewers: davidxl, eraman, mehdi_amini Subscribers: mehdi_amini, davide, llvm-commits Differential Revision: https://reviews.llvm.org/D25041 llvm-svn: 282630
2016-09-26[thinlto] Basic thinlto fdo heuristicPiotr Padlewski1-13/+41
Summary: This patch improves thinlto importer by importing 3x larger functions that are called from hot block. I compared performance with the trunk on spec, and there were about 2% on povray and 3.33% on milc. These results seems to be consistant and match the results Teresa got with her simple heuristic. Some benchmarks got slower but I think they are just noisy (mcf, xalancbmki, omnetpp)- running the benchmarks again with more iterations to confirm. Geomean of all benchmarks including the noisy ones were about +0.02%. I see much better improvement on google branch with Easwaran patch for pgo callsite inlining (the inliner actually inline those big functions) Over all I see +0.5% improvement, and I get +8.65% on povray. So I guess we will see much bigger change when Easwaran patch will land (it depends on new pass manager), but it is still worth putting this to trunk before it. Implementation details changes: - Removed CallsiteCount. - ProfileCount got replaced by Hotness - hot-import-multiplier is set to 3.0 for now, didn't have time to tune it up, but I see that we get most of the interesting functions with 3, so there is no much performance difference with higher, and binary size doesn't grow as much as with 10.0. Reviewers: eraman, mehdi_amini, tejohnson Subscribers: mehdi_amini, llvm-commits Differential Revision: https://reviews.llvm.org/D24638 llvm-svn: 282437
2016-08-30NFC: add early exit in ModuleSummaryAnalysisPiotr Padlewski1-29/+32
Summary: Changed this code because it was not very readable. The one question that I got after changing it is, should we count calls to intrinsics? We don't add them to caller summary, so maybe we shouldn't also count them? Reviewers: tejohnson, eraman, mehdi_amini Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D23949 llvm-svn: 280036
2016-08-19[PM] Rework the new PM support for building the ModuleSummaryIndex toChandler Carruth1-33/+30
directly produce the index as the value type result. This requires making the index movable which is straightforward. It greatly simplifies things by allowing us to completely avoid the builder API and the layers of abstraction inherent there. Instead both pass managers can directly construct these when run by value. They still won't be constructed truly eagerly thanks to the optional in the legacy PM. The code that directly builds the index can also just share a direct function. A notable change here is that the result type of the analysis for the new PM is no longer a reference type. This was really problematic when making changes to how we handle result types to make our interface requirements *much* more strict and precise. But I think this is an overall improvement. Differential Revision: https://reviews.llvm.org/D23701 llvm-svn: 279216
2016-08-12[PM] Port ModuleSummaryIndex analysis to new pass managerTeresa Johnson1-0/+13
Summary: Port the ModuleSummaryAnalysisWrapperPass to the new pass manager. Use it in the ported BitcodeWriterPass (similar to how we use the legacy ModuleSummaryAnalysisWrapperPass in the legacy WriteBitcodePass). Also, pass the -module-summary opt flag through to the new pass manager pipeline and through to the bitcode writer pass, and add a test that uses it. Reviewers: mehdi_amini Subscribers: llvm-commits, mehdi_amini Differential Revision: https://reviews.llvm.org/D23439 llvm-svn: 278508
2016-08-11Use range algorithms instead of unpacking begin/endDavid Majnemer1-3/+3
No functionality change is intended. llvm-svn: 278417
2016-07-17[ThinLTO] Perform profile-guided indirect call promotionTeresa Johnson1-7/+27
Summary: To enable profile-guided indirect call promotion in ThinLTO mode, we simply add call graph edges for each profitable target from the profile to the summaries, then the summary-guided importing will consider the callee for importing as usual. Also we need to enable the indirect call promotion pass creation in the PassManagerBuilder when PerformThinLTO=true (we are in the ThinLTO backend), so that the newly imported functions are considered for promotion in the backends. The IC promotion profiles refer to callees by GUID, which required adding GUIDs to the per-module VST in bitcode (and assigning them valueIds similar to how they are assigned valueIds in the combined index). Reviewers: mehdi_amini, xur Subscribers: mehdi_amini, davidxl, llvm-commits Differential Revision: http://reviews.llvm.org/D21932 llvm-svn: 275707
