#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "rtl.h"
#include "df.h"
#include "memmodel.h"
#include "tm_p.h"
#include "insn-config.h"
#include "regs.h"
#include "emit-rtl.h"
#include "recog.h"
#include "diagnostic-core.h"
#include "addresses.h"
#include "tree-pass.h"
#include "rtl-iter.h"
#include "cfgrtl.h"
#include "target.h"
#include "function-abi.h"
#include "cfgcleanup.h"

Include dependency graph for regcprop.cc:

Data Structures
struct	queued_debug_insn_change
struct	value_data_entry
struct	value_data
struct	kill_set_value_data

Functions
static void	kill_value_one_regno (unsigned, struct value_data *)
static void	kill_value_regno (unsigned, unsigned, struct value_data *)
static void	kill_value (const_rtx, struct value_data *)
static void	set_value_regno (unsigned, machine_mode, struct value_data *)
static void	init_value_data (struct value_data *)
static void	kill_clobbered_value (rtx, const_rtx, void *)
static void	kill_set_value (rtx, const_rtx, void *)
static void	copy_value (rtx, rtx, struct value_data *, bool frame_related)
static bool	mode_change_ok (machine_mode, machine_mode, unsigned int)
static rtx	maybe_mode_change (machine_mode, machine_mode, machine_mode, unsigned int, unsigned int)
static bool	incompatible_frame_status (bool, bool)
static rtx	find_oldest_value_reg (enum reg_class, rtx, struct value_data *, bool frame_related)
static bool	replace_oldest_value_reg (rtx , enum reg_class, rtx_insn , struct value_data *)
static bool	replace_oldest_value_addr (rtx , enum reg_class, machine_mode, addr_space_t, rtx_insn , struct value_data *)
static bool	replace_oldest_value_mem (rtx, rtx_insn , struct value_data )
static bool	copyprop_hardreg_forward_1 (basic_block, struct value_data *)
void	debug_value_data (struct value_data *)
static void	validate_value_data (struct value_data *)
static void	free_debug_insn_changes (struct value_data *vd, unsigned int regno)
static void	kill_value_one_regno (unsigned int regno, struct value_data *vd)
static void	kill_value_regno (unsigned int regno, unsigned int nregs, struct value_data *vd)
static void	set_value_regno (unsigned int regno, machine_mode mode, struct value_data *vd)
static void	kill_autoinc_value (rtx_insn insn, struct value_data vd)
static void	apply_debug_insn_changes (struct value_data *vd, unsigned int regno)
static void	cprop_find_used_regs (rtx loc, void data)
static void	kill_clobbered_values (rtx_insn insn, struct value_data vd)
void	copyprop_hardreg_forward_bb_without_debug_insn (basic_block bb)
rtl_opt_pass *	make_pass_cprop_hardreg (gcc::context *ctxt)

Variables
static object_allocator< queued_debug_insn_change >	queued_debug_insn_change_pool ("debug insn changes pool")
static bool	skip_debug_insn_p

Function Documentation

◆ apply_debug_insn_changes()

void apply_debug_insn_changes	(	struct value_data *	vd,
		unsigned int	regno )

static

Apply all queued updates for DEBUG_INSNs that change some reg to
register REGNO.

References apply_change_group(), apply_debug_insn_changes(), value_data_entry::debug_insn_changes, value_data::e, queued_debug_insn_change::insn, queued_debug_insn_change::loc, queued_debug_insn_change::new_rtx, queued_debug_insn_change::next, and validate_change().

Referenced by apply_debug_insn_changes(), and cprop_find_used_regs().

◆ copy_value()

void copy_value	(	rtx	dest,
		rtx	src,
		struct value_data *	vd,
		bool	frame_related )

static

Assert that SRC has been copied to DEST.  Adjust the data structures
to reflect that SRC contains an older copy of the shared value.

References copy_value(), value_data::e, fixed_regs, frame_pointer_needed, value_data_entry::frame_related, GET_MODE, GET_MODE_PRECISION(), global_regs, HARD_FRAME_POINTER_REGNUM, hard_regno_nregs(), i, INVALID_REGNUM, value_data_entry::mode, value_data_entry::next_regno, value_data_entry::oldest_regno, partial_subreg_p(), REG_CAN_CHANGE_MODE_P, REG_NREGS, REGNO, set_value_regno(), subreg_lowpart_offset(), validate_value_data(), and kill_set_value_data::vd.

Referenced by copy_value(), copyprop_hardreg_forward_1(), and set_value_regno().

