Fix pathological complexity explosion for certain shaders.#1594
Merged
HansKristian-Work merged 1 commit intomasterfrom Jan 15, 2021
Merged
Fix pathological complexity explosion for certain shaders.#1594HansKristian-Work merged 1 commit intomasterfrom
HansKristian-Work merged 1 commit intomasterfrom
Conversation
Certain shaders where functions have a *ton* of merging control flow will end up with exponential time complexity to figure out parameter preservation semantics. The trivial fix to make it O(1) again is to terminate recursive traversal early if we've seen the path before. Simple oversight :(
This was referenced Jan 19, 2021
bors bot
added a commit
to gfx-rs/wgpu
that referenced
this pull request
Jan 23, 2021
1163: Bump gfx to latest master r=kvark a=mkeeter **Connections** - This bumps `gfx` to [#3610](gfx-rs/gfx#3610), and also includes [#3608](gfx-rs/gfx#3608) and [#3609](gfx-rs/gfx#3608) - [Here](gfx-rs/wgpu-native#66) is a draft PR to `wgpu-native` - `wgpu-rs` requires a one-line fix to the `texture_view_drop` call (which now takes a boolean); I can PR this next. **Description** This fixes [pathological shader complexity in SPIRV-Cross](KhronosGroup/SPIRV-Cross#1594), as well as a few other `gfx` PRs. **Testing** I updated `wgpu-native` to use this branch, then updated my [toy raytracer](https://github.com/mkeeter/rayray) to use the resulting `dylibs` and confirmed that it no longer takes forever to compile the pathological shader. In addition, I updated `wgpu-rs` and went through the examples; nothing seems out of place. Co-authored-by: Matt Keeter <matt.j.keeter@gmail.com>
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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.
Certain shaders where functions have a ton of merging control flow
will end up with exponential time complexity to figure out parameter
preservation semantics.
The trivial fix to make it O(1) again is to terminate recursive traversal early if we've seen
the path before. Simple oversight :(
Fix #1591.