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path: root/source/slang/slang-emit-glsl.cpp
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2020-05-29Bug fix problem with ray tracing from fragment shader (#1362)jsmall-nvidia
* Added GLSL_460 if ray tracing is used on fragment shader. Moved GLSL specific setup init function. * Split out _requireRayTracing method.
2020-05-29Feature/ast syntax standard (#1360)jsmall-nvidia
* Small improvements to documentation and code around DiagnosticSink * Made methods/functions in slang-syntax.h be lowerCamel Removed some commented out source (was placed elsewhere in code) * Making AST related methods and function lowerCamel. Made IsLeftValue -> isLeftValue.
2020-05-26Improvements around hashing (#1355)jsmall-nvidia
* Fields from upper to lower case in slang-ast-decl.h * Lower camel field names in slang-ast-stmt.h * Fix fields in slang-ast-expr.h * slang-ast-type.h make fields lowerCamel. * slang-ast-base.h members functions lowerCamel. * Method names in slang-ast-type.h to lowerCamel. * GetCanonicalType -> getCanonicalType * Substitute -> substitute * Equals -> equals ToString -> toString * ParentDecl -> parentDecl Members -> members * * Make hash code types explicit * Use HashCode as return type of GetHashCode * Added conversion from double to int64_t * Split Stable from other hash functions * toHash32/64 to convert a HashCode to the other styles. GetHashCode32/64 -> getHashCode32/64 GetStableHashCode32/64 -> getStableHashCode32/64 * Other Get/Stable/HashCode32/64 fixes * GetHashCode -> getHashCode * Equals -> equals * CreateCanonicalType -> createCanonicalType * Catches of polymorphic types should be through references otherwise slicing can occur. * Fixes for newer verison of gcc. Fix hashing problem on gcc for Dictionary. * Another fix for GetHashPos * Fix signed issue around GetHashPos
2020-05-01Improve GLSL coverage of boolean binary ops (#1335)Tim Foley
* Improve GLSL coverage of boolean binary ops This change ensures that the `&&`, `||`, `&`, `|`, and `^` apply correctly to vectors of `bool` values when targetting GLSL. Most of the changes are in the GLSL emit path, where the IR instructions for these operators are bottlenecked through a small set of helper routines to cover the different cases. In general: * The vector variants of the operations are implemented by casting to `uint` vectors, performing bitwise ops, then casting back * The scalar variants are handled by conveting the bitwise operations to their equivalent logical operator (the one interesting case there is bitwise `^` where the equivalent logical operation on `bool` is `!=`) This change makes it clear that our IR really shouldn't have distinct opcodes for logical vs. bitwise and/or/xor, and instead should just have a single family of operations where the behavior differs based on the type of the operand. That is already *de facto* the way things work (a user can always write `&`, `|` and `^` and expect them to work on `bool` and vectors of `bool`), so that the GLSL output path has to deal with the overlap. Having two sets of IR ops here actually makes for more code instead of less. * Fixups: review feedback and test ! operator
2020-04-27Add support for generic load/store on byte-addressed buffers (#1334)Tim Foley
* Add support for generic load/store on byte-addressed buffers Introduction ============ The HLSL `*ByteAddressBuffer` types originaly only supported loading/storing `uint` values or vectors of the same, using `Load`/`Load2`/`Load3`/`Load4` or `Store`/`Store2`/`Store3`/`Store4`. More recent versions of dxc have added support for generic `Load<T>` and `Store<T>`, which adds a two main pieces of functionality for users. The first and more fundamental feature is that `T` can be a type that isn't 32 bits in size (or a vector with elements of such a type), thus exposing a capability that is difficult or impossible to emulate on top of 32-bit load/store (depending on what guarantees `*StructuredBuffer` makes about the atomicity of loads/stores). The secondary benefit of having a generic `Load<T>` and `Store<T>` is that it becomes possible to load/store types like `float` without manual bit-casting, and also becomes possible to load/store `struct` types so long as all the fields are loadable/storable. This change adds generic `Load<T>` and `Store<T>` to the Slang standard library definition of byte-address buffers, and tries to bring those same benefits to as many targets as possible. In particular, the secondary benefits become available on all targets, including DXBC: byte-address buffers can be used to directly load/store types other than `uint`, including user-defined `struct` types, so long as all of the fields of those types can be loaded/stored. The ability to load/store non-32-bit types depends on target capabilities, and so is only available where direct support for those types is available. For 16-bit types like `half` this includes both Vulkan and D3D12 DXIL with appropriate extensions or shader models. The implementation is somewhat involved, so I will try to explain the pieces here. Standard Library ================ The changes to the Slang standard library in `hlsl.meta.slang` are pretty simple. We add new `Load<T>` and `Store<T>` generic methods to `*ByteAddressBuffer`, and route them through to a new IR opcode. Right now the generic `Load<T>` and `Store<T>` do *not* place any constraints on the type `T`, although in practice they should only work when `T` is a fixed-size type that only contains "first class" uniform/ordinary data (so no resources, unless the target makes resource types first class). Our front-end checking cannot currently represent first-class-ness and validate it (nor can it represent fixed-size-ness), so these gaps will have to do for now. Rather than directly translate `Load<T>` or `Store<T>` calls into a single instruction, we instead bottleneck them through internal-use-only subroutines. The design choice here is intended to ensure that for some large user-defined type like `MassiveMaterialStruct` we only emit code for loading all of its fields *once* in the output HLSL/GLSL rather than once per load site. While downstream compilers are likely to inline all of this logic anyway, we are doing what we can to avoid generating bloated