Move RBM_SAVED_LOCALLOC_SP reservation from compCompile to setFrameType in LSRA#121745
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jakobbotsch merged 4 commits intomainfrom Jan 2, 2026
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Move RBM_SAVED_LOCALLOC_SP reservation from compCompile to setFrameType in LSRA#121745jakobbotsch merged 4 commits intomainfrom
jakobbotsch merged 4 commits intomainfrom
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[WIP] Move RBM_SAVED_LOCALLOC_SP assignment to setFrameType
Move RBM_SAVED_LOCALLOC_SP reservation from compCompile to setFrameType in LSRA
Nov 18, 2025
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Nov 18, 2025
Co-authored-by: jakobbotsch <[email protected]>
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Pull Request Overview
This PR relocates ARM-specific register reservation code from the compCompile function to the setFrameType function in LSRA. The change moves the logic that reserves RBM_SAVED_LOCALLOC_SP (R9 on ARM) for stack unwinding when localloc is used, placing it closer to related register reservation code.
Key changes:
- Removes the
#ifdef TARGET_ARMblock fromcompCompileincompiler.cpp - Adds the same logic to
setFrameTypeinlsra.cpp, positioned after theRBM_OPT_RSVDreservation code - Includes a new JITDUMP statement for debugging visibility when the register is reserved
Reviewed Changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| src/coreclr/jit/compiler.cpp | Removed ARM-specific register reservation block from compCompile function |
| src/coreclr/jit/lsra.cpp | Added ARM-specific register reservation to setFrameType with JITDUMP logging |
Co-authored-by: Copilot <[email protected]>
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AndyAyersMS
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Dec 12, 2025
This was referenced Jan 9, 2026
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Move the code that adds
RBM_SAVED_LOCALLOC_SPtorsMaskResvdfromcompCompileintosetFrameTypein LSRAPlan
compiler.cpplines 4953-4959 (insidecompCompile)lsra.cppsetFrameType()function after line 2718compiler.cpp(lines 4953-4959)lsra.cppinsetFrameType()after existingrsMaskResvdsettingChanges Made
#ifdef TARGET_ARMblock that setsRBM_SAVED_LOCALLOC_SPinrsMaskResvdfrom thecompCompilefunctionsetFrameType()after the existing code that setsrsMaskResvdfor large frame offsetsREG_SAVED_LOCALLOC_SPis reservedBuild Status
✅ CoreCLR build succeeded with changes
✅ CoreCLR build succeeded with JITDUMP addition
✅ No CodeQL security issues detected
Security Summary
No security vulnerabilities were introduced or detected in this change. The code is a straightforward refactoring that moves existing logic to a more appropriate location without changing its behavior.
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