385 lines
14 KiB
C
385 lines
14 KiB
C
/* Communication between reload.c and reload1.c.
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Copyright (C) 1987, 91-95, 97-99, 2000 Free Software Foundation, Inc.
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This file is part of GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* If secondary reloads are the same for inputs and outputs, define those
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macros here. */
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#ifdef SECONDARY_RELOAD_CLASS
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#define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
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SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
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#define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
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SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
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#endif
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/* If either macro is defined, show that we need secondary reloads. */
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#if defined(SECONDARY_INPUT_RELOAD_CLASS) || defined(SECONDARY_OUTPUT_RELOAD_CLASS)
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#define HAVE_SECONDARY_RELOADS
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#endif
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/* If MEMORY_MOVE_COST isn't defined, give it a default here. */
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#ifndef MEMORY_MOVE_COST
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#ifdef HAVE_SECONDARY_RELOADS
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#define MEMORY_MOVE_COST(MODE,CLASS,IN) \
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(4 + memory_move_secondary_cost ((MODE), (CLASS), (IN)))
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#else
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#define MEMORY_MOVE_COST(MODE,CLASS,IN) 4
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#endif
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#endif
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extern int memory_move_secondary_cost PARAMS ((enum machine_mode, enum reg_class, int));
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/* Maximum number of reloads we can need. */
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#define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
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/* Encode the usage of a reload. The following codes are supported:
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RELOAD_FOR_INPUT reload of an input operand
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RELOAD_FOR_OUTPUT likewise, for output
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RELOAD_FOR_INSN a reload that must not conflict with anything
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used in the insn, but may conflict with
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something used before or after the insn
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RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object
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that is an input reload
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RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS
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RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output
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RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS
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RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded
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operand; these don't conflict with
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any other addresses.
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RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS
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reloads; usually secondary reloads
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RELOAD_OTHER none of the above, usually multiple uses
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RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input
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that is marked RELOAD_OTHER.
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This used to be "enum reload_when_needed" but some debuggers have trouble
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with an enum tag and variable of the same name. */
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enum reload_type
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{
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RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN,
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RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS,
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RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS,
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RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR,
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RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS
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};
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#ifdef MAX_INSN_CODE
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/* Each reload is recorded with a structure like this. */
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struct reload
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{
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/* The value to reload from */
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rtx in;
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/* Where to store reload-reg afterward if nec (often the same as
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reload_in) */
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rtx out;
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/* The class of registers to reload into. */
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enum reg_class class;
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/* The mode this operand should have when reloaded, on input. */
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enum machine_mode inmode;
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/* The mode this operand should have when reloaded, on output. */
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enum machine_mode outmode;
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/* The mode of the reload register. */
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enum machine_mode mode;
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/* the largest number of registers this reload will require. */
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int nregs;
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/* Positive amount to increment or decrement by if
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reload_in is a PRE_DEC, PRE_INC, POST_DEC, POST_INC.
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Ignored otherwise (don't assume it is zero). */
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int inc;
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/* A reg for which reload_in is the equivalent.
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If reload_in is a symbol_ref which came from
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reg_equiv_constant, then this is the pseudo
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which has that symbol_ref as equivalent. */
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rtx in_reg;
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rtx out_reg;
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/* Used in find_reload_regs to record the allocated register. */
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int regno;
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/* This is the register to reload into. If it is zero when `find_reloads'
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returns, you must find a suitable register in the class specified by
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reload_reg_class, and store here an rtx for that register with mode from
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reload_inmode or reload_outmode. */
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rtx reg_rtx;
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/* The operand number being reloaded. This is used to group related reloads
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and need not always be equal to the actual operand number in the insn,
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though it current will be; for in-out operands, it is one of the two
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operand numbers. */
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int opnum;
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/* Gives the reload number of a secondary input reload, when needed;
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otherwise -1. */
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int secondary_in_reload;
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/* Gives the reload number of a secondary output reload, when needed;
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otherwise -1. */
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int secondary_out_reload;
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/* If a secondary input reload is required, gives the INSN_CODE that uses the
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secondary reload as a scratch register, or CODE_FOR_nothing if the
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secondary reload register is to be an intermediate register. */
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enum insn_code secondary_in_icode;
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/* Likewise, for a secondary output reload. */
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enum insn_code secondary_out_icode;
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/* Classifies reload as needed either for addressing an input reload,
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addressing an output, for addressing a non-reloaded mem ref, or for
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unspecified purposes (i.e., more than one of the above). */
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enum reload_type when_needed;
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/* Nonzero for an optional reload. Optional reloads are ignored unless the
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value is already sitting in a register. */
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unsigned int optional:1;
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/* nonzero if this reload shouldn't be combined with another reload. */
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unsigned int nocombine:1;
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/* Nonzero if this is a secondary register for one or more reloads. */
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unsigned int secondary_p:1;
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/* Nonzero if this reload must use a register not already allocated to a
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group. */
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unsigned int nongroup:1;
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};
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extern struct reload rld[MAX_RELOADS];
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extern int n_reloads;
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#endif
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extern rtx *reg_equiv_constant;
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extern rtx *reg_equiv_memory_loc;
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extern rtx *reg_equiv_address;
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extern rtx *reg_equiv_mem;
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/* All the "earlyclobber" operands of the current insn
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are recorded here. */
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extern int n_earlyclobbers;
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extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
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/* Save the number of operands. */
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extern int reload_n_operands;
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/* First uid used by insns created by reload in this function.