code. Emit and C++/CUDA ================= Over in `slang-emit-c-like.cpp` we translate the new ops into output code in a straightforward way. A call like `obj.Load<Foo>(offset)` will eventually output as a call like `obj.Load<Foo>(offset)` in the generated code, by default. For the CPU C++ and CUDA C++ codegen paths, this is enough to make a workable implementation, and we add suitable templated `Load<T>` and `Store<T>` declarations to the prelude for those targets. Legalization ============ For targets like DXBC and GLSL there is no way to emit a load operation for an aggregate type like a `struct`, so we introduce a legalization pass on the IR that will translate our byte-address-buffer load/store ops into multiple ops that are legal for the target. Scalarization ------------- The big picture here is easy enough to understand: when we see a load of a `struct` type from a byte-address buffer, we translate that into loads for each of the fields, and then assemble a new `struct` value from the results. We do similar things for arrays, matrices, and optionally for vectors (depending on the target). Bit Casting ----------- After scalarization alone, we might have a load of a `float` or a `float3` that isn't legal for D3D11/DXBC, but that *would* be legal if we just loaded a `uint` or `uint3` and then bit-casted it. The legalization pass thus includes an option to allow for loads/stores to be translated to operate on a same-size unsigned integer type and then to bit-cast. To make this work actually usable, I had to add some more details to the implementation of the bit-cast op during HLSL emit and, more importantly, I had to customize the way that the byte-address buffer load/store ops get emitted to HLSL so that it prefers to use the existing operations like `Load`/`Load2`/`Load3`/`Load4` instead of the generic one, whenever operating on `uint`s or vectors of `uint`. Translation to Structured Buffers --------------------------------- Even after scalarizing all byte-address-buffer loads/stores, we still have a problem for GLSL targets, because a single global `buffer` declaration used to back a byte-address buffer can only have a single element type (currently always `uint`), so the granularity of loads/stores it can express is fixed at declaration time. If we want to load a `half` from a byte-address buffer, we need a dedicated `buffer` declaration in the output GLSL with an element type of `half`. The solution we employ here is to translate all byte-address buffer loads into "equivalent" structured-buffer ops when targetting GLSL. We add logic to find the underlying global shader parameter that was used for a load/store and introduce a new structured-buffer parameter with the desired element type (e.g., `half`) and then rewrite the load/store op to use that buffer instead. We copy layout information from the original buffer to the new one, so that in the output GLSL all the various `buffer`s will use a single `binding` and thus alias "for free." We don't want to create a new global buffer for every load/store, so we try to cache these "equivalent" structured buffers as best as we can. For the caching I ended up needing a pair to use as a key, so I tweaked the `KeyValuePair<K,V>` type in `core` so that it could actually work for that purpose. Because we are working at the level of IR instructions instead of stdlib functions at this work I had to add new IR opcodes to represent structured-buffer load/store that only (currently) apply to GLSL. Layout ====== In order to translate a load/store of a `struct` type into per-field load/store we need a way to access layout information for the types of the fields. Previously layout information has been an AST-level concern that then gets passed down to the IR only when needed and only on global parameters, so layout information isn't always available in cases like this, at the actual load/store point. As an expedient move for now I've introduced a dedicated module that does IR-level layout and caches its results on the IR types themselves. This approach *only* supports the "natural" layout of a type, and thus is usable for structured buffers and byte-address buffers (or general pointer load/store on targets that support it), but which is *not* usable for things like constant buffer layout. We've known for a while that the Right Way to do layout going forward is to have an IR-based layout system, and this could either be seen as a first step toward it, or else as a gross short-term hack. YMMV. Details ======= The GLSL "extension tracker" stuff around type support needed to be tweaked to recognize that types like `int16_t` aren't actually available by default. I switched it from using a "black list" of unavailable types at initialization time over to using a "white list" of types that are known to always be available without any extensions. Tests ===== There are two tests checked in here: one for the basic case of a `struct` type that has fields that should all be natively loadable, and one that stresses 16-bit types. Each test uses both load and store operations. Future Directions ================= Right now we translate vector load/store to GLSL as load/store of individual scalars, which means the assumed alignment is just that of the scalars (consistent with HLSL byte-address buffer rules). We could conceivably introduce some controls to allow outputting the vector load/store ops more directly to GLSL (e.g., declaring a `buffer` of `float4`s), which might enable more efficient load/store based on the alignment rules for `buffer`s. The IR layout work has a number of rough edges, but the most worrying is probably the assumption that all matrices are laid out in row-major order. Slang really needs an overhaul of its handling of matrices and matrix layout, so I don't know if we can do much better in the near term. At some point the IR-based layout system needs to be reconciled with our current AST-base layout, and we need to figure out how "natural" layout and the currently computed layouts co-exist (in particular, we need to make sure that the IR-based layout and the existing layout logic for structured buffers will agree). This probably needs to come along once we have moved the core layout logic to operate on IR types instead of AST types (a change we keep talking about). As part of this work I had to touch the implementation of bit-casting for HLSL, and it seems like that logic has some serious gaps. We really ought to consider a separate legalization pass that can turn IR bitcast instructions into the separate ops that a target actually supports so that we can implement `uint64_t`<->`double` and other conersions that are technically achievable, but which are hard to express in HLSL today. * fixup: missing files
