[Bug other/67648] No need to save callee-saved registers in interrupt handler

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67648

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
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   Target Milestone|---                         |6.0

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> ---
Julia, we should avoid changing call_used_regs in
ix86_conditional_register_usage.   Instead, we should
only save and restore caller-saved registers changed by
interrupt handler.