1/* Register note definitions. 2 Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 3 Free Software Foundation, Inc. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 3, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING3. If not see 19<http://www.gnu.org/licenses/>. */ 20 21/* This file defines all the codes that may appear on individual 22 EXPR_LIST rtxes in the REG_NOTES chain of an insn. The codes are 23 stored in the mode field of the EXPR_LIST. Source files define 24 DEF_REG_NOTE appropriately before including this file. */ 25 26/* Shorthand. */ 27#define REG_NOTE(NAME) DEF_REG_NOTE (REG_##NAME) 28 29/* REG_DEP_TRUE is used in scheduler dependencies lists to represent a 30 read-after-write dependency (i.e. a true data dependency). This is 31 here, not grouped with REG_DEP_ANTI and REG_DEP_OUTPUT, because some 32 passes use a literal 0 for it. */ 33REG_NOTE (DEP_TRUE) 34 35/* The value in REG dies in this insn (i.e., it is not needed past 36 this insn). If REG is set in this insn, the REG_DEAD note may, 37 but need not, be omitted. */ 38REG_NOTE (DEAD) 39 40/* The REG is autoincremented or autodecremented in this insn. */ 41REG_NOTE (INC) 42 43/* Describes the insn as a whole; it says that the insn sets a 44 register to a constant value or to be equivalent to a memory 45 address. If the register is spilled to the stack then the constant 46 value should be substituted for it. The contents of the REG_EQUIV 47 is the constant value or memory address, which may be different 48 from the source of the SET although it has the same value. A 49 REG_EQUIV note may also appear on an insn which copies a register 50 parameter to a pseudo-register, if there is a memory address which 51 could be used to hold that pseudo-register throughout the function. */ 52REG_NOTE (EQUIV) 53 54/* Like REG_EQUIV except that the destination is only momentarily 55 equal to the specified rtx. Therefore, it cannot be used for 56 substitution; but it can be used for cse. */ 57REG_NOTE (EQUAL) 58 59/* The register is always nonnegative during the containing loop. 60 This is used in branches so that decrement and branch instructions 61 terminating on zero can be matched. There must be an insn pattern 62 in the md file named `decrement_and_branch_until_zero' or else this 63 will never be added to any instructions. */ 64REG_NOTE (NONNEG) 65 66/* Identifies a register set in this insn and never used. */ 67REG_NOTE (UNUSED) 68 69/* REG_CC_SETTER and REG_CC_USER link a pair of insns that set and use 70 CC0, respectively. Normally, these are required to be consecutive 71 insns, but we permit putting a cc0-setting insn in the delay slot 72 of a branch as long as only one copy of the insn exists. In that 73 case, these notes point from one to the other to allow code 74 generation to determine what any require information and to 75 properly update CC_STATUS. These notes are INSN_LISTs. */ 76REG_NOTE (CC_SETTER) 77REG_NOTE (CC_USER) 78 79/* Points to a CODE_LABEL. Used by JUMP_INSNs to say that the CODE_LABEL 80 contained in the REG_LABEL_TARGET note is a possible jump target of 81 this insn. This note is an INSN_LIST. */ 82REG_NOTE (LABEL_TARGET) 83 84/* Points to a CODE_LABEL. Used by any insn to say that the CODE_LABEL 85 contained in the REG_LABEL_OPERAND note is used by the insn, but as an 86 operand, not as a jump target (though it may indirectly be a jump 87 target for a later jump insn). This note is an INSN_LIST. */ 88REG_NOTE (LABEL_OPERAND) 89 90/* REG_DEP_OUTPUT and REG_DEP_ANTI are used in scheduler dependencies lists 91 to represent write-after-write and write-after-read dependencies 92 respectively. */ 93REG_NOTE (DEP_OUTPUT) 94REG_NOTE (DEP_ANTI) 95 96/* REG_BR_PROB is attached to JUMP_INSNs and CALL_INSNs. It has an 97 integer value. For jumps, it is the probability that this is a 98 taken branch. For calls, it is the probability that this call 99 won't return. */ 100REG_NOTE (BR_PROB) 101 102/* REG_VALUE_PROFILE is attached when the profile is read in to an 103 