Replace 'constant_ref' with 'function_ref', which references a SILFunction directly, and 'global_addr', which references a global variable VarDecl. Get rid of the SILConstant-to-SILFunction mapping in SILModule and replace it with an ilist of SILFunctions. Allow SILFunctions to be 'external' by not having any blocks in their body.
For now, SILFunctions still carry around their SILConstant "name", because name mangling and IRGen still rely on access to the original decl in order to recover IRGen information, which unfortunately leaves IRGen's CodeRefs in a gross, awkward intermediate state. Lifting mangling, AbstractCC, and other linkage attributes to SIL should clear up this up.
Swift SVN r4865
The value semantics primitives load/move/assign/init/destroy lower trivially to SIL value semantics operators, and the bridge casting operations introduce r/r semantics that should be visible to the ARC optimizer, so move the lowering for these builtins up to SILGen. Add a BUILTIN_SIL_OPERATION metaprogramming macro to Builtins.def, and add a facility similar to IRGen's former SpecializedCallEmission so we can handle builtin call emissions as special cases.
This also sets up the framework for eventually reintroducing special-case handling of known functions like &&, ||, Bool.getLogicValue, Int.convertFromIntegerLiteral, etc. in SILGen.
Swift SVN r4862
Add an IsaInst to represent type tests, and implement SILGen for IsSubtypeExpr AST nodes. Get rid of SuperIsArchetypeExpr because it's not really necessary to have it different from IsaSubtype--the SIL and IR behavior is identical.
Swift SVN r4855
Create a UnaryInstructionBase that factors all the boilerplate out of all the unary instructions. It'll be easy to generalize to all fixed-arity instructions, but let's start simple. No functionality change.
Swift SVN r4854
Teach SILGen how to emit the implicit elementwise constructor for structs and the implicit default constructor for classes, and eliminate the now dead IRGen code for them. Add a StructInst SIL instruction to represent constructing a loadable struct value from elements, analogous to TupleInst for tuples.
Swift SVN r4778
Otherwise we try to release junk pointers when we reassign class fields in the struct. Add an attribute to InitializeVarInst so that when dataflow analysis comes online, it knows that these InitializeVars need to be eliminated and can't be lowered to default constructor calls (since we're already in a constructor).
Swift SVN r4730
The Verifier wasn't actually verifying function bodies, because I neglected to visit the actual basic blocks after checking the entry point arguments in verifySILFunction. This revealed a SILType identity issue where TypeConverter::getLoweredType and SILType::getEmptyTupleType returned non-identical SILTypes for the empty tuple type; fix that by removing SILType::getEmptyTupleType, moving TypeConverter into SILModule, and forcing all SILType creation through TypeConverter.
Swift SVN r4616
Archetype and protocol 'x.metatype' expressions eventually need to do a dynamic lookup, like 'x.metatype' for classes. These instructions represent that lookup.
Swift SVN r4534
All the other implicit conversions have been given their own instructions, so specialize this ill-specified instruction to its one remaining use, for converting compatible function types.
Swift SVN r4482
Swift doesn't yet type-check function thinness, so variables, arguments, and return values are always thick. When we store, pass as argument, or return a function value that SIL tracks as thin, emit a new 'thin_to_thick_function' instruction to represent converting the type to the thick type and adding a null context pointer.
Swift SVN r4470
Make converting a SIL address to a Builtin.RawPointer its own instruction separate from implicit_convert, which will let me get rid of a goofy edge case in IRGenSIL.
Swift SVN r4412
Reference and call uncurried function applications when appropriate to the call site, following the same logic implemented in CallEmission/CalleeSource in IRGen. Add ClassMethodInst and SuperMethodInst instructions to represent method and super dispatch. Change how closures and ClosureInst are represented in SIL so that closures are functions with an extra implicit uncurry level and so that ClosureInst applies the outer uncurries of an uncurried function type to give a curried type as a result. This breaks...pretty much everything else SIL-dependent; I'll clean it up next.
Swift SVN r4368
Rename 'ZeroAddr' to 'InitializeVar' and remove ZeroValue since only things with memory locations should ever be in a 'default-initialize' state. Add a ModuleInst so we don't need to use ZeroValue as a hack to represent ModuleExpr values.
