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* Use slang- prefix on slang compiler and core source (#973)jsmall-nvidia2019-05-31
| | | | | | | | | | | | * Prefixing source files in source/slang with slang- * Prefix source in source/slang with slang- prefix. * Rename core source files with slang- prefix. * Update project files. * Fix problems from automatic merge.
* WIP: Support for other source target language (#971)jsmall-nvidia2019-05-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * WIP: Setting up C/Cpp source compilation targets. * WIP: Emitting C/CPP. * WIP: Split out SourceSink, and use it for source output on emit. * SourceSink -> SourceStream * * Made SourceStream use m_ prefixing of members. * Make all methods use lower camel * Removed methods from SourceStream interface that are not used externally (use _ prefixing) * Improvements to documentation * EmitContext is now effectively empty, so just use SharedEmitContext as EmitContext. * SharedEmitContext -> EmitContext * Methods to LowerCamel in emit.cpp * Split out EmitContext and ExtensionUsageTracker into separate files. * Split out EmitVisitor into slang-c-like-source-emitter files. * EmitVisitor -> CLikeSourceEmitter * Tidy up around CLikeSourceEmitter - simplify header. * Small tidy up - removing repeated comments that are in header. * Remove EmitContext paramter threading. * Small tidy up. Use prefixed macros for slang-c-like-source-emitter.h * Small tidy up in slang-c-like-source-emitter.cpp * First pass at splitting out UnmangleContext. * MangledNameParser -> MangledLexer. * WIP making EmitOp (EOp) enum available outside of cpp * Generating EmitOpInfo from macro. * Split out emit precedence handling. Don't use kOp_ style anymore, just use an array indexed by EmitOp. * Disable C simple test for now. * Keep g++/clang happy with token pasting. * Fix win32 narrowing warning.
* Hotfix/improve glsl semantic conversion (#965)jsmall-nvidia2019-05-21
| | | | | | | | | | | * Specify glsl semantic format - such that conversions are possible from hlsl sematics. * Comment improvements. Give appropriate type in glsl for sv_tessfactor. Note that sv_tessfactor is not functional though. * Work in progress for comparison of types. * * Fix type comparison issues around the hash. * Fix tests whos output changed with use of isTypeEqual
* Fix bitwise And & Or for scalar bool (#960)Robert Stepinski2019-05-01
| | | | | | * Convert bitwise Or & And to logical operations on scalar bools * Test bitwise operations on scalar bools
* String/List closer to conventions, and use Index type (#959)jsmall-nvidia2019-04-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * List made members m_ Tweaked types to closer match conventions. * Use asserts for checking conditions on List. Other small improvements. * List<T>.Count() -> getSize() * List<T> Add -> add First -> getFirst Last -> getLast RemoveLast -> removeLast ReleaseBuffer -> detachBuffer GetArrayView -> getArrayView * List<T>:: AddRange -> addRange Capacity -> getCapacity Insert -> insert InsertRange -> insertRange AddRange -> addRange RemoveRange -> removeRange RemoveAt -> removeAt Remove -> remove Reverse -> reverse FastRemove -> fastRemove FastRemoveAt -> fastRemoveAt Clear -> clear * List<T> FreeBuffer -> _deallocateBuffer Free -> clearAndDeallocate SwapWith -> swapWith * List<T> SetSize -> setSize Reserve -> reserve GrowToSize growToSize * UnsafeShrinkToSize -> unsafeShrinkToSize Compress -> compress FindLast -> findLastIndex FindLast -> findLastIndex Simplify Contains * List<T> Removed m_allocator (wasn't used) Swap -> swapElements Sort -> sort Contains -> contains ForEach -> forEach QuickSort -> quickSort InsertionSort -> insertionSort BinarySearch -> binarySearch Max -> calcMax Min -> calcMin * Initializer::Initialize -> initialize List<T>:: Allocate -> _allocate Init -> _init IndexOf -> indexOf * * Put #include <assert.h> in common.h, and remove unneeded inclusions * Small refactor of ArrayView - remove stride as not used * getSize -> getCount setSize -> setCount unsafeShrinkToSize->unsafeShrinkToCount growToSize -> growToCount m_size -> m_count * Some tidy up around Allocator. * Use Index type on List. * Refactor of IntSet. First tentative look at using Index. * Made Index an Int Did preliminary fixes. Made String use Index. * Partial refactor of String. * String::Buffer -> getBuffer ToWString -> toWString * Small improvements to String. String:: Buffer() -> getBuffer() Equals() -> equals * Try to use Index where appropriate. * Fix warnings on windows x86 builds.
* Initial support for the `precise` keyword (#958)Tim Foley2019-04-29
| | | | | | | | | | | | | | | | | | | | | | Fixes #858 The `precise` keyword exists in both HLSL and GLSL and when applied to a variable declaration is supposed to indicate that all computations that contribute to the value of that variable should not be altered based on "fast-math" optimizations. The main examples are that separate multiply and add operations should not be turned into fused multiply-add (fma) operations, and that operations cannot ignore the possibility of infinity or not-a-number values (e.g., by assuming that `x * 0.0f` is always `0.0f`). (Aside: it is possible that my understanding of what the semantics of `precise` are in HLSL and GLSL is imperfect so that either the GLSL variant isn't sufficient to provide the semantics of the HLSL keyword, or that the definition of "all computations that contribute" to a value isn't actually correct. We may need to revise this implementation based on subsequent learnings.) The basic idea here is to turn the AST `precise` keyword into a `[precise]` decoration in the IR and then emit that as a `precise` keyword again in the output. The main catch is that whereas most of our existing IR decorations apply to things like global shader parameters or `struct` members that usually stick around for the duration of compilation, `[precise]` will get slapped on local variables that will often get optimized away by our SSA pass. There are two ways a variable can get eliminated/replaced during the SSA pass: 1. A use of the variable can be replaced with an ordinary instruction that computes its value. 2. A use of the variable can be replaced with a reference to a "phi node" that will take on the appropriate value based on control flow. These two cases already had logic to copy a "name hint" decoration from the variable over to an instruction that will replace it, and I simply extended them to also propagate over a `[precise]` decoration. The test case added with this change intentionally constructs a case where `[precise]` needs to be propagated over to an SSA "phi node" in order to generate correct output code. The other gotcha is that we can emit variable declarations in various places in `emit.cpp`, and all of these needed to handle `[precise]`. Not only do we have actually local variables (`IRVar`), but we also have SSA phi nodes (`IRParam`), and then there are cases where an intermediate computation (an ordinary instruction) should be `[precise]` and thus we need to emit it as a temporary (not folding it into its use sites) and make sure that the temporary itself gets the `precise` keyword. I have manually confirmed that in the output SPIR-V, this change results in the `NoContraction` SPIR-V decoration being added to the relevant operations, and the output DXBC contains a multiply and an add in place of a multiply-add. The output DXIL does not show any obvious changes due to `precise`, although the exact order and operands of the math instructions emitted does differ when `precise` is added/removed. In all cases the output is equivalent to hand-written HLSL/GLSL with a `precise`-qualified local variable.
* Enable appropriate GLSL extension for unbounded-size resource arrays (#957)Tim Foley2019-04-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes #941 The GLSL we were emitting for unbounded-size arrays was the obvious: ```hlsl // This HLSL: Texture2D t[]; ``` ```glsl // ... becomes this GLSL: texture2D t[]; ``` Unfortunately, the legacy GLSL behavior for an array without a declared size is what is called an "implicitly-sized" array, which means that it is assumed to actually have a fixed size, which is determined by the maximum integer constant value used to index into it (and only integer constants are allowed to be used when indexing into it). Users hadn't noticed the issue for a while, because most of our users who rely on unbounded-size arrays were also using the HLSL `NonUniformResourceIndex` function: ```hlsl float4 v = t[NonUniformResourceIndex(idx)].Sample(...); ``` When mapping such code to GLSL we use the `nonuniformEXT` qualifier added by the `GL_EXT_nonuniform_qualifier` extension, and it turns out that a secondary feature of that extension is that it changes the GLSL language semantics for arrays (of resources) with an unspecified size, so that they instead behave like we want. So users were happy and we were blissfully ignorant of the lurking issue. The problem is that as soon as a user neglects to use `NonUniformResourceIndex` (perhaps because an index really is uniform): ```hlsl cbuffer C { uint definitelyUniform; } ... float4 v = t[definitelyUniform].Sample(...); ``` Now the code we emit doesn't need `nonuniformEXT` so it doesn't enable `GL_EXT_nonuniform_qualifier` and the declaration of `t` now falls under the "implicitly-sized" array rules, and thus the code fails because `definitelyUniform` is being used as an index but is *not* an integer constant. The fix is pretty simple: when emitting a declaration of a global shader parameter to GLSL, we check if it is an unbounded-size array of resources and, if so, enable the `GL_EXT_nonuniform_qualifier` extension. We don't need any clever handling to deal with resource parameters nested in `struct` types or in entry-point parameter lists, etc., because previous IR passes will have split up complex types and moved everything to the global scope already.
* Update glslang version (#940)Tim Foley2019-04-08
| | | | | | | | | | * Update glslang This moves to a version of glslang that is hosted with the slang project and that includes a patch for a high-priority fix that hasn't been upstreamed into the main glslang repository yet. * Change a GLSL extension name The glslang codebase changed the extension name required to enable certain features from `GL_KHX_shader_explicit_arithmetic_types` to `GL_EXT_shader_explicit_arithmetic_types`.
* Add better control over image formats for GLSL/SPIR-V targets (#939)Tim Foley2019-04-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Add better control over image formats for GLSL/SPIR-V targets Currently Slang emits GLSL code assuming all R/W images need to have explicit formats, and thus we try to infer a format from the element type of the image. E.g., given a `RWTexture2D<half4>` we might infer that a qualifier of `layout(rgba16f)` should be used. This strategy has two notable shortcomings: * Sometimes the user will want a format that doesn't match an existing HLSL type. E.g., if they want the equivalent of `layout(r11f_g11f_b10f)`, then what should they put in their `RWTexture2D<...>` to make the inference do what they need? * Sometimes the user knows that they don't need to specify a format *at all*, because using the `GL_EXT_shader_image_load_formatted` extension, they can still perform non-atomic load/store on images with no format specified in the SPIR-V. This change adds two features directed at these challenges. First, we add an explicit `[format(...)]` attribute that can be used to specify an explicit image format, including ones that don't match any HLSL type. An example of using this new attribute is: ```hlsl [format("r11f_g11f_b10f")] RWTexture2D<float3> myImage; ``` For simplicity in initial bring-up, the new formats all use the same naming as formats in GLSL (this should make it easy for a programmer who knows what they expect to get in the GLSL output). We can change the naming convention for formats at a later time, so long as we keep these existing names in as a compatibility feature. Note that this is *not* given a `vk::` prefix since the attribute should signal the programmer's intent to provide an image with that format on *all* targets (although only some targets might act on that information). Also note that the attribute takes a string (`[format("rgba8")`) instead of a bare identifier (`[format(rgba8)]`) because this is consistent with the existing convention for attributes in HLSL. When `[format(...)]` is left off, the default compiler behavior will still be to infer a format, but this behavior can be overidden for a single image using an explicit format of `"unknown"`: ```hlsl [format("unknown")] RWTexture2D<float4> mysteryMachine; ``` The second new feature is that if a user knows they are coding for a GPU that supports the `"unknown"` format in all non-atomic cases, then they can opt into making that the default for images without an explicit `[format(...)]`, using the new `-default-image-format-unknown` command-line option for `slangc`. The new test case included with this change confirms that we correctly see the explicit formats in the output GLSL and *no* formats for images without explicit `[format(...)]` when using the new command-line option. The test stresses images declared at global scope, in parameter blocks, and in entry-point parameter lists, to try and make sure that all the relevant IR passes in the compiler preserve the format information. * fixup: missing file
* Avoid SPIRV validation error by removing readonly flag from shaderRecord ↵Nima Nikfetrat2019-04-02
| | | | buffer (#936)
* GLSL half texture access (#931)jsmall-nvidia2019-03-27
| | | | | | | | | | | | * * Added $c macro - that will do casting to target type. Used here to cast texture reads back to half. Works in tandem with $z which will close parens. * half-texture.slang test * Make binding failing if TextureView fails * Simplify logic around parens. * Improve comment around $c macro. * Test against hlsl output to avoid error on CI.
