[LLVMdev] Work in progress patch to speed up andersen's implementation
Daniel Berlin
dberlin at dberlin.org
Wed Apr 25 11:09:14 PDT 2007
Hi guys, i'm not going to have time to work on this for a month or
two, so i figured i'd post it.
This patch
1. reworks the andersen's implementation to support field sensitivity
(though field-sensitive constraints are not generated directly yet),
and uses it to do indirect function call support.
2. Rewrites the solver to be state of the art in terms of speed.
kimwitu++ used to take <i stopped it after a few hours> to solve, and
now it takes < 2 seconds.
3. Reworks the rest of the implementation to make it easy to support
offline variable substitution.
There are still more improvements to be made, and in particular
implementing ovs. This is not more than a couple hundred lines of
code, and would speed it up by another few orders of magnitude (as
well as reduce memory usage greatly).
The main thing blocking this patch, however, is that someone needs to
rewrite bitmap.c/bitmap.h, obstack.c and obstack.h, into C++. They
are currently just modified versions of what gcc is using.
You can get rid of the obstacks, of course.
Using set<u32> or BitVector or something like it will result in a
slowdown of mammoth proporations, and about a 10x memory increase.
Trust me here, you don't want to use a non-sparse bitmap.
BDD's are acceptable, but are about a 2x slowdown. With various
optimizations that are going to be published in the next few months,
you can get bitmaps to use just as little memory as BDDs would, while
being much faster.
Anyway, i've attached the patch.
The two new .h files go include/llvm/ADT
the two new .cc files go into lib/VMCore
Of course, you can put them wherever you really want.
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/* Functions to support general ended bitmaps.
Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
Free Software Foundation, Inc.
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 2, 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 COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#ifndef GCC_BITMAP_H
#define GCC_BITMAP_H
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdbool.h>
#include "obstack.h"
/* Fundamental storage type for bitmap. */
typedef unsigned long hashval_t;
typedef unsigned long BITMAP_WORD;
/* BITMAP_WORD_BITS needs to be unsigned, but cannot contain casts as
it is used in preprocessor directives -- hence the 1u. */
#define BITMAP_WORD_BITS (1 * 32 * 1u)
/* Number of words to use for each element in the linked list. */
#ifndef BITMAP_ELEMENT_WORDS
#define BITMAP_ELEMENT_WORDS ((128 + BITMAP_WORD_BITS - 1) / BITMAP_WORD_BITS)
#endif
/* Number of bits in each actual element of a bitmap. */
#define BITMAP_ELEMENT_ALL_BITS (BITMAP_ELEMENT_WORDS * BITMAP_WORD_BITS)
/* Obstack for allocating bitmaps and elements from. */
typedef struct bitmap_obstack
{
struct bitmap_element_def *elements;
struct bitmap_head_def *heads;
struct obstack obstack;
} bitmap_obstack;
/* Bitmap set element. We use a linked list to hold only the bits that
are set. This allows for use to grow the bitset dynamically without
having to realloc and copy a giant bit array.
The free list is implemented as a list of lists. There is one
outer list connected together by prev fields. Each element of that
outer is an inner list (that may consist only of the outer list
element) that are connected by the next fields. The prev pointer
is undefined for interior elements. This allows
bitmap_elt_clear_from to be implemented in unit time rather than
linear in the number of elements to be freed. */
typedef struct bitmap_element_def
{
struct bitmap_element_def *next; /* Next element. */
struct bitmap_element_def *prev; /* Previous element. */
unsigned int indx; /* regno/BITMAP_ELEMENT_ALL_BITS. */
BITMAP_WORD bits[BITMAP_ELEMENT_WORDS]; /* Bits that are set. */
} bitmap_element;
/* Head of bitmap linked list. */
typedef struct bitmap_head_def {
bitmap_element *first; /* First element in linked list. */
bitmap_element *current; /* Last element looked at. */
unsigned int indx; /* Index of last element looked at. */
bitmap_obstack *obstack; /* Obstack to allocate elements from.
