summaryrefslogtreecommitdiffstats
path: root/source/slang/syntax.cpp
Commit message (Collapse)AuthorAge
* Fix a bug in IR use-def information (#406)Tim Foley2018-02-13
| | | | | | | | | | | The basic problem here is that when unlinking an `IRUse` from the linked list of uses, there were several cases where I was failing to set the `prevLink` field of the next node to match the `prevLink` field of the node being removed. That doesn't show up when walking the linked list of uses forward, but it breaks it whenever you have subsequent unlinking operations. This change fixes the bugs of that kind I could find, and also adds a debug validation method to try to avoid breaking it again. I also made more access to `IRUse` go through accessor methods rather than using fields directly, to try to avoid this kind of error. I stopped short of making anything `private`, because I tend to find that it creates more hassles than it avoids. A few other fixes along the way: - Made the `List<T>` type default-initialize elements when you resize it. I hadn't realized we weren't doing that. - Add a standalone `dumpIR(IRGlobalValue*)` so help when debugging issues.
* Falcor fixes (#402)Tim Foley2018-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Re-define deprecated compile flags By including these flags in the header file, with a value of zero, we can allow some existing code to compile even after the major changes to the implementation. * The `SLANG_COMPILE_FLAG_NO_CHECKING` option will effectively be ignored, since checking is always enabled. * The `SLANG_COMPILE_FLAG_SPLIT_MIXED_TYPES` option will now act as if it is always enabled (and indeed some of the code has been relying on this flag being set always). * Make subscript operators writable for writable textures This even had a `TODO` comment saying that we needed to fix it, and now I'm seeing semantic checking failures because we didn't define these and so we find assignment to non l-values. * Fix definitions of any() and all() intrinsics These should always return a scalar `bool` value, but they were being defined wrong in two ways: 1. They were using their generic type parameter `T` in the return type 2. They were returning a vector in the vector case, and a matrix in the matrix case. This change just alters the return type to be `bool` in all cases. * Fix bug in SSA construction When eliminating a trivial phi node, it is possible that the phi is still recorded as the "latest" value for a local variable in its block. When later code queries that value from the block (which can happen whenever another block looks up a variable in its predecessors), it would get the old phi and not the replacement value. I simply added a loop that checks if the value we look up is a phi that got replaced, and then continues with the replacement value (which might itself be a phi...). A more advanced solution might try to get clever and have the map itself hold `IRUse` values so that we can replace them seamlessly. * Simplify IR control flow representation This change gets rid of various special-case operations for conditional and unconditional branches, and instead requires emit logic to recognize when a direct branch is targetting a `break` or `continue` label. The new approach here isn't perfect, but it seems beter than what we had before, because it can actually work in the presence of control-flow optimizations (including our current critical-edge-splitting step). * Load from groupshared isn't groupshared When loading from a `groupshared` variable, the resulting temporary shouldn't have the `groupshared` qualifier on it. This might eventually need to generalize to a better understanding of storage modifiers in the IR, but I don't really want to deal with that right now. * Don't emit references to typedefs in output code Now that we are using the IR for all codegen, we shouldn't be dealing with surface-level things like `typedef` declarations in the output code; just use the type that was being referred to in the first place. * Fix floating-point literal printing for IR The IR was calling `emit()` instead of `Emit()` (we really need to normalize our convention here), and was implicitly invoking a default constructor on `String` that takes a `double` (that constructor should really be marked `explicit`), and which doesn't meet our requirements for printing floating-point values. * Fix error when importing module that doesn't parse We already added a case to bail out if semantic checking fails, but neglected to add a case if there is an error during parsing of a module to be imported. Note: this logic doesn't correctly register the module as being loaded (but still in error), so users could see multiple error messages if there are multiple `import`s for the same module. * Improve error message for overload resolution failure - Drop debugging info from the candidate printing - Add cases to print `double` and `half` types properly * Fixup: switch loopTest to ifElse in expected IR output
* Fix legalization of generic types (#377)Tim Foley2018-01-21
| | | | | | | | Previously, all legalizations of a generic type would use the name of the original decl for the "ordinary" part of things, and this would lead to collisions because the names didn't include the mangled generic arguments. This is now fixed by storing the mangled name of the original inside of `struct` declarations created for legalization, and using those names instead. Also adds support for `getElementPtr` instructions when doing IR type legalization. Also tries to make a `DeclRefType` convert to a string using the underlying `DeclRef`. This doesn't help because `DeclRef::toString` doesn't actually include generic arguments either.
* specialize witness tables when needed when specializing ↵Yong He2018-01-21
| | | | `lookup_witness_table` instruction. (#376)
* Improvements and bug fixes for global type parametersYong He2018-01-21
| | | | | | 1. allow spReflection_FindTypeByName to accept arbitrary type expression string 2. allow const int generic value to be used as expression value, and as array size 3. various bug fixes in witness table specialization / function cloning during specializeIRForEntryPoint to avoid creating duplicate global values, not copying the right definition of a function from the other module, not cloning witness tables that are required by specializeGenerics etc.
* bug fixesYong He2018-01-20
| | | | | fixes #373 fixes bug that misses current translation unit's scope when resolving entry-point global type argument expression.
* bug fixes to get falcor example shader code to compile.Yong He2018-01-16
| | | | | 1. prevent cyclic lookups when an interface inherits transitively from itself. 2. in `createGlobalGenericParamSubstitution`, create a default substitution for the base type declref before using it to lookup the witness table.
* remove out-of-date changesYong He2018-01-13
|
* Support nested genericsYong He2018-01-12
| | | | fixes #362
* Refactor substitution representation in DeclRefBase (#363)Yong He2018-01-12
| | | | | | | | | | | | This commit changes the type of `DeclRefBase::substitutions` from `RefPtr<Substitutions>` to `SubstitutionSet`, which is a new type defined as following: ``` struct SubstitutionSet { RefPtr<GenericSubstitution> genericSubstitutions; RefPtr<ThisTypeSubstitution> thisTypeSubstitution; RefPtr<GlobalGenericParamSubstitution> globalGenParamSubstitutions; } ``` This change get rid of most helper functions to retreive the substitution of a certain type, as well as surgery operations to insert a `ThisTypeSubstitution` or `GlobalGenericTypeSubstittuion` at top or bottom of the substitution chain. It also simplies type comparison when certain type of substitution should not be considered as part of type definition.