2020-04-08Replace /* unhandled */ in source emit with a real error (#1313)Tim Foley
For a long time the various source-to-source back-ends have been emitted the text `/* unhandled */` when they encounter an IR instruction opcode that didn't have any emit logic implemented. This choice had two apparent benefits: * In most common cases, emitting `/* unhandled */` in place of an expression would lead to downstream compilation failure, so most catastrophic cases seemed to work as desired (e.g., if we emit `int i = /* unhandled */;` we get a downstream parse error and we know something is wrong. * In a few cases, if a dead-but-harmless instruction slips through (e.g., a type formed in the body of a specialized generic function), we would emit `/* unhandled */;`, which is a valid empty statement. It is already clear from the above write-up that the benefits of the policy aren't really that compelling, and where it has recently turned out to be a big liability is that there are actually plenty of cases where emitting `/* unhandled */` instead of a sub-expression won't cause downstream compilation failure, and will instead silently compute incorrect results: * Emitting `/* unhandled */ + b` instead of `a + b` * Emitting `/* unhandled */(a)` instead of `f(a)`, or even `/* unhandled */(a, b)` instead of `f(a,b)` * Emitting `f(/*unhandled*/)` instead of `f(a)` in cases where `f` is a built-in with both zero-argument and one-argument overloads The right fix here is simple: where we would have emitted `/* unhandled */` to the output we should instead diagnose an internal compiler error, thus leading to compilation failure. This change appears to pass all our current tests, but it is possible that there are going to be complicated cases in user code that were relying on the previous lax behavior. I know from experience that we sometimes see `/* unhandled */` in output for generics, and while we have eliminated many of those cases I don't have confidence we've dealt with them all. When this change lands we should make sure that the first release that incorporates it is marked as potentially breaking for clients, and we should make sure to test the changes in the context of the client codebases before those codebases integrate the new release.
2020-03-25Unroll target improvements (#1291)jsmall-nvidia
* Add unroll support for CUDA, and preliminary for C++. Document [unroll] support. * Fix loop-unroll to run on CPU, and test on CPU and elsewhere. Fix bug in emitting loop unroll condition. * Improved comment. * Added support for vk/glsl loop unrolling.
2020-03-11Clean-ups related to expanded standard library coverage (#1269)Tim Foley
This change continues the work already started in moving the definitions of many built-in functions to the standard library. The main focus in this change was reducing the number of operations that had to be special-cased on the CPU and CUDA targets by making sure that the scalar cases of built-in functions map to the proper names in the prelude (e.g., `F32_sin()`) via the ordinary `__target_intrinsic` mechanism. In some cases this cleanup meant that special-case logic that was constructing definitions for those functions using C++ code could be scrapped. Additional changes made along the way: * A few scalar functions that were missing in the CPU/CUDA preludes got added: `round`, hyperbolic trigonometric functions, `frexp`, `modf`, and `fma` * The floating-point `min()` and `max()` definitions in the preludes were changed to use intrinsic operations on the target (which are likely to follow IEEE semantics, while our definitions did not) * For the CUDA target, many of the functions had their names translated during code emit from, e.g., `sin` to `sinf`. This change makes the CUDA target more closely match the C++/CPU target in using names like `F32_sin` consistently. * For the CUDA target, a few additional functions have intrinsics that don't exist (portably) on CPU: `sincos()` and `rsqrt()`. * For the Slang stdlib definitions to work, a new `$P` replacement was defined for `__targert_intrinsic` that expands to a type based on the first operand of the function (e.g., `F32` for `float`). * I removed the dedicated opcodes for matrix-matrix, matrix-vector, and vector-matrix multiplication, and instead turned them into ordinary functions with definitions and `__target_intrinsic` modifiers to map them appropriately for HLSL and GLSL. This is realistically how we would have implemented these if we'd had `__target_intrinsic` from the start. Notes about possible follow-on work: * The `ldexp` function is still left in the Slang stdlib because it has to account for a floating-point exponent and the `math.h` version only handles integers for the exponent. It is possible that we can/should define another overload for `ldexp` (and `frexp`) that uses an integer for exponent, and then have that one be a built-in on CPU/CUDA, with the HLSL `frexp` being defined in the stdlib to delegate to the correct `frexp` for those targets. * The `firstbithigh` and related functions are missing for our CPU and CUDA targets, and will need to be added. It is worth nothing that `firstbithigh` apparently has some very odd functionality around signed integer arguments (which are supported, despite MSDN being unclear on that point). General cleanup will be required for those functions. * Maxing the various matrix and vector products no longer be intrinsic ops might affect how we emit code for them as sub-expressions (both whether we fold them into use sites and how we parenthize them). This doesn't seem to affect any of our existing tests, but we could consider marking these functions with `[__readNone]` to ensure they can be folded, and then also adding whatever modifier(s) we might invent to control precdence and parentheses insertion during emit.
