/* Register note definitions. Copyright (C) 2004-2024 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, 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. CFA related notes meant for RTX_FRAME_RELATED_P instructions should be declared with REG_CFA_NOTE macro instead of REG_NOTE. */ /* Shorthand. */ #define REG_NOTE(NAME) DEF_REG_NOTE (REG_##NAME) #ifndef REG_CFA_NOTE # define REG_CFA_NOTE(NAME) REG_NOTE (NAME) #endif /* 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) /* 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. It has an integer value (in an INT_LIST). For jumps, it is the probability that this is a taken branch. The integer represents a value of profile_probability type. Use to_reg_br_prob_note and from_reg_br_prob_note to extract the actual value. */ REG_NOTE (BR_PROB) /* Attached to a move insn which receives the result of a call; 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. It contains CONCAT of two integer value. First specifies the branch predictor that added the note, second specifies the predicted hitrate of branch in a fixed point arithmetic based on REG_BR_PROB_BASE. */ 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_CFA_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_CFA_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_CFA_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_CFA_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_CFA_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_CFA_NOTE (CFA_EXPRESSION) /* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex for FRAME_RELATED_EXPR intuition. The DWARF expression computes the value of the given register. */ REG_CFA_NOTE (CFA_VAL_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_CFA_NOTE (CFA_RESTORE) /* Like CFA_RESTORE but without actually emitting CFI. This can be used to tell the verification infrastructure that a register is saved without intending to restore it. */ REG_CFA_NOTE (CFA_NO_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_CFA_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_CFA_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_CFA_NOTE (CFA_FLUSH_QUEUE) /* Attached to insns that are RTX_FRAME_RELATED_P, indicating an authentication of the return address. Currently it's only used by AArch64. The argument is ignored. */ REG_CFA_NOTE (CFA_NEGATE_RA_STATE) /* 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.cc, indicates that the return value of a call can be used to reinitialize a pseudo reg. */ REG_NOTE (RETURNED) /* Indicates the instruction is a stack check probe that should not be combined with other stack adjustments. */ REG_NOTE (STACK_CHECK) /* 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) /* Indicates that the call is an untyped_call. These calls are special in that they set all of the target ABI's return value registers to a defined value without explicitly saying so. For example, a typical untyped_call sequence has the form: (call (mem (symbol_ref "foo"))) (set (reg pseudo1) (reg result1)) ... (set (reg pseudon) (reg resultn)) The ABI specifies that result1..resultn are clobbered by the call, but the RTL does not indicate that result1..resultn are the results of the call. */ REG_NOTE (UNTYPED_CALL) /* Indicate that a call should not be verified for control-flow consistency. The target address of the call is assumed as a valid address and no check to validate a branch to the target address is needed. The call is marked when a called function has a 'notrack' attribute. This note is used by the compiler when the option -fcf-protection=branch is specified. */ REG_NOTE (CALL_NOCF_CHECK) /* The values passed to callee, for debuginfo purposes. */ REG_NOTE (CALL_ARG_LOCATION)