This patch also implements some of the missing functions used by RLE and DSE in new projection
that exist in the old projection.
New projection provides better memory usage, eventually we will phase out the old projection code.
New projection is now copyable, i.e. we have a proper constructor for it. This helps make the code
more readable.
We do see a bit increase in compilation time in compiling stdlib -O, this is a result of the way
we now get types of a projection path, but I expect this to go down (away) with further improvement
on how memory locations are constructed and cached with later patches.
=== With the OLD Projection. ===
Total amount of memory allocated.
--------------------------------
Bytes Used Count Symbol Name
13032.01 MB 50.6% 2158819 swift::SILPassManager::runPassesOnFunction(llvm::ArrayRef<swift::SILFunctionTransform*>, swift::SILFunction*)
2879.70 MB 11.1% 3076018 (anonymous namespace)::ARCSequenceOpts::run()
2663.68 MB 10.3% 1375465 (anonymous namespace)::RedundantLoadElimination::run()
1534.35 MB 5.9% 5067928 (anonymous namespace)::SimplifyCFGPass::run()
1278.09 MB 4.9% 576714 (anonymous namespace)::SILCombine::run()
1052.68 MB 4.0% 935809 (anonymous namespace)::DeadStoreElimination::run()
771.75 MB 2.9% 1677391 (anonymous namespace)::SILCSE::run()
715.07 MB 2.7% 4198193 (anonymous namespace)::GenericSpecializer::run()
434.87 MB 1.6% 652701 (anonymous namespace)::SILSROA::run()
402.99 MB 1.5% 658563 (anonymous namespace)::SILCodeMotion::run()
341.13 MB 1.3% 962459 (anonymous namespace)::DCE::run()
279.48 MB 1.0% 415031 (anonymous namespace)::StackPromotion::run()
Compilation time breakdown.
--------------------------
Running Time Self (ms) Symbol Name
25716.0ms 35.8% 0.0 swift::runSILOptimizationPasses(swift::SILModule&)
25513.0ms 35.5% 0.0 swift::SILPassManager::runOneIteration()
20666.0ms 28.8% 24.0 swift::SILPassManager::runFunctionPasses(llvm::ArrayRef<swift::SILFunctionTransform*>)
19664.0ms 27.4% 77.0 swift::SILPassManager::runPassesOnFunction(llvm::ArrayRef<swift::SILFunctionTransform*>, swift::SILFunction*)
3272.0ms 4.5% 12.0 (anonymous namespace)::SimplifyCFGPass::run()
3266.0ms 4.5% 7.0 (anonymous namespace)::ARCSequenceOpts::run()
2608.0ms 3.6% 5.0 (anonymous namespace)::SILCombine::run()
2089.0ms 2.9% 104.0 (anonymous namespace)::SILCSE::run()
1929.0ms 2.7% 47.0 (anonymous namespace)::RedundantLoadElimination::run()
1280.0ms 1.7% 14.0 (anonymous namespace)::GenericSpecializer::run()
1010.0ms 1.4% 45.0 (anonymous namespace)::DeadStoreElimination::run()
966.0ms 1.3% 191.0 (anonymous namespace)::DCE::run()
496.0ms 0.6% 6.0 (anonymous namespace)::SILCodeMotion::run()
=== With the NEW Projection. ===
Total amount of memory allocated.
--------------------------------
Bytes Used Count Symbol Name
11876.64 MB 48.4% 22112349 swift::SILPassManager::runPassesOnFunction(llvm::ArrayRef<swift::SILFunctionTransform*>, swift::SILFunction*)
2887.22 MB 11.8% 3079485 (anonymous namespace)::ARCSequenceOpts::run()
1820.89 MB 7.4% 1877674 (anonymous namespace)::RedundantLoadElimination::run()
1533.16 MB 6.2% 5073310 (anonymous namespace)::SimplifyCFGPass::run()
1282.86 MB 5.2% 577024 (anonymous namespace)::SILCombine::run()
772.21 MB 3.1% 1679154 (anonymous namespace)::SILCSE::run()
721.69 MB 2.9% 936958 (anonymous namespace)::DeadStoreElimination::run()
715.08 MB 2.9% 4196263 (anonymous namespace)::GenericSpecializer::run()
Compilation time breakdown.