2020-03-05Feature/glslang spirv version (#1256)jsmall-nvidia
* WIP add support for __spirv_version . * Added IRRequireSPIRVVersionDecoration * SPIR-V version passed to glslang. Enable VK wave tests. Split ExtensionTracker out, so can be cast and used externally to emit. Added SourceResult. * Fix warning on Clang. * Missing hlsl.meta.h * Refactor communication/parsing of __spirv_version with glslang. * Fix some debug typos. Be more precise in handling of substring handling. * Make glslang forwards and backwards binary compatible. * Small comment improvements. * Added slang-spirv-target-info.h/cpp * Fix for major/minor on gcc. * Another fix for gcc/clang. * VS projects include slang-spirv-target-info.h/cpp * Removed SPIRVTargetInfo Added SemanticVersion. Don't bother with passing a target to glslang. Should be separate from 'version'. * Renamed slang-emit-glsl-extension-tracker.cpp/.h -> slang-glsl-extension-tracker.cpp/.h Fixed some VS project issues. * Fix a comment. * Added slang-semantic-version.cpp/.h * Added slang-glsl-extension-tracker.cpp/.h * Added split that can check for input has all been parsed. * Fix problem on x86 win build.
2020-03-03__spirv_version Decoration (#1255)jsmall-nvidia
* WIP add support for __spirv_version . * Added IRRequireSPIRVVersionDecoration
2020-03-02Renamed UnownedStringSlice::size to getLength to make match String. (#1254)jsmall-nvidia
2020-02-10Add attributes to enable dual-source blending on Vulkan (#1210)Tim Foley
This change adds support for the `[[vk::location(...)]]` and `[[vk::index(...)]]` attributes, which can be used together to mark up shader outputs for dual-source blending on Vulkan. HLSL/Slang code like the following: ```hlsl struct Output { [[vk::location(0)]] float4 a : SV_Target0; [[vk::location(0), vk::index(1)]] float4 b : SV_Target1; } [shader("fragment")] Output main(...) { ...} ``` can be used to set up dual-source blending on both D3D and Vulkan APIs. The output GLSL for the above will look something like: ```glsl layout(location = 0) out vec4 a; layout(location = 0, index = 1) out vec4 b; void main() { ... } ``` The more or less straightforward parts of this change were: * Added new `attribute_syntax` declarations to the stdlib, for `[[vk::location(...)]]` and `[[vk::index(...)]]` * Added new AST node types for the new attribute cases, sharing a base class so that argument checking can be shared * Added checks for the arguments to the new attributes in `slang-check-modifier.cpp` (eventually this kind of logic shouldn't be needed for new attributes) * Updated GLSL emit logic so that it treats the `index`/`space` parts of a variable layout as the `location`/`index` for varying parameters. * Updated GLSL legalization so that when it translates entry-point parameters into globals (and scalarizes structures) it handles both a binding index and space for the parameters. * Added a cross-compilation test case to verify that the basics of the feature work The remaining work is all in `slang-parameter-binding.cpp`. There is some work that isn't technically related to this change (and which could be reverted if it causes problems), around the detection and handling of fragment shader outputs with `SV_Target` semantics. The basic changes (which could be backed out and then merged separately) are: * Made the special-case `SV_Target` logic only trigger for fragment shaders (that is the only place where `SV_Target` should appear, but we weren't guarding against it) * Made the logic to reserve a `u<N>` register for `SV_Target<N>` only trigger for D3D Shader Model 5.0 and below (since it is not required for SM 5.1 and up). This could be a breaking change for some users, but that seems unlikely. * Fixed one test case that relied on the behavior of reserving `u0` for `SV_Target0` even though it was a SM6.0 test. * Also added more comments to the system-value handling logic. The more interesting changes come up starting in `processEntryPointVaryingParameterDecl()`. The basic issue is that we have so far only supported implicit layout for varying parameters on GLSL/Vulkan, but the `[[vk::location(...)]]` attribute is a form of explicit layout annotation. Rather than try to kludge something that only works in narrow cases, I instead opted to try to fix things more generally. In `processEntryPointVaryingParameterDecl()` we now check for the `location` and `index` attributes when we are on "Khronos" targets (Vulkan/OpenGL/GLSL) and immediately add them to the variable layout being constructed if they are found. There is nothing in this logic specific to fragment-shader outputs, so this feature now applies to any varying input/output on Khronos targets. Allowing explicit layouts creates the potential for mixing implicit and explicit layout. For example, consider: ```hlsl struct Output { float4 color : COLOR; [[vk::location(0)]] float3 normal : NORMAL; } ``` What `location` should `color` get? Should this code be an error? There are two cases where this conundrum can come up: when working with `struct` types used for varying parameters, and the entry-point parameter list itself. For the varying `struct` case we currently make an expedient choice. We handle fields with both implicit or explicit layotu with appropriate logic, but logic that doesn't account for the case of mixing the two. Then