Collaboration diagram for csa_reflist:

Data Fields
HOST_WIDE_INT	sp_offset

rtx_insn *	insn

rtx *	ref

struct csa_reflist *	next

Detailed Description

Combine stack adjustments.
   Copyright (C) 1987-2024 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.

Track stack adjustments and stack memory references.  Attempt to
reduce the number of stack adjustments by back-propagating across
the memory references.

This is intended primarily for use with targets that do not define
ACCUMULATE_OUTGOING_ARGS.  It is of significantly more value to
targets that define PREFERRED_STACK_BOUNDARY more aligned than
STACK_BOUNDARY (e.g. x86), or if not all registers can be pushed
(e.g. x86 fp regs) which would ordinarily have to be implemented
as a sub/mov pair due to restrictions in calls.cc.

Propagation stops when any of the insns that need adjusting are
(a) no longer valid because we've exceeded their range, (b) a
non-trivial push instruction, or (c) a call instruction.

Restriction B is based on the assumption that push instructions
are smaller or faster.  If a port really wants to remove all
pushes, it should have defined ACCUMULATE_OUTGOING_ARGS.  The
one exception that is made is for an add immediately followed
by a push.

This structure records two kinds of stack references between stack
adjusting instructions: stack references in memory addresses for
regular insns and all stack references for debug insns.