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Used in find_equiv_reg. */
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extern int reload_first_uid;
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/* Nonzero if indirect addressing is supported when the innermost MEM is
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of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to
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which these are valid is the same as spill_indirect_levels, above. */
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extern char indirect_symref_ok;
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/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
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extern char double_reg_address_ok;
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extern int num_not_at_initial_offset;
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#ifdef MAX_INSN_CODE
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/* These arrays record the insn_code of insns that may be needed to
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perform input and output reloads of special objects. They provide a
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place to pass a scratch register. */
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extern enum insn_code reload_in_optab[];
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extern enum insn_code reload_out_optab[];
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#endif
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struct needs
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{
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/* [0] is normal, [1] is nongroup. */
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short regs[2][N_REG_CLASSES];
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short groups[N_REG_CLASSES];
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};
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#if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET
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/* This structure describes instructions which are relevant for reload.
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Apart from all regular insns, this also includes CODE_LABELs, since they
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must be examined for register elimination. */
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struct insn_chain
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{
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/* Links to the neighbour instructions. */
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struct insn_chain *next, *prev;
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/* Link through a chains set up by calculate_needs_all_insns, containing
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all insns that need reloading. */
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struct insn_chain *next_need_reload;
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/* The basic block this insn is in. */
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int block;
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/* The rtx of the insn. */
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rtx insn;
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/* Register life information: record all live hard registers, and all
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live pseudos that have a hard register. */
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regset_head live_throughout;
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regset_head dead_or_set;
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/* Copies of the global variables computed by find_reloads. */
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struct reload *rld;
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int n_reloads;
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/* Indicates which registers have already been used for spills. */
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HARD_REG_SET used_spill_regs;
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/* Describe the needs for reload registers of this insn. */
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struct needs need;
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/* Nonzero if find_reloads said the insn requires reloading. */
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unsigned int need_reload:1;
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/* Nonzero if find_reloads needs to be run during reload_as_needed to
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perform modifications on any operands. */
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unsigned int need_operand_change:1;
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/* Nonzero if eliminate_regs_in_insn said it requires eliminations. */
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unsigned int need_elim:1;
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/* Nonzero if this insn was inserted by perform_caller_saves. */
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unsigned int is_caller_save_insn:1;
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};
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/* A chain of insn_chain structures to describe all non-note insns in
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a function. */
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extern struct insn_chain *reload_insn_chain;
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/* Allocate a new insn_chain structure. */
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extern struct insn_chain *new_insn_chain PARAMS ((void));
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extern void compute_use_by_pseudos PARAMS ((HARD_REG_SET *, regset));
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#endif
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/* Functions from reload.c: */
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/* Return a memory location that will be used to copy X in mode MODE.
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If we haven't already made a location for this mode in this insn,
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call find_reloads_address on the location being returned. */
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extern rtx get_secondary_mem PARAMS ((rtx, enum machine_mode,
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int, enum reload_type));
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/* Clear any secondary memory locations we've made. */
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extern void clear_secondary_mem PARAMS ((void));
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/* Transfer all replacements that used to be in reload FROM to be in
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reload TO. */
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extern void transfer_replacements PARAMS ((int, int));
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/* IN_RTX is the value loaded by a reload that we now decided to inherit,
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or a subpart of it. If we have any replacements registered for IN_RTX,
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chancel the reloads that were supposed to load them.
