1/* Register note definitions. 2 Copyright (C) 2004-2016 Free Software Foundation, Inc. 3 4This file is part of GCC. 5 6GCC is free software; you can redistribute it and/or modify it under 7the terms of the GNU General Public License as published by the Free 8Software Foundation; either version 3, or (at your option) any later 9version. 10 11GCC is distributed in the hope that it will be useful, but WITHOUT ANY 12WARRANTY; without even the implied warranty of MERCHANTABILITY or 13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14for more details. 15 16You should have received a copy of the GNU General Public License 17along with GCC; see the file COPYING3. If not see 18<http://www.gnu.org/licenses/>. */ 19 20/* This file defines all the codes that may appear on individual 21 EXPR_LIST, INSN_LIST and INT_LIST rtxes in the REG_NOTES chain of an insn. 22 The codes are stored in the mode field of the rtx. Source files 23 define DEF_REG_NOTE appropriately before including this file. */ 24 25/* Shorthand. */ 26#define REG_NOTE(NAME) DEF_REG_NOTE (REG_##NAME) 27 28/* REG_DEP_TRUE is used in scheduler dependencies lists to represent a 29 read-after-write dependency (i.e. a true data dependency). This is 30 here, not grouped with REG_DEP_ANTI and REG_DEP_OUTPUT, because some 31 passes use a literal 0 for it. */ 32REG_NOTE (DEP_TRUE) 33 34/* The value in REG dies in this insn (i.e., it is not needed past 35 this insn). If REG is set in this insn, the REG_DEAD note may, 36 but need not, be omitted. */ 37REG_NOTE (DEAD) 38 39/* The REG is autoincremented or autodecremented in this insn. */ 40REG_NOTE (INC) 41 42/* Describes the insn as a whole; it says that the insn sets a 43 register to a constant value or to be equivalent to a memory 44 address. If the register is spilled to the stack then the constant 45 value should be substituted for it. The contents of the REG_EQUIV 46 is the constant value or memory address, which may be different 47 from the source of the SET although it has the same value. A 48 REG_EQUIV note may also appear on an insn which copies a register 49 parameter to a pseudo-register, if there is a memory address which 50 could be used to hold that pseudo-register throughout the function. */ 51REG_NOTE (EQUIV) 52 53/* Like REG_EQUIV except that the destination is only momentarily 54 equal to the specified rtx. Therefore, it cannot be used for 55 substitution; but it can be used for cse. */ 56REG_NOTE (EQUAL) 57 58/* The register is always nonnegative during the containing loop. 59 This is used in branches so that decrement and branch instructions 60 terminating on zero can be matched. There must be an insn pattern 61 in the md file named `decrement_and_branch_until_zero' or else this 62 will never be added to any instructions. */ 63REG_NOTE (NONNEG) 64 65/* Identifies a register set in this insn and never used. */ 66REG_NOTE (UNUSED) 67 68/* REG_CC_SETTER and REG_CC_USER link a pair of insns that set and use 69 CC0, respectively. Normally, these are required to be consecutive 70 insns, but we permit putting a cc0-setting insn in the delay slot 71 of a branch as long as only one copy of the insn exists. In that 72 case, these notes point from one to the other to allow code 73 generation to determine what any require information and to 74 properly update CC_STATUS. These notes are INSN_LISTs. */ 75REG_NOTE (CC_SETTER) 76REG_NOTE (CC_USER) 77 78/* Points to a CODE_LABEL. Used by JUMP_INSNs to say that the CODE_LABEL 79 contained in the REG_LABEL_TARGET note is a possible jump target of 80 this insn. This note is an INSN_LIST. */ 81REG_NOTE (LABEL_TARGET) 82 83/* Points to a CODE_LABEL. Used by any insn to say that the CODE_LABEL 84 contained in the REG_LABEL_OPERAND note is used by the insn, but as an 85 operand, not as a jump target (though it may indirectly be a jump 86 target for a later jump insn). This note is an INSN_LIST. */ 87REG_NOTE (LABEL_OPERAND) 88 89/* REG_DEP_OUTPUT and REG_DEP_ANTI are used in scheduler dependencies lists 90 to represent write-after-write and write-after-read dependencies 91 respectively. */ 92REG_NOTE (DEP_OUTPUT) 93REG_NOTE (DEP_ANTI) 94REG_NOTE (DEP_CONTROL) 95 96/* REG_BR_PROB is attached to JUMP_INSNs and CALL_INSNs. It has an 97 integer value (in an INT_LIST). For jumps, it is the probability 98 that this is a taken branch. For calls, it is the probability that 99 this call won't return. */ 100REG_NOTE (BR_PROB) 101 102/* Attached to a call insn; indicates that the call is malloc-like and 103 that the pointer returned cannot alias anything else. */ 104REG_NOTE (NOALIAS) 105 106/* REG_BR_PRED is attached to JUMP_INSNs and CALL_INSNSs. It contains 107 CONCAT of two integer value. First specifies the branch predictor 108 that added the