1 /* Alignment-related classes. 2 Copyright (C) 2018-2020 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 /* Align flags tuple with alignment in log form and with a maximum skip. */ 21 22 struct align_flags_tuple 23 { 24 /* Values of the -falign-* flags: how much to align labels in code. 25 log is "align to 2^log" (so 0 means no alignment). 26 maxskip is the maximum allowed amount of padding to insert. */ 27 int log; 28 int maxskip; 29 30 /* Normalize filled values so that maxskip is not bigger than 1 << log. */ normalizealign_flags_tuple31 void normalize () 32 { 33 int n = (1 << log); 34 if (maxskip > n) 35 maxskip = n - 1; 36 } 37 38 /* Return original value of an alignment flag. */ get_valuealign_flags_tuple39 int get_value () 40 { 41 return maxskip + 1; 42 } 43 }; 44 45 /* Alignment flags is structure used as value of -align-* options. 46 It's used in target-dependant code. */ 47 48 class align_flags 49 { 50 public: 51 /* Default constructor. */ 52 align_flags (int log0 = 0, int maxskip0 = 0, int log1 = 0, int maxskip1 = 0) 53 { 54 levels[0].log = log0; 55 levels[0].maxskip = maxskip0; 56 levels[1].log = log1; 57 levels[1].maxskip = maxskip1; 58 normalize (); 59 } 60 61 /* Normalize both components of align_flags. */ normalize()62 void normalize () 63 { 64 for (unsigned i = 0; i < 2; i++) 65 levels[i].normalize (); 66 } 67 68 /* Get alignment that is common bigger alignment of alignments F0 and F1. */ max(const align_flags f0,const align_flags f1)69 static align_flags max (const align_flags f0, const align_flags f1) 70 { 71 int log0 = MAX (f0.levels[0].log, f1.levels[0].log); 72 int maxskip0 = MAX (f0.levels[0].maxskip, f1.levels[0].maxskip); 73 int log1 = MAX (f0.levels[1].log, f1.levels[1].log); 74 int maxskip1 = MAX (f0.levels[1].maxskip, f1.levels[1].maxskip); 75 return align_flags (log0, maxskip0, log1, maxskip1); 76 } 77 78 align_flags_tuple levels[2]; 79 }; 80 81 /* Define maximum supported code alignment. */ 82 #define MAX_CODE_ALIGN 16 83 #define MAX_CODE_ALIGN_VALUE (1 << MAX_CODE_ALIGN) 84