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Return non-zero if we chanceled any reloads. */
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extern int remove_address_replacements PARAMS ((rtx in_rtx));
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/* Like rtx_equal_p except that it allows a REG and a SUBREG to match
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if they are the same hard reg, and has special hacks for
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autoincrement and autodecrement. */
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extern int operands_match_p PARAMS ((rtx, rtx));
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/* Return 1 if altering OP will not modify the value of CLOBBER. */
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extern int safe_from_earlyclobber PARAMS ((rtx, rtx));
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/* Search the body of INSN for values that need reloading and record them
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with push_reload. REPLACE nonzero means record also where the values occur
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so that subst_reloads can be used. */
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extern int find_reloads PARAMS ((rtx, int, int, int, short *));
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/* Compute the sum of X and Y, making canonicalizations assumed in an
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address, namely: sum constant integers, surround the sum of two
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constants with a CONST, put the constant as the second operand, and
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group the constant on the outermost sum. */
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extern rtx form_sum PARAMS ((rtx, rtx));
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/* Substitute into the current INSN the registers into which we have reloaded
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the things that need reloading. */
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extern void subst_reloads PARAMS ((void));
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/* Make a copy of any replacements being done into X and move those copies
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to locations in Y, a copy of X. We only look at the highest level of
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the RTL. */
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extern void copy_replacements PARAMS ((rtx, rtx));
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/* Change any replacements being done to *X to be done to *Y */
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extern void move_replacements PARAMS ((rtx *x, rtx *y));
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/* If LOC was scheduled to be replaced by something, return the replacement.
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Otherwise, return *LOC. */
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extern rtx find_replacement PARAMS ((rtx *));
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/* Return nonzero if register in range [REGNO, ENDREGNO)
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appears either explicitly or implicitly in X
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other than being stored into. */
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extern int refers_to_regno_for_reload_p PARAMS ((int, int, rtx, rtx *));
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/* Nonzero if modifying X will affect IN. */
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extern int reg_overlap_mentioned_for_reload_p PARAMS ((rtx, rtx));
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/* Return nonzero if anything in X contains a MEM. Look also for pseudo
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registers. */
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extern int refers_to_mem_for_reload_p PARAMS ((rtx));
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/* Check the insns before INSN to see if there is a suitable register
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containing the same value as GOAL. */
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extern rtx find_equiv_reg PARAMS ((rtx, rtx, enum reg_class, int, short *,
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int, enum machine_mode));
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/* Return 1 if register REGNO is the subject of a clobber in insn INSN. */
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extern int regno_clobbered_p PARAMS ((int, rtx));
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/* Return 1 if X is an operand of an insn that is being earlyclobbered. */
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int earlyclobber_operand_p PARAMS ((rtx));
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/* Functions in reload1.c: */
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extern int reloads_conflict PARAMS ((int, int));
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int count_occurrences PARAMS ((rtx, rtx));
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/* Initialize the reload pass once per compilation. */
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extern void init_reload PARAMS ((void));
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/* The reload pass itself. */
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extern int reload PARAMS ((rtx, int, FILE *));
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/* Mark the slots in regs_ever_live for the hard regs
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used by pseudo-reg number REGNO. */
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extern void mark_home_live PARAMS ((int));
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/* Scan X and replace any eliminable registers (such as fp) with a
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replacement (such as sp), plus an offset. */
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extern rtx eliminate_regs PARAMS ((rtx, enum machine_mode, rtx));
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/* Emit code to perform a reload from IN (which may be a reload register) to
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OUT (which may also be a reload register). IN or OUT is from operand
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OPNUM with reload type TYPE. */
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extern rtx gen_reload PARAMS ((rtx, rtx, int, enum reload_type));
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/* Deallocate the reload register used by reload number R. */
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extern void deallocate_reload_reg PARAMS ((int r));
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/* Functions in caller-save.c: */
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/* Initialize for caller-save. */
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extern void init_caller_save PARAMS ((void));
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/* Initialize save areas by showing that we haven't allocated any yet. */
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extern void init_save_areas PARAMS ((void));
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/* Allocate save areas for any hard registers that might need saving. */
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extern void setup_save_areas PARAMS ((void));
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/* Find the places where hard regs are live across calls and save them. */
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extern void save_call_clobbered_regs PARAMS ((void));
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/* Replace (subreg (reg)) with the appropriate (reg) for any operands. */
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extern void cleanup_subreg_operands PARAMS ((rtx));
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