* bruteforce implementation of witness table resolution for associated (#358)Yong He2018-01-09
|
* Bug fixes for Slang integration (#356)Yong He2018-01-04
| | | | | | | | | | | | * fix #353 * move validateEntryPoint to after all entrypoints has been checked * bug fix: DeclRefType::SubstituteImpl should change ioDiff * bug fix: generic resource usage should have count of 1 instead of 0. * update test case
* fixup substitution of typedef associated type implementation via GetType() call.Yong He2017-12-28
|
* Merge branch 'struct-in-generic'Yong He2017-12-28
|\
| * Fix substitution for associatedtype.Yong He2017-12-28
| | | | | | | | | | | | fixes #341 When a typedef definition is used to satisfy an associated type, we must also substitute the resulting typedef type using parent substitution, in the case that the typedef is a generic application.
* | Fix NameExprType returning deleted canonical type when it's in a generic parent.Yong He2017-12-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fixes #339 `NamedExpressionType::CreateCanonicalType()` may return a deleted pointer. The original implementation is as follows: ``` Type* NamedExpressionType::CreateCanonicalType() { return GetType(declRef)->GetCanonicalType(); } ``` If `GetType()` returns a newly constructed Type (this happens when the `typedef` is defined inside a generic parent, which triggers a non-trivial substitution), the temporary type will be deleted when the function returns. The fix is to store the temporary type as a field of NamedExpressionType (`innerType`). A relevant fix (though not the true cause of issue #339) is to have `Type::GetCanonicalType()` also hold a `RefPtr` to the constructed canonical type, when the canonical type is not `this`. This prevents a returned canonical type being assigned to a RefPtr, which makes it possible for that RefPtr to be the sole owner of the canonical type and deleteing the canonical type when that RefPtr is destroyed.
* | Support nested generic types (e.g. L<T<S>>)Yong He2017-12-27
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | fixes #325 This commit includes following changes: 1. Including a default DeclaredSubtypeWitness argument when creating a default GenericSubstitution for a DeclRefType, so that the witness argument can be successfully replaced with an actual witness table after specialization. (check,cpp) 2. Not emitting full mangled name for struct field members. Since the declref of the member access instruction do not include necessary generic substitutions for its parent generic parameters, so the mangled names of the declaration site and use site mismatches. Instead we just emit the original name for struct fields. (emit.cpp) 3. Allow IRWitnessTable to represent a generic witness table for generic structs. Adds necessary fields to IRWitnessTable for generic specialization. For now, the user field of the IRUse is not used and is nullptr. (ir-inst.h) 4. Make IRProxyVal use an IRUse instead of an IRValue*, so that an IRValue referenced by IRProxyVal (as a substitution argument) can be managed by the def-use chain for easy replacement. This is used for specializing witness tables. (ir.cpp, ir.h) 5. Add a `String dumpIRFunc(IRFunc*)` function for debugging. 6. Add name mangling for generic / specialized witness tables (mangle.cpp) 7. improved natvis file for inspecting witness tables. 8. Add specialization of witness tables: 1) `findWitnessTable` will simply return the specialize IRInst for a generic witness table. 2) make `cloneSubstitutionArg` call `cloneValue` to clone the argument instead of calling `context->maybeCloneValue`, so we can make use of the cloned value lookup machanism to directly return the specialized witness table (which is done when we process the `specialize` instruction on the generic witness table before process the decl ref). 3) bug fix: the argument in ir.cpp:3338 should be `newArg` instead of `arg`. 4) add `specializeWitnessTable` function to specailize a generic witness table. It clones the witness table, and recursively calls `getSpecailizedFunc` for the witness table entries. 5) make `specailizeGenerics` function also handle the case when an operand of the `specialize` instruction is a witness table. We will call `specializeWitnessTable` here and replace the `specialize` instruction with the specialized witness table. The replacement mechanism based on IR def-use chain works here because we have already make IRProxyVal a part of the def-use chain. 9. Add two more test cases for nested generics with constraints. (generic-list.slang and generic-struct-with-constraint.slang)
* Support for transitive subtype witnesses (#331)Tim Foley2017-12-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Change stdlib `saturate` to explicitly specialize `clamp` This exposes issue #329, and so gives us an easy way to see if transitive subtype witnesses have been implemented correctly. * Fixup: invoke correct `clamp` overloads When switching the `clamp` calls in the stdlib definition of `saturate` I made two big mistakes: 1. I was passing in `<T>` in all cases, instead of, e.g., `<vector<T,N>>` in the vector case 2. Of course, the overloads don't actually take `<vector<T,N>>` for the vector case, because `vector<T,N>` is not a `__BuiltinArithmeticType` (`T` is), so instead it should be `clamp<T,N>(...)`. The issue behind (2) is that we don't support "conditional conformances," which would be a way to say that when `T : __BuiltinArithmeticType` then `vector<T,N> : __BuiltinArithmeticType`. That would be a great long-term wish-list feature, but not something I can see us adding in a hurry. Anyway the fix here is the simple one: change the vector/matrix call sites to invoke the correct overload in each case. * Add a notion of transitive subtype witnesses There are two pieces here: 1. Add the `TransitiveSubtypeWitness` class. This is a witness that `A : C` that works by storing nested subtype witnesses that show that `A : B` and `B : C` for some intermediate type `B`. All the basic `Val` operations are easy enough to define on this. - The one gotcha case is whether we can ever simplify away a `TransitiveSubtypeWitness` as part of substitution. That is, if we end up substituting so that both `A` and `B` end up as the same type, then we really just need the `B : C` sub-part. Stuff like that is left as future work. 2. Make the logic in `check.cpp` that constructs subtype witnesses based on found inheritance and constraint declarations able to build up transitive chains. Most of the required infrastructure was already there (the search process maintains a trail of "breadcrumbs" that represent all the steps getting from `A : B` to `B : C` to `C : D` ...). This change does *not* deal with the required changes in the IR to take advantage of transitive witnesses.