◆ copyprop_hardreg_forward_1()

bool copyprop_hardreg_forward_1	(	basic_block	bb,
		struct value_data *	vd )

static

Perform the forward copy propagation on basic block BB.

References ADDR_SPACE_GENERIC, alternative_class(), apply_change_group(), asm_noperands(), BB_END, BB_HEAD, CALL_INSN_FUNCTION_USAGE, CALL_P, function_abi::clobbers_reg_p(), copy_value(), copyprop_hardreg_forward_1(), cprop_find_used_regs(), DEBUG_BIND_INSN_P, delete_insn(), delete_insn_and_edges(), df_insn_rescan(), dump_file, value_data::e, exp(), extract_constrain_insn(), find_oldest_value_reg(), find_reg_note(), value_data_entry::frame_related, GET_CODE, GET_MODE, hard_regno_nregs(), i, kill_set_value_data::ignore_set_reg, incompatible_frame_status(), insn_callee_abi(), kill_set_value_data::insn_is_frame_related, INSN_UID(), INSN_VAR_LOCATION_LOC, INVALID_REGNUM, kill_autoinc_value(), kill_clobbered_values(), kill_set_value(), kill_value(), kill_value_regno(), operand_alternative::matches, may_trap_p(), maybe_mode_change(), MEM_P, value_data_entry::mode, value_data::n_debug_insn_changes, NEXT_INSN(), value_data_entry::next_regno, NONDEBUG_INSN_P, NONJUMP_INSN_P, noop_move_p(), note_stores(), note_uses(), NULL, NULL_RTX, value_data_entry::oldest_regno, OP_IN, OP_INOUT, OP_OUT, ORIGINAL_REGNO, partial_subreg_p(), PATTERN(), preprocess_constraints(), recog_data, REG_ATTRS, REG_NOTE_KIND, REG_NOTES, REG_NREGS, reg_overlap_mentioned_p(), REG_P, REG_POINTER, REGNO, replace_oldest_value_addr(), replace_oldest_value_mem(), replace_oldest_value_reg(), rtx_equal_p(), RTX_FRAME_RELATED_P, SET, SET_DEST, SET_SRC, set_value_regno(), side_effects_p(), single_set(), stack_pointer_rtx, subreg_lowpart_offset(), targetm, validate_change(), validate_unshare_change(), VAR_LOC_UNKNOWN_P, kill_set_value_data::vd, which_op_alt(), and XEXP.

Referenced by copyprop_hardreg_forward_1(), copyprop_hardreg_forward_bb_without_debug_insn(), and set_value_regno().

◆ copyprop_hardreg_forward_bb_without_debug_insn()

void copyprop_hardreg_forward_bb_without_debug_insn ( basic_block bb )

Do copyprop_hardreg_forward_1 for a single basic block BB.
DEBUG_INSN is skipped since we do not want to involve DF related
staff as how it is handled in function pass_cprop_hardreg::execute.

NOTE: Currently it is only used for shrink-wrap.  Maybe extend it
to handle DEBUG_INSN for other uses.

Copy propagation on hard registers.
   Copyright (C) 1989-2026 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/>.

References copyprop_hardreg_forward_1(), copyprop_hardreg_forward_bb_without_debug_insn(), free(), init_value_data(), and skip_debug_insn_p.

Referenced by copyprop_hardreg_forward_bb_without_debug_insn(), and prepare_shrink_wrap().

◆ cprop_find_used_regs()

void cprop_find_used_regs	(	rtx *	loc,
		void *	data )

static

Called via note_uses, for all used registers in a real insn
apply DEBUG_INSN changes that change registers to the used
registers.

References apply_debug_insn_changes(), cprop_find_used_regs(), value_data_entry::debug_insn_changes, value_data::e, FOR_EACH_SUBRTX, free_debug_insn_changes(), REG_P, and REGNO.

Referenced by copyprop_hardreg_forward_1(), and cprop_find_used_regs().

◆ debug_value_data()

DEBUG_FUNCTION void debug_value_data ( struct value_data * vd )

extern

Dump the value chain data to stderr.

References CLEAR_HARD_REG_SET, debug_value_data(), value_data::e, fputc(), GET_MODE_NAME, i, INVALID_REGNUM, value_data_entry::mode, value_data_entry::next_regno, value_data_entry::oldest_regno, SET_HARD_REG_BIT, TEST_HARD_REG_BIT, and kill_set_value_data::vd.

Referenced by debug_value_data(), and set_value_regno().

