Making it easier to work with shaders https://git.yummers.dev/slang.git/atom?h=master 2025-10-01T02:08:23+00:00 2025-10-01T02:08:23+00:00 Yong He yonghe@outlook.com 2025-10-01T02:08:23+00:00 urn:sha1:e4611e2e30a3e5969d402f5ed7e72706a0e3b024 This allows us to specialize functions whose argument is a sub element of a constant buffer, instead of being only applicable to entire buffer element. Closes #8421. This change also implements a proper heuristic to determine when to specialize the calls and defer the buffer loads. This PR addresses a pathological case exposed in `slangpy\slangpy\benchmarks\test_benchmark_tensor.py`, which used to take 27ms to finish, and now takes 1.25ms. For example, given: ``` struct Bottom { float bigArray[1024]; [mutating] void setVal(int index, float value) { bigArray[index] = value; } } struct Root { Bottom top[2]; [mutating] void setTopVal(int x, int y, float value) { top[x].setVal(y, value); } } RWStructuredBuffer<Root> sb; [shader("compute")] [numthreads(1, 1, 1)] void compute_main(uint3 tid: SV_DispatchThreadID) { sb[0].setTopVal(1, 2, 100.0f); } ``` We are now able to specialize the call to `setTopVal` into: ``` void compute_main(uint3 tid: SV_DispatchThreadID) { setTopVal_specialized(0, 1, 2, 100.0f); } void setTopVal_specialized(int sbIdx, int x, int y, float value) { Bottom_setVal_specialized(sbIdx, x, y, value); } void Bottom_setVal_specialized(int sbIdx, int x, int y, float value) { sb[sbIdx].top[x].bigArray[y] = value; } ``` And get rid of all unnecessary loads. Achieving this requires a combination of function call specialization and buffer-load-defer pass. The buffer-load-defer pass has been completely rewritten to be more correct and avoid introducing redundant loads. This PR also adds tests to make sure pointers, bindless handles, and loads from structured buffer or constant buffers works as expected. 2025-09-30T00:45:08+00:00 Yong He yonghe@outlook.com 2025-09-30T00:45:08+00:00 urn:sha1:a6deb5ed82cb8fc6b4f4c5c5fee264e09f97ff89 Part of the effort to improve the performance of generated SPIRV code. The existing lower-buffer-element-type pass works by loading the entire buffer element content from memory, and translate it to logical type stored in a local variable at the earliest reference of a buffer handle. This means that is can generate inefficient code that reads more than necessary. Consider this example: ``` struct BigStruct { bool values[1024]; } ConstantBuffer<BigStruct> cb; void test(BigStruct v) { if (v.values[0]) { printf("ok"); } } [numthreads(1,1,1)] void computeMain() { test(cb); } ``` In IR, the `computeMain` function before lower-buffer-element-type pass is something like following: ``` func test: %v = param : BigStruct %barr = fieldExtract(%v, "values") %element = elementExtract(%barr, 0) ... // uses %element func computeMain: %v = load(cb) call %test %v ``` The existing lower-buffer-element-type pass will rewrite the bool array in `BigStruct` into `int` array so it is legal in SPIRV. However, it does so by inserting the translation on the first `load` of the constant buffer: ``` struct BigStruct_std430 { int values[1024]; } var cb : ConstantBuffer<BigStruct_std430>; func computeMain: %tmpVar : var<BigStruct> call %unpackStorage(%tmpVar, cb) %v : BigStruct = load %tmpVar call %test %v ``` This means that the entire array will be loaded and translated to int, before calling `test`, which only uses one element. It turns out that the downstream compiler isn't always able to optimize out this inefficient translation/copy. This PR completely rewrites the way buffer-element-type lowering is handled to avoid producing this inefficient code. It works in two parts: first we turn on the `transformParamsToConstRef` pass for SPIRV target as well, so we will translate the `test` function to take the `v` parameter as `constref`. The second part is a redesigned buffer-element-type pass that defers the storage-type to logical-type translation until a value is actually used by a `load` instruction. In this example, after `transformParamsToConstRef`, the IR is: ``` func test: %v = param : ConstRef<BigStruct> %barr = fieldAddr(%v, "values") %elementPtr = elementAddr(%barr, 0) %element = load(%elementPtr) ... // uses %element func computeMain: call %test %cb ``` The new `buffer-element-type-lowering` pass will take this IR, and insert translation at latest possible time across the entire call graph, and translate the IR into: ``` func test: %v = param : ConstRef<BigStruct_std430> %barr = fieldAddr(%v, "values") %elementPtr : ptr<int> = elementAddr(%barr, 0) %element_int = load(%elementPtr) %element = cast(%element_int) : %bool ... // uses %element func computeMain: call %test %cb ``` In this new IR, there is no longer a load and conversion of the entire array. See new comment in `slang-ir-lower-buffer-element-type.cpp` for more details of how the pass works. This PR also address many other issues surfaced by turning on `transformParamsToConstRef` pass on SPIRV backend. --------- Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com> 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> 2025-07-11T23:54:43+00:00 Yong He yonghe@outlook.com 2025-07-11T23:54:43+00:00 urn:sha1:1e1a49ccf595dcc99bd9792a47199ec89d5b4370 * Fixup address spaces after inlining. * add -O0 2025-01-22T17:10:35+00:00 Anders Leino aleino@nvidia.com 2025-01-22T17:10:35+00:00 urn:sha1:04353fb7602b7eb6a8b86193510ebe0c670b7724 * Reimplement the GLSL atomic* functions in terms of __intrinsic_op Many of these functions map directly to atomic IR instructions. The functions taking atomic_uint are left as they are. This helps to address #5989, since the destination pointer type validation can then be written only for the atomic IR instructions. * Add validation for atomic operations Diagnose an error if the destination of the atomic operation is not appropriate, where appropriate means it's either: - 'groupshared' - from a device buffer This closes #5989. * Add tests for GLSL atomics destination validation Attempting to use the GLSL atomic functions on destinations that are neither groupshared nor from a device buffer should fail with the following error: error 41403: cannot perform atomic operation because destination is neither groupshared nor from a device buffer. * Validate atomic operations after address space specialization Address space specialization for SPIR-V is not done as part of `linkAndOptimizeIR`, as it is for e.g. Metal, so opt out and add a separate call for SPIR-V. * Allow unchecked in/inout parameters for non-SPIRV targets * Clean up callees left without uses during address space specialziation * format code --------- Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com> Co-authored-by: Yong He <yonghe@outlook.com> 2024-10-29T06:49:26+00:00 Ellie Hermaszewska ellieh@nvidia.com 2024-10-29T06:49:26+00:00 urn:sha1:f65d756bff8d4c5cbc15bd0322a2ae8e6b896a21 * format * Minor test fixes * enable checking cpp format in ci 2024-10-09T14:35:10+00:00 Yong He yonghe@outlook.com 2024-10-09T14:35:10+00:00 urn:sha1:ac6f04c15995061ebe8e0ddf62ecf7eb979afb65 * Fix spirv lowering logic around pointer to unsized array. * Fix. --------- Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com> 2024-08-19T22:06:34+00:00 Ellie Hermaszewska ellieh@nvidia.com 2024-08-19T22:06:34+00:00 urn:sha1:f77a5ac9d1547a4394bba4ab8e94d905972c79b7 * Remove using SpvStorageClass values casted into AddressSpace values Also removes support for specific storage classes in __target_intrinsic snippets * remove SLANG_RETURN_NEVER macro * squash warnings * Make nonexhaustive switch statement error on gcc * Add SLANG_EXHAUSTIVE_SWITCH_BEGIN/END macros --------- Co-authored-by: Yong He <yonghe@outlook.com> 2024-07-25T22:00:14+00:00 Yong He yonghe@outlook.com 2024-07-25T22:00:14+00:00 urn:sha1:c9d89a40775a055873adf82cfb0ee1cb6bdcb93c * Overhaul IR lowering of pointer types. * Propagate address space in IRBuilder. * Fixup. * Fix. * Fix. * Change how Ptr type is printed to text. * Fix. 2024-07-10T23:17:10+00:00 Yong He yonghe@outlook.com 2024-07-10T23:17:10+00:00 urn:sha1:746d47bb491e0b97e35ab373b4b78d33b9a61164 * Specialize address space during spirv legalization. * Fix. * Fix building doc. * Fix cmake. * Update assert.