If NULL, then use ggc_alloc. */
} bitmap_head;
typedef struct bitmap_head_def *bitmap;
/* Global data */
extern bitmap_element bitmap_zero_bits; /* Zero bitmap element */
extern bitmap_obstack bitmap_default_obstack; /* Default bitmap obstack */
/* Clear a bitmap by freeing up the linked list. */
extern void bitmap_clear (bitmap);
/* Copy a bitmap to another bitmap. */
extern void bitmap_copy (bitmap, bitmap);
/* True if two bitmaps are identical. */
extern bool bitmap_equal_p (bitmap, bitmap);
/* True if the bitmaps intersect (their AND is non-empty). */
extern bool bitmap_intersect_p (bitmap, bitmap);
/* True if the complement of the second intersects the first (their
AND_COMPL is non-empty). */
extern bool bitmap_intersect_compl_p (bitmap, bitmap);
/* True if MAP is an empty bitmap. */
#define bitmap_empty_p(MAP) (!(MAP)->first)
/* Count the number of bits set in the bitmap. */
extern unsigned long bitmap_count_bits (bitmap);
/* BENH */
extern bool bitmap_singleton_p(bitmap);
extern bool bitmap_multi_p(bitmap);
/* Boolean operations on bitmaps. The _into variants are two operand
versions that modify the first source operand. The other variants
are three operand versions that to not destroy the source bitmaps.
The operations supported are &, & ~, |, ^. */
extern void bitmap_and (bitmap, bitmap, bitmap);
extern void bitmap_and_into (bitmap, bitmap);
extern void bitmap_and_compl (bitmap, bitmap, bitmap);
extern bool bitmap_and_compl_into (bitmap, bitmap);
#define bitmap_compl_and(DST, A, B) bitmap_and_compl (DST, B, A)
extern void bitmap_compl_and_into (bitmap, bitmap);
extern void bitmap_clear_range (bitmap, unsigned int, unsigned int);
extern bool bitmap_ior (bitmap, bitmap, bitmap);
extern bool bitmap_ior_into (bitmap, bitmap);
extern void bitmap_xor (bitmap, bitmap, bitmap);
extern void bitmap_xor_into (bitmap, bitmap);
/* DST = A | (B & ~C). Return true if DST changes. */
extern bool bitmap_ior_and_compl (bitmap DST, bitmap A, bitmap B, bitmap C);
/* A |= (B & ~C). Return true if A changes. */
extern bool bitmap_ior_and_compl_into (bitmap DST, bitmap B, bitmap C);
/* Clear a single register in a register set. */
extern void bitmap_clear_bit (bitmap, int);
/* Set a single register in a register set. */
extern void bitmap_set_bit (bitmap, int);
/* BENH: set a single register, returning true if the set changed. */
extern bool bitmap_set_bit_p(bitmap, int);
/* Return true if a register is set in a register set. */
extern int bitmap_bit_p (bitmap, int);
/* Debug functions to print a bitmap linked list. */
extern void debug_bitmap (bitmap);
extern void debug_bitmap_file (FILE *, bitmap);
/* Print a bitmap. */
extern void bitmap_print (FILE *, bitmap, const char *, const char *);
/* Initialize and release a bitmap obstack. */
extern void bitmap_obstack_initialize (bitmap_obstack *);
extern void bitmap_obstack_release (bitmap_obstack *);
/* Initialize a bitmap header. OBSTACK indicates the bitmap obstack
to allocate from, NULL for GC'd bitmap. */
static inline void
bitmap_initialize (bitmap head, bitmap_obstack *obstack)
{
head->first = head->current = NULL;
head->obstack = obstack;
}
/* Allocate and free bitmaps from obstack, malloc and gc'd memory. */
extern bitmap bitmap_obstack_alloc (bitmap_obstack *obstack);
extern void bitmap_obstack_free (bitmap);
/* A few compatibility/functions macros for compatibility with sbitmaps */
