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
llvm-svn: 278830
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
llvm-svn: 278481
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
llvm-svn: 278242
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
llvm-svn: 277936
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
llvm-svn: 277908
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
llvm-svn: 277765
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
llvm-svn: 277033
Gor Nishanov