* Allow plugging in types with resources for interface parameters (#913)Tim Foley2019-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Allow plugging in types with resources for interface parameters The key feature enabled by this change is that you can take a shader declared with interface-type parameters: ```hlsl ConstantBuffer<ILight> gLight; float4 myShader(IMaterial material, ...) { ... } ``` and specialize its interface-type parameters to concrete type that can contain resources like textures, samplers, etc. The hard part of doing this layout is that we need to support signatures that include a mix of interface and non-interface types. Imagine this contrived example: ```hlsl float4 myShader( Texture2D diffuseMap, ILight light, Texture2D specularMap) { ... } ``` We end up wanting `diffuseMap` to get `register(t0)` and `specularMap` to get `register(t1)`, so that they have the same location no matter what we plug in for `light`. But if we plug in a concrete type for `light` that needs a texture register, we need to allocate it *somewhere*. We handle this by having the `TypeLayout` for `light` come back with a "primary" type layout that doesn't have any texture registers, but with a "pending" type layout that includes the texture register requirements of whatever concrete type we plug in. This split between "primary" and "pending" layout then needs to work its way up the hierarchy, so that an aggregate `struct` type with a mix of interface and non-interface fields (recursively), needs to compute an aggregate "primary type layout" and an aggregate "pending type layout," and then each field needs to be able to compute its offset in the primary/pending layout of the aggregate. A large chunk of the work in this PR is then just implementing the split between primary and pending data, and ensuring that layouts are computed appropriately. The next catch is that when a "parameter group" (either a parameter block or constant buffer) contains one or more values of interface type, then we can allow the parameter group to "mask" some of the resource usage of the concrete types we plug in, but others "bleed through." For example, if we have: ```hlsl struct MyStuff { float3 color; ILight light; } ConstantBuffer<MyStuff> myStuff; struct SpotLight { float3 position; Texture2D shadowMap; } `` If we plug in the `SpotLight` type for `myStuff.light`, then the `float3` data for the light can be "masked" by the fact that we have a constant buffer (we can just allocate the `float3` `position` right after `color`), but the `Texture2D` needed for `shadowMap` needs to "bleed through" and become "pending" data for the `myStuff` shader parameter. Adding support for that detail more or less required a full rewrite of the logic for allocating parameter group type layouts. The next detail is that when we go to legalize a declaration like the `myStuff` buffer, we will end up with something like: ```hlsl struct MyStuff_stripped { float3 color; } struct Wrapped { MyStuff_stripped primary; SpotLight pending; } ConstantBuffer<Wrapped> myStuff; ``` This "wrapped" version of the buffer type more accurately reflects the layout we need/want for the uniform/ordinary data, but in order to further legalize it and pull out the resource-type fields like `shadowMap` we need to have accurate layout information, and the problem is that layout information for the original buffer can't apply to this new "wrapped" buffer. The last major piece of this change is logic that runs during existential type legalization to compute new layouts for "wrapped" buffers like these that embeds correct offset/binding/register information for any resources nested inside them. A key challenge in that code is that existential legalization needs to erase any "pending" data from the program entirely, so that offset information that used to be relatie to the "pending" part of a surrounding type now needs to be relative to the primary part. The work here may not be 100% complete for all scenarios, but it does well enough on the new and existing tests that I want to checkpoint it. Note that a few other tests have had their output changed, but in all cases I've reviewed the diffs and determined that the change in observable behavior is consistent with what we intened Slang's behavior to be. Note that there is still one major piece of support for interface-type parameters that is missing here, and which might force us to revisit some of the decisions in this code: we don't properly support user-defined `struct` types with interface-type fields. * fixup: typos
* Fix handling of enum tags that aren't literals (#926)Tim Foley2019-03-25
| | | | | | | | | | | | | | | | | | | | | | | | An `enum` case currently lowers to the IR as the value of its tag expression, so if we have: ```hlsl enum E { X = 99, } ``` then `X` will lower as IR for the expression `99` which is just a literal. If instead we have: ```hlsl enum E { X = 99u, } ``` then after type checking the expression is `int(99u)`, which will get emitted to the global (module) scope as a cast/conversion instruction, that then gets referenced at the use sites of `E.X`. The emit logic wasn't set up to handle the case of referencing something directly from the global scope, so this change makes it so that side-effect-free global instructions are treated just like literal constants. This simple handling is fine for now since it will only apply to `enum` tag values (true global constants declared with `static const` have different handling).
* First pass support for half on vk (#912)jsmall-nvidia2019-03-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Look at getting half to work on vk. * Alter half test so can always produce consistent test results. * First pass working half on vk. * Improve comments for vulkan extensions around half. * Upgraded vulkan headers to v1.1.103 https://github.com/KhronosGroup/Vulkan-Headers * * Add getFeatures on Render interface * Vulkan renderer determines at startup if it can support half * Parse render-features on render-test * Small changes to half-calc.slang test. * Structured buffer half access works as expected for Vk, but isn't for dx12, so disable for now. * Require the half feature for renderers for the half-structured-buffer.slang test. * * Added ToolReturnCode to be more rigerous about how a return code is passed back from a tool * Added support for a tool being able to pass back an 'ignored' result. * Used enum codes to indicate meanings * Made spawnAndWait return a ToolReturnCode * Ignore tests that don't have required render-feature * Fix macro line continuation usage. * Check dx12 has half support. * Checking for half on dx12 - if CheckFeatureSupport fails, don't fail renderer initialization. * Fix typo.
* Hotfix/bool fix (#907)jsmall-nvidia2019-03-14
| | | | | | | | * * Handle ! for bool vector in glsl * Handle operators that have a boolean return value * || or && take bool * * Add comment in bool-op.slang test about doing || or && on vector types not supported for GLSL targets
* Add support for vector/scalar compares for GLSL (#903)jsmall-nvidia2019-03-13
| | | | | | | | | | | * * leftSide and rightSide set op to nullptr, before was just uninitialized * Added support for GLSL for vector/scalar comparisons * Added test * * Remove unneeded precedence code. * Simplify function to _maybeEmitGLSLCast * * Take into account precedence & closing of brackets in same way as function call, if function call used for vector comparison (as on GLSL)
* On GLSL targets emit 3 component texture layouts as 4 component (#904)jsmall-nvidia2019-03-13
| | | | | | * * On GLSL targets, output texture layouts that are 3 component as 4 component, because 4 component style is not supported by glslang currently * * Improve comment around SPIR-V and 3 component layouts.
* Fix GLSL emit logic for select exprYong He2019-03-10
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* Improve support for interfaces as shader parameters (#886)Tim Foley2019-03-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Improve support for interfaces as shader parameters This change adds two main things over the existing support: 1. It is now possible to plug in concrete types that actually contain (uniform/ordinary) fields for the existential type parameters introduced by interface-type shader parameters. The `interface-shader-param2.slang` test shows that this works. 2. There is a limited amount of support for doing correct layout computation and generating output code that matches that layout, so that interface and ordinary-type fields can be interleaved to a limited extent. The `interface-shader-param3.slang` test confirms this behavior. There are several moving pieces in the change. * When it comes to terminology, we try to draw a more clear distinction between existial type parameters/arguments and existential/object value parametes/arguments. A simple way to look at it is that an `IFoo[3]` shader parameter introduces a single existential type parameter (so that a concrete type argument like `SomeThing` can be plugged in for the `IFoo`) but introduces three existential object/value parameters (to represent the concrete values for the array elements). * At the IR level, we support a few new operations. A `BindExistentialsType` can take a type that is not itself an interface/existential type but which depends on interfaces/existentials (e.g., `ConstantBuffer<IFoo>`) and plug in the concrete types to be used for its existential type slots. * Then a `wrapExistentials` instruction can take a type with all the existentials plugged in (possibly by `BindExistentialsType`) and wrap it into a value of the existential-using type (e.g., turn `ConstantBuffer<SomeThing>` into a `ConstantBuffer<IFoo>`). * The IR passes for doing generic/existential specialization have been updated to be able to desugar uses of these new operations just enough so that a `ConstantBuffer<IFoo>` can be used. * When we specialize an IR parameter of an interface type like `IFoo` based on a concrete type `SomeThing`, we turn the parameter into an `ExistentialBox<SomeThing>` to reflect the fact that we are conceptually referring to `SomeThing` indirectly (it shouldn't be factored into the layout of its surrounding type). * Parameter binding was updated so that it passes along the bound existential type arguments in a `Program` or `EntryPoint` to type layout, so that we can take them into account. The type layout code needs to do a little work to pass the appropriate range of arguments along to sub-fields when computing layout for aggregate types. * Type layout was updated to have a notion of "pending" items, which represent the concrete types of data that are logically being referenced by existential value slots. The basic idea is that these values aren't included in the layout of a type by default, but then they get "flushed" to come after all the non-existential-related data in a constant buffer, parameter block, etc. * The logic for computing a parameter group (`ConstantBuffer` or `ParameterBlock`) layout was updated to always "flush" the pending items on the element type of the group, so that the resource usage of specialized existential slots would be taken into account. * The type legalization pass has been adapted so that we can derive two different passes from it. One does resource-type legalization (which is all that the original pass did). The new pass uses the same basic machinery to legalize `ExistentialBox<T>` types by moving them out of their containing type(s), and then turning them into ordinary variables/parameters of type `T`. Big things missing from this change include: - Nothing is making sure that "pending" items at the global or entry-point level will get proper registers/bindings allocated to them. For the uniform case, all that matters in the current compiler is that we declare them in the right order in the output HLSL/GLSL, but for resources to be supported we will need to compute this layout information and start associating it with the existential/interface-type fields. - Nothing is being done to support `BindExistentials<S, ...>` where `S` is a `struct` type that might have existential-type fields (or nested fields...). Eventually we need to desugar a type like this into a fresh `struct` type that has the same field keys as `S`, but with fields replaced by suitable `BindExistentials` as needed. (The hard part of this would seem to be computing which slots go to which fields). As a practial matter, this missing feature means that interface-type members of `cbuffer` declarations won't work. The current tests carefully avoid both of these problems. They don't declare any buffer/texture fields in the concrete types, and they don't make use of `cbuffer` declarations or `ConstantBuffer`s over structure types with interface-type fields. * fixup: add override to methods * fixup: typos
* Hotfix/fix stdlib error reporting (#866)jsmall-nvidia2019-02-27
| | | | | | | | | | | | | | | | * * Add 'identity' version of bit casts (asint, asuint, asfloat) for scalar and vector * Added identity bit casts for matrix (cos no op). We don't support matrix asint on glsl targets * Added tests in bit-cast.slang * Use kIRPseudoOp_Pos for identity asuint/asint/asfloat casts. * * Stop crash if error in stdlib * Use the buildin source manager when compiling stdlib - fixes that line numbers are displayed * Typo fix * Output line directives for 'meta' slang souce files into stdlib * Improve comments and function names.