at the end of layout for the `struct` we issue an error if there was a mix of implicit and explicit layout (such that our results aren't likely to be valid). For the entry point varying parameter case, things were already using a `ScopeLayoutBuilder` type (that encapsulates some logic shared between entry-point and global parameters). The entry-point-specific bits were moved out into a `SimpleScopeLayoutBuilder` and it was updated so that rather than assuming all parameters use implicit layout it does a two-phase layout approach similar to what we use for the global scope: * First all parameters are enumerated to collect explicit bindings and mark certain ranges as "used" * Next the parameters are enumerated again and those without explicit bindings get allocated space using a "first fit" algorithm In principle we could extend the two-phase approach to apply to `struct` types as well, but that would be best saved for a future refactoring of some of this parameter binding logic, since I would like to exploit more of the opportunities for sharing code across the uniform/varying and struct/entry-point/global cases. By moving the point where entry point parameters get their offsets assigned, it was necessary to move around some of the logic that removes varying parameter usage (and other things that shouldn't "leak" out of an entry point) to a different point in the entry point layout process. While adding these various pieces does not quite enable us to support explicit bindings on entry point parameters (e.g., putting `uniform Texture2D t : register(t0)` in an entry point parameter list) or in `struct` types (e.g., explicit `packoffset` annotations on fields), it starts to provide some of the infrastructure that we'd need in order to support those cases.
2020-02-07Change handling of strings for HLSL/GLSL targets (#1204)Tim Foley
* Change handling of strings for HLSL/GLSL targets This change switches our handling of string literals and `getStringHash` to something that is more streamlined at the cost of potentially being less general/flexible. * `String` is now allowed as a parameter type in user-defined functions * `getStringHash` is now allowed to apply to `String`-type values that aren't literals * The list of strings in an IR module is now generated during IR lowering as part of lowering a string literal expression, rather than being defined by recursively walking the IR of the module looking for `getStringHash` calls. The public API still refers to these as "hashed" strings, but they are realistically now "static strings." * When emitting code for HLSL/GLSL, the `String` type emits as `int`, and `getStringHash(x)` emits as `x`. In terms of implementation, the choice was whether to translate `String` over to `int` in an explicit IR pass, or to lump it into the emit pass. While adding the logic to emit clutters up an already complicated step, it is ultimately much easier to make the change there than to write a clean IR pass to eliminate all `String` use. Note that other targets that can handle a more full-featured `String` type are *not* addressed by this change and thus do not support `String` at all. It may be woth emitting `String` as `const char*` on those targets, and emitting string literals directly, but the `getStringHash` function would need to be implemented in the "prelude" then, and we probably want to pick a well-known/-documented hash algorithm before we go that far. This change also brings along some some clean-ups to the `gpu-printing` example, since it can now take advantage of the new functionality of `String`. * Fix up tests for new string handling * Add global string literal list to string-literal test (since we now list *all* static string literals and not just those passed to `getStringHash`) * Disable `getStringHash` test on CPU, since we don't have a working `String` on that platform right now (only HLSL/GLSL) Co-authored-by: Tim Foley <tim.foley.is@gmail.com>
2020-02-06Literal handling improvements (#1202)jsmall-nvidia
* WIP: 64 literal diagnostic and truncation. * Improve how integer truncation is handled/supported. Added literal-int64.slang test. Set a suffix on all literals. Fixed problem on C++ based targets where l suffix was not the same as int() cast. So on C++ derived emitters, int() is used instead of l suffix to have same behavior across targets. * Add literal diagnostic testing. * Allow lexer to lex - in front of literals. * Fix lexing and converting int literal with -. * Too large small values of floats become inf. Handling writing inf types out on different targets. Add function to deterimine if a float literals kind. * Roll back the support of lexer lexing negative literals. * Fixed tests broken because of diagnostics numbers. Improved _isFinite * Fix compilation on linux. * Fix problem with abs on linux - use Math::Abs. * Fix typo. * * Improve warnings for float literals zeroed * Improved 64 bit type documentation * Handle half * Improved comments * Fixed tests broken * Use capital letters for suffixes. * Make default behavior on outputting a int literal that is an 'int32_t' is cast (not suffix) to avoid platform inconsistencies. Improve documentation for 64 bit types. Make tests cover material in docs. * Fixed tests. * Rename FloatKind::Normal -> Finite * Fix half zero check.
