Summary:
If heap allocation of a coroutine is elided, we need to make sure that we will update an address stored in the coroutine frame from f.destroy to f.cleanup.
Before this change, CoroSplit synthesized these stores after coro.begin:
```
store void (%f.Frame*)* @f.resume, void (%f.Frame*)** %resume.addr
store void (%f.Frame*)* @f.destroy, void (%f.Frame*)** %destroy.addr
```
In those cases where we did heap elision, but were not able to devirtualize all indirect calls, destroy call will attempt to "free" the coroutine frame stored on the stack. Oops.
Now we use select to put an appropriate coroutine subfunction in the destroy slot. As bellow:
```
store void (%f.Frame*)* @f.resume, void (%f.Frame*)** %resume.addr
%0 = select i1 %need.alloc, void (%f.Frame*)* @f.destroy, void (%f.Frame*)* @f.cleanup
store void (%f.Frame*)* %0, void (%f.Frame*)** %destroy.addr
```
Reviewers: majnemer
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D25377
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283625 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Without the fix, if there was a function inlined into the coroutine with debug information, CloneFunctionInto(NewF, &F, VMap, /*ModuleLevelChanges=*/true, Returns); would duplicate all of the debug information including the DICompileUnit.
We know use VMap to indicate that debug metadata for a File, Unit and FunctionType should not be duplicated when we creating clones that will become f.resume, f.destroy and f.cleanup.
Reviewers: majnemer
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D24417
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282899 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
If coroutine has no suspend points, remove heap allocation and turn a coroutine into a normal function.
Also, if a pattern is detected that coroutine resumes or destroys itself prior to coro.suspend call, turn the suspend point into a simple jump to resume or cleanup label. This pattern occurs when coroutines are used to propagate errors in functions that return expected<T>.
Reviewers: majnemer
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D24408
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282414 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
A frontend may designate a particular suspend to be final, by setting the second argument of the coro.suspend intrinsic to true. Such a suspend point has two properties:
* it is possible to check whether a suspended coroutine is at the final suspend point via coro.done intrinsic;
* a resumption of a coroutine stopped at the final suspend point leads to undefined behavior. The only possible action for a coroutine at a final suspend point is destroying it via coro.destroy intrinsic.
This patch adds final suspend handling logic to CoroEarly and CoroSplit passes.
Now, the final suspend point example from docs\Coroutines.rst compiles and produces expected result (see test/Transform/Coroutines/ex5.ll).
Reviewers: majnemer
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D24068
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280646 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
[Coroutines] Part 9: Add cleanup subfunction.
This patch completes coroutine heap allocation elision. Now, the heap elision example from docs\Coroutines.rst compiles and produces expected result (see test/Transform/Coroutines/ex3.ll)
Intrinsic Changes:
* coro.free gets a token parameter tying it to coro.id to allow reliably discovering all coro.frees associated with a particular coroutine.
* coro.id gets an extra parameter that points back to a coroutine function. This allows to check whether a coro.id describes the enclosing function or it belongs to a different function that was later inlined.
CoroSplit now creates three subfunctions:
# f$resume - resume logic
# f$destroy - cleanup logic, followed by a deallocation code
# f$cleanup - just the cleanup code
CoroElide pass during devirtualization replaces coro.destroy with either f$destroy or f$cleanup depending whether heap elision is performed or not.
Other fixes, improvements:
* Fixed buglet in Shape::buildFrame that was not creating coro.save properly if coroutine has more than one suspend point.
* Switched to using variable width suspend index field (no longer limited to 32 bit index field can be as little as i1 or as large as i<whatever-size_t-is>)
Reviewers: majnemer
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23844
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279971 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
CoroSplit pass processes the coroutine twice. First, it lets it go through
complete IPO optimization pipeline as a single function. It forces restart
of the pipeline by inserting an indirect call to an empty function "coro.devirt.trigger"
which is devirtualized by CoroElide pass that triggers a restart of the pipeline by CGPassManager.
(In later patches, when CoroSplit pass sees the same coroutine the second time, it splits it up,
adds coroutine subfunctions to the SCC to be processed by IPO pipeline.)
Documentation and overview is here: http://llvm.org/docs/Coroutines.html.
Upstreaming sequence (rough plan)
1.Add documentation. (https://reviews.llvm.org/D22603)
2.Add coroutine intrinsics. (https://reviews.llvm.org/D22659)
3.Add empty coroutine passes. (https://reviews.llvm.org/D22847)
4.Add coroutine devirtualization + tests.
ab) Lower coro.resume and coro.destroy (https://reviews.llvm.org/D22998)
c) Do devirtualization (https://reviews.llvm.org/D23229)
5.Add CGSCC restart trigger + tests. <= we are here
6.Add coroutine heap elision + tests.
7.Add the rest of the logic (split into more patches)
Reviewers: mehdi_amini, majnemer
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D23234
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277936 91177308-0d34-0410-b5e6-96231b3b80d8
This adds boilerplate code for all coroutine passes,
the passes are no-ops for now.
Also, a small test has been added to verify that passes execute in
the expected order or not at all if coroutine support is disabled.
Patch by Gor Nishanov!
Differential Revision: https://reviews.llvm.org/D22847
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277033 91177308-0d34-0410-b5e6-96231b3b80d8