#define dump_bitmap(file, bitmap) bitmap_print (file, bitmap, "", "\n")
#define bitmap_zero(a) bitmap_clear (a)
extern unsigned bitmap_first_set_bit (bitmap);
/* Compute bitmap hash (for purposes of hashing etc.) */
extern hashval_t bitmap_hash(bitmap);
/* Allocate a bitmap from a bit obstack. */
#define BITMAP_ALLOC(OBSTACK) bitmap_obstack_alloc (OBSTACK)
/* Do any cleanup needed on a bitmap when it is no longer used. */
#define BITMAP_FREE(BITMAP) \
((void)(bitmap_obstack_free (BITMAP), (BITMAP) = NULL))
/* Iterator for bitmaps. */
typedef struct
{
/* Pointer to the current bitmap element. */
bitmap_element *elt1;
/* Pointer to 2nd bitmap element when two are involved. */
bitmap_element *elt2;
/* Word within the current element. */
unsigned word_no;
/* Contents of the actually processed word. When finding next bit
it is shifted right, so that the actual bit is always the least
significant bit of ACTUAL. */
BITMAP_WORD bits;
} bitmap_iterator;
/* Initialize a single bitmap iterator. START_BIT is the first bit to
iterate from. */
static inline void
bmp_iter_set_init (bitmap_iterator *bi, bitmap map,
unsigned start_bit, unsigned *bit_no)
{
bi->elt1 = map->first;
bi->elt2 = NULL;
/* Advance elt1 until it is not before the block containing start_bit. */
while (1)
{
if (!bi->elt1)
{
bi->elt1 = &bitmap_zero_bits;
break;
}
if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
break;
bi->elt1 = bi->elt1->next;
}
/* We might have gone past the start bit, so reinitialize it. */
if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
/* Initialize for what is now start_bit. */
bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
bi->bits = bi->elt1->bits[bi->word_no];
bi->bits >>= start_bit % BITMAP_WORD_BITS;
/* If this word is zero, we must make sure we're not pointing at the
first bit, otherwise our incrementing to the next word boundary
will fail. It won't matter if this increment moves us into the
next word. */
start_bit += !bi->bits;
*bit_no = start_bit;
}
/* Initialize an iterator to iterate over the intersection of two
bitmaps. START_BIT is the bit to commence from. */
static inline void
bmp_iter_and_init (bitmap_iterator *bi, bitmap map1, bitmap map2,
unsigned start_bit, unsigned *bit_no)
{
bi->elt1 = map1->first;
bi->elt2 = map2->first;
/* Advance elt1 until it is not before the block containing
start_bit. */
while (1)
{
if (!bi->elt1)
{
bi->elt2 = NULL;
break;
}
if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
break;
bi->elt1 = bi->elt1->next;
}
/* Advance elt2 until it is not before elt1. */
while (1)
{
if (!bi->elt2)
{
bi->elt1 = bi->elt2 = &bitmap_zero_bits;
break;
}
if (bi->elt2->indx >= bi->elt1->indx)
break;
bi->elt2 = bi->elt2->next;
}
/* If we're at the same index, then we have some intersecting bits. */
if (bi->elt1->indx == bi->elt2->indx)
{
/* We might have advanced beyond the start_bit, so reinitialize
for that. */
if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
bi->bits >>= start_bit % BITMAP_WORD_BITS;
}
else
{
/* Otherwise we must immediately advance elt1, so initialize for
that. */
bi->word_no = BITMAP_ELEMENT_WORDS - 1;
bi->bits = 0;
}
/* If this word is zero, we must make sure we're not pointing at the
first bit, otherwise our incrementing to the next word boundary
will fail. It won't matter if this increment moves us into the
next word. */
start_bit += !bi->bits;
*bit_no = start_bit;
}
/* Initialize an iterator to iterate over the bits in MAP1 & ~MAP2.
