s390x: Fix epilog for some tail-call ABI routines#11689
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alexcrichton merged 1 commit intobytecodealliance:mainfrom Sep 11, 2025
Merged
s390x: Fix epilog for some tail-call ABI routines#11689alexcrichton merged 1 commit intobytecodealliance:mainfrom
alexcrichton merged 1 commit intobytecodealliance:mainfrom
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When using the tail-call ABI and the callee needs to pop a non-zero amount of bytes, the stack pointer may never be implicitly restored via the LOAD MULTIPLE instruction in the epilog, but will always be manually updated. In some rare cases involving exception handling, the epilog for such functions incorrectly did include the stack pointer in the LOAD MULTIPLE list. It turns out that the is_reg_saved_in_prologue routine did not handle the stack pointer correctly. Note that this only makes any difference for functions where cranelift common code includes the stack pointer in the list of clobbered registers passed to compute_frame_layout, which normally never happens as modifications to the stack pointer should be invisible to common code register tracking ... Fixes: bytecodealliance#11602
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…1689) When using the tail-call ABI and the callee needs to pop a non-zero amount of bytes, the stack pointer may never be implicitly restored via the LOAD MULTIPLE instruction in the epilog, but will always be manually updated. In some rare cases involving exception handling, the epilog for such functions incorrectly did include the stack pointer in the LOAD MULTIPLE list. It turns out that the is_reg_saved_in_prologue routine did not handle the stack pointer correctly. Note that this only makes any difference for functions where cranelift common code includes the stack pointer in the list of clobbered registers passed to compute_frame_layout, which normally never happens as modifications to the stack pointer should be invisible to common code register tracking ... Fixes: bytecodealliance#11602
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When using the tail-call ABI and the callee needs to pop a non-zero amount of bytes, the stack pointer may never be implicitly restored via the LOAD MULTIPLE instruction in the epilog, but will always be manually updated.
In some rare cases involving exception handling, the epilog for such functions incorrectly did include the stack pointer in the LOAD MULTIPLE list. It turns out that the
is_reg_saved_in_prologue routine did not handle the stack pointer correctly.
Note that this only makes any difference for functions where cranelift common code includes the stack pointer in the list of clobbered registers passed to compute_frame_layout, which normally never happens as modifications to the stack pointer should be invisible to common code register tracking ...
Fixes: #11602