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/* Register note definitions.

   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010

   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

.  */

/* This file defines all the codes that may appear on individual

   EXPR_LIST rtxes in the REG_NOTES chain of an insn.  The codes are

   stored in the mode field of the EXPR_LIST.  Source files define

   DEF_REG_NOTE appropriately before including this file.  */

/* Shorthand.  */

#define REG_NOTE(NAME) DEF_REG_NOTE (REG_##NAME)

/* REG_DEP_TRUE is used in scheduler dependencies lists to represent a

   read-after-write dependency (i.e. a true data dependency).  This is

   here, not grouped with REG_DEP_ANTI and REG_DEP_OUTPUT, because some

   passes use a literal 0 for it.  */

REG_NOTE (DEP_TRUE)

/* The value in REG dies in this insn (i.e., it is not needed past

   this insn).  If REG is set in this insn, the REG_DEAD note may,

   but need not, be omitted.  */

REG_NOTE (DEAD)

/* The REG is autoincremented or autodecremented in this insn.  */

REG_NOTE (INC)

/* Describes the insn as a whole; it says that the insn sets a

   register to a constant value or to be equivalent to a memory

   address.  If the register is spilled to the stack then the constant

   value should be substituted for it.  The contents of the REG_EQUIV

   is the constant value or memory address, which may be different

   from the source of the SET although it has the same value.  A

   REG_EQUIV note may also appear on an insn which copies a register

   parameter to a pseudo-register, if there is a memory address which

   could be used to hold that pseudo-register throughout the function.  */

REG_NOTE (EQUIV)

/* Like REG_EQUIV except that the destination is only momentarily

   equal to the specified rtx.  Therefore, it cannot be used for

   substitution; but it can be used for cse.  */

REG_NOTE (EQUAL)

/* The register is always nonnegative during the containing loop.

   This is used in branches so that decrement and branch instructions

   terminating on zero can be matched.  There must be an insn pattern

   in the md file named `decrement_and_branch_until_zero' or else this

   will never be added to any instructions.  */

REG_NOTE (NONNEG)

/* Identifies a register set in this insn and never used.  */

REG_NOTE (UNUSED)

/* REG_CC_SETTER and REG_CC_USER link a pair of insns that set and use

   CC0, respectively.  Normally, these are required to be consecutive

   insns, but we permit putting a cc0-setting insn in the delay slot

   of a branch as long as only one copy of the insn exists.  In that

   case, these notes point from one to the other to allow code

   generation to determine what any require information and to

   properly update CC_STATUS.  These notes are INSN_LISTs.  */

REG_NOTE (CC_SETTER)

REG_NOTE (CC_USER)

/* Points to a CODE_LABEL.  Used by JUMP_INSNs to say that the CODE_LABEL

   contained in the REG_LABEL_TARGET note is a possible jump target of

   this insn.  This note is an INSN_LIST.  */

REG_NOTE (LABEL_TARGET)

/* Points to a CODE_LABEL.  Used by any insn to say that the CODE_LABEL

   contained in the REG_LABEL_OPERAND note is used by the insn, but as an

   operand, not as a jump target (though it may indirectly be a jump

   target for a later jump insn).  This note is an INSN_LIST.  */

REG_NOTE (LABEL_OPERAND)

/* REG_DEP_OUTPUT and REG_DEP_ANTI are used in scheduler dependencies lists

   to represent write-after-write and write-after-read dependencies

   respectively.  */

REG_NOTE (DEP_OUTPUT)

REG_NOTE (DEP_ANTI)

REG_NOTE (DEP_CONTROL)

/* REG_BR_PROB is attached to JUMP_INSNs and CALL_INSNs.  It has an

   integer value.  For jumps, it is the probability that this is a

   taken branch.  For calls, it is the probability that this call

   won't return.  */

REG_NOTE (BR_PROB)

/* Attached to a call insn; indicates that the call is malloc-like and

   that the pointer returned cannot alias anything else.  */

REG_NOTE (NOALIAS)

/* REG_BR_PRED is attached to JUMP_INSNs and CALL_INSNSs.  It contains

   CONCAT of two integer value.  First specifies the branch predictor

   that added the note, second specifies the predicted hitrate of

   branch in the same format as REG_BR_PROB note uses.  */

REG_NOTE (BR_PRED)

/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex

   for DWARF to interpret what they imply.  The attached rtx is used

   instead of intuition.  */

REG_NOTE (FRAME_RELATED_EXPR)

