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 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 3, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along 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. */ 31static unsigned const BITS_PER_BITPACK_WORD = HOST_BITS_PER_WIDE_INT; 32 33typedef unsigned HOST_WIDE_INT bitpack_word_t; 34 35struct 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 */ 48void bp_pack_var_len_unsigned (struct bitpack_d *, unsigned HOST_WIDE_INT); 49void bp_pack_var_len_int (struct bitpack_d *, HOST_WIDE_INT); 50unsigned HOST_WIDE_INT bp_unpack_var_len_unsigned (struct bitpack_d *); 51HOST_WIDE_INT bp_unpack_var_len_int (struct bitpack_d *); 52 53/* In data-streamer-out.c */ 54void streamer_write_zero (struct output_block *); 55void streamer_write_uhwi (struct output_block *, unsigned HOST_WIDE_INT); 56void streamer_write_hwi (struct output_block *, HOST_WIDE_INT); 57void streamer_write_gcov_count (struct output_block *, gcov_type); 58void streamer_write_string (struct output_block *, struct lto_output_stream *, 59 const char *, bool); 60void streamer_write_string_with_length (struct output_block *, 61 struct lto_output_stream *, 62 const char *, unsigned int, bool); 63void bp_pack_string_with_length (struct output_block *, struct bitpack_d *, 64 const char *, unsigned int, bool); 65void bp_pack_string (struct output_block *, struct bitpack_d *, 66 const char *, bool); 67void streamer_write_uhwi_stream (struct lto_output_stream *, 68 unsigned HOST_WIDE_INT); 69void streamer_write_hwi_stream (struct lto_output_stream *, HOST_WIDE_INT); 70void streamer_write_gcov_count_stream (struct lto_output_stream *, gcov_type); 71void streamer_write_data_stream (struct lto_output_stream *, const void *, 72 size_t); 73 74/* In data-streamer-in.c */ 75const char *streamer_read_string (struct data_in *, struct lto_input_block *); 76const char *streamer_read_indexed_string (struct data_in *, 77 struct lto_input_block *, 78 unsigned int *); 79const char *bp_unpack_indexed_string (struct data_in *, struct bitpack_d *, 80 unsigned int *); 81const char *bp_unpack_string (struct data_in *, struct bitpack_d *); 82unsigned HOST_WIDE_INT streamer_read_uhwi (struct lto_input_block *); 83HOST_WIDE_INT streamer_read_hwi (struct lto_input_block *); 84gcov_type streamer_read_gcov_count (struct lto_input_block *); 85 86/* Returns a new bit-packing context for bit-packing into S. */ 87static inline struct bitpack_d 88bitpack_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. */ 98static inline void 99bp_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. */ 127static inline void 128streamer_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. */ 137static inline struct bitpack_d 138streamer_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. */ 148static inline bitpack_word_t 149bp_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 177static inline void 178streamer_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 195static inline unsigned char 196streamer_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 207static inline void 208streamer_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 225static inline HOST_WIDE_INT 226streamer_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 246static inline void 247bp_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 265static inline HOST_WIDE_INT 266bp_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 306static inline void 307streamer_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 314static inline enum LTO_tags 315streamer_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