Making it easier to work with shaders https://git.yummers.dev/slang.git/atom?h=master 2025-10-16T18:53:10+00:00 2025-10-16T18:53:10+00:00 Julius Ikkala julius.ikkala@gmail.com 2025-10-16T18:53:10+00:00 urn:sha1:537697d3aa21b418c348b1017005603668b6a4cb On the shader-host-callable target, test `gh-4874.slang` generates IR that contains global constants referencing global params. These need to get inlined into functions, as otherwise `introduceExplicitGlobalContext()` will fail with "no outer func at use site for global", making the test crash the compiler. 2025-10-16T18:52:38+00:00 Yong He yonghe@outlook.com 2025-10-16T18:52:38+00:00 urn:sha1:0257cb001b6f5c31e4ac0435d546fe638a17c48a `SemanticsVisitor::CheckInvokeExprWithCheckedOperands` made several references to `expr` parameter in its `inout` parameter l-value-ness validation logic to access arguments, which is wrong because `expr` is not necessarily the same as `result`/`invoke` (the result of calling `ResolveInvoke()` in the first line of the function. Changing it to `invoke` for consistency. Also add a special case logic to return early in case the resolved invoke expr is `argument[0]` when the original invoke expr is `T(funcThatReturnsT())`. Closes #8659. 2025-10-08T09:19:13+00:00 Ronan ro.cailleau@gmail.com 2025-10-08T09:19:13+00:00 urn:sha1:1300678a36bf8d7081647aef3e2a37dbd496aaf5 - Allows using `Vector/Matrix` type with yet unresolved dimensions - Simpler implementation and in-line with default `Array` - Added `test/bugs/gh-8512.slang` 2025-09-23T16:39:39+00:00 Gangzheng Tong tonggangzheng@gmail.com 2025-09-23T16:39:39+00:00 urn:sha1:d61d6b57dfb0788ebf3449bfde6db288fe4e44a8 This fixes a type mismatch issue. See the generated cuda code ```cuda struct Query_0 { EmptyExample_0 query_0; uint hasNonEmptyAbsorbingBoundary_0; }; struct Query_1 { uint hasNonEmptyAbsorbingBoundary_0; }; struct GlobalParams_0 { Query_0* gQuery_0; RWStructuredBuffer<float3 > gInput_0; RWStructuredBuffer<float> gOutput_0; }; ... Query_1 _S4 = *globalParams_0->gQuery_0; // ==> type mismatch at call site! ``` **Root Cause:** During the empty type legalization pass in Slang's IR processing, struct types were being optimized. e.g., `Query_0` → `Query_1` with empty type removed), but this created an inconsistency: **Function parameters were updated:** When Query_compute_0 function was legalized, its parameter type was correctly updated from `Query_0` to the optimized `Query_1` **Global parameter types were NOT updated:** The `ParameterBlock<Struct>` type in globalParams still referenced the old `Query_0` type The PR adds special handling for type operands in the `legalizeInst` function. This triggers the legalization of the `StructType` from the original `legalizeOperand` call site. The leaglized result will be saved in the type-to-legal-type map and be re-used when the same type requires legalization again (e.g. in the `IRFunc` as parameter) Fixes: https://github.com/shader-slang/slang/issues/7905 2025-09-23T01:20:13+00:00 Theresa Foley 10618364+tangent-vector@users.noreply.github.com 2025-09-23T01:20:13+00:00 urn:sha1:c35b763f811298a6e9c61a4a8eaf805ea98bd608 Overview ======== This change is the start of an attempt to address how the Slang compiler codebase has ended up conflating two similar, but semantically distinct, concepts: * The long-standing notion of `ref` parameters (only allowed for use in the builtin modules), which are encoded using a wrapper `Type` in the AST as part of the representation of the parameters of a `FuncType`. * A recently-introduced notion of explicit reference types that mirror the built-in `Ptr` type, with a relationship comparable to that between pointer and reference types in C++. The change splits the `Ref<T>` type in the core module into two distinct types, with one for each of the two use cases. Similarly, the `RefType` class in the compiler's AST is split into two distinct classes, to represent the two cases. Background ========== The `Ref<T>` type in the core module (hidden and not intended for users to ever see or use) was originally introduced to encode the `ref` parameter-passing mode, comparable to the hidden `Out<T>` and `InOut<T>` types used to encode `out` and `inout` parameter-passing modes. The `Ref<T>` type in the core module was encoded as a instance of the `RefType` class in the Slang AST (similar to how `Out<T>` mapped to an `OutType`). These AST classes were *only* intended to be used by the compiler front-end as part of its encoding of function types. The `FuncType` class needed a way to distinguish an `inout int` parameter from a plain (implicitly `in`) `int` parameter, so these wrapper like `RefType` and `OutType` were introduced to encode both the parameter type (`T`) and the parameter-passing mode in a form that could be passed around as a `Type`. Notably, the `Ref<T>` type (and `Out<T>`, etc.) were *not* intended to be type names that ever get uttered in Slang code (not even in the builtin modules), and the vast majority of the compiler code was not supposed to ever encounter them. They were an implementation detail of `FuncType`, and nothing else. (In hindsight it may have been a mistake to use a nominal type declared in the core module to implement these wrappers; it might have been a good idea to use an entirely separate class of `Type` for this case...) Recent changes to the builtin modules introduced functions that wanted to *return* a reference (so that the parameter-passing-mode modifiers like `ref` could not trivially be used), and as part of those changes the appealingly-named `Ref<T>` type in the core module was re-used for this new case. Builtin operations were declared with an explicit `Ref<T>` return type, and parts of the compiler front-end that had previously been blissfully unaware of the AST's `RefType` (and `InOutType`, etc.) had to start accounting for the possibility that an explicit `Ref<T>` would show up. Related changes also introduced a comparable conflation of the (unfortunately-named) `constref` parameter-passing modifier and builtin operations that wanted to return an explicit reference that is read-only. Both use cases were mapped to the core-module `ConstRef<T>` type, which appeared in the AST as an instance of the `ConstRefType` class. The overlapping use of `ConstRef<T>`` is actually significantly more troublesome than the `Ref<T>` case because, despite what its name implies, `constref` was not really supposed to be the read-only analogue of `ref`, but rather it is closer to the "immutable value borrow" analogue to `inout`'s "mutable value borrow." The semantics of a "value borrow" vs. a "memory reference" in Slang have not been very carefully codified, and the conflation around `ConstRef<T>` has contributed to things becoming increasingly muddy in the compiler back-end. Main Changes ============ Core Module ----------- The `Ref<T>` type has been replaced with two distinct types, with one for each use case: * `RefParam<T>` is intended for use when encoding a `ref` parameter in a function type * `ExplicitRef<T>` is intended for use when an operation in a builtin module wants to return a reference The other types used to represent parameter-passing modes (e.g., `InOut<T>`) were renamed to better indicate that their role in defining parameter types (e.g., `InOutParam<T>`). The `ExplicitRef<T>` type was given additional generic parameters for the allowed access and the address space, akin to what `Ptr<T>` now supports. The pointer dereference operator (prefix `*`) in the core module should now properly propagate the access and address space of the pointer over to the reference that gets returned. The two distinct use cases of `ConstRef<T>` were not split in the way as `Ref<T>`, instead the case for the `constref` parameter-passing mode uses `ConstParamRef<T>`, while cases that previously used `ConstRef<T>` to represent a read-only explicit reference instead now use `ExplicitRef<T, Access.Read>`. Prior to this change there were two subscripts declared on pointers: one in the `Ptr` type itself, and another in an `extension` for pointers with `Access.ReadWrite`. The comments on the code seemed to indicate that the catch-all subscript used to only have a `get` accessor, while the `ref` was only available on read-write pointers, but it seems that subsequent changes converted the default subscript to support `ref`. This change eliminates the subscript added via `extension`, since it is redundant. AST and Front-End ================= Similar to the changes in the core module, the AST `RefType` class was split into: * `RefParamType` for the case of encoding `ref` parameters * `ExplicitRefType` for the case where the user meant an explicit reference type All the other classes that represent wrappers for encoding parameter-passing modes (e.g., `OutType`) were similarly renamed (e.g., `OutParamType`). The `ConstRefType` class was simply renamed to `ConstRefParamType`, because any use cases of `ConstRefType` that intended an explicit reference type will now use `ExplicitRefType` with `Acccess.Read`. For convenience, this change includes type aliases to map the old names for these types over to the new ones (e.g., `using OutType = OutParamType`) so that the change doesn't need to affect quite so many lines of code. The `RefType` and `ConstRefType` names are intentionally left undefined, since it woudl be unsafe to assume that existing use sites should default to either of the two possible interpretations. All use cases of `RefType` and `ConstRefType` (and their former shared base class `RefTypeBase`) were audited and updated to refer to either `RefParamType`/`ConstRefParamType` or `ExplicitRefType`, as appropriate (based on whether the