introduce a common superclass, SILNode.
This is in preparation for allowing instructions to have multiple
results. It is also a somewhat more elegant representation for
instructions that have zero results. Instructions that are known
to have exactly one result inherit from a class, SingleValueInstruction,
that subclasses both ValueBase and SILInstruction. Some care must be
taken when working with SILNode pointers and testing for equality;
please see the comment on SILNode for more information.
A number of SIL passes needed to be updated in order to handle this
new distinction between SIL values and SIL instructions.
Note that the SIL parser is now stricter about not trying to assign
a result value from an instruction (like 'return' or 'strong_retain')
that does not produce any.
The main loop of mandatory inlining is spending a lot of time managing complex
iterator invalidation issues. This is the first in a series of commits that move
the main inlining loop to only delete the callee and to do all cleanups after we
have finished inlining.
This specific optimization (the quick retain/release peephole), I am not going
to do in MandatoryInlining, we already have guaranteed arc opts afterwards that
will be able to hit such a peephole so no perf should be lost.
*NOTE* The reason why I had to touch some of the code motion tests is that the
routine I am using to ensure that strong_retain/release_value is emitted as
appropriate is also used by codemotion. Code motion tests had cargo culted some
code from previous tests that retained Builtin.Int32. I changed the routines
though so that when a retain/release is inserted, if it is trivial, nothing is
inserted. No routine was relying on the actual usage of the inserted
retain/releases, so everything will be safe. This addition to the relevant code
caused me to need to change the tests in code motion to use actual non-trivial
values. The same code paths are being tested in terms of blocking code
motion/etc.
rdar://31521023
In dead-array elimination we assume that the array allocation is post-dominated by all its final releases.
The only exception are branches to dead-end ("unreachable") blocks. So we just ignored all paths which didn't end up in a final release.
Now we explicitly pass the set of dead-end blocks and just ignore those blocks.
This is safer and it's also needed in the upcoming re-write of StackPromotion.
It looks like the devirtualizer used to have problems computing
method types in the presence of generic substitutions, covariant
returns and other things, so it would bail if a perticular set
of pre-conditions was not met on the types of original method call
and the devirtualized method call.
I don't think any of this is necessary anymore. If this patch
introduces any regressions, we need to fix the root cause instead
of re-introducing this logic.
SubstitutionList is going to be a more compact representation of
a SubstitutionMap, suitable for inline allocation inside another
object.
For now, it's just a typedef for ArrayRef<Substitution>.
We preserve the current behavior of assuming Any ownership always and use
default arguments to hide this change most of the time. There are asserts now in
the SILBasicBlock::{create,replace,insert}{PHI,Function}Argument to ensure that
the people can only create SILFunctionArguments in entry blocks and
SILPHIArguments in non-entry blocks. This will ensure that the code in tree
maintains the API distinction even if we are not using the full distinction in
between the two.
Once the verifier is finished being upstreamed, I am going to audit the
createPHIArgument cases for the proper ownership. This is b/c I will be able to
use the verifier to properly debug the code. At that point, I will also start
serializing/printing/parsing the ownershipkind of SILPHIArguments, but lets take
things one step at a time and move incrementally.
In the process, I also discovered a CSE bug. I am not sure how it ever worked.
Basically we replace an argument with a new argument type but return the uses of
the old argument to refer to the old argument instead of a new argument.
rdar://29671437
Before this commit all code relating to handling arguments in SILBasicBlock had
somewhere in the name BB. This is redundant given that the class's name is
already SILBasicBlock. This commit drops those names.
Some examples:
getBBArg() => getArgument()
BBArgList => ArgumentList
bbarg_begin() => args_begin()
This eliminates all inline creation of SILBasicBlock via placement new.
There are a few reasons to do this:
1. A SILBasicBlock is always created with a parent function. This commit
formalizes this into the SILBasicBlock API by only allowing for SILFunctions to
create SILBasicBlocks. This is implemented via the type system by making all
SILBasicBlock constructors private. Since SILFunction is a friend of
SILBasicBlock, SILFunction can still create a SILBasicBlock without issue.
2. Since all SILBasicBlocks will be created in only a few functions, it becomes
very easy to determine using instruments the amount of memory being allocated
for SILBasicBlocks by simply inverting the call tree in Allocations.
With LTO+PGO, normal inlining can occur if profitable so there shouldn't be
overhead that we care about in shipping compilers.
- Look through BB arguments with multiple predecessors.
- Provide a new helper function to figure out the exact type of the underlying object. It will be used by subsequent commits to improve the escape analysis.
This establishes a real def-use relation from the self-parameter to any instruction which uses the dynamic-self type.
This is an addition to what was already done for opened archetypes.
The biggest part of this commit is to rename "OpenedArchetypeOperands" to "TypeDependentOperands" as this name is now more appropriate.
Other than that the change includes:
*) type-dependent operands are now printed after a SIL instruction in a comment as "type-defs:" (for debugging)
*) FuncationSignatureOpts doesn't need to explicitly check if a function doesn't bind dynamic self to remove a dead self metadata argument
*) the check if a function binds dynamic self (used in the inliner) is much simpler now
*) also collect type-dependent operands for ApplyInstBase::SubstCalleeType and not only in the substitution list
*) with this SILInstruction::mayHaveOpenedArchetypeOperands (used in CSE) is not needed anymore and removed
*) add type dependent operands to dynamic_method instruction
Regarding the generated code it should be a NFC.
*) cast optimizer: when a bridging cast is replaced with a function call and the owning convention of the instruction and the call parameter do not match, compensating retain/release instructions must be inserted.
*) cast optimizer: when a consuming dead cast instruction is removed a compensating release instruction must be inserted
*) mem2reg: An alloc_stack location which contains a destroy_addr must not be considered as a write-only location. The destroy_addr must be preserved.
rdar://problem/27601057
Some modifications for the ms-extension option of the clang.exe in the Visual Studio 2015 development environment
This patch is only for swiftc.exe. I used the library set of Visual Studio 2015 Update 1 and recent version of swift-clang as the compiler. If you are using the real MSVC compiler, more patch might be required.
We ended up adding the same instruction twice to a SmallVector of
instructions to be deleted. To avoid this, we'll track these
to-be-deleted instructions in a SmallSetVector instead.
We were also failing to add an instruction that we can delete to the set
of instructions to be deleted, so I fixed that as well.
I've added a test case, but it's currently disabled because fixing this
turned up another issue in the same code which I still need to take a
look at.
Fixes rdar://problem/25369617.
Reinstates commit 0c2ca94ef7
With two bug fixes:
*) use after free asan crash
*) wrong check in ValueLifetimeAnalysis::isWithinLifetime
And some refactoring
For a release on a guaranteed function paramater, we know right away
that its not the final release and therefore does not call deinit.
Therefore we know it does not read or write memory other than the reference
count.
This reduces the compilation time of dead store and redundant load elim. As
we need to go over alias analysis to make sure tracked locations do not alias
with it.
This is done by splitting the transformation into an analysis phase and a transformation phase (which does not use the dominator tree anymore).
The domintator tree is recalucated once after the whole function is processed.
This change eventually solves the compile time problem of rdar://problem/24410167.
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.
