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* WholeProgramDevirt: print remarks with devirtualized method names.Ivan Krasin2016-08-051-2/+18
| | | | | | | | | | | | | | | | | | Summary: Chrome on Linux uses WholeProgramDevirt for speed ups, and it's important to detect regressions on both sides: the toolchain, if fewer methods get devirtualized after an update, and Chrome, if an innocently looking change caused many hot methods become virtual again. The need to track devirtualized methods is not Chrome-specific, but it's probably the only user of the pass at this time. Reviewers: kcc Differential Revision: https://reviews.llvm.org/D23219 llvm-svn: 277856
* Print remarks from WholeProgramDevirt pass for each call site.Ivan Krasin2016-07-121-0/+10
| | | | | | | | | | | | | Summary: It's useful to have some visibility about which call sites are devirtualized, especially for debug purposes. Another use case is a regression test on the application side (like, Chromium). Reviewers: pcc Differential Revision: http://reviews.llvm.org/D22252 llvm-svn: 275145
* IR: Introduce llvm.type.checked.load intrinsic.Peter Collingbourne2016-06-251-12/+142
| | | | | | | | | | | | | | | | This intrinsic safely loads a function pointer from a virtual table pointer using type metadata. This intrinsic is used to implement control flow integrity in conjunction with virtual call optimization. The virtual call optimization pass will optimize away llvm.type.checked.load intrinsics associated with devirtualized calls, thereby removing the type check in cases where it is not needed to enforce the control flow integrity constraint. This patch also introduces the capability to copy type metadata between global variables, and teaches the virtual call optimization pass to do so. Differential Revision: http://reviews.llvm.org/D21121 llvm-svn: 273756
* IR: New representation for CFI and virtual call optimization pass metadata.Peter Collingbourne2016-06-241-75/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bitset metadata currently used in LLVM has a few problems: 1. It has the wrong name. The name "bitset" refers to an implementation detail of one use of the metadata (i.e. its original use case, CFI). This makes it harder to understand, as the name makes no sense in the context of virtual call optimization. 2. It is represented using a global named metadata node, rather than being directly associated with a global. This makes it harder to manipulate the metadata when rebuilding global variables, summarise it as part of ThinLTO and drop unused metadata when associated globals are dropped. For this reason, CFI does not currently work correctly when both CFI and vcall opt are enabled, as vcall opt needs to rebuild vtable globals, and fails to associate metadata with the rebuilt globals. As I understand it, the same problem could also affect ASan, which rebuilds globals with a red zone. This patch solves both of those problems in the following way: 1. Rename the metadata to "type metadata". This new name reflects how the metadata is currently being used (i.e. to represent type information for CFI and vtable opt). The new name is reflected in the name for the associated intrinsic (llvm.type.test) and pass (LowerTypeTests). 2. Attach metadata directly to the globals that it pertains to, rather than using the "llvm.bitsets" global metadata node as we are doing now. This is done using the newly introduced capability to attach metadata to global variables (r271348 and r271358). See also: http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html Differential Revision: http://reviews.llvm.org/D21053 llvm-svn: 273729
* [PM] Remove support for omitting the AnalysisManager argument to newChandler Carruth2016-06-171-1/+2
| | | | | | | | | | | | | | | | | | | | pass manager passes' `run` methods. This removes a bunch of SFINAE goop from the pass manager and just requires pass authors to accept `AnalysisManager<IRUnitT> &` as a dead argument. This is a small price to pay for the simplicity of the system as a whole, despite the noise that changing it causes at this stage. This will also helpfull allow us to make the signature of the run methods much more flexible for different kinds af passes to support things like intelligently updating the pass's progression over IR units. While this touches many, many, files, the changes are really boring. Mostly made with the help of my trusty perl one liners. Thanks to Sean and Hal for bouncing ideas for this with me in IRC. llvm-svn: 272978
* [PM] Port WholeProgramDevirt to the new pass manager.Davide Italiano2016-06-141-0/+6
| | | | llvm-svn: 272721
* Re-apply r269081 and r269082 with a fix for MSVC.Peter Collingbourne2016-05-101-51/+13
| | | | llvm-svn: 269094
* Revert r269081 and r269082 while I try to find the right incantation to fix ↵Peter Collingbourne2016-05-101-12/+51
| | | | | | MSVC build. llvm-svn: 269091
* WholeProgramDevirt: Move logic for finding devirtualizable call sites to ↵Peter Collingbourne2016-05-101-51/+12
| | | | | | | | | | | | | Analysis. The plan is to eventually make this logic simpler, however I expect it to be a little tricky for the foreseeable future (at least until we're rid of pointee types), so move it here so that it can be reused to build a summary index for devirtualization. Differential Revision: http://reviews.llvm.org/D20005 llvm-svn: 269081
* Re-commit optimization bisect support (r267022) without new pass manager ↵Andrew Kaylor2016-04-221-1/+6
| | | | | | | | | | support. The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling). Differential Revision: http://reviews.llvm.org/D19172 llvm-svn: 267231
* Revert "Initial implementation of optimization bisect support."Vedant Kumar2016-04-221-6/+1
| | | | | | | | This reverts commit r267022, due to an ASan failure: http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549 llvm-svn: 267115
* Initial implementation of optimization bisect support.Andrew Kaylor2016-04-211-1/+6
| | | | | | | | | | | | This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations. The bisection is enabled using a new command line option (-opt-bisect-limit). Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit. A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used. The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check. Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute. A new function call has been added for module and SCC passes that behaves in a similar way. Differential Revision: http://reviews.llvm.org/D19172 llvm-svn: 267022
* [NFC] Header cleanupMehdi Amini2016-04-181-1/+2
| | | | | | | | | | | | | | Removed some unused headers, replaced some headers with forward class declarations. Found using simple scripts like this one: clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap' Patch by Eugene Kosov <claprix@yandex.ru> Differential Revision: http://reviews.llvm.org/D19219 From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 266595
* Silencing warnings from MSVC 2015 Update 2. All of these changes silence ↵Aaron Ballman2016-03-301-1/+1
| | | | | | "C4334 '<<': result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)". NFC. llvm-svn: 264929
* Fix evaluation order. Spotted by Alexander Riccio!Peter Collingbourne2016-03-081-1/+1
| | | | llvm-svn: 262907
* Fix GCC build.Peter Collingbourne2016-02-091-0/+4
| | | | llvm-svn: 260317
* WholeProgramDevirt: introduce.Peter Collingbourne2016-02-091-0/+724
This pass implements whole program optimization of virtual calls in cases where we know (via bitset information) that the list of callees is fixed. This includes the following: - Single implementation devirtualization: if a virtual call has a single possible callee, replace all calls with a direct call to that callee. - Virtual constant propagation: if the virtual function's return type is an integer <=64 bits and all possible callees are readnone, for each class and each list of constant arguments: evaluate the function, store the return value alongside the virtual table, and rewrite each virtual call as a load from the virtual table. - Uniform return value optimization: if the conditions for virtual constant propagation hold and each function returns the same constant value, replace each virtual call with that constant. - Unique return value optimization for i1 return values: if the conditions for virtual constant propagation hold and a single vtable's function returns 0, or a single vtable's function returns 1, replace each virtual call with a comparison of the vptr against that vtable's address. Differential Revision: http://reviews.llvm.org/D16795 llvm-svn: 260312
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