2020-01-30Support for 64 bit integer types (#1191)jsmall-nvidia
* * For integer literals add postfix, and use unsigned/signed output appropriately * Extend GLSL extension handling by type, and for adding 64 bit int extensions * Added tests for int/uint64 types * Add explicit Int/UInt64 emit functions to avoid ambiguity.
2019-10-22User IR-based layout for all IR steps (#1084)Tim Foley
This change builds on previous work that moves toward a more IR-based representation of layout. Those steps added some instructions for representing layout in the IR (initially just proxies for the AST layout objects), and an explicit lowering pass that could build a target-specific IR module that binds parameters and entry points to layout information. This change aims to complete that work, in the sense that the IR representation of layout is now self-contained and does not rely on having pointers back into the AST-level representation. Achieving this requires two main kinds of work: 1. Update any code that used layout information derived from the IR (most notably all the `slang-emit-*` code) to use the new IR representation and its accessors. 2. Update any code that *constructs* layouts using information derived from the IR to construct IR layouts instead. The biggest new infrastructure feature in this change is support for "attributes" in the IR (I'd welcome feedback on the naming). An attribute can either be thought of like key/value arguments that can be added to certain instructions to encode optional data, or alternatively like a decoration that is referenced as an operand instead of a child. The value of attributes over decorations is that they can affect the hash/identity of an instruction (which decorations can't), while the advantage of decorations is that they can easily be added/removed over the lifetime of an instruction (which attributes can't). We mostly use them here to represent operands that are logically optional. Once attributes are available, the encoding of layout information into the IR is mostly straightforward: * An `IRVarLayout` has a fixed operand for its type layout, and can accept a few different attributes * Zero or more `IRVarOffsetAttr`s that specify the offset of the variable for a given resource kind. These are equivalent to the `VarLayout::ResourceInfo`s at the AST level. * An optional `IRUserSemanticAttr` and `IRSystemValueSemanticAttr` to represent the (possibly derived) semantic of a varying input/output parameter. * An option `IRStageAttr` to represent the known stage for a parameter. * An `IREntryPointLayout` has a var layout for the entry point parameters (logically grouped in to a struct) and another var layout for the result parameter. * There is a small type hierarchy rooted at `IRTypeLayout` where each subtype can add fixed operands and attributes that are expected to appear. It also supports `IRTypeSizeAttr`s that serve a similar role to the `IRVarOffsetAttr`s. * Structure types maintain the mapping of fields to their var layouts using `IRStructFieldLayoutAttr`s. With the encoding in place, most of the changes in category (1) (code that just *uses* rather than *creates* layouts) was straightforward. The biggest different beyond name changes was that everything needs to be fetched using accessors instead of bare fields. It would have been possible to stage this commit and make the diffs smaller by first introducing mandatory acessors to the AST layout types. The changes in category (2) were more involved. There were a lot of places in the existing code where a `TypeLayout` or `VarLayout` would be created, and then initialized piecemeal over several lines of code (and sometimes even across functions). Because of the way that layouts need to support many optional properties, it did not seem practical to just have monolithic factory functions that took all the options as arguments, so I instead opted for a builder approach. The builders for `IRVarLayout` and `IREntryPointLayout` are both straightforward, and honestly there is no realy need for a builder for entry point layouts right now, but I was trying to future-proof in case we decidd to add some optional attributes to them. The builders for type layouts are more involved because of the inheritance hierarchy. Each concrete sub-type of type layout needs to define its own builder type that customizes the opcode, operands, and attributes of the final instruction. The refactoring that had to go into this change was a nice excuse to clean up a few ugly warts in the AST layout code that were largely there to support IR use cases. While this change adds a lot of new infrastructure code to the IR, most of the client code has stayed the same or gotten simpler. One annoying wart that remains with this change is the notion of an "offset element type layout" for parameter group types. That idea was added to deal with a legacy feature in the reflection API that we realized was a mistake, but unfortunately having that "offset" layout handy made writing a few other pieces of code simpler so that there are use cases of the feature even in the IR. Removing those uses is do-able, but requires careful refactoring so it is best left to a follow-on change. Another thing that could be considered for a follow-on change is how much information should be specified when constructing a `Builder` for an IR type layout, and how much should be allowed to be specified statefully/piecemeal. It would be nice to force all the required operands to be specified up front, but `IRParameterGroupTypeLayout::Builder` doesn't currently work that way because so much of the client code that needs it involved a lot of stateful setting and would need to be refactored heavily to provide the necessary information up front.
