Revert "JIT: support SSA-aware PHI jump threading"#126969
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MichalStrehovsky wants to merge 1 commit intomainfrom
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Revert "JIT: support SSA-aware PHI jump threading"#126969MichalStrehovsky wants to merge 1 commit intomainfrom
MichalStrehovsky wants to merge 1 commit intomainfrom
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This reverts commit 578644c.
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/azp run runtime-nativeaot-outerloop |
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Pull request overview
Reverts the previously introduced SSA-aware PHI jump-threading support in CoreCLR JIT redundant-branch optimizations, likely to validate/restore behavior for outer-loop scenarios.
Changes:
- Remove SSA/VN rewrite machinery for non-local PHI uses during jump threading and revert PHI-based threading to require locally-consumed PHIs.
- Simplify
optJumpThreadCheckfrom a multi-state result back to a boolean eligibility check, removing related helper APIs. - Remove the accompanying JIT regression test (
JumpThreadPhi) and the dedicatedCompMemKindentry that was only used by the reverted feature.
Reviewed changes
Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.
Show a summary per file
| File | Description |
|---|---|
| src/tests/JIT/opt/RedundantBranch/JumpThreadPhi.csproj | Removes the test project introduced with the reverted change. |
| src/tests/JIT/opt/RedundantBranch/JumpThreadPhi.cs | Removes the test case introduced with the reverted change. |
| src/coreclr/jit/redundantbranchopts.cpp | Reverts SSA-aware PHI jump-threading handling, removing PHI-use tracking and SSA/VN rewrites; restores stricter eligibility checks. |
| src/coreclr/jit/compmemkind.h | Removes the RedundantBranch allocator kind that is no longer referenced after the revert. |
| src/coreclr/jit/compiler.h | Removes the JumpThreadCheckResult API surface and related declarations, matching the reverted implementation. |
This was referenced Apr 16, 2026
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Checking if this broke outerloops.
Reverts #126812