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From: "siddhesh at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/113514] Wrong __builtin_dynamic_object_size when
 using a set local variable
Date: Mon, 22 Jan 2024 13:58:59 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113514

--- Comment #5 from Siddhesh Poyarekar <siddhesh at gcc dot gnu.org> ---
What seems to be happening is that early_objsz bails out since the subobject
size at that point is not a constant; I remember concluding that it's safes=
t to
stick to constant sizes here, but I can't remember why I came to that
conclusion.  Then in constant propagation (literally the next pass in -O2),=
 the
reference gets folded into a MEM_REF and we have the classic case of the
subobject reference being lost, due to which we see the whole object size t=
here
instead of the subobject size.

I need to try and remember why I decided against generating expressions in
early_objsz.=