* Make AST and IR share type legalization code (#303)Tim Foley2017-12-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Make AST and IR share type legalization code A previous change already made it so that the AST-to-AST lowering/legalization pass could work together with IR-based lowering of `import`ed code, but that change didn't take into account the case where a function written in the AST needed to call an IR function and pass in a type that required legalization. Both the IR-based and AST-based passes had their own approaches to type legalization, that mostly agreed on the desired output, but they ended up creating their own representations for legalized types which would mean that for a function call the caller and callee might end up legalizing the parameter list to use different types. This change tries to fix this issue (and adds a new test case that relies on the fix) by massively overhauling the AST-based legalization pass so that it uses the same type legalization code as the IR. The shared code has been moved out into `legalize-types.{h,cpp}`. Notes: - I eliminated the `FilteredTupleType` type, since it was starting to cause code duplication in a lot of places. Instead, type legalization just creates new `struct` types to represent the result of filtering. - One big consequence of this is that the `LegalType::pair` case needs to remember for each field in the original type which field (if any) in the new `struct` type it maps to - A big source of complexity (and probably bugs) in this code is trying to figure out how to parent these new `struct` definitions effectively. A good follow-on change would be something that outputs declarations on-demand during the AST emit logic (as we do for the IR), just to avoid some of this song and dance. - The old AST type legalization had a notion of both a "tuple" type and a "varying tuple" type. The "tuple" case was quite complex, and combined behavior currently handled by `LegalType::pair` (for splitting into ordinary and special sides) and `LegalType::tuple` (for holding multiple distinct elements to represent the fields of an aggregate). The "varying tuple" case was closer to `LegalType::tuple`, so I tried to just re-use the existing logic for that too. The one place this potentially gets messy is in `reifyTuple()`. - The messiest bit of handling the "varying tuple" concept (which is used for GLSL shader inputs/outputs since they have to be scalarized) is that when passing them as function arguments we need to reify the tuple back into a structured value. Because the `LegalExpr` hierarchy doesn't have type information, but constructing a value of the "original" type requires such information, things get a little messy. - I did *not* try to deal with any of the logic related to handling system inputs/outputs for cross-compilation purposes. Of course, the long-term goal is that any actual cross-compilation is handled via the IR, but this change can't afford to break the AST-based path just yet. As a result, there is still quite a bit of complexity in the handling of assignment, to deal with cases where "fixups" are required. * fixup: bad code in macro, not caught by Visual Studio compiler * fixup: more stuff missed by VS compiler * fixup: VS continutes to miss stuff in UNREACHABLE_RETURN
* Fix substitution mechanism to remove special cases for global params (#297)Yong He2017-11-24
| | | | | | | | | | | | | | | | Add a new function: `substituteSubstitutions(Substitutions * substHead, Substitutions subst, int * ioDiff)` This function substitutes the type arguments referenced in a linked list of substitutions headed at `substHead` using the substitutions specified by `subst`. If the linked list `substHead` does not contain `GlobalGenericParamSubstitution` entries, they will be added to the bottom (outter most) of the linked list. Note that this function should be called when `substHead` is known to be the head of substitution linked list because the existance of `GlobalGenericPaaramSubstitution` is detected assuming the linked lists starts at `substHead`. If a substitution that is not the head of a substitution linked list is passed in, duplicate `GlobalGenericParamSubstitution`s could be appended to the linked list. This means that this function should *not* be called in places like `GenericSubstitution::SubstitutionImpl()` for its outer substitutions, because `outer` is obviously not the head of the linked list. Instead, use this function to substitution the substitution lists of `DeclRef` etc. instead of calling `declRef.substitutions->SubstituteImpl()` where the head to the linked list is known as a member of that class. With this function, IRSpecContext::maybeCloneType() is simplified down to `originalType->Substitute(subst)` Updates `DeclRefBase::SubstituteImpl` and `DeclRefType::SubstituteImpl` to call `substituteSubstitutions` instead of making direct `substitutions->SubstituteImpl` call. Providing actual implementation of `GlobalGenericParamSubstitution::SubstituteImpl` instead of just returning `this` to deal with potential situations where a true substitution is needed.
* Add logic to propagate GlobalGenericParamSubstitutionYong He2017-11-21
|
* fixup global generic parametersYong He2017-11-20
| | | | | | 1. simplify RoundUpToAlignment() 2. add new a render-compute test case to cover the situation where the entry-point interface (parameter/return types of an entry-point function) is dependent on the global generic type. 3. initial fixes to get this test case to compile (but is not producing correct HLSL output yet)
* IR: Add support for `out` and `inout` parameters (#289)Tim Foley2017-11-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These were already being handled a little bit, by lowering an `out T` or `inout T` function parameter in the AST to a function parameter with type `T*` in the IR, and then emiting explicit loads/stores. The HLSL emit logic, however, couldn't tell the difference between an `out` parameter, an `inout`, or a true pointer (if we ever needed to support them...). The intention (not fully implemented) was that we'd use a hierarchy of types rooted at `PtrTypeBase`: - `PtrTypeBase` - `Ptr`: "real" pointers in the C/C++ sense - `OutTypeBase`: pointers used to represent by-reference parameter passing - `OutType`: IR level type for an `out` parameter - `InOutType`: IR level type for an `inout` or `in out` parameter Actually implementing this involved: - Adding a bit more flexibility to the `Session::getPtrType` logic to allow for creating any of the concrete types above - Making the `lower-to-ir` logic create the right type for function parameters (instead of just using `PtrType`) - Making the HLSL emit logic check for the `OutType` and `InOutType` cases rather than just `PtrType` - Changing a bunch of small places in the code so that they use `PtrTypeBase` instead of `PtrType` when they should handle any of the above cases, and also make a few places check for `OutTypeBase` instead of `PtrType` or `PtrTypeBase`, when they are really trying to capture by-reference parameters - Add a test case that uses all of the different cases we care about (without these fixes, this test case generates errors from fxc because of variables being used before being initialized, becaues parameters get declared `out` that should be `inout`). A minor point here is that we are playing a bit fast and loose right now because the IR does not actually enforce any type checks. From the standpoint of the front end, `Ptr<T>`, `Out<T>`, and `InOut<T>` are all unrelated types (each is just a `struct` declared in `core.meta.slang`), but this doesn't really matter because none of these are types our current users are explicitly using. In the IR it makes perfect sense to allow `Out<T>` or `InOut<T>` as the operand of a `load` or `store` instruction (and ditto for `getFieldAddr`, etc.) - there instructions just apply to any `PtrTypeBase`. The place where this potentially gets tricky is whether an `Out<T>` can be used where a `Ptr<T>` is expected, or vice vers (e.g., can I just pass my local variable's pointer directly to an `Out<T>` function parameter? I'm going to ignore these issues for now, since the code currently works for our test case.
