25 Commits

Author SHA1 Message Date
Simon Pilgrim
431da84b02 Fix spelling mistakes in Transforms comments. NFC.
Identified by Pedro Giffuni in PR27636.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287488 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-20 13:19:49 +00:00
Chris Bieneman
92cb3eecbd [CMake] NFC. Updating CMake dependency specifications
This patch updates a bunch of places where add_dependencies was being explicitly called to add dependencies on intrinsics_gen to instead use the DEPENDS named parameter. This cleanup is needed for a patch I'm working on to add a dependency debugging mode to the build system.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287206 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-17 04:36:50 +00:00
Gor Nishanov
a1184492ba [coroutines] Store an address of destroy OR cleanup part in the coroutine frame.
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
2016-10-08 00:22:50 +00:00
Gor Nishanov
40fec41b24 [Coroutines] Part15c: Fix coro-split to correctly handle definitions between coro.save and coro.suspend
Summary:
In the case below, %Result.i19 is defined between coro.save and coro.suspend and used after coro.suspend. We need to correctly place such a value into the coroutine frame.

```
  %save = call token @llvm.coro.save(i8* null)
  %Result.i19 = getelementptr inbounds %"struct.lean_future<int>::Awaiter", %"struct.lean_future<int>::Awaiter"* %ref.tmp7, i64 0, i32 0
  %suspend = call i8 @llvm.coro.suspend(token %save, i1 false)
  switch i8 %suspend, label %exit [
    i8 0, label %await.ready
    i8 1, label %exit
  ]
await.ready:
  %val = load i32, i32* %Result.i19

```

Reviewers: majnemer

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D24418

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282902 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-30 19:24:19 +00:00
Gor Nishanov
b76c0e472e [Coroutines] Part15b: Fix dbg information handling in coro-split.
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
2016-09-30 19:05:06 +00:00
Gor Nishanov
a7eae488f2 [Coroutines] Part 15a: Lower coro.subfn.addr in CoroCleanup
Summary: Not all coro.subfn.addr intrinsics can be eliminated in CoroElide through devirtualization. Those that remain need to be lowered in CoroCleanup.

Reviewers: majnemer

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D24412

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282897 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-30 18:41:35 +00:00
Gor Nishanov
8a7cd49d0b [Coroutines] Part14: Handle coroutines with no suspend points.
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
2016-09-26 15:49:28 +00:00
Gor Nishanov
6ff9c199ca [Coroutines] Part13: Handle single edge PHINodes across suspends
Summary:
If one of the uses of the value is a single edge PHINode, handle it.

Original:

    %val = something
    <suspend>
    %p = PHINode [%val]

After Spill + Part13:

    %val = something
    %slot = gep val.spill.slot
    store %val, %slot
    <suspend>
    %p = load %slot

Plus tiny fixes/changes:
   * use correct index for coro.free in CoroCleanup
   * fixup id parameter in coro.free to allow authoring coroutine in plain C with __builtins

Reviewers: majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24242

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281020 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-09 05:39:00 +00:00
Gor Nishanov
5b6d16cd6c [Coroutines] Part12: Handle alloca address-taken
Summary:
Move early uses of spilled variables after CoroBegin.

For example, if a parameter had address taken, we may end up with the code
like:
        define @f(i32 %n) {
          %n.addr = alloca i32
          store %n, %n.addr
          ...
          call @coro.begin

This patch fixes the problem by moving uses of spilled variables after CoroBegin.

Reviewers: majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24234

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280678 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-05 23:45:45 +00:00
Gor Nishanov
ac396ea37f [Coroutines] Part11: Add final suspend handling.
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
2016-09-05 04:44:30 +00:00
Gor Nishanov
b6a139826b [Coroutines] Part 10: Add coroutine promise support.
Summary:
1) CoroEarly now lowers llvm.coro.promise intrinsic that allows to obtain
a coroutine promise pointer from a coroutine frame and vice versa.

2) CoroFrame now interprets Promise argument of llvm.coro.begin to
place CoroutinPromise alloca at a deterministic offset from the coroutine frame.

Now, the coroutine promise example from docs\Coroutines.rst compiles and produces expected result (see test/Transform/Coroutines/ex4.ll).

Reviewers: majnemer

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23993

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280184 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-31 00:35:41 +00:00
Gor Nishanov
bce16c69f0 [Coroutines] Part 9: Add cleanup subfunction.
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
2016-08-29 14:34:12 +00:00
Gor Nishanov
07ea3b0b35 [Coroutines] Fix unused var warning in release build
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279610 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-24 05:20:30 +00:00
Gor Nishanov
c5f116c1ce [Coroutines] Part 8: Coroutine Frame Building algorithm
Summary:
This patch adds coroutine frame building algorithm. Now, simple coroutines such as ex0.ll and ex1.ll (first examples from docs\Coroutines.rst can be compiled).

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)
...

7. Split coroutine into subfunctions. (https://reviews.llvm.org/D23461)
8. Coroutine Frame Building algorithm  <= we are here
9. Add f.cleanup subfunction.
10+. The rest of the logic

Reviewers: majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23586

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279609 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-24 04:44:35 +00:00
Gor Nishanov
6795b93241 [Coroutines] Part 7: Split coroutine into subfunctions
Summary:
This patch adds simple coroutine splitting logic to CoroSplit pass.

