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memmodel.h revision 1.1.1.2 
      1 /* Prototypes of memory model helper functions.
      2    Copyright (C) 2011-2018 Free Software Foundation, Inc.
      3 
      4 This file is part of GCC.
      5 
      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.
     10 
     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.
     15 
     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/>.  */
     19 
     20 #ifndef GCC_MEMMODEL_H
     21 #define GCC_MEMMODEL_H
     22 
     23 /* Suppose that higher bits are target dependent. */
     24 #define MEMMODEL_MASK ((1<<16)-1)
     25 
     26 /* Legacy sync operations set this upper flag in the memory model.  This allows
     27    targets that need to do something stronger for sync operations to
     28    differentiate with their target patterns and issue a more appropriate insn
     29    sequence.  See bugzilla 65697 for background.  */
     30 #define MEMMODEL_SYNC (1<<15)
     31 
     32 /* Memory model without SYNC bit for targets/operations that do not care.  */
     33 #define MEMMODEL_BASE_MASK (MEMMODEL_SYNC-1)
     34 
     35 /* Memory model types for the __atomic* builtins.
     36    This must match the order in libstdc++-v3/include/bits/atomic_base.h.  */
     37 enum memmodel
     38 {
     39   MEMMODEL_RELAXED = 0,
     40   MEMMODEL_CONSUME = 1,
     41   MEMMODEL_ACQUIRE = 2,
     42   MEMMODEL_RELEASE = 3,
     43   MEMMODEL_ACQ_REL = 4,
     44   MEMMODEL_SEQ_CST = 5,
     45   MEMMODEL_LAST = 6,
     46   MEMMODEL_SYNC_ACQUIRE = MEMMODEL_ACQUIRE | MEMMODEL_SYNC,
     47   MEMMODEL_SYNC_RELEASE = MEMMODEL_RELEASE | MEMMODEL_SYNC,
     48   MEMMODEL_SYNC_SEQ_CST = MEMMODEL_SEQ_CST | MEMMODEL_SYNC,
     49   /* Say that all the higher bits are valid target extensions.  */
     50   MEMMODEL_MAX = INTTYPE_MAXIMUM (int)
     51 };
     52 
     53 /* Return the memory model from a host integer.  */
     54 static inline enum memmodel
     55 memmodel_from_int (unsigned HOST_WIDE_INT val)
     56 {
     57   return (enum memmodel) (val & MEMMODEL_MASK);
     58 }
     59 
     60 /* Return the base memory model from a host integer.  */
     61 static inline enum memmodel
     62 memmodel_base (unsigned HOST_WIDE_INT val)
     63 {
     64   return (enum memmodel) (val & MEMMODEL_BASE_MASK);
     65 }
     66 
     67 /* Return TRUE if the memory model is RELAXED.  */
     68 static inline bool
     69 is_mm_relaxed (enum memmodel model)
     70 {
     71   return (model & MEMMODEL_BASE_MASK) == MEMMODEL_RELAXED;
     72 }
     73 
     74 /* Return TRUE if the memory model is CONSUME.  */
     75 static inline bool
     76 is_mm_consume (enum memmodel model)
     77 {
     78   return (model & MEMMODEL_BASE_MASK) == MEMMODEL_CONSUME;
     79 }
     80 
     81 /* Return TRUE if the memory model is ACQUIRE.  */
     82 static inline bool
     83 is_mm_acquire (enum memmodel model)
     84 {
     85   return (model & MEMMODEL_BASE_MASK) == MEMMODEL_ACQUIRE;
     86 }
     87 
     88 /* Return TRUE if the memory model is RELEASE.  */
     89 static inline bool
     90 is_mm_release (enum memmodel model)
     91 {
     92   return (model & MEMMODEL_BASE_MASK) == MEMMODEL_RELEASE;
     93 }
     94 
     95 /* Return TRUE if the memory model is ACQ_REL.  */
     96 static inline bool
     97 is_mm_acq_rel (enum memmodel model)
     98 {
     99   return (model & MEMMODEL_BASE_MASK) == MEMMODEL_ACQ_REL;
    100 }
    101 
    102 /* Return TRUE if the memory model is SEQ_CST.  */
    103 static inline bool
    104 is_mm_seq_cst (enum memmodel model)
    105 {
    106   return (model & MEMMODEL_BASE_MASK) == MEMMODEL_SEQ_CST;
    107 }
    108 
    109 /* Return TRUE if the memory model is a SYNC variant.  */
    110 static inline bool
    111 is_mm_sync (enum memmodel model)
    112 {
    113   return (model & MEMMODEL_SYNC);
    114 }
    115 
    116 #endif  /* GCC_MEMMODEL_H  */
    117