context of the code indicated it was working with parameter-passing mode wrapper types, or explicit reference types). In many (many) cases comments were added to the code that was updated (and some unrelated code that needed to be audited along the way) to note cases where there appears to be something fishy going on in the compiler and/or there are obvious opportunities for next-step improvement. The `QualType` constructor used to infer l-value-ness when passed a `RefType` or `ConstRefType`; that code was introduced to support explicit reference types. The code was updated to consult the access argument of an `ExplicitRefType` to try and determine the right l-value-ness to use. There is some ambiguity about what should be done in the case where the value of the generic argument representing the access cannot be statically determined; a better solution may be needed. Many other cases in the front-end that were working with `RefType` and `ConstRefType` for explicit references also need to figure out l-value-ness, and these were changed to rely on the logic already added to `QualType` so that it wouldn't have to be duplicated. It isn't clear if this structure is the best way to tackle the problem, but it seems to at least be an upgrade over the more strictly ad-hoc logic that was in place before. Future Work =========== IR-Level Work ------------- The most obvious next step to take is that the split that was made in the compiler front-end needs to be properly plumbed through all of the back-end. There appears to be a lot of code in the back end of the compiler that has made the same conflation of `ref` parameters and explicit reference types that the front-end did. In practice, any uses of `ExplicitRef<T>` in the front-end should desugar into plain pointer-based code in the IR. Clean Up Parameter-Passing Modes -------------------------------- The code that handles different parameter-passing modes (`ParameterDirection`s) and their wrapper types is somewhat scattered and messy (as found while auditing use cases of `RefType`). A cleanup pass is warranted to ensure that most code only needs to think about `ParameterDirection`s. There should ideally be only a single operation in the front-end that handles determining the `ParameterDirection` of a parameter based on its modifiers. Similarly, there should be one operation to wrap a value type based on a parameter direction, and one operation to derive a `ParameterDirection` from the wrapper type. Ideally, the accessors for `FuncType` should not provide unrestricted access to the potentially-wrapped parameter types, and should instead return some kind of `ParamInfo` struct that encodes both a `ParameterDirection` and the unwrapped `Type` of the parameter. Clean Up `QualType` ------------------- A significant piece of future work that appears required is to drastically clean up and improve the way that `QualType`s are represente and handled in the front-end. There are currently various distinct `bool` flags in `QualType` (some with very unclear meaning) and differnet parts of the codebase consult/modify only subsets of them; a clear enumeration of the "value categories" (to use the C++ terminology) that Slang supports could be quite helpful. Naively, a `QualType` should at least encode the basic information that a `Ptr` type encodes: * A value type * Allowed access (read-only, read-write, etc.) * Address space The main additional thing that a `QualType` needs is a way to distinguish cases where an expression evaluates to: * A reference to a memory location, where all the information from a `Ptr` is relevant * A simple value, such that the access and address space are irrelevant * A reference to an abstract storage location (a `property`, `subscript`, or an implicit conversion that needs to support being an l-value), in which case address space is irrelevant and the "allowed access" basically amounts to a listing of the accessors the storage location supports Eliminate Explicit Reference Types ---------------------------------- Finally, twe should eventually eliminate the `ExplicitRef<T>` type from the core module (and all of the supporting code from the front-end), since the feature is not a good fit for the Slang language. We should find some other way to decorate operations in the builtin module that need to returns a reference rather than a value (note how `ref` accessors already avoided exposing explicit reference types, by design). --------- Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com> 2025-09-02T23:43:48+00:00 James Helferty (NVIDIA) jhelferty@nvidia.com 2025-09-02T23:43:48+00:00 urn:sha1:f02b08490aa905f42a8d90381db84b1f8e409c0c Changes default for render-test to sm_6_5. Since sm_6_5 is the new default, remove the -use-dxil option, add -use-dxcb option Remove -use-dxil option from all test cases. Add -use-dxcb