/* Generic streaming support for various data types.
Copyright (C) 2011-2020 Free Software Foundation, Inc.
Contributed by Diego Novillo <dnovillo@google.com>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#ifndef GCC_DATA_STREAMER_H
#define GCC_DATA_STREAMER_H
#include "lto-streamer.h"
/* Data structures used to pack values and bitflags into a vector of
words. Used to stream values of a fixed number of bits in a space
efficient way. */
static unsigned const BITS_PER_BITPACK_WORD = HOST_BITS_PER_WIDE_INT;
typedef unsigned HOST_WIDE_INT bitpack_word_t;
struct bitpack_d
{
/* The position of the first unused or unconsumed bit in the word. */
unsigned pos;
/* The current word we are (un)packing. */
bitpack_word_t word;
/* The lto_output_stream or the lto_input_block we are streaming to/from. */
void *stream;
};
/* In data-streamer.c */
void bp_pack_var_len_unsigned (struct bitpack_d *, unsigned HOST_WIDE_INT);
void bp_pack_var_len_int (struct bitpack_d *, HOST_WIDE_INT);
unsigned HOST_WIDE_INT bp_unpack_var_len_unsigned (struct bitpack_d *);
HOST_WIDE_INT bp_unpack_var_len_int (struct bitpack_d *);
/* In data-streamer-out.c */
void streamer_write_zero (struct output_block *);
void streamer_write_uhwi (struct output_block *, unsigned HOST_WIDE_INT);
void streamer_write_hwi (struct output_block *, HOST_WIDE_INT);
void streamer_write_poly_uint64 (struct output_block *, poly_uint64);
void streamer_write_gcov_count (struct output_block *, gcov_type);
void streamer_write_string (struct output_block *, struct lto_output_stream *,
const char *, bool);
void streamer_write_string_with_length (struct output_block *,
struct lto_output_stream *,
const char *, unsigned int, bool);
void bp_pack_string_with_length (struct output_block *, struct bitpack_d *,
const char *, unsigned int, bool);
void bp_pack_string (struct output_block *, struct bitpack_d *,
const char *, bool);
void streamer_write_uhwi_stream (struct lto_output_stream *,
unsigned HOST_WIDE_INT);
void streamer_write_hwi_stream (struct lto_output_stream *, HOST_WIDE_INT);
void streamer_write_gcov_count_stream (struct lto_output_stream *, gcov_type);
void streamer_write_data_stream (struct lto_output_stream *, const void *,
size_t);
void streamer_write_wide_int (struct output_block *, const wide_int &);
void streamer_write_widest_int (struct output_block *, const widest_int &);
/* In data-streamer-in.c */
const char *streamer_read_string (class data_in *, class lto_input_block *);
const char *streamer_read_indexed_string (class data_in *,
class lto_input_block *,
unsigned int *);
const char *bp_unpack_indexed_string (class data_in *, struct bitpack_d *,
unsigned int *);
const char *bp_unpack_string (class data_in *, struct bitpack_d *);
unsigned HOST_WIDE_INT streamer_read_uhwi (class lto_input_block *);
HOST_WIDE_INT streamer_read_hwi (class lto_input_block *);
poly_uint64 streamer_read_poly_uint64 (class lto_input_block *);
gcov_type streamer_read_gcov_count (class lto_input_block *);
wide_int streamer_read_wide_int (class lto_input_block *);
widest_int streamer_read_widest_int (class lto_input_block *);
/* Returns a new bit-packing context for bit-packing into S. */
static inline struct bitpack_d
bitpack_create (struct lto_output_stream *s)
{
struct bitpack_d bp;
bp.pos = 0;
bp.word = 0;
bp.stream = (void *)s;
return bp;
}
/* Pack the NBITS bit sized value VAL into the bit-packing context BP. */
static inline void
bp_pack_value (struct bitpack_d *bp, bitpack_word_t val, unsigned nbits)
{
bitpack_word_t word = bp->word;
int pos = bp->pos;
/* Verify that VAL fits in the NBITS. */
gcc_checking_assert (nbits == BITS_PER_BITPACK_WORD
|| !(val & ~(((bitpack_word_t)1<<nbits)-1)));
/* If val does not fit into the current bitpack word switch to the
next one. */
if (pos + nbits > BITS_PER_BITPACK_WORD)
{
streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
word);
word = val;
pos = nbits;
}
else
{
word |= val << pos;
pos += nbits;
}
bp->word = word;
bp->pos = pos;
}
/* Pack VAL into the bit-packing context BP, using NBITS for each
coefficient. */
static inline void
bp_pack_poly_value (struct bitpack_d *bp,
const poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t> &val,
unsigned nbits)
{
for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
bp_pack_value (bp, val.coeffs[i], nbits);
}
/* Finishes bit-packing of BP. */
static inline void
streamer_write_bitpack (struct bitpack_d *bp)
{
streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
bp->word);
bp->word = 0;
bp->pos = 0;
}
/* Returns a new bit-packing context for bit-unpacking from IB. */
static inline struct bitpack_d
streamer_read_bitpack (class lto_input_block *ib)
{
struct bitpack_d bp;
bp.word = streamer_read_uhwi (ib);
bp.pos = 0;
bp.stream = (void *)ib;
return bp;
}
/* Unpacks NBITS bits from the bit-packing context BP and returns them. */
static inline bitpack_word_t
bp_unpack_value (struct bitpack_d *bp, unsigned nbits)
{
bitpack_word_t mask, val;
int pos = bp->pos;
mask = (nbits == BITS_PER_BITPACK_WORD
? (bitpack_word_t) -1
: ((bitpack_word_t) 1 << nbits) - 1);
/* If there are not continuous nbits in the current bitpack word
switch to the next one. */
if (pos + nbits > BITS_PER_BITPACK_WORD)
{
bp->word = val
= streamer_read_uhwi ((class lto_input_block *)bp->stream);
bp->pos = nbits;
return val & mask;
}
val = bp->word;
val >>= pos;
bp->pos = pos + nbits;
return val & mask;
}
/* Unpacks a polynomial value from the bit-packing context BP in which each
coefficient has NBITS bits. */
static inline poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t>
bp_unpack_poly_value (struct bitpack_d *bp, unsigned nbits)
{
poly_int_pod<NUM_POLY_INT_COEFFS, bitpack_word_t> x;
for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
x.coeffs[i] = bp_unpack_value (bp, nbits);
return x;
}
/* Write a character to the output block. */
static inline void
streamer_write_char_stream (struct lto_output_stream *obs, char c)
{
/* No space left. */
if (obs->left_in_block == 0)
lto_append_block (obs);
/* Write the actual character. */
char *current_pointer = obs->current_pointer;
*(current_pointer++) = c;
obs->current_pointer = current_pointer;
obs->total_size++;
obs->left_in_block--;
}
/* Read byte from the input block. */
static inline unsigned char
streamer_read_uchar (class lto_input_block *ib)
{
if (ib->p >= ib->len)
lto_section_overrun (ib);
return (ib->data[ib->p++]);
}
/* Output VAL into OBS and verify it is in range MIN...MAX that is supposed
to be compile time constant.