◆ find_oldest_value_reg()

rtx find_oldest_value_reg	(	enum reg_class	cl,
		rtx	reg,
		struct value_data *	vd,
		bool	frame_related )

static

Find the oldest copy of the value contained in REGNO that is in
register class CL and has mode MODE.  If found, return an rtx
of that oldest register, otherwise return NULL.

References value_data::e, find_oldest_value_reg(), value_data_entry::frame_related, gcc_assert, GET_MODE, hard_regno_nregs(), i, in_hard_reg_set_p(), incompatible_frame_status(), maybe_mode_change(), value_data_entry::mode, value_data_entry::next_regno, NULL_RTX, value_data_entry::oldest_regno, ORIGINAL_REGNO, REG_ATTRS, REG_CAN_CHANGE_MODE_P, reg_class_contents, REG_NREGS, REG_POINTER, REGNO, stack_pointer_rtx, and kill_set_value_data::vd.

Referenced by copyprop_hardreg_forward_1(), find_oldest_value_reg(), replace_oldest_value_reg(), and set_value_regno().

◆ free_debug_insn_changes()

void free_debug_insn_changes	(	struct value_data *	vd,
		unsigned int	regno )

static

Free all queued updates for DEBUG_INSNs that change some reg to
register REGNO.

References value_data_entry::debug_insn_changes, value_data::e, free_debug_insn_changes(), value_data::n_debug_insn_changes, queued_debug_insn_change::next, NULL, and queued_debug_insn_change_pool.

Referenced by cprop_find_used_regs(), free_debug_insn_changes(), and kill_value_one_regno().

◆ incompatible_frame_status()

bool incompatible_frame_status	(	bool	to_frame_related,
		bool	from_frame_related )

static

Copy propagation must not replace a value in a frame-related
instruction with one produced by a non–frame-related instruction.
Doing so may cause the DCE pass to delete the original frame-related
instruction, which would in turn produce incorrect DWARF information
(see PR122274).  TO_FRAME_RELATED indicates whether the destination
instruction receiving the propagated value is frame-related.
FROM_FRAME_RELATED indicates whether the instruction providing that
value is frame-related.
Return true if copy propagation is not permitted.

References incompatible_frame_status().

Referenced by copyprop_hardreg_forward_1(), find_oldest_value_reg(), incompatible_frame_status(), and set_value_regno().

◆ init_value_data()

void init_value_data ( struct value_data * vd )

static

Initialize VD such that there are no known relationships between regs.

References value_data_entry::debug_insn_changes, value_data::e, value_data_entry::frame_related, i, init_value_data(), INVALID_REGNUM, value_data::max_value_regs, value_data_entry::mode, value_data::n_debug_insn_changes, value_data_entry::next_regno, NULL, and value_data_entry::oldest_regno.

Referenced by copyprop_hardreg_forward_bb_without_debug_insn(), init_value_data(), and set_value_regno().

◆ kill_autoinc_value()

void kill_autoinc_value	(	rtx_insn *	insn,
		struct value_data *	vd )

static

Kill any register used in X as the base of an auto-increment expression,
and install that register as the root of its own value list.

References value_data::e, FOR_EACH_SUBRTX, value_data_entry::frame_related, GET_CODE, GET_MODE, GET_RTX_CLASS, kill_autoinc_value(), kill_value(), PATTERN(), REGNO, RTX_AUTOINC, RTX_FRAME_RELATED_P, set_value_regno(), kill_set_value_data::vd, and XEXP.

Referenced by copyprop_hardreg_forward_1(), and kill_autoinc_value().

◆ kill_clobbered_value()

void kill_clobbered_value	(	rtx	x,
		const_rtx	set,
		void *	data )

static

Called through note_stores.  If X is clobbered, kill its value.

References GET_CODE, kill_clobbered_value(), and kill_value().

Referenced by kill_clobbered_value(), kill_clobbered_values(), and set_value_regno().

◆ kill_clobbered_values()

void kill_clobbered_values	(	rtx_insn *	insn,
		struct value_data *	vd )

static

Apply clobbers of INSN in PATTERN and C_I_F_U to value_data VD.

References kill_clobbered_value(), kill_clobbered_values(), and note_stores().

Referenced by copyprop_hardreg_forward_1(), and kill_clobbered_values().

◆ kill_set_value()

void kill_set_value	(	rtx	x,
		const_rtx	set,
		void *	data )

static

Called through note_stores.  If X is set, not clobbered, kill its
current value and install it as the root of its own value list.

References value_data::e, value_data_entry::frame_related, GET_CODE, GET_MODE, kill_set_value_data::ignore_set_reg, kill_set_value_data::insn_is_frame_related, kill_set_value(), kill_value(), REG_P, REGNO, rtx_equal_p(), set_value_regno(), and kill_set_value_data::vd.