to two tests that needed it. Fixes #7611 2025-08-29T22:52:34+00:00 ArielG-NV 159081215+ArielG-NV@users.noreply.github.com 2025-08-29T22:52:34+00:00 urn:sha1:7758625d3fea67e55e98e7e4103d56c9918365be Resolves #7628 Resolves: #8197 Primary Goals: 1. Add `Access` to pointer 2. AddressSpace::GroupShared support for pointers (SPIR-V) 3. Add `__getAddress()` to replace `&` * `&` is not updated to `require(cpu)` since slangpy uses `&`. This means we must: (1) merge PR; (2) replace `&` with `__getAddress()`; (3) add `require(cpu)` to `&` Changes: * Added to `Ptr` the `Access` generic argument & logic (for `Access::Read`). * Moved the generic argument `AddressSpace` from `Ptr` to the end of the type. * Added pointer casting support between any `Ptr` as long as the `AddressSpace` is the same * Disallow globallycoherent T* and coherent T* * Disallow const T*, T const*, and const T* * Fixed .natvis display of `ConstantValue` `ValOperandNode` * Support generic resolution of type-casted integers * Added `VariablePointer` emitting for spirv + other minor logic needed for groupshared pointers Breaking Changes: * Anyone using the `AddressSpace` of `Ptr` will now have to account for the `Access` argument * we disallow various syntax paired with `Ptr` and `T*` --------- Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com> 2025-08-28T17:45:07+00:00 Jay Kwak 82421531+jkwak-work@users.noreply.github.com 2025-08-28T17:45:07+00:00 urn:sha1:c19e2e92ae8e713225262a17f39a438cd511d416 When `SIMPLE` type test is used with `-g[1-3]` option, the filecheck pattern will most likely to match to the string itself on the embedded source code rather than match to the emitted spirv-asm code. This commit avoids the problem by removing the embedded source code. This commit also provides an option to keep the embedded source code, `-preserve-embedded-source`. The source code removal is happening in two steps: 1. iterate all output lines and find SPIRV-ASM in the following pattern: `%N = OpExtInst %void %M DebugSource %fileId %sourceId`. And then, store the "%sourceId" value to identify which SPIRV instructions are for the embedded source code. 2. iterate all output lines again to find the `%sourceId = OpString "...."` and replace the whole string with the following string, ``` %1 = OpString "// slang-test removed the embedded source // Use `-preserve-embedded-source` to keep it explicitly " ``` This change revealed problems in the existing tests: - tests/bugs/spirv-debug-info.slang : The expected text was missing and it had to be added. The file also had Carrage-Return character on all lines and the pre-commit git hook removed them. - tests/spirv/debug-info.slang : the expected keyword DebugValue had to change to DebugDeclare, because that's what we get with ToT. - tests/spirv/debug-value-dynamic-index.slang : This test is currently failing, and it will pass once DebugLocalVariable instruction missing for parameter of the entry point function #7693 is resolved. --------- Co-authored-by: slangbot <ellieh+slangbot@nvidia.com> 2025-08-22T20:48:20+00:00 Lujin Wang 143145775+lujinwangnv@users.noreply.github.com 2025-08-22T20:48:20+00:00 urn:sha1:cd9e1f67184c1361558e18993e5cb392dc1131f0 Fixes the Slang compiler internal error "subscript had no getter" when reading from mesh shader output index arrays (e.g., `triangles[0].x`). ## Problem The `OutputIndices` struct was missing a `ref` accessor in its `__subscript` implementation, causing the compiler to fail when trying to materialize subscript expressions as r-values. ## Solution Added the missing `ref` accessor to `OutputIndices.__subscript` using the `kIROp_MeshOutputRef` intrinsic operation, matching the pattern used in `OutputVertices` and `OutputPrimitives`. ## Files Changed - `source/slang/core.meta.slang` - Added missing `ref` accessor - `tests/bugs/gh-7925.slang` - Test case to reproduce and verify the fix Fixes #7925 Generated with [Claude Code](https://claude.ai/code) --------- Co-authored-by: Claude <noreply@anthropic.com> Co-authored-by: Lujin Wang <lujinwangnv@users.noreply.github.com> Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com> Co-authored-by: slangbot <ellieh+slangbot@nvidia.com> Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com> 2025-08-20T22:13:52+00:00 Julius Ikkala julius.ikkala@gmail.com 2025-08-20T22:13:52+00:00 urn:sha1:cbd73dde3dd2da790bb663385a229ce22965c43c Fixes #8185. The previous implementation is incorrect and basically only works in the `x = 0` case. `delta` was the smallest possible positive value representable as a float, but that's below the rounding error of addition with almost all reasonably sized floats. This fixed implementation is based on bit twiddling instead. I've checked the float case against the C++ `nextafterf` with both a -inf -> inf and inf -> -inf sweep, in addition to the test included in this PR.