1 /* Generic streaming support for various data types. 2 3 Copyright (C) 2011-2015 Free Software Foundation, Inc. 4 Contributed by Diego Novillo <dnovillo@google.com> 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free 10 Software Foundation; either version 3, or (at your option) any later 11 version. 12 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 #ifndef GCC_DATA_STREAMER_H 23 #define GCC_DATA_STREAMER_H 24 25 #include "vec.h" 26 #include "lto-streamer.h" 27 28 /* Data structures used to pack values and bitflags into a vector of 29 words. Used to stream values of a fixed number of bits in a space 30 efficient way. */ 31 static unsigned const BITS_PER_BITPACK_WORD = HOST_BITS_PER_WIDE_INT; 32 33 typedef unsigned HOST_WIDE_INT bitpack_word_t; 34 35 struct bitpack_d 36 { 37 /* The position of the first unused or unconsumed bit in the word. */ 38 unsigned pos; 39 40 /* The current word we are (un)packing. */ 41 bitpack_word_t word; 42 43 /* The lto_output_stream or the lto_input_block we are streaming to/from. */ 44 void *stream; 45 }; 46 47 /* In data-streamer.c */ 48 void bp_pack_var_len_unsigned (struct bitpack_d *, unsigned HOST_WIDE_INT); 49 void bp_pack_var_len_int (struct bitpack_d *, HOST_WIDE_INT); 50 unsigned HOST_WIDE_INT bp_unpack_var_len_unsigned (struct bitpack_d *); 51 HOST_WIDE_INT bp_unpack_var_len_int (struct bitpack_d *); 52 53 /* In data-streamer-out.c */ 54 void streamer_write_zero (struct output_block *); 55 void streamer_write_uhwi (struct output_block *, unsigned HOST_WIDE_INT); 56 void streamer_write_hwi (struct output_block *, HOST_WIDE_INT); 57 void streamer_write_gcov_count (struct output_block *, gcov_type); 58 void streamer_write_string (struct output_block *, struct lto_output_stream *, 59 const char *, bool); 60 void streamer_write_string_with_length (struct output_block *, 61 struct lto_output_stream *, 62 const char *, unsigned int, bool); 63 void bp_pack_string_with_length (struct output_block *, struct bitpack_d *, 64 const char *, unsigned int, bool); 65 void bp_pack_string (struct output_block *, struct bitpack_d *, 66 const char *, bool); 67 void streamer_write_uhwi_stream (struct lto_output_stream *, 68 unsigned HOST_WIDE_INT); 69 void streamer_write_hwi_stream (struct lto_output_stream *, HOST_WIDE_INT); 70 void streamer_write_gcov_count_stream (struct lto_output_stream *, gcov_type); 71 void streamer_write_data_stream (struct lto_output_stream *, const void *, 72 size_t); 73 74 /* In data-streamer-in.c */ 75 const char *streamer_read_string (struct data_in *, struct lto_input_block *); 76 const char *streamer_read_indexed_string (struct data_in *, 77 struct lto_input_block *, 78 unsigned int *); 79 const char *bp_unpack_indexed_string (struct data_in *, struct bitpack_d *, 80 unsigned int *); 81 const char *bp_unpack_string (struct data_in *, struct bitpack_d *); 82 unsigned HOST_WIDE_INT streamer_read_uhwi (struct lto_input_block *); 83 HOST_WIDE_INT streamer_read_hwi (struct lto_input_block *); 84 gcov_type streamer_read_gcov_count (struct lto_input_block *); 85 86 /* Returns a new bit-packing context for bit-packing into S. */ 87 static inline struct bitpack_d 88 bitpack_create (struct lto_output_stream *s) 89 { 90 struct bitpack_d bp; 91 bp.pos = 0; 92 bp.word = 0; 93 bp.stream = (void *)s; 94 return bp; 95 } 96 97 /* Pack the NBITS bit sized value VAL into the bit-packing context BP. */ 98 static inline void 99 bp_pack_value (struct bitpack_d *bp, bitpack_word_t val, unsigned nbits) 100 { 101 bitpack_word_t word = bp->word; 102 int pos = bp->pos; 103 104 /* Verify that VAL fits in the NBITS. */ 105 gcc_checking_assert (nbits == BITS_PER_BITPACK_WORD 106 || !