* First steps toward supporting interface-type parameters on shaders (#852)Tim Foley2019-02-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * First steps toward supporting interface-type parameters on shaders What's New ---------- From the perspective of a user, the main thing this change adds is the ability to declare top-level shader parameters (either at global scope, or in an entry-point parameter list) with interface types. For example, the following becomes possible: ```hlsl // Define an interface to modify values interface IModifier { float4 modify(float4 val); } // Define some concrete implementations struct Doubler : IModifier { float4 modify(float4 val) { return val + val; } } struct Squarer : IModifier { ... } // Define a global shader parameter of interface type IModifier gGlobalModifier; // Define an entry point with an interface-type `uniform` parameter void myShader( unifrom IModifier entryPointModifier, float4 inColor : COLOR, out float4 outColor : SV_Target) { // Use the interface-type parameters to compute things float4 color = inColor; color = gGlobalModifier.modify(color); color = entryPointModifier.modify(color); outColor = color; } ``` The user can specialize that shader by specifying the concrete types to use for global and entry-point parameters of interface types (e.g., plugging in `Doubler` for `gGlobalModifier` and `Squarer` for `entryPointModifier`). The "plugging in" process is done in terms of a concept of both global and local "existential slots" which are a new `LayoutResourceKind` that represents the holes where concrete types need to be plugged in for existential/interface types. In simple cases like the above, each interface-type parameter will yield a single existential slot in either the global or entry-point parameter layout. Users can query the start slot and number of slots for each shader parameter, just like they would for any other resource that a parameter can consume. Before generating specialized code, the user plugs in the name of the concrete type they would like to use for each slot using `spSetTypeNameForGlobalExistentialSlot` and/or `spSetTypeNameForEntryPointExistentialSlot`. There are some major limitations to the implementation in this first change: * Parameters must be of interface type (e.g., `IFoo`) and not an array (`IFoo[3]`), or buffer (`ConstantBuffer<IFoo>`) over an interface type. Similarly, `struct` types with interface-type fields still don't work. * The work on interface-type function parameters still doesn't include support for `out` or `inout` parameters, nor for functions that return interface types (that isn't technically related to this change, but affects its usefullness). * No work is being done to correctly lay out shader parameters once the concrete types for existential slots are known, so that this change really only works when the concrete type that gets plugged in is empty. These limitations are severe enough that this feature isn't really usable as implemented in this change, and this merely represents a stepping stone toward a more complete implementation. Implementation -------------- The API side of thing largely mirrors what was already done to support passing strings for the type names to use for global/entry-point generic arguments, so there should be no major surprises there. The logic in `check.cpp` computes the list of existential slots when creating unspecialized `Program`s and `EntryPoint`s (this is logically the "front end" of the compiler), and then checks the supplied argument types against what is expected in each slot when creating specialized `Program`s and `EntryPoint`s. This again mirrors how generic arguments are handled. Type layout was extended to compute the number of existential slots that a type consumes, and will thus automatically assign ranges of slots to top-level and entry-point shader parameters in the same way it already allocates `register`s and `binding`s. The big missing feature is the ability to specialize a layout to account for the concrete types plugged into the existential-type slots. IR generation for specialized programs and entry points was slightly extended so that it attaches information about the concrete types plugged into the existential slots, and the witness tables that show how they conform to the interface for that slot. The linking step needed some small tweaks to make sure that information gets copied over to the target-specific program when we start code generation. The meat of the IR-level work is in `ir-bind-existentials.cpp`, which takes the information that was placed in the IR module by the generation/linking steps and uses it to rewrite shader parameters. For example, if there is a shader parameter `p` of type `IModifier`, and the corresponding existential slot has the type `Doubler` in it, we will rewrite the parameter to have type `Doubler`, and rewrite any uses of `p` to instead use `makeExistential(p, /*witness that Doubler conforms to IModifier*/)`. Once the replacement is done on the parameters, the existing work for specializing existential-based code when the input type(s) are known kicks in and does the rest. Testing ------- A single compute test is added to validate that this feature works. It is narrowly tailored to not require any of the features not supported by the initial implementation (e.g., all of the concrete types used have no members). The test case *does* include use of an associated type through one of these existential-type parameters, which has exposed a subtle bug in how "opening" of existential values is implemented in the front-end. Rather than fix the underlying problem, I cleaned up the code in the front-end to special case when the existential value being opened is a variable bound with `let`, to directly use a reference to that variable rather than introduce a temporary. Similarly, in the IR generation step, I added an optimization to make variables declared with `let` skip introducing an IR-level variable and just use the SSA value of their initializer directly instead. * fixup: missing files * fixup: incorrect type for unreachable return * fixup: actually comment ir-bind-existentials.cpp
* Split front- and back-ends (#846)Tim Foley2019-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Split front- and back-ends This change is a major refactor of several of the types that provide the behind-the-scenes implementation of the public C API. The goal of this refactor is primarily to allow for future API services that let the user operate both the front- and back-ends of the compiler in a more complex fashion. For example, as user should be able to compile a bunch of source code into modules, look up types, functions, etc. in those modules, specialize generic types/functions to the types they've looked up, and then finally request target code to be gernerated for specialized entry points. The back-end code generation they trigger should re-use the front-end compilation work (parsing, semantic checking, IR generation) that was already performed. The most visible change is that `CompileRequest` has been split up into several smaller types that take responsibility for parts of what it did: * The `Linkage` type owns the storage for `import`ed modules, and well as the `TargetRequest`s that represent code-generation targets. The intention is that an application could use a single `Linkage` for the duration of its runtime (so long as it was okay with the memory usage), so that each `import`ed module only gets loaded once. For now, this type needs to manage the search paths, file system, and source manager, because of its responsibility for loading files. * A `FrontEndCompileRequest` owns the stuff related to parsing, semantic checking, and initial IR generation. This most notably includes the `TranslationUnitRequest`s and the `FrontEndEntryPointRequest`s (which used to be just `EntryPointRequest`s). It's main job is to produce AST and IR modules for each translation unit, and to find and validate the entry points. The front-end request does *not* interact with generic arguments for global or entry-point generic parameters. * The main output of both `import` operations and front-end translation units is the `Module` type, which is just a simple container for both the AST module (to service the reflection/layout APIs, and also for semantic checking of code that `import`s the module) and the IR module (for linking and code generation). This type captures the commonalities between the old `LoadedModule` (which is now just an alias for `Module`) and `TranslationUnitRequest` (which now owns a `Module`). * The secondary output of front-end compilation is a `Program`, which comprises a list of referenced `Module`s and validated `EntryPoint`s that will be used together. Layout and code generation both need a `Program` to tell them what modules and entry points will be used together (we don't want to just code-gen everythin that has ever been loaded into the linakge). The `Program`s created by the front-end do not include generic arguments, so they may provide incomplete layout information and/or be unsuitable for code generation. * A `BackEndCompileRequest` owns stuff related to turning a `Program` into output kernels for the targets of a `Linkage`. Most of the data it owns beyond the `Program` to be compiled is minor, so this is a good candidate for demotion from a heap-allocated object to just a `struct` of options that gets passed around. * The `CompileRequestBase` type is an attempt to wrap up the common functionality of both front-end and back-end compile requests. Most of it is just exposing the availability of a linkage and `DiagnosticSink`, so this type is a good candidate for subsequent removal. The main interesting thing it has is the flags related to dumping and validation of IR, so there is probably a good refactoring still to be made around deciding how options should be handled going forward. * Behind the scenes, the `Program` type is set up to handle some level of on-line compilation and layout work. The `Program` knows the `Linkage` it belongs to, and allows for a `TargetProgram` to be looked up based on a specific `TargetRequest`. A `TargetProgram` then allows layout information and compiled kernel code to be asked for on-demand, in order to support eventual "live" compilation scenarios. * The `EndToEndCompileRequest` type is a composition/coordination type that replaces the old `CompileRequest` in a way that uses the services of the various other types. It owns a few pieces of state that only make sense in the context of an end-to-end compile (e.g., there is really no way to "pass through" code when the front- and back-ends are run separately) or a command-line compile (everything to do with specifying output paths for files is really just for the benefit of `slangc`, and might even be moved there over time). * One important detail is that the `EndToEndCompilRequest` owns all of the string-based generic arguments for both global and entry-point generic parameters. The logic in `check.cpp` for dealing with those arguments has been heavily refactored to separate out the parsings steps that are specific to end-to-end compilation with string-based type arguments, and the semantic checking steps that result in a specialized `Program` (which can be exposed through new APIs that aren't tied to end-to-end compilation). It is perhaps not surprising that this change had a lot of consequences, so I'll briefly run over some of the main categories of changes required: * I changed the way that global generic arguments are passed via API (use `spSetGlobalGenericArgs` instead of the generic arguments for `spAddEntryPointEx`, which are not just for entry-point generics), which has been a change that we've needed for a long time. This is technically a breaking API change, although we should have very few client applications that care about it. * A bunch of places that used to take "big" objects like `CompileRequest` now just take the sub-pieces they care about (e.g., a function might have only needed a `Linkage` and a `DiagnosticSink`). This makes many subroutines or "context" struct types more generally useful, at the cost of taking more parameters. * In a few cases the conceptually clean separation of the layers breaks down (often for edge-case or compatibility features), and so we may pass along additional objects that are allowed to be null, but are used when present. A big example of this is how the back-end code generation routines accept an `EndToEndCompileRequest` that is optional, and only used to check whether "pass through" compilation is needed. We should probably look into cleaning this kind of logic up over time so that we don't need to violate the apparent separation of phases of compilation. * In cases where separation of layers was being broken for the sake of GLSL features, I went ahead and ripped them out, since all of that should be dead code anyway. * In many cases I increased the encapsulation of data in the core types to help track down use sites and make sure they are following invariants better. * In cases where code was doing, e.g., `context->shared->compileRequest->session->getThing()` I have tried to introduce convenience routines so that the usage site is just `context->getThing()` to improve encapsulation and allow changes to be made more easily going forward. * The `noteInternalErrorLoc` functionality was moved off of the compile request and into `DiagnosticSink`, since that is the one type you can rely on having around when you want to note an internal error. We may consider going forward if (and how) it should reset the counter used for noting locations on internal errors. * A few APIs now take `DiagnosticSink*` arguments where they didn't before, and as a result some public APIs need to create `DiagnosticSink`s to pass in, before going ahead and ignoring the messages. In the future there should be variations of these APIs that accept an `ISlangBlob**` parameter for the output. * fixup: missing include for compilers with accurate template checking (non-VS) * fixup: review feedback
* Output readonly for suitable glsl buffers (#845)jsmall-nvidia2019-02-13
| | | | | | | | | | * Output readonly on buffers for glsl if resource is readonly. Didn't add to emitGLSLParameterGroup because the cases there seem to to either be implicitly read only, or allow write. * * Improve comments around use of 'readonly' on glsl output * Use readonly with shaderRecord * Add comment pointing out shader record can be rw on vk, so might require changes in the future.
