255 lines
11 KiB
Modula-2
255 lines
11 KiB
Modula-2
/* Register note definitions.
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Copyright (C) 2004-2023 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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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 GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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/* This file defines all the codes that may appear on individual
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EXPR_LIST, INSN_LIST and INT_LIST rtxes in the REG_NOTES chain of an insn.
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The codes are stored in the mode field of the rtx. Source files
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define DEF_REG_NOTE appropriately before including this file.
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CFA related notes meant for RTX_FRAME_RELATED_P instructions
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should be declared with REG_CFA_NOTE macro instead of REG_NOTE. */
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/* Shorthand. */
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#define REG_NOTE(NAME) DEF_REG_NOTE (REG_##NAME)
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#ifndef REG_CFA_NOTE
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# define REG_CFA_NOTE(NAME) REG_NOTE (NAME)
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#endif
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/* REG_DEP_TRUE is used in scheduler dependencies lists to represent a
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read-after-write dependency (i.e. a true data dependency). This is
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here, not grouped with REG_DEP_ANTI and REG_DEP_OUTPUT, because some
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passes use a literal 0 for it. */
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REG_NOTE (DEP_TRUE)
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/* The value in REG dies in this insn (i.e., it is not needed past
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this insn). If REG is set in this insn, the REG_DEAD note may,
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but need not, be omitted. */
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REG_NOTE (DEAD)
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/* The REG is autoincremented or autodecremented in this insn. */
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REG_NOTE (INC)
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/* Describes the insn as a whole; it says that the insn sets a
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register to a constant value or to be equivalent to a memory
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address. If the register is spilled to the stack then the constant
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value should be substituted for it. The contents of the REG_EQUIV
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is the constant value or memory address, which may be different
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from the source of the SET although it has the same value. A
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REG_EQUIV note may also appear on an insn which copies a register
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parameter to a pseudo-register, if there is a memory address which
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could be used to hold that pseudo-register throughout the function. */
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REG_NOTE (EQUIV)
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/* Like REG_EQUIV except that the destination is only momentarily
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equal to the specified rtx. Therefore, it cannot be used for
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substitution; but it can be used for cse. */
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REG_NOTE (EQUAL)
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/* The register is always nonnegative during the containing loop.
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This is used in branches so that decrement and branch instructions
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terminating on zero can be matched. There must be an insn pattern
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in the md file named `decrement_and_branch_until_zero' or else this
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will never be added to any instructions. */
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REG_NOTE (NONNEG)
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/* Identifies a register set in this insn and never used. */
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REG_NOTE (UNUSED)
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/* Points to a CODE_LABEL. Used by JUMP_INSNs to say that the CODE_LABEL
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contained in the REG_LABEL_TARGET note is a possible jump target of
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this insn. This note is an INSN_LIST. */
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REG_NOTE (LABEL_TARGET)
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/* Points to a CODE_LABEL. Used by any insn to say that the CODE_LABEL
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contained in the REG_LABEL_OPERAND note is used by the insn, but as an
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operand, not as a jump target (though it may indirectly be a jump
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target for a later jump insn). This note is an INSN_LIST. */
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REG_NOTE (LABEL_OPERAND)
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/* REG_DEP_OUTPUT and REG_DEP_ANTI are used in scheduler dependencies lists
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to represent write-after-write and write-after-read dependencies
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respectively. */
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REG_NOTE (DEP_OUTPUT)
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REG_NOTE (DEP_ANTI)
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REG_NOTE (DEP_CONTROL)
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/* REG_BR_PROB is attached to JUMP_INSNs. It has an
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integer value (in an INT_LIST). For jumps, it is the probability
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that this is a taken branch. The integer represents a value of
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profile_probability type. Use to_reg_br_prob_note and from_reg_br_prob_note
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to extract the actual value. */
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REG_NOTE (BR_PROB)
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/* Attached to a call insn; indicates that the call is malloc-like and
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that the pointer returned cannot alias anything else. */
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REG_NOTE (NOALIAS)
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/* REG_BR_PRED is attached to JUMP_INSNs. It contains
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CONCAT of two integer value. First specifies the branch predictor
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that added the note, second specifies the predicted hitrate of
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branch in a fixed point arithmetic based on REG_BR_PROB_BASE. */
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REG_NOTE (BR_PRED)
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/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex
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for DWARF to interpret what they imply. The attached rtx is used
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instead of intuition. */
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REG_CFA_NOTE (FRAME_RELATED_EXPR)
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/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex
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for FRAME_RELATED_EXPR intuition. The insn's first pattern must be
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a SET, and the destination must be the CFA register. The attached
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rtx is an expression that defines the CFA. In the simplest case, the
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rtx could be just the stack_pointer_rtx; more common would be a PLUS
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with a base register and a constant offset. In the most complicated
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cases, this will result in a DW_CFA_def_cfa_expression with the rtx
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expression rendered in a dwarf location expression. */
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REG_CFA_NOTE (CFA_DEF_CFA)
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/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex
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for FRAME_RELATED_EXPR intuition. This note adjusts the expression
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from which the CFA is computed. The attached rtx defines a new CFA
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expression, relative to the old CFA expression. This rtx must be of
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the form (SET new-cfa-reg (PLUS old-cfa-reg const_int)). If the note
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rtx is NULL, we use the first SET of the insn. */
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REG_CFA_NOTE (CFA_ADJUST_CFA)
