[PATCH] Fix ICE in distribute_notes (PR bootstrap/51796)

[Eric Botcazou]

> I'd find that very fragile.  E.g. distribute_notes itself reverses the
> order of all notes, and for no REG_NOTES I think we rely on any ordering.

AFAIK distribute_notes is the only routine that redistributes the RTL notes for 
a fixed insn, so I'm a little skeptical about the purported fragility here.
My point is that the complexity should be in fixup_args_size_notes instead of 
distribute_notes.  Tentative patch attached.


	PR bootstrap/51796
	* calls.c (emit_call_1): Make sure REG_NORETURN note comes first.
	* combine.c (distribute_notes): If i3 is a noreturn call, allow
	old_size to be equal to args_size if !ACCUMULATE_OUTGOING_ARGS.
	* expr.c (fixup_args_size_notes): Put REG_ARGS_SIZE notes on
	noreturn calls even when the delta is 0.
	* rtlanal.c (find_and_remove_reg_note): New function.
	* rtl.h (find_and_remove_reg_note): Declare it.


-- 
Eric Botcazou
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