* Fix typos in diagnostic message and comments (#843)jsmall-nvidia2019-02-13
| | | | | | | * * Fix some comment typos * Fix typo in diagnostic message * Fix typo in expected output of undefined-in-preprocessor-conditional
* Fix vector compares on GLSL targets (#833)jsmall-nvidia2019-02-08
| | | | | | | | | | * * Make vector comparisons out correct functions on glsl * Test for vector comparisons * Typo fixes * Glsl vector comparisons use functions. * Added a coercion test.
* Allow entry points to have explicit generic parameters (#826)Tim Foley2019-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Allow entry points to have explicit generic parameters Prior to this change, the Slang implementation required users to use global `type_param` declarations in order to specialize a full shader. For example: ```hlsl type_param L : ILight; ParameterBlock<L> gLight; [shader("fragment")] float4 fs(...) { ... gLight.doSomething() ... } ``` With this change we can rewrite code like the above using explicit generics, plus the ability to have `uniform` entry-point parameters: ```hlsl [shader("fragment")] float4 fs<L : ILight>( uniform ParameterBlock<L> light, ...) { ... light.doSomething() ... } ``` Having this support in place should make it possible for us to eliminate global generic type parameters and the complications they cause (both at a conceptual and implementation level). The most central and visible piece of the change is that `EntryPointRequest` now holds a `DeclRef<FuncDecl>` instead of just ` RefPtr<FuncDecl>`, which allows it to refer to a specialization of a generic function. Various places in the code that refer to the `EntryPointRequest::decl` member now use a `getFuncDecl()` or `getFuncDeclRef()` method as appropriate (see `compiler.h`). In order to fill in the new data, the `findAndValidateEntryPoint` function has been greaterly overhauled. The changes to its operation include: * The by-name lookup step for the entry point function has been adapted to accept either a function or a generic function. * The generic argument strings provided by API or command line are no longer parsed all the way to `Type`s, but instead just to `Expr`s in the first pass. * There are now two cases for checking the global generic arguments against their matching parameters. The first case is the new one, where we plug the generic argument `Expr`s into the explicit generic parameters of an entry point (that case re-uses existing semantic checking logic). The second case is the pre-existing code for dealing with global generic type arguments. The `lower-to-ir.cpp` logic for hadling entry points then had to be extended. Making it deal with a full `DeclRef` instead of just a `Decl` was the easy part (just call `emitDeclRef` instead of `ensureDecl`). The more interesting bits were: * We need to carefully add the `IREntryPointDecoration` to the nested function and not the generic in the case where we have a generic entry point. There is a handy `getResolvedInstForDecorations` that can extract the return value for an IR generic so that we can decorate the right hting. * We need to make sure that in the case where we emit a `specialize` instruction (which normally wouldn't get a linkage decoration), we attach an `[export(...)]` decoration to it with the mangled name of the decl-ref, so that it can be found during the linking step. The IR linking step is then slightly more complicated because the mangled entry point name could either refer directly to an `IRFunc` or to a `specialize` instruction for a generic entry point. The logic was refactored to first clone the entry point symbol without concern for which case it is (the old code was specific to functions), and then *if* the result is a `specialize` instruction, we attempt to run generic specialization on-demand. That on-demand specialization is a bit of a kludge, but it deals with the fact that all the downstream passing only expect to see an `IRFunc`. A future cleanup might try to split out that specialization step into its own pass, which ends up being a limited form of the specialization pass. Since I was already having to touch a lot of the code around IR linking, I went ahead and refactored the signature of the operations. I eliminated the need for the caller to create, pass in, and then destroy an `IRSpecializationState` (really an IR *linking* state), and replaced it with a structure local to the pass (that data structure was a remnant of an older approach in the compiler), and then also renamed the main operation to `linkIR` to reflect what it is doing in our conceptual flow. Smaller changes made along the way include: * Refactored `visitGenericAppExpr` to create a subroutine `checkGenericAppWithCheckedArgs` so that it can be used by the entry-point validation logic described above). * Refactored the declarations around the IR passes in `emitEntryPoint()` (`emit.cpp`), to show that things are more self-contained than they used to be (e.g., that the `TypeLegalizationContext` is now only needed by one pass). * Refactored the generic specialization code so that there is a stand-along free function that can perform specialization on a `specialize` instruction without all the other context being required. This is only to support the limited specialization that needs to be done as part of linking. * Updated the `global-type-param.slang` test to actually test entry-point generic parameters. In a later pass we can/should rework all the tests/examples for global type parameters over to use explicit entry-point generic parameters (at which point we should rename the tests as well). For now I am leaving thigns with just one test case, with the expectation that bugs will be found and ironed out as we expand to more tests. * fixup * Fixup: don't leave entry-point decorations on stuff we don't want to keep The IR `[entryPoint]` decoration is effectively a "keep this alive" decoration, which means that attaching it to something we don't intend to keep around can lead to Bad Things. The approach to generic entry points was attaching `[entryPoint]` to the underlying `IRFunc` because that seemed to make sense, but that meant that the `specialize` instruction at global scope scould instantiate that generic and then keep it alive, even if the resulting function wouldn't be valid according to the language rules. As a quick fix, I'm attaching `[entryPoint]` to the `specialize` instruction instead in such cases, and then re-attaching it to the result of explicit specialization during linking. * Port most of remaining test and rename global type parameters This change ports as many as possible of the existing tests for global type parameters over to use entry-point generic parameters instead. For the most part this is a mechanical change. A few test cases remain using global generic parameters, as does the `model-viewer` example application. The reason for this is that the shaders have either or both the following features: * A vertex and fragment shader that can/shold agree on their parameters * A type declaration (e.g., a `struct`) that is dependent on one of the generic type parameters In these cases, it would really only make sense to switch to explicit parameters once we support shader entry points nested inside of a `struct` type, so that we can use an outer generic `struct` as a mechanism to scope the entry points and other type-dependent declrations. Since global-scope type parameters need to persist for at least a bit longer, I went ahead and renamed all the use sites over to use `type_param` for consistency.
* Feature/casting tidyup (#822)jsmall-nvidia2019-02-04
| | | | | | | | | | * Use 'is' over 'as' where appropriate. * dynamic_cast -> dynamicCast * Replace 'dynamicCast' with 'as' where has no change in behavior/ambiguity. * Replace dynamicCast with as where doesn't change behavior/non ambiguous.
* Feature/as refactor review (#821)jsmall-nvidia2019-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Replace dynamicCast with as where does not change behavior (ie not Type derived). Use free function where scoping is clear. * Replace uses of dynamicCast with as when there is no difference in behavior. * Remove the IsXXXX methods from Type. * Don't have separate smart pointer to store canonicalType on Type. * Simplify Slang.FilteredMemberRefList.Adjust, such does the cast directly. * Use free as where appropriate. * Use free function version of casts where appropriate. * Fix text in casting.md * Fix typos in decl-refs.md * Remove the uses of free function as on RefDecl. Add 'canAs' to RefDecl as a way to test if a cast is possible. Moved 'as' into RefDeclBase. * Use 'is' to test for as cast on smart pointers. Fix small scope issue. * * Cache stringType and enumTypeType on the Session * Make DeclRefType::Create return a RefPtr * Make casting of result use the *method* .as (cos using free function would mean objects being wrongly destroyed) * Make results from createInstance ref'd to avoid possible leaks. * Fix typo in template parameter for is on RefPtr.