Swift SVN r4319
Converting from a protocol type to a more general protocol type is different at the implementation level from converting a concrete type to a protocol type, since the witness tables and concrete value can be copied directly from the original existential container to the new without adding another indirection. This instruction represents that operation.
Swift SVN r3887
Upcasting isn't quite a no-op like the other implicit conversions because the underlying pointer type still needs to be bitcast. The additional semantic information will be useful for SIL consumers as well.
Swift SVN r3872
I was being lazy by not mangling the context arguments onto the types of closure SIL constants and then having ClosureInst pass the type of its callee through T -> T. Now closure functions get emitted with the right types, ClosureInst properly partially applies the type, and the SIL Verifier properly checks that the argument types all line up correctly.
Swift SVN r3815
This is inconsistent with ElementAddr and Extract, but allows all the hairy logic of accessing class fields in IRGen to stand without a bunch of pointless refactoring.
Swift SVN r3778
ExistentialMethod -> ProtocolMethod for better specificity.
[De]AllocExistential -> [De]InitExistential because it doesn't necessarily allocate anything.
Swift SVN r3710
Generate explicit destructors by emitting their bodies then emitting release sequences for the class's members. Eventually we'll need to also emit implicit destructors for classes without explicit destructors and to chain a call to the base class destructor, which will require adding a new linkable entity flag onto SILConstant for destructors, similar to getter/setters.
Swift SVN r3655
Add an instruction to represent super-to-archetype downcasts. Since archetypes are address-only, it needs to take a reference to the destination archetype as a parameter.
Swift SVN r3643
Needed to represent deinitializing a partially-initialized existential in which the value witness table has been populated by alloc_existential but the value has not been initialized yet.
Swift SVN r3565
Move SILType to its own header, and make it its own container type consisting of a Type with an "isAddress" bit for representing address types. Move the "isAddressOnly" information from SILGen's TypeInfo onto SILType as a second bit, because address-only-ness is extremely useful for verification outside of SILGen. Instead of mangling function types during type lowering, rely on the fact that SILType is no longer a Type to force us to mangle argument and return types when we see them. (We may eventually need SILFunctionType and SILTupleType things to represent lowered SIL function and tuple types containing addresses, but for now we can lower function and tuple components as needed.)
Swift SVN r3551
Change over SIL Values and Instructions to work in terms of SILTypes, and update SILGen to lower types where needed. Add LValueType logic to SILType lowering to get rid of those annoying lvalue qualifiers so we can ignore RequalifyExprs. Tighten up the XFAILs in the SIL tests and disable the checks that currently crash.
Swift SVN r3538
Determining constant types requires help from SILGen because of address-only types, and the type of a constant after SILGen should always be readily available from the ConstantRefInst. Initialize SIL Function objects with their lowered type as well so that it's available to IRGen and SIL passes.
Swift SVN r3526
ProjectExistential derives the value pointer from an existential, and AllocExistential initializes an existential's witness tables and allocates its value. Tweak SILGen's handling of ExistentialMemberRefExprs to emit a project_existential between querying the method and applying it.
Swift SVN r3508
Pass down the AST type from the ArchetypeMemberRefExpr, which has the right locally-bound archetypes, rather than derive the method type from the decl.
Swift SVN r3504
Add instructions to represent type coercion and downcast conversion operations. Factor out a common ConversionInst base class for Convert and these instructions, and rename ConvertInst to ImplicitConvertInst to distinguish it from these new explicit conversion instructions.
Swift SVN r3490
Have SpecializeInst own its Substitution array so that a SpecializeInst can be instantiated independently of a backing SpecializeExpr in the AST.
Swift SVN r3483
Subscripts are just another kind of property. Refactor some logic from ApplyExpr codegen to visit index arguments consistently with apply arguments. Also move the logic for determining SIL constant types onto SILModule because it's too hairy to calculate on the fly.
Swift SVN r3452
If the operand of a TupleElementExpr is an lvalue, derive the address of the element from the operand rather than try to extract a value from it as the code was doing before.
Swift SVN r3392
