Fix std430 layout support for cbuffers in .slang files #8432
+26
−2
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Co-authored-by: bmillsNV <[email protected]>
Co-authored-by: bmillsNV <[email protected]>
Co-authored-by: bmillsNV <[email protected]>
Copilot
AI
changed the title
Copilot finished work on behalf of
bmillsNV
September 11, 2025 00:06
|
Copilot, I think it needs to warn when layout (std430) etc are used when compiling for other targets (warn instead of error to make it a non-breaking PR), and accept these layout modifiers when compiling for GLSL/SPIRV without requiring |
davli-nv
requested changes
Sep 25, 2025
| // Check for GLSL layout qualifiers when GLSL input is allowed | ||
| if (parser->options.allowGLSLInput && parser->pendingModifiers) | ||
| // Check for GLSL layout qualifiers (layout modifiers can be used even without allowGLSLInput) | ||
| if (parser->pendingModifiers) |
There was a problem hiding this comment.
Copilot, I think it needs to warn when layout (std430) etc are used when compiling for other targets (warn instead of error to make it a non-breaking PR), and accept these layout modifiers when compiling for GLSL/SPIRV without requiring -allow-glsl
| int2 a[2]; | ||
| }; | ||
|
|
||
| ConstantBuffer<B, Std430DataLayout> c; |
There was a problem hiding this comment.
Copilot, for simplicity this ConstantBuffer can be dropped
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The
layout(std430) cbuffersyntax was not working correctly in.slangfiles, causing incorrect ArrayStride values in generated SPIR-V. Arrays ofint2were getting ArrayStride 16 (std140 layout) instead of ArrayStride 8 (std430 layout).The issue occurred because the
parseHLSLCBufferDeclfunction only processed GLSL layout qualifiers whenallowGLSLInputwas enabled, but layout parsing itself is always available. This meant that whilelayout(std430)was parsed and attached as a modifier, it was ignored during cbuffer processing in.slangfiles.Before:
After:
This fix ensures that
layout(std430) cbufferdeclarations work consistently whether using.slangor.glslfiles, and that the generated SPIR-V uses the correct layout rules for buffer members.Fixes #8373.
💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.