*/
static inline void
bmp_iter_and_compl_init (bitmap_iterator *bi, bitmap map1, bitmap map2,
unsigned start_bit, unsigned *bit_no)
{
bi->elt1 = map1->first;
bi->elt2 = map2->first;
/* Advance elt1 until it is not before the block containing start_bit. */
while (1)
{
if (!bi->elt1)
{
bi->elt1 = &bitmap_zero_bits;
break;
}
if (bi->elt1->indx >= start_bit / BITMAP_ELEMENT_ALL_BITS)
break;
bi->elt1 = bi->elt1->next;
}
/* Advance elt2 until it is not before elt1. */
while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
bi->elt2 = bi->elt2->next;
/* We might have advanced beyond the start_bit, so reinitialize for
that. */
if (bi->elt1->indx != start_bit / BITMAP_ELEMENT_ALL_BITS)
start_bit = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
bi->word_no = start_bit / BITMAP_WORD_BITS % BITMAP_ELEMENT_WORDS;
bi->bits = bi->elt1->bits[bi->word_no];
if (bi->elt2 && bi->elt1->indx == bi->elt2->indx)
bi->bits &= ~bi->elt2->bits[bi->word_no];
bi->bits >>= start_bit % BITMAP_WORD_BITS;
/* If this word is zero, we must make sure we're not pointing at the
first bit, otherwise our incrementing to the next word boundary
will fail. It won't matter if this increment moves us into the
next word. */
start_bit += !bi->bits;
*bit_no = start_bit;
}
/* Advance to the next bit in BI. We don't advance to the next
nonzero bit yet. */
static inline void
bmp_iter_next (bitmap_iterator *bi, unsigned *bit_no)
{
bi->bits >>= 1;
*bit_no += 1;
}
/* Advance to the next nonzero bit of a single bitmap, we will have
already advanced past the just iterated bit. Return true if there
is a bit to iterate. */
static inline bool
bmp_iter_set (bitmap_iterator *bi, unsigned *bit_no)
{
/* If our current word is nonzero, it contains the bit we want. */
if (bi->bits)
{
next_bit:
while (!(bi->bits & 1))
{
bi->bits >>= 1;
*bit_no += 1;
}
return true;
}
/* Round up to the word boundary. We might have just iterated past
the end of the last word, hence the -1. It is not possible for
bit_no to point at the beginning of the now last word. */
*bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
/ BITMAP_WORD_BITS * BITMAP_WORD_BITS);
bi->word_no++;
while (1)
{
/* Find the next nonzero word in this elt. */
while (bi->word_no != BITMAP_ELEMENT_WORDS)
{
bi->bits = bi->elt1->bits[bi->word_no];
if (bi->bits)
goto next_bit;
*bit_no += BITMAP_WORD_BITS;
bi->word_no++;
}
/* Advance to the next element. */
bi->elt1 = bi->elt1->next;
if (!bi->elt1)
return false;
*bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
bi->word_no = 0;
}
}
/* Advance to the next nonzero bit of an intersecting pair of
bitmaps. We will have already advanced past the just iterated bit.