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)
...
7. Split coroutine into subfunctions <= we are here
8. Coroutine Frame Building algorithm
9. Handle coroutine with unwinds
10+. The rest of the logic

Reviewers: majnemer

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23461

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278830 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-16 18:04:14 +00:00
Benjamin Kramer
94e4f70d0e [Coroutines] Move class into anonymous namespace.
Hopefully fixes visibility warnings from GCC. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278485 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-12 08:47:13 +00:00
Gor Nishanov
b6ae34d909 [Coroutines]: Part6b: Add coro.id intrinsic.
Summary:
1. Make coroutine representation more robust against optimization that may duplicate instruction by introducing coro.id intrinsics that returns a token that will get fed into coro.alloc and coro.begin. Due to coro.id returning a token, it won't get duplicated and can be used as reliable indicator of coroutine identify when a particular coroutine call gets inlined.
2. Move last three arguments of coro.begin into coro.id as they will be shared if coro.begin will get duplicated.
3. doc + test + code updated to support the new intrinsic.

Reviewers: mehdi_amini, majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23412

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278481 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-12 05:45:49 +00:00
Gor Nishanov
bd0032e1a2 [Coroutines] Part 6: Elide dynamic allocation of a coroutine frame when possible
Summary:
A particular coroutine usage pattern, where a coroutine is created, manipulated and
destroyed by the same calling function, is common for coroutines implementing
RAII idiom and is suitable for allocation elision optimization which avoid
dynamic allocation by storing the coroutine frame as a static `alloca` in its
caller.

coro.free and coro.alloc intrinsics are used to indicate which code needs to be suppressed
when dynamic allocation elision happens:
```
entry:
  %elide = call i8* @llvm.coro.alloc()
  %need.dyn.alloc = icmp ne i8* %elide, null
  br i1 %need.dyn.alloc, label %coro.begin, label %dyn.alloc
dyn.alloc:
  %alloc = call i8* @CustomAlloc(i32 4)
  br label %coro.begin
coro.begin:
  %phi = phi i8* [ %elide, %entry ], [ %alloc, %dyn.alloc ]
  %hdl = call i8* @llvm.coro.begin(i8* %phi, i32 0, i8* null,
                          i8* bitcast ([2 x void (%f.frame*)*]* @f.resumers to i8*))
```
and
```
  %mem = call i8* @llvm.coro.free(i8* %hdl)
  %need.dyn.free = icmp ne i8* %mem, null
  br i1 %need.dyn.free, label %dyn.free, label %if.end
dyn.free:
  call void @CustomFree(i8* %mem)
  br label %if.end
if.end:
  ...
```

If heap allocation elision is performed, we replace coro.alloc with a static alloca on the caller frame and coro.free with null constant.

Also, we need to make sure that if there are any tail calls referencing the coroutine frame, we need to remote tail call attribute, since now coroutine frame lives on the stack.

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. (https://reviews.llvm.org/D23234)
6.Add coroutine heap elision + tests.  <= we are here
7.Add the rest of the logic (split into more patches)

Reviewers: mehdi_amini, majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23245

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278242 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-10 16:40:39 +00:00
Gor Nishanov
303ae673f8 CoroSplit: Squash unused variable FnTrigger warning in NDEBUG
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277938 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-06 21:11:10 +00:00
Gor Nishanov
2007f371f4 [Coroutines] Part 5: Add CGSCC restart trigger
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
2016-08-06 20:44:39 +00:00
Gor Nishanov
fa2883261f Part 4c: Coroutine Devirtualization: Devirtualize coro.resume and coro.destroy.
Summary:
This is the 4c patch of the coroutine series. CoroElide pass now checks if PostSplit coro.begin
is referenced by coro.subfn.addr intrinsics. If so replace coro.subfn.addrs with an appropriate coroutine
subfunction associated with that coro.begin.

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 <= we are here
5.Add CGSCC restart trigger + tests.
6.Add coroutine heap elision + tests.
7.Add the rest of the logic (split into more patches)

Reviewers: majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23229

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277908 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-06 02:16:35 +00:00
David Majnemer
5964d136e5 [coroutines] Part 4[ab]: Coroutine Devirtualization: Lower coro.resume and coro.destroy.
This is the forth patch in the coroutine series. CoroEaly pass now lowers coro.resume
and coro.destroy intrinsics by replacing them with an indirect call to an address
returned by coro.subfn.addr intrinsic. This is done so that CGPassManager recognizes
devirtualization when CoroElide replaces a call to coro.subfn.addr with an appropriate
function address.

Patch by Gor Nishanov!

Differential Revision: https://reviews.llvm.org/D22998

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277765 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-04 20:30:07 +00:00
David Majnemer
41856d9dd9 Really try to pacify the build bots :/
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277037 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-28 21:22:31 +00:00
David Majnemer
69388b7364 Try to passify the builders
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277036 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-28 21:16:51 +00:00
David Majnemer
880190560d [coroutines] Part 3 of N: Adding Boilerplate for Coroutine Passes
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
2016-07-28 21:04:31 +00:00