* Initial support for uniform parameters on entry points (#815)Tim Foley2019-01-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Initial support for uniform parameters on entry points The basic feature this work adds is the ability to define a shader entry point like: ```hlsl [shader("fragment")] float4 main( uniform Texture2D t, uniform SamplerState s, float2 uv : UV) { return t.Sample(s,uv); } ``` In this example, the `uniform` keyword is used to mark that the given entry point parameters are *not* varying input/output flowing through the pipeline, but rather uniform shader parameters that should function as if the shader was declared more like: ```hlsl Texture2D t, SamplerState s, [shader("fragment")] float4 main( float2 uv : UV) { return t.Sample(s,uv); } ``` Allowing `uniform` parameters on entry points makes it easier to define multiple entry points in one file without accidentally polluting the global scope with shader parameters that only certain entry points care about. This feature is also more or less a prerequisite for allowing generic type parameters directly on entry point functions, since the main use case for those type parameters is for determining what goes in various `ConstantBuffer`s or `ParameterBlock`s. There are two main pieces to the implementation. First, we need to be able to compute appropriate layout information for entry points that include `uniform` parameters. Second, we need to transform the entry point function to move any `uniform` parameters to be ordinary global-scope shader parameters, to make sure that all other back-end passes don't need to worry about this special case. The latter piece of the implementation is, relatively speaking, simpler. The pass in `ir-entry-point-uniforms.{h,cpp}` converts entry point parameters that are determined to be uniform (using the already-computed layout information) into fields of a `struct` type and then declares a global shader parameter based on that `struct` type (and applies already-computed layout information to that parameter). After that, the remaining IR passes (notably including type legalization) will handle things just as for any other global shader parameter. The changes to the layout step are more significant, but most of the changes are just cleanups and fixes to enable the feature. The two major changes that enable entry-point `uniform` parameters are: * In `collectEntryPointParameters` we now dispatch out to a new `computeEntryPointParameterTypeLayout` function, which decided whether to compute the type layout for a `uniform` parameter, or for a varying parameter (what used to be the default behavior handled by `processEntryPointParameterDecl`). * The main `generateParameterBindings` routine was extended so that it allocates registers/bindings to the resources required by each entry point (using `completeBindingsForParameter`) after it has allocated registers/binding to all of the global-scope parameters (this addition is mirrored in `specializeProgramLayout`). The effect of these changes is that the `uniform` parameters of any entry points specified in a compile request will be laid out after the global-scope parameters, in the order the entry points were specified in the compile request. A bunch of smaller changes were made around parameter layout that are worth enumerating so that the diffs make some sense: * The `EntryPointLayout` type was changed so that instead of trying to *be* a `StructTypeLayout`, it instead *owns* one, in the same fashion as `ProgramLayout`. This commonality was factored into a base class `ScopeLayout`, and a bunch of edits followed from that change. * Because `uniform` parameters are moved out of the entry point parameter list early in the IR transformations, the logic in `ir-glsl-legalize.cpp` that tried to look up parameter layout information by index would no longer work if the entry point parameter list had been altered. Instead, that logic now looks for the decorations directly on the parameters. * The `UsedRange` type in `parameter-binding.cpp` was tracking the existing parameter associated with a range using a `ParameterInfo*` (which accounts for the possibility of multiple `VarDecl`s mapping to the same logical shader parameter), when just using a `VarLayout*` is sufficient for all current use cases. The overhead of allocating a `ParameterInfo` seems like overkill for entry-point parameters, where there can't possibly be multiple declarations of the "same" parameter, so avoiding these overheads was a focus when trying to deduplicate code between the global and entry-point parameter cases. * A bunch of parameter binding logic that was specific to GLSL input has been deleted completely. There was no way to even execute this code in the compiler today, and there is pretty much zero chance of us needing (or wanting) to deal with GLSL input in the future. This includes custom `UsedRangeSet`s specific to each translation unit, which were only needed for global-scope `in` and `out` varying declarations in GLSL. * A bunch of functions with `EntryPointParameter` in their names were renamed to use `EntryPointVaryingParameter` to help distinguish that they only apply to the varying case, while entry point `uniform` parameters are handled elsewhere. * The `completeBindingsForParameter` function was re-worked into something that can be used for both global-scope shader parameters (where we have a `ParameterInfo` and possibly explicit bindings) and entry-point parameters (where we expect to have neither). This helps unify the (fairly subtle) logic for how we allocate and assign bindings for resources, constant buffers, parameter blocks, etc. * A small change was made so that the entry-point stage is attached directly to top-level parameters of the entry point, and *not* recursively to every field along the way. This could be a breaking change for some applications, but it makes more logical sense (to me); we'll have to check if this affects Falcor. This change produces different output for several of the reflection tests, but the changes are consistent with no longer attaching stage information to sub-fields of varying `struct`-type parameters. * Because there is a bunch of repeated logic in `parameter-binding.cpp` that has to do with computing a `struct` layout for ordinary/uniform data, I tried to factor that into a single `ScopeLayoutBuilder` type, which handles computing the offsets for any parameters with ordinary data, and then also handles wrapping up the layout in a constant buffer layout if there was any ordinary data at the end. * A similar convenience routine `maybeAllocateConstantBufferBinding` was added because I noticed multiple places in `parameter-binding.cpp` that were trying to allocate a constant buffer binding for global uniforms, and they were wildly inconsistent (and in most cases used logic that would only work for D3D). * The main `generateParameterBindings` routine is significantly shortened by using all of these utilities that were introduced. I tried to comment the places that changed to explain the overall flow correctly. * The `specializeProgramLayout` routine (used to take a `ProgramLayout` from `generateParameterBindings` and specialize it based on knowledge of global generic arguments) had basically been rewritten with more explicit commenting/rationale for what happens in each step. It makes use of the same shared utilities as `generateParameterBindings` and `collectEntryPointParameters`. In terms of testing: * I added a test case to specifically test the new behavior, and in particular I made sure to include a mix of both global and entry-point parameters and also to have entry-point parameters of both ordinary and resource/object types. * I tweaked an existing test for global type parameters to use an entry-point `uniform` parameter instead of a global one, in an effort to migrate it toward being able to use an explicitly generic entry point. * fixups from merge
* Feature/as refactor (#817)jsmall-nvidia2019-01-31
| | | | | | | | | | | | | | | | | | | | | | | | * Made dynamicCast a free function. * Replace As with as or dynamicCast depending on if it is a type. * Fix problem with using non smart pointer cast. * Removed legacy asXXXX methods. * Remove As from Type. * Removed As from Qual type -> made coercable into Type*, such that can just use free 'as'. * Remove left over QualType::As() impl. * Remove As from SyntaxNodeBase. * Made as for instructions implemented by dynamicCast. * Replace As on DeclRef. Use the global as<> to do the cast. * Add const safe versions of dynamicCast and as for IRInst
* Support function parameters of existential (interface) type (#802)Tim Foley2019-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Support function parameters of existential (interface) type The basic idea here is that you can define a function that takes an interface-type parameter: ```hlsl interface IThing { void doSOmething(); } void coolFunction(IThing thing) { ... thing.doSomething() ... } ``` and call it with a concrete value that implements the given interface: ```hlsl struct Stuff : IThing { void doSomething() { /* secret sauce */ } } ... Stuff stuff; coolFunction(stuff); ``` The compiler implementation will specialize `coolFunction` based on the concrete type that was actually passed in, resulting in output code along the lines of: ```hlsl struct Stuff { ... } void Stuff_doSomething(Stuff this) { /* secret sauce */ } void coolFunction_Stuff(Stuff thing) { ... Stuff_doSomething(thing); } ``` In terms of implementation the new specialization approach has been integrated into the existing pass for generic specialization (which has been refactored significantly along the way), because generic specialization can open up opportunities for existential/interface simplification and vice versa, so there is no fixed interleaving of the two passes that can clean up everything. The new logic therefore subsumes the old code for simplifying existential types (which only worked on local variables) in `ir-existential.{h,cpp}`. The local simplification rules from that implementation have become part of the core specialization pass instead, so that they can open up further transformation opportunities enabled by existential-type simplifications. This code in place right now only handles the basic case of a function parameter that directly uses an interface type, and not one that wraps up an interface type in an array, structure, etc. Additional simplifications need to be introduced to deal with those cases as well. * fixup: typos
* Merge branch 'master' into yong-fixYong He2019-01-28
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| * Feature/bit cast glsl (#808)jsmall-nvidia2019-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * First attempt at asint, asuint, asfloat intrinsics. * Test with countbits * Placing glsl definitions first makes them get picked up. * Some more improvements around asint. * Add support for vector versions of asint/asunit * Fix some typos in asuint/asint intrinsics for glsl. Simplified and increased coverage of as/u/int tests. * Added bit-cast-double test. Added notional support for asdouble bit casts to glsl - but couldn't test because glslang doesn't seem to support the extension. * Try to get double bit casts working - doesn't work cos of block issue. * Only output parents on intrinic replacement if return type is not void.
* | fix up empty-struct-parametersYong He2019-01-25
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* | Move glsl entry point legalization to later stage of compilation.Yong He2019-01-25
|/ | | | This allows generic types to be used in entry point parameters.
* Fixing GLSL sign function.Yong He2019-01-23
| | | | fixes #602
* Initial support for dynamic dispatch using "tagged union" types (#772)Tim Foley2019-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Initial support for dynamic dispatch using "tagged union" types Suppose a user declares some generic shader code, like the following: ```hlsl interface IFrobnicator { ... } type_param T : IFrobincator; ParameterBlock<T : IFrobnicator> gFrobnicator; ... gFrobincator.frobnicate(value); ``` and then they have some concrete implementations of the required interface: ```hlsl struct A : IFrobnicator { ... } struct B : IFrobnicator { ... } ``` The current Slang compiler allows them to generate distinct compiled kernels for the case of `T=A` and the case of `T=B`. This means that the decision of which implementation to use must be made at or before the time when a shader gets bound in the application. This change adds a new ability where the Slang compiler can generate code to handle the case where `T` might be *either* `A` or `B`, and which case it is will be determined dynamically at runtime. This means a single compiled kernel can handle both cases, and the decision about which code path to run can be made any time before the shader executes. This new option is supported by defining a *tagged union* type. Via the API, the user specifies that `T` should be specialized to `__TaggedUnion(A,B)` (the double underscore indicates that this is an experimental and unsupported feature at present). We refer to the types `A` and `B` here as the "case" types of the tagged union. Conceptually, the compiler synthesizes a type something like: ```hlsl struct TU { union { A a; B b; } payload; uint tag; } ``` The user can then allocate a constant buffer to hold their tagged union type, and when they pick a concrete type to use (say `B`), they fill in the first `sizeof(B)` bytes of their buffer with data describing a `B` instance, and then set the `tag` field to the appopriate 0-based index of the case type they chose (in this case the `B` case gets the tag value `1`). Actually implementing tagged unions takes a few main steps: * Type parsing was extended to special-case `__TaggedUnion` as a contextual keyword. This is really only intended to be used when parsing types from the API or command-line, and Bad Things are likely to happen if a user ever puts it directly in their code. Eventually construction of tagged unions should be an API feature and not part of the language syntax. * Semantic checking was extended to recognize that a tagged union like `__TaggedUnion(A,B)` shoud support an interface like `IFrobnicator` whenever all of the case types suport it, as long as the interface is "safe" for use with tagged unions (which means it doesn't use a few of the advancd langauge features like associated types). * The IR was extended with instructions to represent tagged union types and to extract their tag and the payload for the different cases as needed. * IR generation was extended to synthesize implementations of interface methods for any interface that a tagged union needs to support. Right now the implementation is simplistic and only handles simple method requirements, which it does by emitting a `switch` instruction to pick between the different cases. * A new IR pass was introduced to "desugar" any tagged union types used in the code. The downstream HLSL and GLSL compilers don't support `union`s, so we have to instead emit a tagged union as a "bag of bits" and implement loading the data for particular cases from it manually. * Final code emit mostly Just Works after the above steps, but we had to introduce an explicit IR instruction for bit-casting to handle the output of the desugaring pass. There are a bunch of gaps and caveats in this implementation, but that seems reasonable for something that is an experimental feature. The various `TODO` comments and assertion failures in unimplemented cases are intended, so that this work can be checked in even if it isn't feature-complete. * fixup: missing files * fixup: typos
* Improve handling of {} initializer list expressions (#778)Tim Foley2019-01-16
| | | | | | | | | | | | | | | | | | Fixes #775 It was reported (in #775) that Slang doesn't handle initializer-list syntax when initializing matrix variables. When starting on a fix for that it became apparent that the time was right to fix two broad issues in the compiler's current handling of `{}`-enclosed initializer lists. The first issue was that the front-end checking of initializer lists wasn't handling the C-style behavior where an initializer list can either contain nested `{}`-enclosed lists for sub-arrays/-structures, or directly contain "leaf" values for initializing those aggregates. For example, the following two variable declarations ought to be equivalent: ```hlsl int4 a[] = { {1, 2, 3, 4}, {5, 6, 7, 8} }; int4 b[] = { 1, 2, 3, 4, 5, 6, 7, 8 }; ``` Getting this distinction right is important because we want to support initializing a matrix either from a list of vectors for its rows, or a list of scalars for its elements (in row-major order). The front-end semantic checking logic for initializer lists was revamped so that it conceptually tries to "read" an expression of a desired type from the initializer list, and decides at each step whether to consume a single expression by coercing it to the desired type, or to recursively read multiple sub-values to construct the type as an aggregate. The logic for deciding between direct vs aggregate initialization could potentially use some tweaking, but luckily it should always handle the case where users introduce explicit `{}`-enclosed sub-lists to make their intention clear, so that existing Slang code should continue to work as before. The second issue was that initializers without the expected number of elements weren't implemented in code generation, so they would lead to internal compiler errors. This change revamps the codegen logic for initializer lists so that it can synthesize default values for fields/elements that were left out during initialization. This includes an attempt to support default initialization of `struct` fields based on explicitly written initialization expressions.