Return true if there is a bit to iterate. */
static inline bool
bmp_iter_and (bitmap_iterator *bi, unsigned *bit_no)
{
/* If our current word is nonzero, it contains the bit we want. */
if (bi->bits)
{
next_bit:
while (!(bi->bits & 1))
{
bi->bits >>= 1;
*bit_no += 1;
}
return true;
}
/* Round up to the word boundary. We might have just iterated past
the end of the last word, hence the -1. It is not possible for
bit_no to point at the beginning of the now last word. */
*bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
/ BITMAP_WORD_BITS * BITMAP_WORD_BITS);
bi->word_no++;
while (1)
{
/* Find the next nonzero word in this elt. */
while (bi->word_no != BITMAP_ELEMENT_WORDS)
{
bi->bits = bi->elt1->bits[bi->word_no] & bi->elt2->bits[bi->word_no];
if (bi->bits)
goto next_bit;
*bit_no += BITMAP_WORD_BITS;
bi->word_no++;
}
/* Advance to the next identical element. */
do
{
/* Advance elt1 while it is less than elt2. We always want
to advance one elt. */
do
{
bi->elt1 = bi->elt1->next;
if (!bi->elt1)
return false;
}
while (bi->elt1->indx < bi->elt2->indx);
/* Advance elt2 to be no less than elt1. This might not
advance. */
while (bi->elt2->indx < bi->elt1->indx)
{
bi->elt2 = bi->elt2->next;
if (!bi->elt2)
return false;
}
}
while (bi->elt1->indx != bi->elt2->indx);
*bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
bi->word_no = 0;
}
}
/* Advance to the next nonzero bit in the intersection of
complemented bitmaps. We will have already advanced past the just
iterated bit. */
static inline bool
bmp_iter_and_compl (bitmap_iterator *bi, unsigned *bit_no)
{
/* If our current word is nonzero, it contains the bit we want. */
if (bi->bits)
{
next_bit:
while (!(bi->bits & 1))
{
bi->bits >>= 1;
*bit_no += 1;
}
return true;
}
/* Round up to the word boundary. We might have just iterated past
the end of the last word, hence the -1. It is not possible for
bit_no to point at the beginning of the now last word. */
*bit_no = ((*bit_no + BITMAP_WORD_BITS - 1)
/ BITMAP_WORD_BITS * BITMAP_WORD_BITS);
bi->word_no++;
while (1)
{
/* Find the next nonzero word in this elt. */
while (bi->word_no != BITMAP_ELEMENT_WORDS)
{
bi->bits = bi->elt1->bits[bi->word_no];
if (bi->elt2 && bi->elt2->indx == bi->elt1->indx)
bi->bits &= ~bi->elt2->bits[bi->word_no];
if (bi->bits)
goto next_bit;
*bit_no += BITMAP_WORD_BITS;
bi->word_no++;
}
/* Advance to the next element of elt1. */
bi->elt1 = bi->elt1->next;
if (!bi->elt1)
return false;
/* Advance elt2 until it is no less than elt1. */
while (bi->elt2 && bi->elt2->indx < bi->elt1->indx)
bi->elt2 = bi->elt2->next;
*bit_no = bi->elt1->indx * BITMAP_ELEMENT_ALL_BITS;
bi->word_no = 0;
}
}
/* Loop over all bits set in BITMAP, starting with MIN and setting
BITNUM to the bit number. ITER is a bitmap iterator. BITNUM
should be treated as a read-only variable as it contains loop
state. */
#define EXECUTE_IF_SET_IN_BITMAP(BITMAP, MIN, BITNUM, ITER) \
for (bmp_iter_set_init (&(ITER), (BITMAP), (MIN), &(BITNUM)); \
bmp_iter_set (&(ITER), &(BITNUM)); \
bmp_iter_next (&(ITER), &(BITNUM)))
/* Loop over all the bits set in BITMAP1 & BITMAP2, starting with MIN
and setting BITNUM to the bit number. ITER is a bitmap iterator.
BITNUM should be treated as a read-only variable as it contains
loop state. */
#define EXECUTE_IF_AND_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER) \
for (bmp_iter_and_init (&(ITER), (BITMAP1), (BITMAP2), (MIN), \
&(BITNUM)); \
bmp_iter_and (&(ITER), &(BITNUM)); \
bmp_iter_next (&(ITER), &(BITNUM)))
/* Loop over all the bits set in BITMAP1 & ~BITMAP2, starting with MIN
and setting BITNUM to the bit number. ITER is a bitmap iterator.
