Adds sections `__TEXT,__swift_as_entry`, and `__TEXT,__swift_as_ret` that
contain relative pointers to async functlets modelling async function entries,
and function returns, respectively.
Emission of the sections can be trigger with the frontend option
`-Xfrontend -enable-async-frame-push-pop-metadata`.
This is done by:
* IRGen adding a `async_entry` function attribute to async functions.
* LLVM's coroutine splitting identifying continuation funclets that
model the return from an async function call by adding the function
attribute `async_ret`. (see #llvm-project/pull/9204)
* An LLVM pass that keys off these two function attribute and emits the
metadata into the above mention sections.
rdar://134460666
This has a few nice benefits:
1. The splitting happens after LLVM optimizations have run. This ensures that
LLVM will not join these blocks no matter what! The author of this commit has
found that in certain cases LLVM does this even at -Onone. By running this late,
we get the benefit we are looking for: working around the bad SelectionDAG
behavior.
2. This block splitting is just a workaround for the above mentioned unfortunate
SelectionDAG behavior. By doing this when we remove the workaround, we will not
have to update SIL level tests... instead we will just remove a small LLVM pass.
Some additional notes:
1. Only moved values will ever have llvm.dbg.addr emitted today, so we do not
have to worry about this impacting the rest of the language.
2. The pass's behavior is tested at the IR level by move_function_dbginfo.swift.
Adapt to API changes in ba664d9, where `AAQueryInfo` now requires the
capturing information. Switch to the new `SimpleAAQueryInfo` which
maintains the status quo for alias analysis.
I left in the old entrypoint as well that doesn't take the AAQueryInfo by having
it delegate to the AAQueryInfo entrypoint passing a default constructed
AAQueryInfo. This matches how people upstream have handled this.
rdar://49450147
SVN r262490 reformulated the Alias Analysis interfaces. The TLI is no longer
needed to construct the AA Result. Because the TLI was used specifically for
the base constructor, we now no longer need that option. Simplify it according
to the new API. NFC.
(cherry picked from commit 12dc8a831c)
(cherry picked from commit 270a4c240781e012a1c0d63c581102707130e02b)
It's like LLVM's MergeFunctions pass, except that it can also merge functions which differ by some constants.
The intention is to merge specialized functions which only differ by metadata lookups. But it can also merge other types of functions.
It gives ~7% code size reducation for the stdlib.
There are still some open TODOs, e.g. to share common code with LLVM's MergeFunctions pass (currently much code is just copied).
Assertion failed: (NumUsePointsToFind > 0 && "There must be at least one
releasing instruction for an alloc"), function canPromoteAlloc
Revert "Fix comment for StackPromotion pass in SIL Passes"
Revert "Reapply the StackPromotion commit
0dd045ca04dcc10a33abf57f7e1b08260c4e3de1."
This reverts commit 3f4b1496bd and commit
199cfca13b.
It promotes allocations of native swift objects and array buffers to the stack if it is possible.
The SIL StackPromotion pass is the main part of the optimization. For details see comments there.
Unfortunately we need an additional LLVM pass to handle array buffers, which is not very nice.
I hope that we can get rid of it in future (again: for details see the comments in StackPromotion.cpp)
The optimization gives performance improvements in some benchmarks, mostly related to array literals:
ArrayLiteral: +12%
Combos: +16%
DictionaryLiteral: + 37%
RIPEMD: +10%
StringBuilder: +27%
StringInterpolation: +11%
And last but not least the new benchmark which is dedicated to test stack promotion:
ObjectAllocation: +52%
This pass does things similar to LLVMARCContract so it makes sense to use the
same naming schema.
Also I am going to be implementing some contracting optimziations here later
today.
Swift SVN r30203
OptimizeARC does not only contain an optimize arc pass: the library also
includes aa. What this really is a repository of the extra passes and
infrastructure that we inject into LLVM. Thus LLVMPasses is a more descriptive
name. It also matches SILPasses.
I also taught lit how to use the new llvm-opt driver for running swift llvm
passes through opt without having to remember how to setup the dynamic swift
llvm pass dylib. You can use this in lit tests by using the substitution
%llvm-opt.
Swift SVN r21654
