* gcc.dg/compat/struct-layout-1_generate.c (dg_options): New. Moved
[official-gcc.git] / gcc / reg-notes.def
blob5a5325f01ae35a05c37403b9cf00917e06e10ce7
1 /* Register note definitions.
2 Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* This file defines all the codes that may appear on individual
21 EXPR_LIST rtxes in the REG_NOTES chain of an insn. The codes are
22 stored in the mode field of the EXPR_LIST. Source files define
23 DEF_REG_NOTE appropriately before including this file. */
25 /* Shorthand. */
26 #define REG_NOTE(NAME) DEF_REG_NOTE (REG_##NAME)
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. */
32 REG_NOTE (DEP_TRUE)
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. */
37 REG_NOTE (DEAD)
39 /* The REG is autoincremented or autodecremented in this insn. */
40 REG_NOTE (INC)
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. */
51 REG_NOTE (EQUIV)
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. */
56 REG_NOTE (EQUAL)
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. */
63 REG_NOTE (NONNEG)
65 /* Identifies a register set in this insn and never used. */
66 REG_NOTE (UNUSED)
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. */
75 REG_NOTE (CC_SETTER)
76 REG_NOTE (CC_USER)
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. */
81 REG_NOTE (LABEL_TARGET)
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. */
87 REG_NOTE (LABEL_OPERAND)
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. */
92 REG_NOTE (DEP_OUTPUT)
93 REG_NOTE (DEP_ANTI)
95 /* REG_BR_PROB is attached to JUMP_INSNs and CALL_INSNs. It has an
96 integer value. For jumps, it is the probability that this is a
97 taken branch. For calls, it is the probability that this call
98 won't return. */
99 REG_NOTE (BR_PROB)
101 /* REG_VALUE_PROFILE is attached when the profile is read in to an
102 insn before that the code to profile the value is inserted. It
103 contains the results of profiling. */
104 REG_NOTE (VALUE_PROFILE)
106 /* Attached to a call insn; indicates that the call is malloc-like and
107 that the pointer returned cannot alias anything else. */
108 REG_NOTE (NOALIAS)
110 /* REG_BR_PRED is attached to JUMP_INSNs and CALL_INSNSs. It contains
111 CONCAT of two integer value. First specifies the branch predictor
112 that added the note, second specifies the predicted hitrate of
113 branch in the same format as REG_BR_PROB note uses. */
114 REG_NOTE (BR_PRED)
116 /* Attached to insns that are RTX_FRAME_RELATED_P, but are too complex
117 for DWARF to interpret what they imply. The attached rtx is used
118 instead of intuition. */
119 REG_NOTE (FRAME_RELATED_EXPR)
121 /* Indicates that REG holds the exception context for the function.
122 This context is shared by inline functions, so the code to acquire
123 the real exception context is delayed until after inlining. */
124 REG_NOTE (EH_CONTEXT)
126 /* Indicates what exception region an INSN belongs in. This is used
127 to indicate what region to which a call may throw. REGION 0
128 indicates that a call cannot throw at all. REGION -1 indicates
129 that it cannot throw, nor will it execute a non-local goto. */
130 REG_NOTE (EH_REGION)
132 /* Used by haifa-sched to save NOTE_INSN notes across scheduling. */
133 REG_NOTE (SAVE_NOTE)
135 /* Indicates that a call does not return. */
136 REG_NOTE (NORETURN)
138 /* Indicates that an indirect jump is a non-local goto instead of a
139 computed goto. */
140 REG_NOTE (NON_LOCAL_GOTO)
142 /* Indicates that a jump crosses between hot and cold sections in a
143 (partitioned) assembly or .o file, and therefore should not be
144 reduced to a simpler jump by optimizations. */
145 REG_NOTE (CROSSING_JUMP)
147 /* This kind of note is generated at each to `setjmp', and similar
148 functions that can return twice. */
149 REG_NOTE (SETJMP)