Summary:
Prototype of a JIT compiler that utilizes ThinLTO summaries to compile modules ahead of time. This is an implementation of the concept I presented in my "ThinLTO Summaries in JIT Compilation" talk at the 2018 Developers' Meeting: http://llvm.org/devmtg/2018-10/talk-abstracts.html#lt8
Upfront the JIT first populates the *combined ThinLTO module index*, which provides fast access to the global call-graph and module paths by function. Next, it loads the main function's module and compiles it. All functions in the module will be emitted with prolog instructions that *fire a discovery flag* once execution reaches them. In parallel, the *discovery thread* is busy-watching the existing flags. Once it detects one has fired, it uses the module index to find all functions that are reachable from it within a given number of calls and submits their defining modules to the compilation pipeline.
While execution continues, more flags are fired and further modules added. Ideally the JIT can be tuned in a way, so that in the majority of cases the code on the execution path can be compiled ahead of time. In cases where it doesn't work, the JIT has a *definition generator* in place that loads modules if missing functions are reached.
Reviewers: lhames, dblaikie, jfb, tejohnson, pree-jackie, AlexDenisov, kavon
Subscribers: mgorny, mehdi_amini, inglorion, hiraditya, steven_wu, dexonsmith, arphaman, jfb, merge_guards_bot, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72486
There's quite a lot of references to Polly in the LLVM CMake codebase. However
the registration pattern used by Polly could be useful to other external
projects: thanks to that mechanism it would be possible to develop LLVM
extension without touching the LLVM code base.
This patch has two effects:
1. Remove all code specific to Polly in the llvm/clang codebase, replaicing it
with a generic mechanism
2. Provide a generic mechanism to register compiler extensions.
A compiler extension is similar to a pass plugin, with the notable difference
that the compiler extension can be configured to be built dynamically (like
plugins) or statically (like regular passes).
As a result, people willing to add extra passes to clang/opt can do it using a
separate code repo, but still have their pass be linked in clang/opt as built-in
passes.
Differential Revision: https://reviews.llvm.org/D61446
This patch adds a new IRTransformations directory to llvm/examples/. This is
intended to serve as a new home for example transformations/analysis
code used by various tutorials.
If LLVM_BUILD_EXAMPLES is enabled, the ExamplesIRTransforms library is
linked into the opt binary and the example passes become available.
To start off with, it contains the CFG simplifications used in the IR
part of the 'Getting Started With LLVM: Basics' tutorial at the US LLVM
Developers Meeting 2019.
Reviewers: paquette, jfb, meikeb, lhames, kbarton
Reviewed By: paquette
Differential Revision: https://reviews.llvm.org/D69416
LLJITBuilder now has a setCompileFunctionCreator method which can be used to
construct a CompileFunction for the LLJIT instance being created. The motivating
use-case for this is supporting ObjectCaches, which can now be set up at
compile-function construction time. To demonstrate this an example project,
LLJITWithObjectCache, is included.
llvm-svn: 365671
Both zero cost example domain specific, and C++ foreign exception handling are
shown. The example's documentation fully explains how to run the example.
Notes:
1) The code uses an extremely simple type info model.
2) Only a single landing pad is used per unwind edge
(one call to llvm.eh.selector)
3) llvm.eh.selector support for filter arguments is not given.
4) llvm.eh.typeid.for is not used.
5) Forced unwind behavior is not supported.
6) Very little if any error handling is given.
7) __attribute__((__aligned__)) is used.
8) The code uses parts from the llvm compiler-rt project and
the llvm Kaleidoscope example.
9) The code has not been ported or tested on WINDOWS.
10) The code was not tested with a cmake build.
11) The code was tested for a debug build on 32bit X86 CentOS LINUX,
and both a debug and release build on OS X 10.6.2 (64bit).
llvm-svn: 95723
Stefan Gränitz