2019-10-08Fixed from Review of Entry Point decoration #1068 (#1072)jsmall-nvidia
* Remove typo around GeometryPrimitiveTypeDecoration * * GeometryPrimitiveTypeDecoration -> GeometryInputPrimitiveTypeDecoration (to try and closer match meaning and the Modifier name) * Remove a small problem around definition of IRGeometryPrimitiveTypeDecoration * Fix comment around IRStreamOutputTypeDecoration
2019-10-08Remove EntryPointLayout* use in emit logic. (#1071)jsmall-nvidia
* Split out EntryPointParamDecoration. * Add profile to EntryPointDecoration. * WIP for GS handling for GLSL. * WIP for StreamOut GLSL * Fixed GLSL geometry output. * Clean up - remove unneeded/commented out code from the entry point change. * Use Op nums to identify GeometryTypeDecorations (as opposed to contained enum). * Remove setSampleRateFlag & doSampleRateInputCheck * Remove EntryPointLayout from emit. * Change to force CI.
2019-10-08Feature/ir entry point profile (#1068)jsmall-nvidia
* Split out EntryPointParamDecoration. * Add profile to EntryPointDecoration. * WIP for GS handling for GLSL. * WIP for StreamOut GLSL * Fixed GLSL geometry output. * Clean up - remove unneeded/commented out code from the entry point change. * Use Op nums to identify GeometryTypeDecorations (as opposed to contained enum).
2019-10-04IR types for subset of Attributes (#1067)jsmall-nvidia
* IROutputControlPointsDecoration * IROutputTopologyDecoration * IRPartitioningDecoration * IRDomainDecoration * Use IRPatchConstantDecoration alone for hlsl output. * IRMaxVertexCountDecoration * IRInstanceDecoration * Removed _emitHLSLAttributeSingleString and _emitHLSLAttributeSingleInt Removed GLSLBindingAttribute and just use NumThreadsAttribute * Added IRNumThreadsDecoration. * Added IRNumThreadsDecoration * Fix build problem on x86. Improve diagnostic text based on review.
2019-09-18Clean up some behavior of operator% (#1060)Tim Foley
Work on #1059 The `%` operator in the Slang implementation had several issues, and this change tries to address some of them: * Renamed most occurences of "mod" describing this operator to be "rem" for "remainder" to better match its semantics in HLSL * Split the operator into distinct integer and floating-point variants (`IRem` and `FRem`) to simplify having different codegen for the two * Added floating-point variants of `operator%` and `operator%=` to the stdlib. * Added custom C++ codegen for `kIROp_FRem` such that it maps to the standard C/C++ `remainder()` function * Added custom GLSL codegen so that `kIROp_FRem` maps to the GLSL `mod()` function (which isn't correct...) * Added a test case to confirm that D3D11, D3D12, and CPU targets all agree on the definition of floating-point `%` * Fixed `render-test-tool` to allow a negative integer in a `data=...` specification. This didn't end up being used in the final test, but still seems like a good fix. * Added a customized baseline for the Vulkan flavor of that test to confirm that we are *not* compiling correctly to SPIR-V just yet Addressing the correctness of the output for GLSL/SPIR-V will have to come as a later change given that the operation we want is not exposed directly by unextended GLSL.
2019-08-08Revise new COM-lite API (#1007)Tim Foley
* Revise new COM-lite API This change revises the "COM-lite" API that was recently introduced to try to streamline it and introduce some missing central/base concepts. The central new abstraction in the API is the notion of a "component type," which is a unit of shader code composition. A component type can have: * IR code for some number of functions/types/etc. * Zero or more global shader parameters * Zero or more "entry point" functions at which execution can start * Zero or more "specialization" parameters (types or values that must be filled in before kernel code can be generated) * Zero or more "requirements" (dependencies on other component types that must be satisfied before kernel code can be generated) Both individual compiled modules, and validated entry points are then examples of component types, and we additionally define a few services that apply to all component types: * We can take N component types and compose them to create a new component type that combines their code, shader parameters, entry points, and specialization parameters. A composed component type may also include requirements from the sub-component types, but it is also possible that by composing thing we satisfy requirements (if `A` requires `B`, and we compose `A` and `B`, then the requirement is now satisfied, and doesn't appear on the composite). * We can take a component type with N specialization parameters, and specialize it by giving N compatible specialization arguments. The result of specialization is a new component type with zero specialization parameters. Under the right circumstances the specialzed component type will be layout compatible with the unspecialized one. * One more example that isn't exposed in the public API today is that we can take a component with requirements and "complete" it by automatically composing it with component types that satisfy those requirements. This can be seen as a kind of linking step that pulls together the transitive closure of dependencies. * We can query the layout for the shader parameters and entry points of a component type, for a specific target. * We can query compiled kernel code for an entry point in a component type (for a specific target). This only works for component types with zero specialization parameters and zero requirements. The idea is that by giving users a fairly general algebra of operations on component types, they can compose final programs in ways that meet their requirements. For example, it becomes possible to incrementally "grow" a component type to represent the global root signature for ray tracing shaders as new entry points are added, in such a way that it always stays layout-compatible with kernels that have already been compiled. Much of the implementation work here is in implementing the unifying component type abstraction, and in particular re-writing code that used to assume a