- /* 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_DEAD = 1,
-
- /* The REG is autoincremented or autodecremented. */
- REG_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_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_EQUAL,
-
- /* This insn copies the return-value of a library call out of the hard reg
- for return values. This note is actually an INSN_LIST and it points to
- the first insn involved in setting up arguments for the call. flow.c
- uses this to delete the entire library call when its result is dead. */
- REG_RETVAL,
-
- /* The inverse of REG_RETVAL: it goes on the first insn of the library call
- and points at the one that has the REG_RETVAL. This note is also an
- INSN_LIST. */
- REG_LIBCALL,
-
- /* 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_NONNEG,
-
- /* There is no conflict *after this insn* between the register in the note
- and the destination of this insn. */
- REG_NO_CONFLICT,
-
- /* Identifies a register set in this insn and never used. */
- REG_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_CC_SETTER, REG_CC_USER,
-
- /* Points to a CODE_LABEL. Used by non-JUMP_INSNs to say that the
- CODE_LABEL contained in the REG_LABEL note is used by the insn.
- This note is an INSN_LIST. */
- REG_LABEL,
-
- /* REG_DEP_ANTI and REG_DEP_OUTPUT are used in LOG_LINKS to represent
- write-after-read and write-after-write dependencies respectively.
- Data dependencies, which are the only type of LOG_LINK created by
- flow, are represented by a 0 reg note kind. */
- REG_DEP_ANTI, REG_DEP_OUTPUT,
-
- /* REG_BR_PROB is attached to JUMP_INSNs and CALL_INSNs.
- It has an integer value. 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_BR_PROB,
-
- /* REG_VALUE_PROFILE is attached when the profile is read in to an insn
- before that the code to profile the value is inserted. It contains
- the results of profiling. */
- REG_VALUE_PROFILE,
-
- /* Attached to a call insn; indicates that the call is malloc-like and
- that the pointer returned cannot alias anything else. */
- REG_NOALIAS,
-
- /* Used to optimize rtl generated by dynamic stack allocations for targets
- where SETJMP_VIA_SAVE_AREA is true. */
- REG_SAVE_AREA,
-
- /* 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_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_FRAME_RELATED_EXPR,
-
- /* Indicates that REG holds the exception context for the function.
- This context is shared by inline functions, so the code to acquire
- the real exception context is delayed until after inlining. */
- REG_EH_CONTEXT,
-
- /* 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_EH_REGION,
-
- /* Used by haifa-sched to save NOTE_INSN notes across scheduling. */
- REG_SAVE_NOTE,
-
- /* Indicates that this insn (which is part of the prologue) computes
- a value which might not be used later, and if so it's OK to delete
- the insn. Normally, deleting any insn in the prologue is an error.
- At present the parameter is unused and set to (const_int 0). */
- REG_MAYBE_DEAD,
-
- /* Indicates that a call does not return. */
- REG_NORETURN,
-
- /* Indicates that an indirect jump is a non-local goto instead of a
- computed goto. */
- REG_NON_LOCAL_GOTO,
-
- /* Indicates that a jump crosses between hot and cold sections
- in a (partitioned) assembly or .o file, and therefore should not be
- reduced to a simpler jump by optimizations. */
- REG_CROSSING_JUMP,
-
- /* This kind of note is generated at each to `setjmp',
- and similar functions that can return twice. */
- REG_SETJMP,
-
- /* Indicate calls that always returns. */
- REG_ALWAYS_RETURN,
-
- /* Indicate that the memory load references a vtable. The expression
- is of the form (plus (symbol_ref vtable_sym) (const_int offset)). */
- REG_VTABLE_REF