* Add support for global generic parameters (#285)Yong He2017-11-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Add support for global generic parameters (In-progress work) This commit include: 1. Update Slang API to allow specification of generic type arguments in an `EntryPointRequest` 2. Add parsing of `__generic_param` construct, which becomes a GlobalGenericParamDecl, contains members of `GenericTypeConstraintDecl`. 3. Semantics checking will check whether the provided type arguments conform to the interfaces as defined by the generic parameter, and store SubtypeWitness values in the EntryPointRequest, which will be used by `specializeIRForEntryPoint` when generating final IR. 4. Add a new type of substitution - `GlobalGenericParamSubstitution` for subsittuting references to `__generic_param` decls or to its member `GenericTypeConsraintDecl` with the actual type argument or witness tables. 5. Update `IRSpecContext` to apply `GlobalGenericParamSubstitution` when specializing the IR for an EntryPointRequest. 6. Update `render-test` to take additional `type` inputs, which specifies the type arguments to substitute into the global `__generic_param` types. This commit does not include ProgramLayout specialization. * IR: pass through `[unroll]` attribute (#284) The initial lowering was adding an `IRLoopControlDecoration` to the instruction at the head of a loop, but this was getting dropped when the IR gets cloned for a particular entry point. The fix was simply to add a case for loop-control decorations to `cloneDecoration`. * fix warnings * IR: support `CompileTimeForStmt` (#286) This statement type is a bit of a hack, to support loops that *must* be unrolled. The AST-to-AST pass handles them by cloning the AST for the loop body N times, and it was easy enough to do the same thing for the IR: emit the instructions for the body N times. The only thing that requires a bit of care is that now we might see the same variable declarations multiple times, so we need to play it safe and overwrite existing entries in our map from declarations to their IR values. Of course a better answer long-term would be to do the actual unrolling in the IR. This is especially true because we might some day want to support compile-time/must-unroll loops in functions, where the loop counter comes in as a parameter (but must still be compile-time-constant at every call site). * Add support for global generic parameters (In-progress work) This commit include: 1. Update Slang API to allow specification of generic type arguments in an `EntryPointRequest` 2. Add parsing of `__generic_param` construct, which becomes a GlobalGenericParamDecl, contains members of `GenericTypeConstraintDecl`. 3. Semantics checking will check whether the provided type arguments conform to the interfaces as defined by the generic parameter, and store SubtypeWitness values in the EntryPointRequest, which will be used by `specializeIRForEntryPoint` when generating final IR. 4. Add a new type of substitution - `GlobalGenericParamSubstitution` for subsittuting references to `__generic_param` decls or to its member `GenericTypeConsraintDecl` with the actual type argument or witness tables. 5. Update `IRSpecContext` to apply `GlobalGenericParamSubstitution` when specializing the IR for an EntryPointRequest. 6. Update `render-test` to take additional `type` inputs, which specifies the type arguments to substitute into the global `__generic_param` types. progress on parameter binding * Add a more contrived test case for specializing parameter bindings * update render-test to align buffers to 256 bytes (to get rid of D3D complains on minimal buffer size). * adding one more test case for parameter binding specialization. * Cleanup according to @tfoleyNV 's suggestions. * fix a bug introduced in the cleanup
* Revise type legalization so it can handle constant buffers (#282)Tim Foley2017-11-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Revise type legalization so it can handle constant buffers The existing legalization approach with "tuples" can handle scalarizing a `struct` type with resource-type fields in it, but it had several big gaps. The most notable is that given a type that mixes uniform and resource fields, we can't just blindly scalarize things: ``` struct P { float4 a; float4 b; Texture2D t; }; cbuffer C { P gParam[8]; }; ``` The existing code was completely ignoring the declaration of `gParam` inside `C`, but even if we fixed that issue, we'd get something like: ``` cbuffer C { float4 gParam_a[8]; float4 gParam_b[8]; }; Texture2D gParam_t[8]; ``` In this case we've completely changed the layout of the uniform buffer, by switching from AOS to SOA. Even if we could get the type layout logic and the IR to agree on this, it would be a surprise to users, and "principle of least surprise" should be a big deal on a project with as many moving parts as ours. The right thing to do is to have legalization create a "stripped" version of the original type `P` and use that: ``` struct P_stripped { float4 a; float4 b; }; cbuffer C { P_stripped gParam[8]; }; Texture2D gParam_t[8]; ``` Then at a call site, this: ``` foo(gParam); ``` becomes: ``` foo(gParam, gParam_t); ``` This is exactly how the current AST-to-AST legalization handles mixed uniform and resource types, but the way it does it involves some annoying kludges: - That pass has a notion of a "tuple" similar to our legalization, but every tuple has an optional "primary" entry for all the uniform data, plus tuple elements for the resources, and a given field may be represented on one side, the other, or both. It makes the code for handling tuples very messy. - That pass does the "stripping" of types by actually marking up the AST declarations (this is okay because it is constructing a new AST as it goes), so that when they get emitted certain fields don't actually show up. That is, we fix the problem with type `P` by actually *modifying* the user's declaration of `P`. That seems out of bounds for the IR. This change fixes the problem in our IR type legalization while trying to avoid the problems of the AST-to-AST pass by using two new ideas: 1. We add a new case for `LegalType` (and `LegalVal`) that is a "pair" type, where a pair consists of both an "ordinary" type (for uniform data) and a "special" type (for resource data). E.g., after legalization, the type for `C` (which can be over-simplified to `ConstantBuffer<P>` for our purposes), will be a `LegalType::pair` where the ordinary side is `ConstantBuffer<P_stripped>` and the special side is a tuple containing the `Texture2D` field. 2. We add a new (and annoyingly hacky) AST-level type called `FilteredTupleType` which is semantically a sort of tuple type (it holds a list of elements, and the elements have their own types), but which remembers an "original type" that it was created from, and for each element remembers the field of the original type that it corresponds to. This is used to construct a type like `P_stripped` as an actual AST-level structural type. The core logic for legalizing an aggregate type had to get more complicated just because of the new pair case, so there is now a `TupleTypeBuilder` that asists with taking an aggregate type, processing its fields, and then picking the right `LegalType` representation for the result. Other smaller changes: - Made the legalization logic actually legalize `PtrType<T>`. E.g., if `T` legalizes to a tuple, we need to construct a tuple of pointer types. The same exact thing needs to be applied to arrays, and any other generic type that should "distribute over" pairs/tuples. - Made the legalization logic actually legalize `ConstantBuffer<T>` and similar. The basic idea there is if `T` maps to a pair, we wrap `ConstantBuffer<...