BITNUM should be treated as a read-only variable as it contains
loop state. */
#define EXECUTE_IF_AND_COMPL_IN_BITMAP(BITMAP1, BITMAP2, MIN, BITNUM, ITER) \
for (bmp_iter_and_compl_init (&(ITER), (BITMAP1), (BITMAP2), (MIN), \
&(BITNUM)); \
bmp_iter_and_compl (&(ITER), &(BITNUM)); \
bmp_iter_next (&(ITER), &(BITNUM)))
#endif /* GCC_BITMAP_H */
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/* obstack.h - object stack macros
Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998,
1999, 2000, 2001, 2002, 2003, 2004, 2005
Free Software Foundation, Inc.
NOTE: The canonical source of this file is maintained with the GNU C Library.
Bugs can be reported to bug-glibc at gnu.org.
This program 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 2, or (at your option) any
later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,
USA. */
/* Summary:
All the apparent functions defined here are macros. The idea
is that you would use these pre-tested macros to solve a
very specific set of problems, and they would run fast.
Caution: no side-effects in arguments please!! They may be
evaluated MANY times!!
These macros operate a stack of objects. Each object starts life
small, and may grow to maturity. (Consider building a word syllable
by syllable.) An object can move while it is growing. Once it has
been "finished" it never changes address again. So the "top of the
stack" is typically an immature growing object, while the rest of the
stack is of mature, fixed size and fixed address objects.
These routines grab large chunks of memory, using a function you
supply, called `obstack_chunk_alloc'. On occasion, they free chunks,
by calling `obstack_chunk_free'. You must define them and declare
them before using any obstack macros.
Each independent stack is represented by a `struct obstack'.
Each of the obstack macros expects a pointer to such a structure
as the first argument.
One motivation for this package is the problem of growing char strings
in symbol tables. Unless you are "fascist pig with a read-only mind"
--Gosper's immortal quote from HAKMEM item 154, out of context--you
would not like to put any arbitrary upper limit on the length of your
symbols.
In practice this often means you will build many short symbols and a
few long symbols. At the time you are reading a symbol you don't know
how long it is. One traditional method is to read a symbol into a
buffer, realloc()ating the buffer every time you try to read a symbol
that is longer than the buffer. This is beaut, but you still will
want to copy the symbol from the buffer to a more permanent
symbol-table entry say about half the time.
With obstacks, you can work differently. Use one obstack for all symbol
names. As you read a symbol, grow the name in the obstack gradually.
When the name is complete, finalize it. Then, if the symbol exists already,
free the newly read name.
The way we do this is to take a large chunk, allocating memory from
low addresses. When you want to build a symbol in the chunk you just
add chars above the current "high water mark" in the chunk. When you
have finished adding chars, because you got to the end of the symbol,
you know how long the chars are, and you can create a new object.
Mostly the chars will not burst over the highest address of the chunk,
because you would typically expect a chunk to be (say) 100 times as
long as an average object.
In case that isn't clear, when we have enough chars to make up
the object, THEY ARE ALREADY CONTIGUOUS IN THE CHUNK (guaranteed)
so we just point to it where it lies. No moving of chars is
needed and this is the second win: potentially long strings need
never be explicitly shuffled. Once an object is formed, it does not
change its address during its lifetime.
When the chars burst over a chunk boundary, we allocate a larger
chunk, and then copy the partly formed object from the end of the old
chunk to the beginning of the new larger chunk. We then carry on
accreting characters to the end of the object as we normally would.
A special macro is provided to add a single char at a time to a
growing object. This allows the use of register variables, which
break the ordinary 'growth' macro.
Summary:
We allocate large chunks.
We carve out one object at a time from the current chunk.
Once carved, an object never moves.
We are free to append data of any size to the currently
growing object.
Exactly one object is growing in an obstack at any one time.
You can run one obstack per control block.
You may have as many control blocks as you dare.
Because of the way we do it, you can `unwind' an obstack
back to a previous state. (You may remove objects much
as you would with a stack.)