* Refactor several IR passes (#761)Tim Foley2018-12-19
| | | | | | | | | | | | | | | | | | | | | | | | | * Refactor several IR passes This change takes some IR passes that lived together in `ir.cpp` and moves them into their own files to improve clarity. In most cases these were passes introduced early in the life of the IR, so that it didn't seem like a big deal to have them all in one file, but now that `ir.cpp` has grown unwieldly this seems like an important cleanup to make. To give a quick rundown of the passes involved: * The IR "linking" step has been pulled out to `ir-link.{h,cpp}`. This code for this pass is pretty much identical to what was in `ir.cpp`, and no attempt has been made to clean up or refactor it in the current change. * The GLSL legalization step has been pulled out to `ir-glsl-legalize.{h,cpp}`. This used to be invoked directly from the linking step, but has been made a new top-level pass invoked from `emit.cpp`. Just like with the linking, the code in the new file is just a copy-paste of what was in `ir.cpp`, and no attempt at cleanup has been made. Also note that it might be a good idea to move this pass later in the overall sequence, but this PR doesn't attempt to do that as it could change results. * The generic specialization step has been pulled out to `ir-specialize.{h,cpp}`. The file name does not explicitly reference *generic* specialization because I anticipate this pass having to perform other kinds of specialization as well. The code in this case amounts to a heavy cleanup/refactoring pass and thus deserves careful scrutiny. The reason for the cleanup is that the generic specialization step used to be part of the "linking" step long ago, and continued to share infrastructure with it long after that stopped making sense. The newly cleaned up pass has much simpler logic that should be easy enough to follow from the comments. * In order to reduce code dulication, the IR "cloning" part of the `ir-specialize-resources.{h,cpp}` pass was pulled into its own files (`ir-clone.{h,cpp}`) that both the generic specialization step and the resource-based specialization step now share. The remaining changes then pertain to deleting a bunch of code out of `ir.cpp` and adding the new files to the build. The only test that needed updating was `vkray/raygen`, where some subtle ordering change in the refactored generic specialization logic has lead to the relative order of the specialized `TraceRay` and `saturate` functions beind reversed. * fixup: typo in assert * fixup: typos in comments
* First step toward supporting use of interfaces as existential types (#716)Tim Foley2018-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * First step toward supporting use of interfaces as existential types Traditional generics involve universal quantification. E.g., a declaration like: ``` void drive<T : IVehicle>(T vehicle); ``` indicates for *for all* types `T` that implement the `IVehicle` interface, the `drive()` function is available. In contrast, whend directly using an interface type like: ``` IVehicle v = ...; v.doSomething(); ``` we only know that there *exists* some concrete type (we could call it `E`) such that `v` refers to a value of type `E`, and `E` implements the `IVehicle` interface. In order to perform an operation like `v.doSomething()` we need to "open" the existential value so that we can look at the concrete type and how it implements the `IVehicle.doSomething` requirement. This change adds a very explicit representation of existentials to Slang's IR. An operation like `e = makeExistential(v, w)` creates a value of some existential type (interfaces being our only existential types for now), by wrapping a concrete value `v` (the type of `v` can be seen as an implicit operand) and a witness table `w` showing that the type of `v` implements the requirements of the chosen interface type. In turn, opening of an existential is handled with operations `extractExistential{Value|Type|WitnessTable}` which pull the corresponding piece of information out of a value of existential type (which somewhere in the code had to have been created with `makeExistential`). The change includes a trivial simplification pass that can detect cases where an `extractExistential*` operation is applied direclty to a `makeExistential` operation, so that there is only one possible result that could be extracted. This allows for simplification of existential types used in trivial ways for local variables (this is mostly so I can check in a functional test, rather than to actually support useful code involving interfaces right now). The logic in the semantic checking phase of the compiler is comparatively more complex. When we are about to perform member lookup given an expression like `obj.member` we will first check if `obj` has an existential type, and if it does we will construct a suitable local context in which we extract the value, type, and witness table from the existential (these all become explicit AST expression nodes), and then use the extracted value as the base of the lookup operation. The nature of existential values is that two different values with the same existential (interface) type could wrap concrete values with differnt types, so that we need to carefully refer only to the extracted type/value/witness-table of specific *values*. We handle this right now by conceptually moving the existential-type value into a local variable (by introducing a `LetExpr` that amounts to `let v = <init> in <body>`) and then require that the extract expressions must refer to the (immutable) variable declaration from which they are extracting a value. (Eventually we should expand this so that when using an immutable local variable of existential type we just use that variable as-is rather than introduce a new temporary) A simple test case is included that uses an interface type in an almost trivial way for a local variable; this test can be run and produces the expected results. A more complex test case that passes an existential into a function is included, but left disabled because a more aggressive simplification approach is required to generate working code from it. * Add missing file for expected test output * Fixups for merge from top-of-tree
* Specialize away resource-type function parameters (#759)Tim Foley2018-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Specialize away resource-type function parameters Work on #397. Introduction ------------ Suppose a user writes a function that takes a resource type as a parameter: ```hlsl float4 getThing(RWStructuredBuffer<float4> buffer, int index) { return buffer[index]; } ``` This function creates challenges when generating code for GLSL-based targets, because a global shader parameter of type `RWStructuredBuffer`: ```hlsl RWStructuredBuffer<float4> gBuffer; ``` translates to a global GLSL `buffer` declaration: ```hlsl buffer _S0 { float4 _data[]; } gBuffer; ``` There is no equivalent to that `buffer` declaration that can be used in function parameter position, and it is illegal in GLSL to pass `gBuffer` into a function. (Aside: yes, we could in principle translate a function parameter like `RWStructuredBuffer<float4> buffer` to `float4 buffer[]`, but that will not in turn generalize to arrays of structured buffers; it is a dead-end strategy) The solution employed by many shader compilers is to "inline everything" to eliminate the need for parameters of resource types, and then rely on dataflow optimization to eliminate locals of resource types. This strategy can of course lead to an increase in code size, and it also means that call stacks are lost when doing step-through debugging. Another serious issue is that an "early `return`" from a function can turn into the equivalent of a multi-level `break` when inlined, and not all of our targets support multi-level `break`. The solution implemented in this change works around some, but not all, of the problems with full inlining. The approach here generates specialized versions of a function like `getThing`, adapted to the actual arguments provided at different call sites. Thus if we have code like: ```hlsl RWStructuredBuffer<float4> gA; RWStructuredBuffer<float4> gB[10]; ... getThing(gA, x); getThing(gA, y); getThing(gB[someVal], z); ``` we will generate two specializations of `getThing`: one specialized for the `buffer` parameter being `gA` and the other for `gB`: ```hlsl float4 getThing_gA(int index) { return gA[index]; } float4 getThing_gB(int _val, int index) { return gB[_val][index]; } ``` and the call sites will change to match: ```hlsl getThing_gA(x); getThing_gA(y); getThing_gB(someVal, z); ``` Note how in the case where the argument being passed in was obtained by indexing into an array of resources, the callee is specialized to the identity of the global shader parameter (`gB`), and now accepts a new parameter to indicate the array index into it. While this description motivates the change based on GLSL output, the same basic issue can arise for other targets. For example, while current HLSL has added the `ConstantBuffer<T>` type, it is not supported on older targets, and it turns out that even dxc does not allow functions to have `ConstantBuffer<T>` parameters. Longer-term, we will likely need to do even more aggressive specialization both in order to generate SPIR-V output directly, and also to deal with function that have return values or `out` parameters of resource types. Implementation -------------- The meat of the change is in `ir-specialize-resources.{h,cpp}`, where we have a pass that looks at all call sites (`IRCall` instructions) in the program, and attempts to replace them with calls to specialized functions, where the specializations are generated on-demand. The code in this pass is heavily commented, so hopefully it serves to explain itself all right. After specialization is complete, we may still have functions like the original `getThing` that will produce invalid code when emitted as GLSL, so we need a way to make sure they don't appear in the output. To date we've had some very ad hoc approaches for ignoring IR constructs that we don't want to affect emitted code, but this change goes ahead and adds a more real dead code elimination (DCE) pass in `ir-dce.{h,cpp}`. This pass follows a straightforward approach of tagging instructions that are "live" and then propagating liveness through the whole program, before making a single pass to delete anything that isn't live. When I first added the DCE pass it eliminated *everything* because there were no "roots" for liveness. I solved this for now by adding a new decoration, `IREntryPointDecoration`, to mark shader entry points in the IR which should always be live (as should anything they depend on). A secondary problem that arose was that for GLSL ray tracing shaders it is possible for the incoming/outgoing payload or attributes parameters to be unused, but eliminating them as dead would change the signature of a shader an potential break the rules for how ray tracing programs communicate. I added a very simple `IRDependsOnDecoration` that allows one IR instruction to keep another alive *as if* it used it, without actually using it. There's also a fixup in the IR dumping logic where I was forgetting to store anything in the mapping from instruction to their names, so that the name of an instruction was getting incremented each time it was referenced. Testing ------- There are three different tests added as part of this change: * The `compute/func-resource-param` test covers the basic `RWStructuredBuffer` case above, which we expect to work fine for D3D11/12, but fail for Vulkan without specialization. * The `cross-compile/func-resource-param-array` test covers the case where we don't just have one resource, but an array of them. This is not an end-to-end compute test primarily because our `render-test` application doesn't yet handle arrays of resources correctly in its binding logic. * The `compute/func-cbuffer-param` test covers the case of a function with a `ConstantBuffer<T>` parameter, which requires specialization to become valid for any of our targets. * fixup: warnings/errors from other compilers * fixup: typos and cleanup * fixup: typos
* Represent global shader parameters explicitly in the IR (#756)Tim Foley2018-12-14
| | | | | | | | | | | | | | | | | | Before this change, global shader parameters were represented in the IR as just being ordinary global variables. The only indication that a particular global represented a parameter was when it got a layotu attached to it (as part of back-end processing), and we've had a number of bugs related to layouts being dropped so that what should have been a shader parameter turned into an ordinary global variable in the output. This change is more strongly motivated by the fact that making shader parameters look like globals means that we cannot easily reason about their value when doing IR transformations. If we see two `load`s from the same global variable can we assume they yield the same value? In the general case we cannot, and this means that any transformation that wants to rely on the fact that an input `Texture2D` shader parameter can't actually change over the life of the program needs to do extra work. The fix here is to introduce a new kind of IR instruction that represents a global shader parameter directly (not a pointer to it as a global would), at which point there isn't even such a notion as a "load" from the parameter, since it represents the value directly. In several cases logic that used to apply to global variables in case they were shader parameters (by looking for a layout) is now moved to apply to these global parameters. The biggest source of issues in this change was that switching from pointers to plain values to represent these shader parameters stresses different cases in type legalization. I also had to deal with the case of legalization for GLSL where we actually *do* need global shader parameters that are writable (since varying output goes in the global scope), but in that case I borrowed the use of pointer-like `Out<...>` and `InOut<...>` types to represent that intent, which we were already using for function parameters representing outputs. A few tests started failing because the changes lead to a slightly different order of code emission, which in some HLSL tests resulted in a function parameter named `s` getting emitted before a global parameter named `s`, leading to the latter getting the name `s_1` instead of `s_0`. A few SPIR-V tests started failing because the new approach means that we no longer end up performing a load from all varying input parameters at the start of `main` and instead reference the varying inputs directly. The resulting code is more idomatic, but it differed from the baselines for those tests.