note, second specifies the predicted hitrate of 109 branch in the same format as REG_BR_PROB note uses. */ 110REG_NOTE (BR_PRED) 111 112/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex 113 for DWARF to interpret what they imply. The attached rtx is used 114 instead of intuition. */ 115REG_NOTE (FRAME_RELATED_EXPR) 116 117/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex 118 for FRAME_RELATED_EXPR intuition. The insn's first pattern must be 119 a SET, and the destination must be the CFA register. The attached 120 rtx is an expression that defines the CFA. In the simplest case, the 121 rtx could be just the stack_pointer_rtx; more common would be a PLUS 122 with a base register and a constant offset. In the most complicated 123 cases, this will result in a DW_CFA_def_cfa_expression with the rtx 124 expression rendered in a dwarf location expression. */ 125REG_NOTE (CFA_DEF_CFA) 126 127/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex 128 for FRAME_RELATED_EXPR intuition. This note adjusts the expression 129 from which the CFA is computed. The attached rtx defines a new CFA 130 expression, relative to the old CFA expression. This rtx must be of 131 the form (SET new-cfa-reg (PLUS old-cfa-reg const_int)). If the note 132 rtx is NULL, we use the first SET of the insn. */ 133REG_NOTE (CFA_ADJUST_CFA) 134 135/* Similar to FRAME_RELATED_EXPR, with the additional information that 136 this is a save to memory, i.e. will result in DW_CFA_offset or the 137 like. The pattern or the insn should be a simple store relative to 138 the CFA. */ 139REG_NOTE (CFA_OFFSET) 140 141/* Similar to FRAME_RELATED_EXPR, with the additional information that this 142 is a save to a register, i.e. will result in DW_CFA_register. The insn 143 or the pattern should be simple reg-reg move. */ 144REG_NOTE (CFA_REGISTER) 145 146/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex 147 for FRAME_RELATED_EXPR intuition. This is a save to memory, i.e. will 148 result in a DW_CFA_expression. The pattern or the insn should be a 149 store of a register to an arbitrary (non-validated) memory address. */ 150REG_NOTE (CFA_EXPRESSION) 151 152/* Attached to insns that are RTX_FRAME_RELATED_P, with the information 153 that this is a restore operation, i.e. will result in DW_CFA_restore 154 or the like. Either the attached rtx, or the destination of the insn's 155 first pattern is the register to be restored. */ 156REG_NOTE (CFA_RESTORE) 157 158/* Attached to insns that are RTX_FRAME_RELATED_P, marks insn that sets 159 vDRAP from DRAP. If vDRAP is a register, vdrap_reg is initalized 160 to the argument, if it is a MEM, it is ignored. */ 161REG_NOTE (CFA_SET_VDRAP) 162 163/* Attached to insns that are RTX_FRAME_RELATED_P, indicating a window 164 save operation, i.e. will result in a DW_CFA_GNU_window_save. 165 The argument is ignored. */ 166REG_NOTE (CFA_WINDOW_SAVE) 167 168/* Attached to insns that are RTX_FRAME_RELATED_P, marks the insn as 169 requiring that all queued information should be flushed *before* insn, 170 regardless of what is visible in the rtl. The argument is ignored. 171 This is normally used for a call instruction which is not exposed to 172 the rest of the compiler as a CALL_INSN. */ 173REG_NOTE (CFA_FLUSH_QUEUE) 174 175/* Indicates what exception region an INSN belongs in. This is used 176 to indicate what region to which a call may throw. REGION 0 177 indicates that a call cannot throw at all. REGION -1 indicates 178 that it cannot throw, nor will it execute a non-local goto. */ 179REG_NOTE (EH_REGION) 180 181/* Used by haifa-sched to save NOTE_INSN notes across scheduling. */ 182REG_NOTE (SAVE_NOTE) 183 184/* Indicates that a call does not return. */ 185REG_NOTE (NORETURN) 186 187/* Indicates that an indirect jump is a non-local goto instead of a 188 computed goto. */ 189REG_NOTE (NON_LOCAL_GOTO) 190 191/* This kind of note is generated at each to `setjmp', and similar 192 functions that can return twice. */ 193REG_NOTE (SETJMP) 194 195/* This kind of note is generated at each transactional memory 196 builtin, to indicate we need to generate transaction restart 197 edges for this insn. */ 198REG_NOTE (TM) 199 200/* Indicates the cumulative offset of the stack pointer accounting 201 for pushed arguments. This will only be generated when 202 ACCUMULATE_OUTGOING_ARGS is false. */ 203REG_NOTE (ARGS_SIZE) 204 205/* Used for communication between IRA and caller-save.c, indicates 206 that the return value of a call can be used to reinitialize a 207 pseudo reg. */ 208REG_NOTE (RETURNED) 209 210/* Used to mark a call with the function decl called by the call. 211 The decl might not be available in the call due to splitting of the call 212 insn. This note is a SYMBOL_REF. */ 213REG_NOTE (CALL_DECL) 214