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- /* Register note definitions.
- Copyright (C) 2004-2015 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/>. */
- /* This file defines all the codes that may appear on individual
- EXPR_LIST, INSN_LIST and INT_LIST rtxes in the REG_NOTES chain of an insn.
- The codes are stored in the mode field of the rtx. 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 (in an INT_LIST). 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 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)
- /* 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)
- /* Used to mark a call with the function decl called by the call.
- The decl might not be available in the call due to splitting of the call
- insn. This note is a SYMBOL_REF. */
- REG_NOTE (CALL_DECL)
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