2016-06-26Apply clang-tidy's modernize-loop-convert to lib/Analysis.Benjamin Kramer1-6/+5
Only minor manual fixes. No functionality change intended. llvm-svn: 273816
2016-05-06ThinLTO: fix assertion and refactor check for hidden use from inline ASM in ↵Mehdi Amini1-31/+43
a helper function This test was crashing, and currently it breaks bootstrapping clang with debuginfo Differential Revision: http://reviews.llvm.org/D20008 From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 268715
2016-04-27[ThinLTO] Refine fix to avoid renaming of uses in inline assembly.Teresa Johnson1-6/+14
Summary: Refine the workaround from r266877 that attempts to prevent renaming of locals in inline assembly, so that in addition to looking for a llvm.used local value, that there is at least one inline assembly call in the module. Otherwise, debug functions added to the llvm.used can block importing/exporting unnecessarily. Reviewers: joker.eph Subscribers: llvm-commits, joker.eph Differential Revision: http://reviews.llvm.org/D19573 llvm-svn: 267717
2016-04-24[ThinLTO] Remove GlobalValueInfo class from indexTeresa Johnson1-11/+8
Summary: Remove the GlobalValueInfo and change the ModuleSummaryIndex to directly reference summary objects. The info structure was there to support lazy parsing of the combined index summary objects, which is no longer needed and not supported. Reviewers: joker.eph Subscribers: joker.eph, llvm-commits Differential Revision: http://reviews.llvm.org/D19462 llvm-svn: 267344
2016-04-24Reorganize GlobalValueSummary with a "Flags" bitfield.Mehdi Amini1-2/+4
Right now it only contains the LinkageType, but will be extended with "hasSection", "isOptSize", "hasInlineAssembly", etc. Differential Revision: http://reviews.llvm.org/D19404 From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 267319
2016-04-20[ThinLTO] Prevent importing of "llvm.used" valuesTeresa Johnson1-0/+25
Summary: This patch prevents importing from (and therefore exporting from) any module with a "llvm.used" local value. Local values need to be promoted and renamed when importing, and their presense on the llvm.used variable indicates that there are opaque uses that won't see the rename. One such example is a use in inline assembly. See also the discussion at: http://lists.llvm.org/pipermail/llvm-dev/2016-April/098047.html As part of this, move collectUsedGlobalVariables out of Transforms/Utils and into IR/Module so that it can be used more widely. There are several other places in LLVM that used copies of this code that can be cleaned up as a follow on NFC patch. Reviewers: joker.eph Subscribers: pcc, llvm-commits, joker.eph Differential Revision: http://reviews.llvm.org/D18986 llvm-svn: 266877
2016-04-11[ThinLTO] Move summary computation from BitcodeWriter to new passTeresa Johnson1-0/+186
Summary: This is the first step in also serializing the index out to LLVM assembly. The per-module summary written to bitcode is moved out of the bitcode writer and to a new analysis pass (ModuleSummaryIndexWrapperPass). The pass itself uses a new builder class to compute index, and the builder class is used directly in places where we don't have a pass manager (e.g. llvm-as). Because we are computing summaries outside of the bitcode writer, we no longer can use value ids created by the bitcode writer's ValueEnumerator. This required changing the reference graph edge type to use a new ValueInfo class holding a union between a GUID (combined index) and Value* (permodule index). The Value* are converted to the appropriate value ID during bitcode writing. Also, this enables removal of the BitWriter library's dependence on the Analysis library that was previously required for the summary computation. Reviewers: joker.eph Subscribers: joker.eph, llvm-commits Differential Revision: http://reviews.llvm.org/D18763 llvm-svn: 265941