Referenced by copyprop_hardreg_forward_1(), kill_set_value(), and set_value_regno().

◆ kill_value()

void kill_value	(	const_rtx	x,
		struct value_data *	vd )

static

Kill X.  This is a convenience function wrapping kill_value_regno
so that we mind the mode the register is in.

References GET_CODE, GET_MODE, kill_value(), kill_value_regno(), REG_NREGS, REG_P, REGNO, simplify_subreg(), SUBREG_BYTE, and SUBREG_REG.

Referenced by copyprop_hardreg_forward_1(), kill_autoinc_value(), kill_clobbered_value(), kill_set_value(), kill_value(), and kill_value_regno().

◆ kill_value_one_regno() [1/2]

void kill_value_one_regno	(	unsigned int	regno,
		struct value_data *	vd )

static

Kill register REGNO.  This involves removing it from any value
lists, and resetting the value mode to VOIDmode.  This is only a
helper function; it does not handle any hard registers overlapping
with REGNO.

References value_data_entry::debug_insn_changes, value_data::e, value_data_entry::frame_related, free_debug_insn_changes(), i, INVALID_REGNUM, kill_value_one_regno(), value_data_entry::mode, queued_debug_insn_change::next, value_data_entry::next_regno, value_data_entry::oldest_regno, and validate_value_data().

◆ kill_value_one_regno() [2/2]

void kill_value_one_regno	(	unsigned	,
		struct value_data *	)

static

References kill_value_one_regno().

Referenced by kill_value_one_regno(), kill_value_one_regno(), and kill_value_regno().

◆ kill_value_regno() [1/2]

void kill_value_regno	(	unsigned int	regno,
		unsigned int	nregs,
		struct value_data *	vd )

static

Kill the value in register REGNO for NREGS, and any other registers
whose values overlap.

References value_data::e, hard_regno_nregs(), i, kill_value_one_regno(), kill_value_regno(), value_data::max_value_regs, and value_data_entry::mode.

◆ kill_value_regno() [2/2]

void kill_value_regno	(	unsigned	,
		unsigned	,
		struct value_data *	)

static

References kill_value(), and kill_value_regno().

Referenced by copyprop_hardreg_forward_1(), kill_value(), kill_value_regno(), and kill_value_regno().

◆ make_pass_cprop_hardreg()

rtl_opt_pass * make_pass_cprop_hardreg ( gcc::context * ctxt )

References make_pass_cprop_hardreg().

Referenced by make_pass_cprop_hardreg(), and make_pass_value_profile_transformations().

◆ maybe_mode_change()

rtx maybe_mode_change	(	machine_mode	orig_mode,
		machine_mode	copy_mode,
		machine_mode	new_mode,
		unsigned int	regno,
		unsigned int	copy_regno )

static

Register REGNO was originally set in ORIG_MODE.  It - or a copy of it -
was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed
in NEW_MODE.
Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX.

References gen_raw_REG(), GET_MODE, GET_MODE_PRECISION(), GET_MODE_SIZE(), hard_regno_nregs(), maybe_mode_change(), mode_change_ok(), NULL_RTX, partial_subreg_p(), stack_pointer_rtx, subreg_regno_offset(), subreg_size_lowpart_offset(), and targetm.

Referenced by copyprop_hardreg_forward_1(), find_oldest_value_reg(), maybe_mode_change(), and set_value_regno().

◆ mode_change_ok()

bool mode_change_ok	(	machine_mode	orig_mode,
		machine_mode	new_mode,
		unsigned int	regno )

static

Return true if a mode change from ORIG to NEW is allowed for REGNO.

References mode_change_ok(), partial_subreg_p(), and REG_CAN_CHANGE_MODE_P.

Referenced by maybe_mode_change(), mode_change_ok(), and set_value_regno().

◆ replace_oldest_value_addr()

bool replace_oldest_value_addr	(	rtx *	loc,
		enum reg_class	cl,
		machine_mode	mode,
		addr_space_t	as,
		rtx_insn *	insn,
		struct value_data *	vd )

static

Similar to replace_oldest_value_reg, but *LOC contains an address.
Adapted from find_reloads_address_1.  CL is INDEX_REG_CLASS or
BASE_REG_CLASS depending on how the register is being considered.