Be host independent, limit range to 31bits. */
static inline void
streamer_write_hwi_in_range (struct lto_output_stream *obs,
HOST_WIDE_INT min,
HOST_WIDE_INT max,
HOST_WIDE_INT val)
{
HOST_WIDE_INT range = max - min;
gcc_checking_assert (val >= min && val <= max && range > 0
&& range < 0x7fffffff);
val -= min;
streamer_write_uhwi_stream (obs, (unsigned HOST_WIDE_INT) val);
}
/* Input VAL into OBS and verify it is in range MIN...MAX that is supposed
to be compile time constant. PURPOSE is used for error reporting. */
static inline HOST_WIDE_INT
streamer_read_hwi_in_range (class lto_input_block *ib,
const char *purpose,
HOST_WIDE_INT min,
HOST_WIDE_INT max)
{
HOST_WIDE_INT range = max - min;
unsigned HOST_WIDE_INT uval = streamer_read_uhwi (ib);
gcc_checking_assert (range > 0 && range < 0x7fffffff);
HOST_WIDE_INT val = (HOST_WIDE_INT) (uval + (unsigned HOST_WIDE_INT) min);
if (val < min || val > max)
lto_value_range_error (purpose, val, min, max);
return val;
}
/* Output VAL into BP and verify it is in range MIN...MAX that is supposed
to be compile time constant.
Be host independent, limit range to 31bits. */
static inline void
bp_pack_int_in_range (struct bitpack_d *bp,
HOST_WIDE_INT min,
HOST_WIDE_INT max,
HOST_WIDE_INT val)
{
HOST_WIDE_INT range = max - min;
int nbits = floor_log2 (range) + 1;
gcc_checking_assert (val >= min && val <= max && range > 0
&& range < 0x7fffffff);
val -= min;
bp_pack_value (bp, val, nbits);
}
/* Input VAL into BP and verify it is in range MIN...MAX that is supposed
to be compile time constant. PURPOSE is used for error reporting. */
static inline HOST_WIDE_INT
bp_unpack_int_in_range (struct bitpack_d *bp,
const char *purpose,
HOST_WIDE_INT min,
HOST_WIDE_INT max)
{
HOST_WIDE_INT range = max - min;
int nbits = floor_log2 (range) + 1;
HOST_WIDE_INT val = bp_unpack_value (bp, nbits);
gcc_checking_assert (range > 0 && range < 0x7fffffff);
if (val < min || val > max)
lto_value_range_error (purpose, val, min, max);
return val;
}
/* Output VAL of type "enum enum_name" into OBS.
Assume range 0...ENUM_LAST - 1. */
#define streamer_write_enum(obs,enum_name,enum_last,val) \
streamer_write_hwi_in_range ((obs), 0, (int)(enum_last) - 1, (int)(val))
/* Input enum of type "enum enum_name" from IB.
Assume range 0...ENUM_LAST - 1. */
#define streamer_read_enum(ib,enum_name,enum_last) \
(enum enum_name)streamer_read_hwi_in_range ((ib), #enum_name, 0, \
(int)(enum_last) - 1)
/* Output VAL of type "enum enum_name" into BP.
Assume range 0...ENUM_LAST - 1. */
#define bp_pack_enum(bp,enum_name,enum_last,val) \
bp_pack_int_in_range ((bp), 0, (int)(enum_last) - 1, (int)(val))
/* Input enum of type "enum enum_name" from BP.
Assume range 0...ENUM_LAST - 1. */
#define bp_unpack_enum(bp,enum_name,enum_last) \
(enum enum_name)bp_unpack_int_in_range ((bp), #enum_name, 0, \
(int)(enum_last) - 1)
/* Output the start of a record with TAG to output block OB. */
static inline void
streamer_write_record_start (struct output_block *ob, enum LTO_tags tag)
{
streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS, tag);
}
/* Return the next tag in the input block IB. */
static inline enum LTO_tags
streamer_read_record_start (class lto_input_block *ib)
{
return streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS);
}
#endif /* GCC_DATA_STREAMER_H */