insn before that the code to profile the value is inserted. It 104 contains the results of profiling. */ 105REG_NOTE (VALUE_PROFILE) 106 107/* Attached to a call insn; indicates that the call is malloc-like and 108 that the pointer returned cannot alias anything else. */ 109REG_NOTE (NOALIAS) 110 111/* REG_BR_PRED is attached to JUMP_INSNs and CALL_INSNSs. It contains 112 CONCAT of two integer value. First specifies the branch predictor 113 that added the note, second specifies the predicted hitrate of 114 branch in the same format as REG_BR_PROB note uses. */ 115REG_NOTE (BR_PRED) 116 117/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex 118 for DWARF to interpret what they imply. The attached rtx is used 119 instead of intuition. */ 120REG_NOTE (FRAME_RELATED_EXPR) 121 122/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex 123 for FRAME_RELATED_EXPR intuition. The insn's first pattern must be 124 a SET, and the destination must be the CFA register. The attached 125 rtx is an expression that defines the CFA. In the simplest case, the 126 rtx could be just the stack_pointer_rtx; more common would be a PLUS 127 with a base register and a constant offset. In the most complicated 128 cases, this will result in a DW_CFA_def_cfa_expression with the rtx 129 expression rendered in a dwarf location expression. */ 130REG_NOTE (CFA_DEF_CFA) 131 132/* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex 133 for FRAME_RELATED_EXPR intuition. This note adjusts the expression 134 from which the CFA is computed. The attached rtx defines a new CFA 135 expression, relative to the old CFA expression. This rtx must be of 136 the form (SET new-cfa-reg (PLUS old-cfa-reg const_int)). If the note 137 rtx is NULL, we use the first SET of the insn. */ 138REG_NOTE (CFA_ADJUST_CFA) 139 140/* Similar to FRAME_RELATED_EXPR, with the additional information that 141 this is a save to memory, i.e. will result in DW_CFA_offset or the 142 like. The pattern or the insn should be a simple store relative to 143 the CFA. */ 144REG_NOTE (CFA_OFFSET) 145 146/* Similar to FRAME_RELATED_EXPR, with the additional information that this 147 is a save to a register, i.e. will result in DW_CFA_register. The insn 148 or the pattern should be simple reg-reg move. */ 149REG_NOTE (CFA_REGISTER) 150 151/* Attached to insns that are RTX_FRAME_RELATED_P, with the information 152 that this is a restore operation, i.e. will result in DW_CFA_restore 153 or the like. Either the attached rtx, or the destination of the insn's 154 first pattern is the register to be restored. */ 155REG_NOTE (CFA_RESTORE) 156 157/* Attached to insn that is RTX_FRAME_RELATED_P, marks insn that sets 158 vDRAP from DRAP. If vDRAP is a register, vdrap_reg is initalized 159 to the argument, if it is a MEM, it is ignored. */ 160REG_NOTE (CFA_SET_VDRAP) 161 162/* Indicates that REG holds the exception context for the function. 163 This context is shared by inline functions, so the code to acquire 164 the real exception context is delayed until after inlining. */ 165REG_NOTE (EH_CONTEXT) 166 167/* Indicates what exception region an INSN belongs in. This is used 168 to indicate what region to which a call may throw. REGION 0 169 indicates that a call cannot throw at all. REGION -1 indicates 170 that it cannot throw, nor will it execute a non-local goto. */ 171REG_NOTE (EH_REGION) 172 173/* Used by haifa-sched to save NOTE_INSN notes across scheduling. */ 174REG_NOTE (SAVE_NOTE) 175 176/* Indicates that a call does not return. */ 177REG_NOTE (NORETURN) 178 179/* Indicates that an indirect jump is a non-local goto instead of a 180 computed goto. */ 181REG_NOTE (NON_LOCAL_GOTO) 182 183/* Indicates that a jump crosses between hot and cold sections in a 184 (partitioned) assembly or .o file, and therefore should not be 185 reduced to a simpler jump by optimizations. */ 186REG_NOTE (CROSSING_JUMP) 187 188/* This kind of note is generated at each to `setjmp', and similar 189 functions that can return twice. */ 190REG_NOTE (SETJMP) 191