(val & ~(((bitpack_word_t)1<<nbits)-1))); 107 108 /* If val does not fit into the current bitpack word switch to the 109 next one. */ 110 if (pos + nbits > BITS_PER_BITPACK_WORD) 111 { 112 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream, 113 word); 114 word = val; 115 pos = nbits; 116 } 117 else 118 { 119 word |= val << pos; 120 pos += nbits; 121 } 122 bp->word = word; 123 bp->pos = pos; 124 } 125 126 /* Finishes bit-packing of BP. */ 127 static inline void 128 streamer_write_bitpack (struct bitpack_d *bp) 129 { 130 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream, 131 bp->word); 132 bp->word = 0; 133 bp->pos = 0; 134 } 135 136 /* Returns a new bit-packing context for bit-unpacking from IB. */ 137 static inline struct bitpack_d 138 streamer_read_bitpack (struct lto_input_block *ib) 139 { 140 struct bitpack_d bp; 141 bp.word = streamer_read_uhwi (ib); 142 bp.pos = 0; 143 bp.stream = (void *)ib; 144 return bp; 145 } 146 147 /* Unpacks NBITS bits from the bit-packing context BP and returns them. */ 148 static inline bitpack_word_t 149 bp_unpack_value (struct bitpack_d *bp, unsigned nbits) 150 { 151 bitpack_word_t mask, val; 152 int pos = bp->pos; 153 154 mask = (nbits == BITS_PER_BITPACK_WORD 155 ? (bitpack_word_t) -1 156 : ((bitpack_word_t) 1 << nbits) - 1); 157 158 /* If there are not continuous nbits in the current bitpack word 159 switch to the next one. */ 160 if (pos + nbits > BITS_PER_BITPACK_WORD) 161 { 162 bp->word = val 163 = streamer_read_uhwi ((struct lto_input_block *)bp->stream); 164 bp->pos = nbits; 165 return val & mask; 166 } 167 val = bp->word; 168 val >>= pos; 169 bp->pos = pos + nbits; 170 171 return val & mask; 172 } 173 174 175 /* Write a character to the output block. */ 176 177 static inline void 178 streamer_write_char_stream (struct lto_output_stream *obs, char c) 179 { 180 /* No space left. */ 181 if (obs->left_in_block == 0) 182 lto_append_block (obs); 183 184 /* Write the actual character. */ 185 char *current_pointer = obs->current_pointer; 186 *(current_pointer++) = c; 187 obs->current_pointer = current_pointer; 188 obs->total_size++; 189 obs->left_in_block--; 190 } 191 192 193 /* Read byte from the input block. */ 194 195 static inline unsigned char 196 streamer_read_uchar (struct lto_input_block *ib) 197 { 198 if (ib->p >= ib->len) 199 lto_section_overrun (ib); 200 return (ib->data[ib->p++]); 201 } 202 203 /* Output VAL into OBS and verify it is in range MIN...MAX that is supposed 204 to be compile time constant. 