References base_reg_class(), DEBUG_INSN_P, GET_CODE, GET_RTX_FORMAT, GET_RTX_LENGTH, i, queued_debug_insn_change::insn, queued_debug_insn_change::loc, NULL, REGNO, regno_ok_for_base_p(), replace_oldest_value_addr(), replace_oldest_value_mem(), replace_oldest_value_reg(), RTX_CODE, SUBREG_REG, XEXP, XVECEXP, and XVECLEN.

Referenced by copyprop_hardreg_forward_1(), replace_oldest_value_addr(), replace_oldest_value_mem(), and set_value_regno().

◆ replace_oldest_value_mem()

bool replace_oldest_value_mem	(	rtx	x,
		rtx_insn *	insn,
		struct value_data *	vd )

static

Similar to replace_oldest_value_reg, but X contains a memory.

References base_reg_class(), DEBUG_INSN_P, GET_MODE, queued_debug_insn_change::insn, MEM_ADDR_SPACE, replace_oldest_value_addr(), replace_oldest_value_mem(), and XEXP.

Referenced by copyprop_hardreg_forward_1(), replace_oldest_value_addr(), replace_oldest_value_mem(), and set_value_regno().

◆ replace_oldest_value_reg()

bool replace_oldest_value_reg	(	rtx *	loc,
		enum reg_class	cl,
		rtx_insn *	insn,
		struct value_data *	vd )

static

If possible, replace the register at *LOC with the oldest register
in register class CL.  Return true if successfully replaced.

References value_data_entry::debug_insn_changes, DEBUG_INSN_P, dump_file, value_data::e, find_oldest_value_reg(), queued_debug_insn_change::insn, INSN_UID(), queued_debug_insn_change::loc, value_data::n_debug_insn_changes, queued_debug_insn_change::new_rtx, queued_debug_insn_change::next, queued_debug_insn_change_pool, REGNO, replace_oldest_value_reg(), RTX_FRAME_RELATED_P, skip_debug_insn_p, validate_change(), and kill_set_value_data::vd.

Referenced by copyprop_hardreg_forward_1(), replace_oldest_value_addr(), replace_oldest_value_reg(), and set_value_regno().

◆ set_value_regno() [1/2]

void set_value_regno	(	unsigned int	regno,
		machine_mode	mode,
		struct value_data *	vd )

static

Remember that REGNO is valid in MODE.

References value_data::e, hard_regno_nregs(), value_data::max_value_regs, value_data_entry::mode, and set_value_regno().

◆ set_value_regno() [2/2]

void set_value_regno	(	unsigned	,
		machine_mode	,
		struct value_data *	)

static

◆ validate_value_data()

void validate_value_data ( struct value_data * vd )

static

References CLEAR_HARD_REG_SET, value_data::e, GET_MODE_NAME, i, internal_error(), INVALID_REGNUM, value_data_entry::mode, value_data_entry::next_regno, value_data_entry::oldest_regno, SET_HARD_REG_BIT, TEST_HARD_REG_BIT, and validate_value_data().

Referenced by copy_value(), kill_value_one_regno(), set_value_regno(), and validate_value_data().

Variable Documentation

◆ queued_debug_insn_change_pool

object_allocator< queued_debug_insn_change > queued_debug_insn_change_pool("debug insn changes pool") ( "debug insn changes pool" )

static

Referenced by free_debug_insn_changes(), and replace_oldest_value_reg().

◆ skip_debug_insn_p

bool skip_debug_insn_p

static

Referenced by copyprop_hardreg_forward_bb_without_debug_insn(), and replace_oldest_value_reg().

Data Structures

Functions

Variables

Function Documentation

◆ apply_debug_insn_changes()

◆ copy_value()

◆ copyprop_hardreg_forward_1()

◆ copyprop_hardreg_forward_bb_without_debug_insn()

◆ cprop_find_used_regs()

◆ debug_value_data()

◆ find_oldest_value_reg()

◆ free_debug_insn_changes()

◆ incompatible_frame_status()

◆ init_value_data()

◆ kill_autoinc_value()

◆ kill_clobbered_value()

◆ kill_clobbered_values()

◆ kill_set_value()

◆ kill_value()

◆ kill_value_one_regno() [1/2]

◆ kill_value_one_regno() [2/2]

◆ kill_value_regno() [1/2]

◆ kill_value_regno() [2/2]

◆ make_pass_cprop_hardreg()

◆ maybe_mode_change()

◆ mode_change_ok()

◆ replace_oldest_value_addr()

◆ replace_oldest_value_mem()

◆ replace_oldest_value_reg()

◆ set_value_regno() [1/2]

◆ set_value_regno() [2/2]

◆ validate_value_data()

Variable Documentation

◆ queued_debug_insn_change_pool

◆ skip_debug_insn_p