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Re: [PATCH][Version 3]Come up with -flive-patching master option.
>
> 2018-11-20 qing zhao <qing.zhao@oracle.com>
>
> * cif-code.def (EXTERN_LIVE_ONLY_STATIC): New CIF code.
> * common.opt: Add -flive-patching flag.
> * doc/invoke.texi: Document -flive-patching.
> * flag-types.h (enum live_patching_level): New enum.
> * ipa-inline.c (can_inline_edge_p): Disable external functions from
> inlining when flag_live_patching is LIVE_PATCHING_INLINE_ONLY_STATIC.
> * opts.c (control_options_for_live_patching): New function.
> (finish_options): Make flag_live_patching incompatible with flag_lto.
> Control IPA optimizations based on different levels of
> flag_live_patching.
>
> gcc/testsuite/ChangeLog:
>
> 2018-11-20 qing zhao <qing.zhao@oracle.com>
>
> * gcc.dg/live-patching-1.c: New test.
> * gcc.dg/live-patching-2.c: New test.
> * gcc.dg/live-patching-3.c: New test.
> * gcc.dg/tree-ssa/writeonly-3.c: New test.
> * gcc.target/i386/ipa-stack-alignment-2.c: New test.
>
I am still somewhat worried about possible use with C++ programs where
we will kill all inlining of comdats, but I guess we could discuss that
when it becomes an issue.
+
+ /* FIXME: disable unreachable code removal. */
Disabling unreachable code removal will really introduce a lot of extra
dead code, can't live patches just provide what they need if the code
was earlier removed.
+
+ /* discovery of functions/variables with no address taken. */
+ if (opts_set->x_flag_ipa_reference_addressable
+ && opts->x_flag_ipa_reference_addressable)
+ error_at (loc,
+ "%<-fipa-reference-addressable%> is incompatible with "
+ "%<-flive-patching=inline-only-static|inline-clone%>");
+ else
+ opts->x_flag_ipa_reference_addressable = 0;
+
+ /* ipa stack alignment propagation. */
+ if (opts_set->x_flag_ipa_stack_alignment
+ && opts->x_flag_ipa_stack_alignment)
+ error_at (loc,
+ "%<-fipa-stack-alignment%> is incompatible with "
+ "%<-flive-patching=inline-only-static|inline-clone%>");
+ else
+ opts->x_flag_ipa_stack_alignment = 0;
Shall we also disable nothrow or we will worry about C++ only ter?
Patch is OK,
thanks!
Honza