* Move mangled name out of IRGlobalValue (#752)Tim Foley2018-12-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Move mangled name out of IRGlobalValue Previously the `IRGlobalValue` type was used as a root for all IR instructions that can have "linkage," in the sense that a definition in one module can satisfy a use in another module. The mangled symbol name was stored in state directly on each `IRGlobalValue`, which created some complications, and also forced IR instructions that wanted to support linkage to wedge into the hierarchy at that specific point. This change moves the mangled name out into a decoration: either an `IRImportDecoration` or an `IRExportDecoration`, both of which inherit from `IRLinkageDecoration` which exposes the mangled name. This change has a few benefits: * We can now have any kind of instruction be exported/imported, without having to inherit from `IRGlobalValue`. This could potentially let `IRStructType` and `IRWitnessTable` be simplified to just have operand lists instead of dummy chldren as they do today. * We can now easily have "global values" like functions that explicitly *don't* get linkage, instead of using a null or empty mangled name as a marker. * We can use the exact opcode on a linkage decoration to distinguish imports from exports, which could be used to more accurately resolve symbols during the linking step. Other than adding the decorations and making sure that AST->IR lowering adds them, the main changes here are around any code that used `IRGlobalValue`. Variables and parameters of type `IRGlobalValue*` were changed to `IRInst*` easily, so the main challenge was around code that *casts* to `IRGlobalValue*. In cases where a cast to `IRGlobalValue` also performed a test for the mangled name being non-null/non-empty, we simply switched the code to check for the presence of an `IRLinkageDecoration`, since that is the new way of indicating a value with linakge. Most of the serious complications arose in `ir.cpp` around the "linking"/target-specialization and generic specialization steps. The "linking" logic was checking for `IRGlobalValue` to opt into some more complicated cloning logic, and just checking for a linkage decoration here wasn't sufficient since the front-end *does* produce global values without linkage in some cases (e.g., for a function-`static` variable we produce a global variable without linkage). This logic was updated to just check for the cases that used to amount to `IRGlobalValue`s directly by opcode. It might be simpler in the short term to have kept `IRGlobalValue` around to make the existing casts Just Work, but I'm confident that this logic could actually be rewritten for much greater clarity and simplicity and that is the better way forward. The generic specialization logic was using some really messy code to generate a new mangled name to represent the specialized symbol, and then searching for an existing match for that name. The original idea there was that an IR module could include "pre-specialized" versions of certain generics to speed up back-end compilation by eliminating the need to specialize in some cases, but this feature has never been implemented so the overhead here is just a waste. Instead, I moved generic specialization to use a simpler dictionary to map the operands to a `specialize` instruction over to the resulting specialized value. This allows for some simplifications in the name mangling logic, because it no longer needs to figure out how to produce mangled names from IR instructions representing types/values. As part of this change I also overhauled the IR emit logic to produce cleaner output by default, borrowing some of the ideas from the logic in `emit.cpp`. IR values are now automatically given names based on their "name hint" decoration, if any, to make the code easier to follow, and I also made it so that types and literals get collapsed into their use sites in a new "simplified" IR dump mode (which is currently the default, with no way to opt into the other mode without tweaking the code). The resulting IR dumps are much nicer to look at, but as a result the one test that involves IR dumping (`ir/string-literal`) doesn't really test what it used to. One weird issue that came up during testing is that the `transitive-interface` test had previously been producing output that made no sense (that is, the expected output file wasn't really sensible), and somehow these changes were altering its behavior. Changing the test to use `int` values instead of `float` was enough to make the output be what I'd expect, and hand inspection of generating DXBC has me convinced we were compiling the `float` case correctly too. There appears to be some issue around tests with floating-point outputs that we should investigate. * fixup: C++ declaration order
* Running tests in slang-test process (#740)jsmall-nvidia2018-12-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * First pass at having an interface to write text to that can be replaced. Simplifed and made more rigerous the interface used to write formatted strings. * Added AppContext to simplify setting up and parsing around of streams. * Added more simplified way to get the std error/out from AppContext. * Work in progress using dll for tools to speed up testing. * First pass at ISlangWriter interface. * Added support for writing VaArgs. Added NullWriter. * Use ISlangWriter for output. * Use ISlangWriter for output - replacing OutputCallback. Make IRDump go to ISlangWriter * SlangWriterTargetType -> SlangWriterChannel Improvements around AppContext * Shared library working with slang-reflection-test. * Dll testing working for render-test. * Include va_list definintion from header. * Fix errors from clang. * Fix typo for linux. * Added -usexes option * Fix typo. * Fix arguments problem on linux. * Fix typo for linux. * Add windows tool shared library projects. * Fix warning from x86 win build. Fix signed warning from slang-test/main.cpp * First attempt at getting premake to work on travis, and run tests. * Try moving build out into script. * Invoke bash scripts so they don't have to be executable. * Drive configuration/tests from env parameters set by travis * Try using source to run travis tests. * Remove the build.linux directory - but doing so will overwrite Makefile. * Made -fno-delete-null-pointer-checks gcc only. * Try to fix warning from -fno-delete-null-pointer-checks * Turn of warnings for unknown switches. * Try to make premake choose the correct tooling. * Disabled missing braces warning. * Disable -Wundefined-var-template on clang. * -Wunused-function disabled for clang. * Fix typo due to SlangBool. * Remove this nullptr tests. * "-Wno-unused-private-field" for clang. * Added "-Wno-undefined-bool-conversion" * Add DominatorList::end fix. * Split scripts into travis_build.sh travis_test.sh * Fix gcc/clang template pre-declaration issue around QualType. * Fix premake to build such that pthread correctly links with slang-glslang
* Decorations are instructions (#748)Tim Foley2018-12-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Make a test case use IR serialization * Make all IR instructions usable as parents This makes it so that every `IRInst` has the list of children that used to be on `IRParentInst` and eliminates `IRParentInst`. Most places in the code were only checking against `IRParentInst` so that they could know whether there were child instructions to iterate over. This change bloats the size of every instruction by two pointers, but we hope to be able to eliminate that overhead with a better encoding later. * Change IR decorations to be instructions. The main change here is that `IRDecoration` now inherits from `IRInst`, and `IRInst` now has a single linked list that holds both decorations *and* children. At each point where code used to loop over `getChildren()` on an `IRInst`, I checked whether it made sense to leave the operation as processing just the children, or if it should process both decorations and children. The thorniest bit was making sure the logic for inserting an instruction into a parent is correct. For the most part, once IR code is built all insertions are explicitly before/after another instruction, so the ordering can't get messed up. The sticking point is any code that does an explicit `insertAtStart` or `insertAtEnd`, but I surveyed those to make sure they are correct in context, and I also made all insertions bottleneck through one routine that does a better job of asserting the preconditions than what was there before. We may still want a "smart" insertion function at some point so that if somebody does `someDecoration->insertAtEnd(someInst)` the decoration intelligently goes to the end of the decoration list, and not the entire decorations-and-children list. All of the existing decoration types were refactored to provide accessors for their operands, rather than directly exposing fields. In most cases the operands are required to be `IRConstant` nodes of fixed types. Not all of these types need to be kept around in the new approach, but they were left in so that as much existing code as possible can be kept working. The `IRBuilder` was extended with factory functions to make the various decoration types and attach them. All the fields in concrete decorations that were using `StringRepresentation` or `Name` pointers are now using IR-level string operands which provide their value as an `UnownedStringSlice`, so logic that was working with those decoration values needed to be updated here and there. I also needed to add the logic to clone string-literal values to the IR cloning pass, since they are now being used in almost every piece of code. A new type of constant IR instruction for literal pointers was added, to handle the cases where an IR decoration needs an operand that is a raw AST-level pointer. These are even being serialized, although we obviously should not rely on them to round-trip through serialization in the future. Ideally, a follow-on change should add a cleanup pass where we remove any decorations from a module that shouldn't be allowed in the serialized code. The biggest overall cleanup is in the serialization logic, where a lot of code just disappears because it can process the raw "decorations and children" list as the logical children of an IR instruction. The only special cases left are literals (which seem like they will always need special-casing) and global values (because they have a mangled name, which we plan to move into a decoration). One other example of a simplification made possible by this change: the `IRNotePatchConstantFunc` instruction was implemented as an instruction only because it couldn't be encoded as a decoration at the time (it needed to have an operand that referenced an IR function). The IR dumping logic was also updated (which meant a change to the `ir/string-literal` test) to try to make it print out all decorations a bit more systematically now that they are encoded like other instructions. The formatting isn't quite perfect, but it is good enough to be able to read what is going on. I didn't include updates to the validation logic to ensure that decorations are being added in ways that follow the invariants, but that would be a nice thing to add next. * fixup: 64-bit issues * fixup: forward declaration issues
* Change how buffers are emitted (#741)Tim Foley2018-12-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Change how buffers are emitted This is a change with a lot of pieces, which can't always be separated out cleanly. I'm going to walk through them in what I hope is a logical order. The main goal of this change was to allow arrays of structured buffers to translate to Vulkan. Consider two declarations of structured buffers in HLSL/Slang: ```hlsl StructuredBuffer<X> single; StructuredBuffer<Y> multiple[10]; ``` The current translation logic was handling `single` by translating it into an *unnamed* GLSL `buffer` block like: ```glsl layout(std430) buffer _S1 { X single[]; }; ``` That syntax allows an expression like `single[i]` in Slang to be translated simply as `single[i]` in GLSL. But that naive translating doesn't work for `multiple`, since we need to declare a array of blocks in GLSL, which requires giving the whole thing a name: ```glsl layout(std430) buffer _S2 { Y _data[]; } multiple[10]; ``` Now a reference to `multiple[i][j]` in Slang needs to become `multiple[i]._data[j]` in GLSL. To avoid having way too many special cases around single structured buffers vs. arrays, it makes sense to allows emit things in the latter form, so that we instead lower `single` as: ```glsl layout(std430) buffer _S1 { X _data[]; } single; ``` So that now a reference to `single[i]` becomes `single._data[i]` in GLSL. Most of that can be handled in the standard library translation of the structured buffer indexing operations. The only wrinkle there is that there were some *old* special-case instructions in the IR intended to handle buffer load/store operations (these were added back when I was trying to keep the "VM" path working). These aren't really needed to have structured-buffer operations work; they can be handled as ordinary functions as far as the stdlib is concerned. I removed the old instructions. Along the way, it became clear that a few other cases follow the same pattern. Byte-addressed buffers are an obvious case. We were lowering HLSL/Slang: ```hlsl ByteAddressBuffer b; ... uint x = b.Load(0); ``` to GLSL like: ```glsl layout(std430) buffer _S1 { uint b[]; }; ... uint x = b[0]; ``` That logic would fail for arrays the same way that the structured buffer case was failing. The fix is the same: use named `buffer` blocks and then