>` around the ordinary side, and `implicitDeref` around the special side. - Removed a bunch of `#ifdef`ed-out code from the end of `ir-legalize-types.cpp`. That was code from my first attempt at legalization that failed miserably (trying to do it via local changes and a work list instead of a global rewrite pass), but it had some code I wanted to reference when writing the version that actually got checked in (should have deleted the code earlier, though). - Added a bunch of cases for `LegalType::none` (and the `LegalVal` equivalent) that helped simplify the logic fo the `pair` case by allowing me to *always* dispatch to both the "ordinary" and "special" sides, even if they might not actually be present. - Renamed `TupleType` and `TupleVal` over to `TuplePseudoType` and `TuplePseudoval` to recognize the fact that we might actually need/want *real* tuples in the type system, to go along with these fake ones (that need to be optimized away). The biggest doubt I have about this change is the whole `FilteredTupleType` thing; it seems like an obviously contrived type to add to the front-end type system that really only solves IR-level problems. A cleaner approach might have been to just add a plain old `TupleType` to the front-end type system (and initially I started with that), and then have yet another `LegalType`/`LegalVal` case that handles mapping from the fields of the original type to the numbered tuple elements. I expect we'll actually want to make that change in the future (especially if we ever add true tuples to the front-end), but for right now I let myself be swayed by the desire to have these stripped/filtered types get names that explain their provenance ("where they came from") to make our output code more debuggable. The way I've done it is probably overkill, though, and we need a much more complete effort on the readability and debuggability of our output before anything like that is worth worrying about. * Fixup: typo * Fixup: fix output of "non-mangled" names for test cases - Make sure to attach high-level decls to variables created as part of type legalization - Also, try to share more of the code between the different cases of variables - Fix up `parameter-blocks` test case that was passing `-no-mangle` but expecting mangled names in the output - Fix up `multiple-parameter-blocks` to not rely on `-no-mangle` for now, because it would lead to two global variables with the same name (need to fix that underlying issue eventually). - Also fix name generation logic so that we only use "original" names (from high-level decls) specifically when the `-no-mangle` flag is on, and otherwise use IR-level names. * Fix: handle constant buffers better in render-test - Don't request both CB and SRV usage for buffers, since that is illegal - Also, don't try to create an SRV when user requested a CB (since the required usage flag won't be there) - Record the input buffer type on the `D3DBinding` for a buffer, and use that to tell us when to bind a CB instead of SRV/UAV - Fix expected output for `cbuffer-legalize` test now that we are actually feeding it correct cbuffer dta.
* Cleanup substitution of DeclaredSubtypeWitness.Yong He2017-11-08
| | | | Now using DeclaredSubtypeWitness::declRef to determine the proper argument index in a GenericSubstitution.
* Cleanup of "suport generic interface method".Yong He2017-11-08
| | | | | | Add a GenericValueParamDecl case in doesGenericSignatureMatchRequirement() Return a substituted DeclaredSubtypeWitness in DeclaredSubtypeWitness::SubstituteImpl() instead of return this.
* Support generic interface methods (#251)Yong He2017-11-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * improve diagnostic messages and prevent fatal errors from crashing the compiler. * fix top level exception catching. * spelling fix * change wording of invalidSwizzleExpr diagnostic * add speculative GenericsApp expr parsing * add new test case of cascading generics call. * Fixing bugs in compiling cascaded generic function calls. Add implementation of DeclaredSubTypeWitness::SubstituteImpl() This is not needed by the type checker, but needed by IR specialization. When input source contains cascading generic function call, the arguments to `specialize` instruction is currently represented as a substitution. The arg values of this subsittution can be a `DeclaredSubTypeWitness` when a generic function uses one of its generic parameter to specialize another generic function. When the top level generics function is being specialized, this substitution argument, which is a `DeclaredSubTypeWitness`, needs to be substituted with the witness that used to specialize the top level function in the specialized specialize instruction as well. * add a test case for cascading generic function call. * parser bug fix * fixes #255 * add test case for issue #255 * Generate missing `specialize` instruction when calling a generic method from an interface constraint. When calling a generic method via an interface, we should be generating the following ir: ... f = lookup_interface_method(...) f_s = specailize(f, declRef) ... This commit fixes this `emitFuncRef` function to emit the needed `specialize` instruction. * fixes #260 This fix follows the second apporach in the disucssion. It generated mangled name for specialized functions by appending new substitution type names to the original mangled name. * Disabling removing and re-inserting specailized functions in getSpecalizeFunc() I am not sure why it is needed, it seems HLSL and GLSL backends are generating forward declarations anyways, so the order of functions in IRModule shouldn't matter. * cleanup and complete test cases. * fix warnings
* Parameter blocks (#245)Tim Foley2017-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Rename existing ParameterBlock to ParameterGroup We are planning to add a new `ParameterBlock<T>` type, which maps to the notion of a "parameter block" as used in the Spire research work. Unfortunately, the compiler codebase already uses the term `ParameterBlock` as catch-all to encompass all of HLSL `cbuffer`/`tbuffer` and GLSL `uniform`/`buffer`/`in`/`out` blocks (all of which are lexical `{}`-enclosed blocks that define parameters...). This change instead renames all of the existing concepts over to `ParameterGroup`, which isn't an ideal name, but at least doesn't directly overlap the new terminology or any existing terminology. The new `ParameterBlockType` case will probably be a subclass of `ParameterGroupType`, since it is a logical extension of the underlying concept. * Add Shader Model 5.1 profiles The HLSL `register(..., space0)` syntax is only allowed on "SM5.1" and later profiles (which is supported by the newer version of `d3dcompiler_47.dll` that comes with the Win10 SDK, but not the older version of `d3dcompiler_47.dll` - good luck figuring out which you have!). This change adds those profiles to our master list of profiles, and nothing else. * First pass at support for `ParameterBlock<T>` - Add the type declaration in stdlib - Add a special case of `ParameterGroupType` for parameter blocks - Handle parameter blocks in type layout (currently handling them identically to constant buffers for now, which isn't going to be right in the long term) - Add an IR pass that basically replaces `ParameterBlock<T>` with `T` - Eventually this should replace it with either `T` or `ConstantBuffer<T>`, depending on whether the layout that was computed required a constant buffer to hold any "free" uniforms - Add first stab at an IR pass to "scalarize" global variables using aggregate types with resources inside. - This currently only applies to global variables, so it won't handle things passed through functions, or used as local variables - It also only supports cases where the references to the original variable are always references to its fields, and not the whole value itself - Add a single test case that technically passes with this level of support, but probably isn't very representative of what we need from the feature * Fold parameter-block desugaring into a more complete "type legalization" pass The basic problem that was arising is that once you desugar `ParameterBlock<T>` into `T`, you then need todeal with splitting `T` into its constituent fields if it contains any resource types. Handling those transformations by following the usual use-def chains wasn't really helping, because you might need systematic rewriting that can really only be handled bottom-up. This change adds a new pass that is intended to perform multiple kinds of type "legalization" at once: - It will turn `ParameterBlock<T>` into `T` - It may at some point also convert `ConstantBuffer<T>` into `T` as well - It will turn an value of an aggregate type that contains resources into N different values (one per field) - As a result of this, it will also deal with AOS-to-SOA conversion of these types Legalization is applied to *every* function/instruction/value, so that it can make large-scale changes that would be tough to manage with a work list. This pass needs to be run *after* generics have been fully specialized, so that we know we are always dealing with fully concrete types, so that their legalization for a given target is completely known. This is still work in progress; there's more to be done to get this working with all our test cases, and finish the remaining `ParameterBlock<T>` work. * Improve binding/layout information when using parameter blocks - When doing type layout for a parameter block, don't include the resources consumed by the element type in the resource usage for the parameter block - Note that this is pretty much identical to how a `ConstantBuffer<T>` does not report any `LayoutResourceKind::Uniform` usage, except that `ParameterBlock<T>` is *also* going to hide underlying texture/sampler reigster usage - The one exception here is that any nested items that use up entire `space`s or `set`s those need to be exposed in the resource usage of the parent (I don't have a test for this) - When type legalization needs to scalarize things, it must propagate layout information down to the new leaf variables. In general, the register/index for a new leaf parameter should be the sum of the offsets for all of the parent variables along the "chain" from the original variable down to the leaf (we aren't dealing with arrays here just yet). - When type legalization decides to eliminate a pointer(-like) type (e.g., desugar `ParameterBlock<T>` over to `T`), actually deal with that in terms of the `LegalVal`s created, so that we can know to turn a `load` into a no-op when applied to a value that got indirection removed. - Hack up the "complex" parameter-block test so that it actually passes (the big hack here is that the HLSL baseline is using names that are generated by the IR, and are unlikely to be stable as we add/remove transformations). - Note: I can't make these be compute tests right now, because regsiter spaces/sets are a feature of D3D12/Vulkan, and our test runner isn't using those APIs.
* cleanup useless codeYong He2017-11-04
|
* fix warningsYong He2017-11-04
|
* merge with fixWarnings branchYong He2017-11-04
|\
| * fix all unreachable code warningsYong He2017-11-04
| |
* | Passing both assoctype-simple and assoctype-complex test cases.Yong He2017-11-04
| |
* | work in-progressYong He2017-11-04
| |
* | associatedtypes: generating almost correct HLSL, but is not calling ↵Yong He2017-11-03
| | | | | | | | correctly mangled function.
* | in-progress workYong He2017-11-03
| |
* | work inprogressYONGH\yongh2017-11-02
| |
* | Adding support for associated types.Yong He2017-11-01
| |
* | work in-progress: type checking associated typesYong He2017-10-31
| |
* | work in-progress, add parsing for assoc type decls and member type expressionsYONGH\yongh2017-10-30
|/
* Initial work on support code generation for generics with constraints (#233)Tim Foley2017-10-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change includes a lot of infrastructure work, but the main point is to allow code like the following: ``` // define an interface interface Helper { float help(); } // define a generic function that uses the interface float test<T : Helper>( T t ) { return t.help(); } // define a type that implements the interface struct A : Helper { float help() { return 1.0 } } // define an ordinary function that calls the // generic function with a concrete type: float doIt() { A a; return test<A>(a); } ``` Getting this to generate valid code involves a lot of steps. This change includes the initial version of all of these steps, but leaves a lot of gaps where more complete implementation is required. The changes include: - Member lookup on types has been centralized, and now handles the case where the type we are looking for a member in is a generic parameter (e.g., given `t.help()` we can now look up `help` in `Helper` by knowing that `t` is a `T` and `T` conforms to `Helper`). - There is an obvious cleanup still to be done here where the same exact logic should be used to look up available "constructor" declarations inside a type when the type is used like a function. - Add a notion of subtype constraint "wittnesses" to the type system. When a generic is declared as taking `<T : Helper>` it really takes two generic parameters: the type `T` and a proof that `T` conforms to `Helper`. The actual arguments to a generic will then include both the type argument and a suitable witness argument (both type-level values). - As it stands right now, a witness wraps a `DeclRef` to the declaration that represents the appropriate subtype relationship. So if we have `struct A : Helper`, that `: Helper` part turns into an `InheritanceDecl` member, and a reference to that member can serve as a witness to the fact that `A` conforms to `Helper`. - Make explicit generic application `G<A,B>` synthesize the additional arguments that represent conformances required by the generic. - This does *not* yet deal with the case where a generic is implicitly specialized as part of an ordinary call `G(a,b)` - A bug fix to not auto-specialize generics during lookup. The problem here was related to an attempted fix of an earlier issue. During checking of a method nested in a generic type, we were running into problems where `DeclRefType::create()` was getting called on an un-specialized reference to `vector`, and this was leading to a crash when the code looked for the arguments for the generic. This was worked around by having name lookup automatically specialize any generics it runs into while going through lookup contexts. That choice creates the problem that in a generic method like this: ``` void test<T>(T val) { ... } ``` any reference to `val` inside the body of `test` will end up getting specialized so that it is effectively `test<T>::val`, when that isn't really needed. - Add front-end logic to check that when a type claims to conform to an interface it actually must provide the methods required by the interface. The checking process goes ahead and builds a front-end "witness table" that maps declarations in the interface being conformed to over to their concrete implementations for the type. - At the moment the