Fix perf regression: limit debug info to relevant subprograms (#8174)#8177
Open
damyanp wants to merge 1 commit intomicrosoft:mainfrom
Open
Fix perf regression: limit debug info to relevant subprograms (#8174)#8177damyanp wants to merge 1 commit intomicrosoft:mainfrom
damyanp wants to merge 1 commit intomicrosoft:mainfrom
Conversation
…oft#8174) PR microsoft#7799 added debug info for global variables across all inlined subprograms, creating O(subprograms x globals) debug instructions. This caused 2-3x slower compilation for shaders with many globals and deeply-inlined functions. Fix: Instead of collecting ALL subprograms for a function (walking every instruction), only collect subprograms from the alloca's actual users -- the instructions that reference the specific global variable. This preserves the debug info feature (globals visible in inlined scopes that use them) while eliminating work for unrelated scopes. The 'Lower static global into Alloca' pass is 3.8x faster on the stress test (41ms -> 11ms), and overall debug compilation is ~10% faster. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
tex3d
approved these changes
Feb 20, 2026
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
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
PR #7799 added debug info for global variables across all inlined subprograms, creating O(subprograms x globals) debug instructions. This caused 2-3x slower compilation for shaders with many globals and deeply-inlined functions.
Fix: Instead of collecting ALL subprograms for a function (walking every instruction), only collect subprograms from the alloca's actual users -- the instructions that reference the specific global variable. This preserves the debug info feature (globals visible in inlined scopes that use them) while eliminating work for unrelated scopes.
The 'Lower static global into Alloca' pass is 3.8x faster on a stress test (41ms -> 11ms), and overall debug compilation is ~10% faster.
Fixed #8174