introduce an explicit `_data` field: ```glsl layout(std430) buffer _S1 { uint _data[]; } b; ... uint x = b._data[0]; ``` Just like with structured buffers, all of the VK translation for operations on byte-addressed buffers can be implemented directly in teh stdlib, so once the emit logic was changed it was just a matter of adding `._data` to a bunch of VK tranlsations. It turns out that arrays of constant buffers have more or less the same problem, and furthermore we have some problems with any code that directly uses the modern HLSL `ConstantBuffer<T>` type. Note: the emit logic around constant buffers sometimes refers to "parameter groups" because that is being used in the compiler as a catch-all term for constant buffers, texture buffers, and parameter blocks. The existing code was going out of its way to reproduce the way that constant buffer declarations are implicitly referenced in HLSL: ```hlsl cbuffer C { float f; } ... float tmp = f; // No reference to `C` here ``` This can be seen in the emit logic with the `isDerefBaseImplicit` function, which is used to take the internal IR representation for a reference to `f` (which is closer to the expression `(*C).f` or `C->f`) and leave off any reference to `C` so that we emit just `f`. That kind of logic just flat out doesn't work in some important cases. Arrays of constant buffers are a clear one: ```hlsl ConstantBuffer<X> cbArray[3]; ... X x = cbArray[0]; ``` There is no way to translate that to an ordinary `cbuffer` declaration at all. The same problem can be created without arrays, though: ```hlsl ConstantBuffer<X> singleCB; ... X x = singleCB; ``` The current strategy for translating constant buffers was translating `singleCB` into a `cbuffer` declaration that reproduced the fields of `X` as its members, which just wouldn't work: ```hlsl cbuffer singleCB { float f; // field of `X` } ... X x = singleCB; // ERROR: there is nothing named `singleCB` in this HLSL ``` The new strategy is more consistent. We still generate a `cbuffer` declaration for a single constant buffer, but we always give it a single field of the chosen element type: ```hlsl cbuffer singleCB { X singleCB; } ... X x = singleCB; // this works fine! ``` And in the array case we generate code that uses the explicit `ConstantBuffer<T>` type: ```hlsl ConstantBuffer<X> cbArray[3]; ... X x = cbArray[0]; ``` The GLSL output is more complicated because unlike with HLSL there is no implicit conversion from a uniform block to its element type (there is no notion of an element type). The array case thus needs a `_data` field similar to what we do for structured buffers: ```glsl layout(std140) uniform _S3 { X _data; } cbArray[3]; ... X x = cbArray[0]._data; ``` And then the non-array case needs to have a similar `_data` field for consistency: ```glsl layout(std140) uniform _S1 { X _data; } singleCB; ... X x = singleCB._data; ``` This is handled by inserting the necessary reference to `_data` whenever we dereference a constant buffer, either as part of a load instruction (loading from the whole CB as a pointer), or an `IRFieldAddress` instruction which forms a pointer into the CB (e.g., `&(singleCB->f)` becomes `singleCB._data.f`). The current emit logic handles `ParameterBlock<X>` differently from `ConstantBuffer<X>`, but really only to allow parameter blocks to be explicitly named in the output, while constant buffers were left implicit by default. Thus the only difference was a legacy one (from back when trying to exactly reproduce the HLSL text we got as input was considered an important goal), and the new approach to emitting constant buffers would get rid of it. I removed the separate logic for emitting `ParameterBlock<X>` and just let the handling for constant buffers deal with it. Note that any resource types inside of a `ParameterBlock<X>` would have been moved out as part of legalization, so that a parameter block is 100% equivalent to a constant buffer when it comes time to emit code. Unsurprisingly, changing the way we generate HLSL and GLSL output for all these buffer types meant that any tests that were directly comparing the output of `slangc` against `fxc`, `dxc`, or `glslang` broke. The basic approach to fixing the breakage in GLSL tests was to update the GLSL baseline to reflect the new output startegy. In some cases I used macros to name the various `_S<digits>` temporaries so that future renaming will hopefully be easier (it would be great if we auto-generated temporary names with a bit more context). There was one GLSL test (`tests/bugs/vk-structured-buffer-binding`) that was using raw GLSL expected output, and this was changed to use a GLSL baseline to generate SPIR-V for comparison. For HLSL tests we were sometimes running the same input file through `slangc` and `fxc`/`dxc`, and in these cases I macro-ized the various `cbuffer` declarations to generate different declarations depending on the compiler. I completely dropped the tests coming from the D3D SDK because they aren't providing much coverage, and updating them would change them so far from the original code that the purported benefit (using a body of existing shaders) would be lost. I also dropped the explicit matrix layout qualifiers in the `matrix-layout` test because the new output strategy breaks those for GLSL (you can't put matrix layout qualifiers on `struct` fields, and now the body of every constant buffer is inside a `struct`). This isn't as big of a loss as it seems, because our handling of those qualifiers wasn't really right to begin with. Slang users should only be setting the matrix layout mode globally (and we should probably switch to error out on the explicit qualifiers for now). The other thing that got dropped is tests involving `packoffset` modifiers. Slang already warns that it doesn't support these, and the way they were used in the test cases is actually misleading. For the binding/layout-related tests, the goal was to show that Slang reproduces the same layout as fxc, in which case explicitly enforcing a layout via `packoffset` seems like cheating (are we sure we enforced the layout fxc would have produced?). The real reason was that Slang used to emit explicit `packoffset` on *every* field of a `cbuffer` it would output, because of an `fxc` bug where you couldn't use `register` on textures/samplers declared inside a `cbuffer` unless *every* field in the `cbuffer` used a `register` or `packoffset` modifier. Slang hasn't required that behavior in a while because it now splits textures and samplers, and the one test case where we needed `packoffset` to work around the `fxc` bug in the baseline HLSL has been macro-ified even more to work around the bug. The amount of churn in the test cases is unfortunate, but it continues to point at the weakness of any testing strategy that checks for exact equivalent between Slang's output and that of other compilers. We need to keep working to replace these tests with better alternatives. In `check.cpp` there is logic to perform implicit dereferencing, so that if you write `obj.f` where `obj` is a `ConstantBuffer<X>` (or some other "pointer-like" type) and `f` is a field in `X`, then this effectively translates as `(*obj).f`. That is, we dereference the value of type `ConstantBuffer<X>` to get a value of type `X`, and then refer to the field of the `X` value. There was a problem where the logic to insert that kind of implicit dereference operation was using a reference (`auto& type = ...`) for the type of the expression being dereferenced, and then clobbering it. This would mean that an expression of type `ConstantBuffer<X>` would have its type overwritten to be just `X` and then codegen would break later on. I'm not sure how we haven't run into that before. The `array-of-buffers` test case was added to confirm that we now support arrays of constant, structured, and byte-address buffers for both DXIL and SPIR-V output. Okay, so that was a lot of stuff, but hopefully it is clear how this all works to make the output of the compiler more consistent and explicit, while also supporting the required new functionality. * fixup: review feedback
* Add support for Vulkan raytraicng "shader record" (#735)Tim Foley2018-11-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The syntax for this is a placeholder for now, since we will probably want to migrate to whatever gets decided on for dxc. To declare that some data should be part of the "shader record" use `layout(shaderRecordNV)` to mirror the GLSL raytracing extension: ```hlsl layout(shaderRecordNV) cbuffer MyShaderRecord { float4 someColor; uint someValue; } ``` The intention (not enforced) is that an application would map `MyShaderRecord` to "root constants" in the "local root signature" when compiling for DXR, while the output code in GLSL will always map to the shader record in Vulkan raytracing: ```glsl layout(shaderRecordNV) buffer MyShaderRecord { float4 someColor; uint someValue; }; ``` This change does *not* support declaring a global value of `struct` type with `layout(shaderRecordNV)` (or a `ParameterBlock` with the modifiers, although that would be a nice-to-have feature) and it does *not* support having the contents of the shader record be mutable (even if GLSL/Vulkan allows it). Those can/should be added in future changes. In terms of implementation, this closely mirrors the way that `layout(push_constant)` buffers were being handled, where the data inside the `ConstantBuffer<X>` (the value of type `X`) gets laid out using ordinary rules (and consuming ordinary `UNIFORM` storage, while the buffer itself is given a different layout resource to reflect that fact that it does not consume a VK `binding` any more, but a different conceptual resource. Note: an alternative design here (that might actually be preferrable) would be to have both push-constant and shader-record buffers be handled as alternative aliases for `ConstantBuffer` (or maybe `ParameterBlock`) so that you have, e.g.: ```hlsl PushConstantBuffer<X> myPushConstants; ShaderRecord<Y> myShaderRecord; ``` This alternative design avoids API-specific decorations on the declarations, and reflects the intent of the programmer very directly, even when they are compiling for a target like D3D that doesn't reflect these choices at the IL level (it could still be exposed through the Slang reflection API).
* Add support for globallycoherent modifier (#732)Tim Foley2018-11-29
| | | | | | | | | The `globallycoherent` modifier indicates that resource might be read or written by threads outside of the current thread group, so that any memory barriers that affect it should guarantee coherency at the global memory scope, and not just thread-group scope. The equivalent GLSL modifier appears to be `coherent`. This change adds the front-end modifier, transforms it into an IR-level decoration during lowering, and then checks for the modifier during code emit. Note: this logic may not behave correctly when `globallycoherent` is added to a field in a `struct`, since the modifier would then need to be propagated to any variables created during type legalization. Checking up on that is left to future work. Note: it isn't entirely clear if `globallycoherent` should be treated as a declaration modifier or a type modifier. The point is moot for now because Slang doesn't have any support for type modifiers, but when we get around to that we will need to make a decision.
* Feature/early depth stencil (#727)jsmall-nvidia2018-11-21
| | | | | | | | | | | | | | * First pass support for early depth stencil. * Add a simple test to check if output has attributes. * Use cross compilation to test [earlydepthstencil] on glsl. * If target is dxil, use dxc to test against. Add hlsl to test earlydepthstencil against. * * Added spSessionHasCompileTargetSupport * Made slang-test use spSessionHasCompileTargetSupport to ignore tests that cannot run
* Add Vulkan cross-compilation for byte-address buffers (#721)Tim Foley2018-11-19
| | | | | | | | | | | | | | | | | | | | | | | | * Add Vulkan cross-compilation for byte-address buffers This covers `ByteAddressBuffer`, `RWByteAddressBuffer`, and `RasterizerOrderedByteAddressBuffer`. A declaration of any of these types translates to a GLSL `buffer` declaration with a single `uint` array of data. Most of the methods on these types then have straightforward translations to operations on the array. The overall translation is similar to what was already being done for structured buffers. While implementing GLSL translation for the various atomic (`Interlocked*`) methods, I discovered that some of these included declarations that aren't actually included in HLSL. I cleaned these up, including in the declarations of the global `Interlocked*` functions. The test case that is included here covers only the most basic functionality: `Load`, `Load2`, `Load4` and `Store`. We should try to back-fill tests for the remaining methods when we have time. Two large caveats with this work: 1. We don't handle arrays of byte-address buffers, just as we don't handle arrays of structured buffers. That will take additional work. 2. We don't handle byte-address (or structured) buffers being passed as function parameters, since the parameter would need to be declared as a bare `uint[]` array. * Fixup: don't lump raytracing acceleration structures in with buffers Raytracing acceleration structures share a common base class with byte-address buffers (they are both buffer resources without a specific element type), and I was mistakently matching on this base class in an attempt to have a catch-all that applied to all byte-address buffers. The fix here was to add a distinct base class for all byte-address buffers and catch that instead. * Fixup: typos