checking is completely broken and bad: it assumes that *any* member with the right name is an appropriate declaration to satisfy a requirement. That obviously needs to be fixed. - Add an explicit operation to the IR for lookup of methods: `lookup_interface_method(w, r)` where `w` is a reference to the "witness" value and `r` is an `IRDeclRef` for the member we want to look up. - Add an explicit notion of witness tables to the IR. These end up being the IR representation of an `InheritanceDecl` in a type, and they are generated by enumerating the members that satisfy the interface requirements (which were handily already enumerated by the front-end checking). The witness table is an explicit IR value, and so it will be referenced/used at the site where conformance is being exploited (e.g., as part of a `specialize` call), so it should be safe to eliminate witness tables that are unused (since they represent conformances that aren't actually exploited). Similarly, the entries in a witness table are uses of the functions that implement interface methods, and so keep those live. - In order to implement the above, I did a bit of a cleanup pass on the IR representation so that there is an `IRUser` base that `IRInst` inherits from, so that we can have users of values that aren't instructions. - One annoying thing is that because of how types and generics are handled in the IR, we needed a way to have a type-level `Val` that wraps an IR-level value: e.g., to allow an IR-level witness table to be used as one of the arguments for specialization of a generic. The design I chose here is to have a "proxy" `Val` subclass (`IRProxyVal`) that wraps an `IRValue*`. These should only ever appear as part of types and `DeclRef`s that are used by the IR. - One annoying bit here is that an IR value might then have a use that is not manifest in the set of IR instructions, and instead only appears as part of a type somewhere. - I'm not 100% happy with this design, but it seems like we'd have to tackle similar issues if/when we eventually allow functions to have `constexpr` or `@Constant` parameters - Make generic specialization also propagate witness table arguments through to their use sites (this is mostly just the existing substitution machinery, once we have `IRProxyVal`), and then include logic to specialize `lookup_interface_method` instructions when their first operand is a concrete witness table. All of this work allows a single limited test using generics with constraints to pass, but more work is needed to make the solution robust.
* Work on IR-based cross-compilation (#222)Tim Foley2017-10-18
| | | | | | | | | | | | | | | There are two big changes here: - Add logic during the initial IR cloning pass for an entry point + target that tries to pick the best possible version of any target-overloaded function. This allows us to pick the intrinsic version of `saturate()` when compiling for HLSL output, but then pick the non-intrinsic version (that is implemented in terms of `clamp()`) when targetting GLSL. - Add an initial specialization pass that tries to deal with generics. This required some fixing work to IR generation, so that we correctly generate explicit operations to specialize a generic for specific types (this is currently implemented as a `specialize` instruction that takes the generic to specialize plus a declaration-reference that represents the specialized form). With that work in place, we can scan for `specialize` instructions inside of non-generic functions, and use them to trigger generation of specialized code. We rely on the name-mangling scheme to help us find pre-existing specializations when possible. There are also a bunch of cleanups encountered along the way: - Don't use the explicit `layout(offset=...)` for uniforms, because it isn't supported by all current drivers. For now we will just assume that our layout rules compute the same values that the driver would for un-marked-up code. We can come back later and try to implement a workaround in the cases where this doesn't apply (e.g., by re-running the layout logic as part of emission, and dropping layout modifiers from variables that don't need explicit layout). - Fix some issues in IR dump printing so that we print function declarations more nicely. - Testing: print out failing pixel when image-diff fails
* Get rid of the `-slang-ir-asm` target (#212)Tim Foley2017-10-13
| | | | | | | | * Get rid of the `-slang-ir-asm` target This is really only useful for debugging, so I've replaced the functionality with a `-dump-ir` command line option (which dump's the IR for an entry point before doing codegen). * fixup: use HLSL target, not DXBC, so test can run on Linux
* IR: overhaul IR design/implementation (#195)Tim Foley2017-10-04
| | | | | | | | | | | | | | | | | | | | | | * IR: overhaul IR design/implementation Closes #192 Closes #188 This is a major overhaul of how the IR is implemented, with the primary goal of just using the AST-level type representation as the IR's type representation, rather than inventing an entire shadow set of types (as captured in issue #192). One consequence of this choice is that types in the IR are no longer explicit "instructions" and are not represented as ordinary operands (so a bunch of `+ 1` cases end up going away when enumerating ordinary operands). Along the way I also got rid of the embedded IDs in the IR (issue #188) because this wasn't too hard to deal with at the same time. Another related change was to split the `IRValue` and `IRInst` cases, so that there are values that are not also instructions. Non-instruction values are now used to represent literals, references to declarations, and would eventually be used for an `undef` value if we need one. IR functions, global variables, and basic blocks are all values (because they can appear as operands), but not instructions. The main benefit of this approach is that the top-level structure of a bytecode (BC) module is much simpler to understand and walk, and BC-level types are represented much more directly (such that we could conceivably use them for reflection soon). * fixup: 64-bit build fix * fixup: try to silence clang's pedantic dependent-type errors * fixup: bug in VM loading of constants
* First attempt at a Linux build (#193)Tim Foley2017-09-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * First attempt at a Linux build - Fix up places where C++ idioms were written assuming lenient behavior of Microsoft's compiler - Add a few more alternatives for platform-specific behavior where Windows was the only platform accounted for. - Add a basic Makefile that can at least invoke our build, even if it isn't going good dependency tracking, etc. - Build `libslang.so` and `slangc` that depends on it, using a relative `RPATH` to make the binary portable (I hope) - Add an initial `.travis.yml` to see if we can trigger their build process. * Fixup: const bug in `List::Sort` I'm not clear why this gets picked up by the gcc *and* clang that Travis uses, but not the (newer) gcc I'm using on Ubuntu here, but I'm hoping it is just some missing `const` qualifiers. * Fixup: reorder specialization of "class info" Clang complains about things being specialized after being instantiated (implicilty), and I hope it is just the fact that I generate the class info for the roots of the hierarchy after the other cases. We'll see. * Fixup: add `platform.cpp` to unified/lumped build * Fixup: Windows uses `FreeLibrary` and not `UnloadLibrary` * Fixup: fix Windows project file to include new source file This obviously points to the fact that we are going to need to be generating these files sooner or later.