program consisted of a flat list of modules and entry points to work with a hierarchical representation that reflects the underlying algebra (e.g., with types to represent composite and specialized component types). There's also a hidden "legacy" case of a component type to deal with some legacy compiler behaviors that can't be directly modeled on top of the simple algebra with modules and entry points. This API is by no means feature-complete or fully developed. It is expected that we will flesh it out more when bringing up application code (e.g., Falcor) on top of the revamped API. One notable thing that went away in this change is explicit support for "entry point groups" and notions of local root signatures (especially the Falcor-specific handling of the `shared` keyword, which a previous change turned into an explicitly supported feature). With the new "building blocks" approach, it should be possible for a DXR application to deal with local root signatures as a matter of policy (on top of the API we provide). If/when we need to provide some kind of emulation of local root signatures for Vulkan (and/or if Vulkan is extended with an explicit notion of local root signatures), we might need to revisit this choice. * Fix debug build There was invalid code inside an `assert()`, so the release build didn't catch it. * fixup: warnings * fixup: more warnings-as-errors * fixup: review notes * fixup: use component type visitors in place of dynamic casting
2019-07-17Change how global-scope constants are handled (#1001)Tim Foley
Before this change, global and function-scope `static const` declarations were represented as instructions of type `IRGlobalConstant`, which was represented similarly to an `IRGlobalVar`: with a "body" block of instructions that compute/return the initial value. This representation inhibited optimizations (because a reference to a global constant would not in general be replaced with a reference to its value), and also caused problems for resource type legalization because the logic for type legalization did not (and still does not) handle initializers on globals (so global *variables* that contain resource types are still unsupported). The change here is simple at the high level: we get rid of `IRGlobalConstant` and instead handle global-scope constants as "ordinary" instructions at the global scope. E.g., if we have a declaration like: static const int a[] = { ... } that will be represented in the IR as a `makeArray` instruction at the global scope, referencing other global-scope instructions that represent the values in the array. This simple choice addresses both of the main limitations. A `static const` variable of integer/float/whatever type is now represented as just a reference to the given IR value and thus enables all the same optimizations. When a `static const` variable uses a type with resources, the existing legalization logic (which can handle most of the "ordinary" instructions already) applies. Another secondary benefit of this approach is that the hacky `IREmitMode` enumeration is no longer needed to help us special-case source code emit for `static const` variables. Beyond just removing `IRGlobalConstant`, and updating the lowering logic to use the initializer direclty, the main change here is to the emit logic to make it properly handle "ordinary" instructions that might appear at global scope. One open issue with this change, that could be addressed in a follow-up change, is that "extern" global constants that need to be imported from another module (but which might not have a known value when the current module is compiled) aren't supported - we don't have a way to put a linkage decoration on them. A future change might re-introduce global constants as a distinct IR instruction type that just references the value as an operand (if it is available). We would then need to replace references to an IR constant with references to its value right after linking.
2019-06-06Split out target code generation from CLikeSourceEmitter (#976)jsmall-nvidia
* * Added SourceStyle to CLikeSourceEmitter, to limit cases to actual target types. * Made Impl methods _ prefixed * Small tidyup * * SourceStream -> SourceWriter * use slang-emit- prefix on SourceWriter file * * Remove EmitContext -> merge into CLikeSourceEmitter * slang-c-like-source-emitter -> slang-emit-source.cpp * ExtensionUsageTracker -> GLSLExtensionTracker slang-extension-usage-tracker.cpp/.h -> slang-emit-glsl-extension-tracker.cpp/.h * emit-source.cpp.h -> emit-c-like.cpp/.h * Small fix to move where some _ prefixed functions are declared in CLikeSourceEmitter. * * CLikeSourceEmitter::CInfo -> Desc * Functions to get and find CodeGenTarget by name * Split out empty language impls * Create an impl based on SourceStyle * * CodeGenTarget conversion to and from string * Move HLSL specific functions to HLSLEmitSource. * Emitting texture and image types. * Move move GLSL specific functionality to GLSLSourceEmitter * Split more out of slang-emit-c-like * Refactor more out of slang-emit-c-like * * tryEmitIRInstExprImpl(IRInst* inst, IREmitMode mode, const EmitOpInfo& inOuterPrec) * Fix bug around output of uintBitsToFloat * More work refactoring out target specifics from slang-emit-c-like * Move functions that are only implemented once in GLSL impl into their Impl method. * Move rate qualification out of slang-emit-c-like * * Added getEmitOpForOp - allows for table usage so different ops can be dealt with the same way * Moved vector comparison to slang-emit-glsl * * * Use EmitOpInfo to control output in slang-emit-c-like.cpp for unary ops * Move more functionality from CLikeSourceEmitter to HLSLSourceEmitter * Make output of parameters implementaion specific. * Extracted interpolation modifiers. * Remove IR from methods that don't need them. * Remove IR from method names. * Refactor handling of output of types - to make the impls implement the full path without lots of cases for specific impls * Add variable declaration modifiers and matrix layout to larget specific in slang-emit. * Make target specific internal functions _ prefixed.