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/* Similar to FRAME_RELATED_EXPR, with the additional information that
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this is a save to memory, i.e. will result in DW_CFA_offset or the
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like. The pattern or the insn should be a simple store relative to
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the CFA. */
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REG_CFA_NOTE (CFA_OFFSET)
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/* Similar to FRAME_RELATED_EXPR, with the additional information that this
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is a save to a register, i.e. will result in DW_CFA_register. The insn
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or the pattern should be simple reg-reg move. */
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REG_CFA_NOTE (CFA_REGISTER)
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/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex
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for FRAME_RELATED_EXPR intuition. This is a save to memory, i.e. will
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result in a DW_CFA_expression. The pattern or the insn should be a
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store of a register to an arbitrary (non-validated) memory address. */
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REG_CFA_NOTE (CFA_EXPRESSION)
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/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex
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for FRAME_RELATED_EXPR intuition. The DWARF expression computes the value of
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the given register. */
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REG_CFA_NOTE (CFA_VAL_EXPRESSION)
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/* Attached to insns that are RTX_FRAME_RELATED_P, with the information
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that this is a restore operation, i.e. will result in DW_CFA_restore
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or the like. Either the attached rtx, or the destination of the insn's
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first pattern is the register to be restored. */
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REG_CFA_NOTE (CFA_RESTORE)
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/* Like CFA_RESTORE but without actually emitting CFI. This can be
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used to tell the verification infrastructure that a register is
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saved without intending to restore it. */
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REG_CFA_NOTE (CFA_NO_RESTORE)
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/* Attached to insns that are RTX_FRAME_RELATED_P, marks insn that sets
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vDRAP from DRAP. If vDRAP is a register, vdrap_reg is initalized
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to the argument, if it is a MEM, it is ignored. */
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REG_CFA_NOTE (CFA_SET_VDRAP)
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/* Attached to insns that are RTX_FRAME_RELATED_P, indicating a window
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save operation, i.e. will result in a DW_CFA_GNU_window_save.
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The argument is ignored. */
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REG_CFA_NOTE (CFA_WINDOW_SAVE)
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/* Attached to insns that are RTX_FRAME_RELATED_P, marks the insn as
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requiring that all queued information should be flushed *before* insn,
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regardless of what is visible in the rtl. The argument is ignored.
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This is normally used for a call instruction which is not exposed to
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the rest of the compiler as a CALL_INSN. */
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REG_CFA_NOTE (CFA_FLUSH_QUEUE)
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/* Attached to insns that are RTX_FRAME_RELATED_P, toggling the mangling status
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of return address. Currently it's only used by AArch64. The argument is
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ignored. */
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REG_CFA_NOTE (CFA_TOGGLE_RA_MANGLE)
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/* Indicates what exception region an INSN belongs in. This is used
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to indicate what region to which a call may throw. REGION 0
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indicates that a call cannot throw at all. REGION -1 indicates
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that it cannot throw, nor will it execute a non-local goto. */
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REG_NOTE (EH_REGION)
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/* Used by haifa-sched to save NOTE_INSN notes across scheduling. */
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REG_NOTE (SAVE_NOTE)
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/* Indicates that a call does not return. */
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REG_NOTE (NORETURN)
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/* Indicates that an indirect jump is a non-local goto instead of a
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computed goto. */
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REG_NOTE (NON_LOCAL_GOTO)
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/* This kind of note is generated at each to `setjmp', and similar
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functions that can return twice. */
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REG_NOTE (SETJMP)
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/* This kind of note is generated at each transactional memory
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builtin, to indicate we need to generate transaction restart
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edges for this insn. */
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REG_NOTE (TM)
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/* Indicates the cumulative offset of the stack pointer accounting
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for pushed arguments. This will only be generated when
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ACCUMULATE_OUTGOING_ARGS is false. */
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REG_NOTE (ARGS_SIZE)
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/* Used for communication between IRA and caller-save.cc, indicates
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that the return value of a call can be used to reinitialize a
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pseudo reg. */
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REG_NOTE (RETURNED)
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/* Indicates the instruction is a stack check probe that should not
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be combined with other stack adjustments. */
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REG_NOTE (STACK_CHECK)
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/* Used to mark a call with the function decl called by the call.
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The decl might not be available in the call due to splitting of the call
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insn. This note is a SYMBOL_REF. */
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REG_NOTE (CALL_DECL)
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/* Indicates that the call is an untyped_call. These calls are special
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in that they set all of the target ABI's return value registers to a
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defined value without explicitly saying so. For example, a typical
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untyped_call sequence has the form:
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(call (mem (symbol_ref "foo")))
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(set (reg pseudo1) (reg result1))
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...
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(set (reg pseudon) (reg resultn))
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The ABI specifies that result1..resultn are clobbered by the call,
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but the RTL does not indicate that result1..resultn are the results
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of the call. */
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REG_NOTE (UNTYPED_CALL)
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/* Indicate that a call should not be verified for control-flow consistency.
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The target address of the call is assumed as a valid address and no check
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to validate a branch to the target address is needed. The call is marked
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when a called function has a 'notrack' attribute. This note is used by the
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compiler when the option -fcf-protection=branch is specified. */
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REG_NOTE (CALL_NOCF_CHECK)
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/* The values passed to callee, for debuginfo purposes. */
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REG_NOTE (CALL_ARG_LOCATION)
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