* Replace old notion of "intrinsic" operationsTim Foley2017-09-07
| | | | | | | | | | | | | | | | | | | | | | | The code previously had an enumerated type for "intrinsic" operations, and allowed functions to be marked `__intrinsic_op(...)` to indicate the operation they map to. The nature of the IR meant that each of these intrinsic ops had to have a corresponding IR opcode, but the `enum` types weren't the same. This change cleans things up a bit by deciding that the `__intrinsic_op(...)` modifier names an actual IR opcode, and so the `IntrinsicOp` enum is gone. The biggest source of complexity here is that there are certain operations that need to be "intrinsic"-ish for the purposes of the current AST-based translation path, because we need them to round-trip from source to AST and back. Right now this is being handled by defining a bunch of "pseudo-ops" which can be used in the `__intrinsic_op` modifier, but which are *not* meant to be represented in the IR. Currently I don't actually handle this during IR generation. In the long run, once we are using IR for everything that needs cross-compilation, we should be able to eliminate the pseudo-ops in favor of just having these be ordinary (inline) functions defined in the stdlib (e.g., the `+=` operator can just have a direct definition). There was a second category of modifier that gets a little caught up in this, which is the `__intrinsic` modifier, which got used in two ways: 1. A function marked `__intrinsic(glsl, ...)` had what I call a "target intrinsic" modifier, which specified how to lower it for a specific target (e.g., GLSL). 2. A function just marked `__intrinsic` was supposed to be a marker for "this function shouldn't be emitted in the output, because the implementation is expected to be provided" The latter category of function should really be an `__intrinsic_op`, so I translated all those uses. I added a tiny bit of sugar so that `__intrinsic_op` without an explicit opcode will look up an opcode based on the name of the function being called, so that an operation like `sin` can automatically be plumbed through to an equivalent IR op. (The first category is a stopgap for the AST-based cross-compilation, and will hopefully be replaced by something better as we get the IR-based path working). Getting the switch from `__intrinsic` to `__intrinsic_op` working required shuffling around some code in `emit.cpp` that handles looking up those modifiers and emitting builtin operations appropriately during cross-compilation. Depending on where we go with things, a possible extension of this approach is to allow multiple operands to `__intrinsic_op` so that the first specifies the opcode, and then the rest are literal arguments to specify "sub-ops." This could help us handle stuff like texture-fetch operations without an explosion in the number of opcodes. I still need to think about whether this is a good idea or not.
* Move implicit conversion operations to stdlibTim Foley2017-09-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Previously, there were a variety of rules in `check.cpp` to pick the conversion cost for various cases involving scalar, vector, and matrix types. - The main problem of the previous approach is that any lowering pass would need to convert an arbitrary "type cast" node into the right low-level operation(s). - The new approach is that a type conversion (implicit or explicit) always resolves as a call to a constructor/initializer for the destination type. This means that the existing rules around marking operations as builtins should work for lowering. - The support this, the checking logic needs to perform lookup of intializers/constructors when asked to perform conversion between types. It does this by re-using the existing logic for lookup and overload resolution if/when a type was applied in an ordinary context. - Next, we define a modifier that can be attached to constructors/initializers to mark them as suitable for implicit conversion, and associate them with the correct cost to be used when doing overload comparisons. - We add the modifier to all the scalar-to-scalar cases in the stdlib, using the logic that previously existed in semantic checking. - Next we add cases for general vector-to-scalar conversions that also convert type, using the same cost computation as above. - This probably misses various cases, but at this point they can hopefully be added just in the stdlib. - One gotcha here is that in lowering, we need to make sure to lower any kind of call expression to another call expression of the same AST node class, so that we don't lose information on what casts were implicit/hidden in teh source-to-source case. Two notes for potential longer-term changes: 1. There is still some duplication between the type conversion declarations here and the "join" logic for types used for generic arguments. Ideally we'd eventually clean up the "join" logic to be based on convertability, but that isn't a high priority right now, as long as joins continue to pick the right type. 2. It is a bit gross to have to declare all the N^2 conversions for vector/matrix types to duplicate the cases for scalars. For the simple scalar-to-vector case, we might try to support multiple conversion "steps" where both a scalar-to-scalar and a scalar-to-vector step can be allowed (this could be tagged on the modifiers already introduced). That simple option doesn't scale to vector-to-vector element type conversions, though, where you'd really want to make it a generic with a constraint like: vector<T,N> init<U>(vector<U,N> value) where T : ConvertibleFrom<U>; Here the `ConvertibleFrom<U>` interface expresses the fact that a conforming type has an initializer that takes a `U`. What doesn't appear in this context is any notion of conversion costs. We'd need some kind of system for computing the conversion cost of the vector conversion from the cost of the `T` to `U` converion.
* Add an explicit `Name` typeTim Foley2017-08-14
| | | | | | | | | | | | | Fixes #23 Up to this point, the compiler has used the ordinary `String` type to represent declaration names, which means a bunch of lookup structures throughout the compiler were string-to-whatever maps, which can reduce efficiency. It also means that things like the `Token` type end up carying a `String` by value and paying for things like reference-counting. This change adds a `Name` type that is used to represent names of variables, types, macros, etc. Names are cached and unique'd globally for a session, and the string-to-name mapping gets done during lexing. From that point on, most mapping is from pointers, which should make all the various table lookups faster. More importantly (possibly), this brings us one step closer to being able to pool-allocate the AST nodes.
* Rename `Name` fields to `name`Tim Foley2017-08-14
| | | | This is in preparation for using `Name` as a type name.