/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex

   for FRAME_RELATED_EXPR intuition.  The insn's first pattern must be

   a SET, and the destination must be the CFA register.  The attached

   rtx is an expression that defines the CFA.  In the simplest case, the

   rtx could be just the stack_pointer_rtx; more common would be a PLUS

   with a base register and a constant offset.  In the most complicated

   cases, this will result in a DW_CFA_def_cfa_expression with the rtx

   expression rendered in a dwarf location expression.  */

REG_NOTE (CFA_DEF_CFA)

/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex

   for FRAME_RELATED_EXPR intuition.  This note adjusts the expression

   from which the CFA is computed.  The attached rtx defines a new CFA

   expression, relative to the old CFA expression.  This rtx must be of

   the form (SET new-cfa-reg (PLUS old-cfa-reg const_int)).  If the note

   rtx is NULL, we use the first SET of the insn.  */

REG_NOTE (CFA_ADJUST_CFA)

/* Similar to FRAME_RELATED_EXPR, with the additional information that

   this is a save to memory, i.e. will result in DW_CFA_offset or the

   like.  The pattern or the insn should be a simple store relative to

   the CFA.  */

REG_NOTE (CFA_OFFSET)

/* Similar to FRAME_RELATED_EXPR, with the additional information that this

   is a save to a register, i.e. will result in DW_CFA_register.  The insn

   or the pattern should be simple reg-reg move.  */

REG_NOTE (CFA_REGISTER)

/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex

   for FRAME_RELATED_EXPR intuition.  This is a save to memory, i.e. will

   result in a DW_CFA_expression.  The pattern or the insn should be a

   store of a register to an arbitrary (non-validated) memory address.  */

REG_NOTE (CFA_EXPRESSION)

/* Attached to insns that are RTX_FRAME_RELATED_P, with the information

   that this is a restore operation, i.e. will result in DW_CFA_restore

   or the like.  Either the attached rtx, or the destination of the insn's

   first pattern is the register to be restored.  */

REG_NOTE (CFA_RESTORE)

/* Attached to insns that are RTX_FRAME_RELATED_P, marks insn that sets

   vDRAP from DRAP.  If vDRAP is a register, vdrap_reg is initalized

   to the argument, if it is a MEM, it is ignored.  */

REG_NOTE (CFA_SET_VDRAP)

/* Attached to insns that are RTX_FRAME_RELATED_P, indicating a window

   save operation, i.e. will result in a DW_CFA_GNU_window_save.

   The argument is ignored.  */

REG_NOTE (CFA_WINDOW_SAVE)

/* Attached to insns that are RTX_FRAME_RELATED_P, marks the insn as

   requiring that all queued information should be flushed *before* insn,

   regardless of what is visible in the rtl.  The argument is ignored.

   This is normally used for a call instruction which is not exposed to

   the rest of the compiler as a CALL_INSN.  */

REG_NOTE (CFA_FLUSH_QUEUE)

/* Indicates that REG holds the exception context for the function.

   This context is shared by inline functions, so the code to acquire

   the real exception context is delayed until after inlining.  */

REG_NOTE (EH_CONTEXT)

/* Indicates what exception region an INSN belongs in.  This is used

   to indicate what region to which a call may throw.  REGION 0

   indicates that a call cannot throw at all.  REGION -1 indicates

   that it cannot throw, nor will it execute a non-local goto.  */

REG_NOTE (EH_REGION)

/* Used by haifa-sched to save NOTE_INSN notes across scheduling.  */

REG_NOTE (SAVE_NOTE)

/* Indicates that a call does not return.  */

REG_NOTE (NORETURN)

/* Indicates that an indirect jump is a non-local goto instead of a

   computed goto.  */

REG_NOTE (NON_LOCAL_GOTO)

/* Indicates that a jump crosses between hot and cold sections in a

   (partitioned) assembly or .o file, and therefore should not be

   reduced to a simpler jump by optimizations.  */

REG_NOTE (CROSSING_JUMP)

/* This kind of note is generated at each to `setjmp', and similar

   functions that can return twice.  */

REG_NOTE (SETJMP)

/* This kind of note is generated at each transactional memory

   builtin, to indicate we need to generate transaction restart

   edges for this insn.  */

REG_NOTE (TM)

/* Indicates the cumulative offset of the stack pointer accounting

   for pushed arguments.  This will only be generated when

   ACCUMULATE_OUTGOING_ARGS is false.  */

REG_NOTE (ARGS_SIZE)

/* Used for communication between IRA and caller-save.c, indicates

   that the return value of a call can be used to reinitialize a

   pseudo reg.  */

REG_NOTE (RETURNED)