205 Be host independent, limit range to 31bits. */ 206 207 static inline void 208 streamer_write_hwi_in_range (struct lto_output_stream *obs, 209 HOST_WIDE_INT min, 210 HOST_WIDE_INT max, 211 HOST_WIDE_INT val) 212 { 213 HOST_WIDE_INT range = max - min; 214 215 gcc_checking_assert (val >= min && val <= max && range > 0 216 && range < 0x7fffffff); 217 218 val -= min; 219 streamer_write_uhwi_stream (obs, (unsigned HOST_WIDE_INT) val); 220 } 221 222 /* Input VAL into OBS and verify it is in range MIN...MAX that is supposed 223 to be compile time constant. PURPOSE is used for error reporting. */ 224 225 static inline HOST_WIDE_INT 226 streamer_read_hwi_in_range (struct lto_input_block *ib, 227 const char *purpose, 228 HOST_WIDE_INT min, 229 HOST_WIDE_INT max) 230 { 231 HOST_WIDE_INT range = max - min; 232 unsigned HOST_WIDE_INT uval = streamer_read_uhwi (ib); 233 234 gcc_checking_assert (range > 0 && range < 0x7fffffff); 235 236 HOST_WIDE_INT val = (HOST_WIDE_INT) (uval + (unsigned HOST_WIDE_INT) min); 237 if (val < min || val > max) 238 lto_value_range_error (purpose, val, min, max); 239 return val; 240 } 241 242 /* Output VAL into BP and verify it is in range MIN...MAX that is supposed 243 to be compile time constant. 244 Be host independent, limit range to 31bits. */ 245 246 static inline void 247 bp_pack_int_in_range (struct bitpack_d *bp, 248 HOST_WIDE_INT min, 249 HOST_WIDE_INT max, 250 HOST_WIDE_INT val) 251 { 252 HOST_WIDE_INT range = max - min; 253 int nbits = floor_log2 (range) + 1; 254 255 gcc_checking_assert (val >= min && val <= max && range > 0 256 && range < 0x7fffffff); 257 258 val -= min; 259 bp_pack_value (bp, val, nbits); 260 } 261 262 /* Input VAL into BP and verify it is in range MIN...MAX that is supposed 263 to be compile time constant. PURPOSE is used for error reporting. */ 264 265 static inline HOST_WIDE_INT 266 bp_unpack_int_in_range (struct bitpack_d *bp, 267 const char *purpose, 268 HOST_WIDE_INT min, 269 HOST_WIDE_INT max) 270 { 271 HOST_WIDE_INT range = max - min; 272 int nbits = floor_log2 (range) + 1; 273 HOST_WIDE_INT val = bp_unpack_value (bp, nbits); 274 275 gcc_checking_assert (range > 0 && range < 0x7fffffff); 276 277 if (val < min || val > max) 278 lto_value_range_error (purpose, val, min, max); 279 return val; 280 } 281 282 /* Output VAL of type "enum enum_name" into OBS. 283 Assume range 0...ENUM_LAST - 1. */ 284 #define streamer_write_enum(obs,enum_name,enum_last,val) \ 285 streamer_write_hwi_in_range ((obs), 0, (int)(enum_last) - 1, (int)(val)) 286 287 /* Input enum of type "enum enum_name" from IB. 288 Assume range 0...ENUM_LAST - 1. */ 289 #define streamer_read_enum(ib,enum_name,enum_last) \ 290 (enum enum_name)streamer_read_hwi_in_range ((ib), #enum_name, 0, \ 291 (int)(enum_last) - 1) 292 293 /* Output VAL of type "enum enum_name" into BP. 294 Assume range 0...ENUM_LAST - 1. */ 295 #define bp_pack_enum(bp,enum_name,enum_last,val) \ 296 bp_pack_int_in_range ((bp), 0, (int)(enum_last) - 1, (int)(val)) 297 298 /* Input enum of type "enum enum_name" from BP. 299 Assume range 0...ENUM_LAST - 1. */ 300 #define bp_unpack_enum(bp,enum_name,enum_last) \ 301 (enum enum_name)bp_unpack_int_in_range ((bp), #enum_name, 0, \ 302 (int)(enum_last) - 1) 303 304 /* Output the start of a record with TAG to output block OB. */ 305 306 static inline void 307 streamer_write_record_start (struct output_block *ob, enum LTO_tags tag) 308 { 309 streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS, tag); 310 } 311 312 /* Return the next tag in the input block IB. */ 313 314 static inline enum LTO_tags 315 streamer_read_record_start (struct lto_input_block *ib) 316 { 317 return streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS); 318 } 319 320 #endif /* GCC_DATA_STREAMER_H */ 321