--------------------------
Running Time Self (ms) Symbol Name
25137.0ms 37.3% 0.0 swift::runSILOptimizationPasses(swift::SILModule&)
24939.0ms 37.0% 0.0 swift::SILPassManager::runOneIteration()
20226.0ms 30.0% 29.0 swift::SILPassManager::runFunctionPasses(llvm::ArrayRef<swift::SILFunctionTransform*>)
19241.0ms 28.5% 83.0 swift::SILPassManager::runPassesOnFunction(llvm::ArrayRef<swift::SILFunctionTransform*>, swift::SILFunction*)
3214.0ms 4.7% 10.0 (anonymous namespace)::SimplifyCFGPass::run()
3005.0ms 4.4% 14.0 (anonymous namespace)::ARCSequenceOpts::run()
2438.0ms 3.6% 7.0 (anonymous namespace)::SILCombine::run()
2217.0ms 3.2% 54.0 (anonymous namespace)::RedundantLoadElimination::run()
2212.0ms 3.2% 131.0 (anonymous namespace)::SILCSE::run()
1195.0ms 1.7% 11.0 (anonymous namespace)::GenericSpecializer::run()
1168.0ms 1.7% 39.0 (anonymous namespace)::DeadStoreElimination::run()
853.0ms 1.2% 150.0 (anonymous namespace)::DCE::run()
499.0ms 0.7% 7.0 (anonymous namespace)::SILCodeMotion::run()
SILValue.h/.cpp just defines the SIL base classes. Referring to specific instructions is a (small) kind of layering violation.
Also I want to keep SILValue small so that it is really just a type alias of ValueBase*.
NFC.
As there are no instructions left which produce multiple result values, this is a NFC regarding the generated SIL and generated code.
Although this commit is large, most changes are straightforward adoptions to the changes in the ValueBase and SILValue classes.
And use the new project_existential_box to get to the address value.
SILGen now generates a project_existential_box for each alloc_existential_box.
And IRGen re-uses the address value from the alloc_existential_box if the operand of project_existential_box is an alloc_existential_box.
This lets the generated code be the same as before.
This change is needed for the next update to ToT LLVM. It can be put
into place now without breaking anything so I am committing it now.
The churn upstream on ilist_node is neccessary to remove undefined
behavior. Rather than updating the different ilist_node patches for the
hacky change required to not use iterators, just use iterators and keep
everything as ilist_nodes. Upstream they want to eventually do this, so
it makes sense for us to just do it now.
Please do not introduce new invocations of
ilist_node::get{Next,Prev}Node() into the tree.
And use project_box to get to the address value.
SILGen now generates a project_box for each alloc_box.
And IRGen re-uses the address value from the alloc_box if the operand of project_box is an alloc_box.
This lets the generated code be the same as before.
Other than that most changes of this (quite large) commit are straightforward.
its fields are initialized. Before:
t.swift:18:24: error: variable 'self.B' captured by a closure before being initialized
after:
t.swift:19:24: error: 'self' captured by a closure before all members were initialized
self.A.withCString { cString -> () in
^
t.swift:14:7: note: 'self.B' not initialized
var B: Int
^
This drives home the fact that 'self' is being captured here, not the individual
properties.
Partial applications of a root self value are an escape point, not a load. This
improves the diagnostic in this case from:
t.swift:18:24: error: variable 'self.B' used before being initialized
self.A.withCString { cString -> () in
^
to:
t.swift:18:24: error: variable 'self.B' captured by a closure before being initialized
self.A.withCString { cString -> () in
^
When a root class delegates to a non-class-bound protocol method, the self value
gets wrapped up in a SIL alloc_stack so it can be passed by address. Recognize
that the store involved is doing this, so we can provide a more specific diagnostic.
Before this, we produced:
variable 'self.x' used before being initialized
Now we produce:
error: use of 'self' in method call 'getg' before all stored properties are initialized
note: 'self.x' not initialized
This came up with other changes I have to modify the optimizer
pipeline. We shouldn't assert if we have an alloc_stack/dealloc_stack
where the only other use of the alloc_stack is a debug_value_addr.
It's easy to avoid this by removing allocations that don't have real
uses prior to attempting to handle the ones that do have real uses (as
opposed to the other way around).
In a bunch of use-cases we use stripSinglePredecessorArgs to eliminate this
case. There is no reason to assume that this is being done in the caller of
RCIdentity. Lets make sure that we handle this case here.
rdar://24156136