*/
/* Don't do the contents of this file more than once. */
#ifndef _OBSTACK_H
#define _OBSTACK_H 1
#ifdef __cplusplus
extern "C" {
#endif
/* We use subtraction of (char *) 0 instead of casting to int
because on word-addressable machines a simple cast to int
may ignore the byte-within-word field of the pointer. */
#ifndef __PTR_TO_INT
# define __PTR_TO_INT(P) ((P) - (char *) 0)
#endif
#ifndef __INT_TO_PTR
# define __INT_TO_PTR(P) ((P) + (char *) 0)
#endif
/* We need the type of the resulting object. If __PTRDIFF_TYPE__ is
defined, as with GNU C, use that; that way we don't pollute the
namespace with <stddef.h>'s symbols. Otherwise, if <stddef.h> is
available, include it and use ptrdiff_t. In traditional C, long is
the best that we can do. */
#ifdef __PTRDIFF_TYPE__
# define PTR_INT_TYPE __PTRDIFF_TYPE__
#else
# ifdef HAVE_STDDEF_H
# include <stddef.h>
# define PTR_INT_TYPE ptrdiff_t
# else
# define PTR_INT_TYPE long
# endif
#endif
#if defined _LIBC || defined HAVE_STRING_H
# include <string.h>
# define _obstack_memcpy(To, From, N) memcpy ((To), (From), (N))
#else
# ifdef memcpy
# define _obstack_memcpy(To, From, N) memcpy ((To), (char *)(From), (N))
# else
# define _obstack_memcpy(To, From, N) bcopy ((char *)(From), (To), (N))
# endif
#endif
struct _obstack_chunk /* Lives at front of each chunk. */
{
char *limit; /* 1 past end of this chunk */
struct _obstack_chunk *prev; /* address of prior chunk or NULL */
char contents[4]; /* objects begin here */
};
struct obstack /* control current object in current chunk */
{
long chunk_size; /* preferred size to allocate chunks in */
struct _obstack_chunk *chunk; /* address of current struct obstack_chunk */
char *object_base; /* address of object we are building */
char *next_free; /* where to add next char to current object */
char *chunk_limit; /* address of char after current chunk */
PTR_INT_TYPE temp; /* Temporary for some macros. */
int alignment_mask; /* Mask of alignment for each object. */
/* These prototypes vary based on `use_extra_arg', and we use
casts to the prototypeless function type in all assignments,
but having prototypes here quiets -Wstrict-prototypes. */
struct _obstack_chunk *(*chunkfun) (void *, long);
void (*freefun) (void *, struct _obstack_chunk *);
void *extra_arg; /* first arg for chunk alloc/dealloc funcs */
unsigned use_extra_arg:1; /* chunk alloc/dealloc funcs take extra arg */
unsigned maybe_empty_object:1;/* There is a possibility that the current
chunk contains a zero-length object. This
prevents freeing the chunk if we allocate
a bigger chunk to replace it. */
unsigned alloc_failed:1; /* No longer used, as we now call the failed
handler on error, but retained for binary
compatibility. */
};
/* Declare the external functions we use; they are in obstack.c. */
extern void _obstack_newchunk (struct obstack *, int);
extern void _obstack_free (struct obstack *, void *);
extern int _obstack_begin (struct obstack *, int, int,
void *(*) (long), void (*) (void *));
extern int _obstack_begin_1 (struct obstack *, int, int,
void *(*) (void *, long),
void (*) (void *, void *), void *);
extern int _obstack_memory_used (struct obstack *);
/* Do the function-declarations after the structs
but before defining the macros. */
void obstack_init (struct obstack *obstack);
void * obstack_alloc (struct obstack *obstack, int size);
void * obstack_copy (struct obstack *obstack, void *address, int size);
void * obstack_copy0 (struct obstack *obstack, void *address, int size);
void obstack_free (struct obstack *obstack, void *block);
void obstack_blank (struct obstack *obstack, int size);
void obstack_grow (struct obstack *obstack, void *data, int size);
void obstack_grow0 (struct obstack *obstack, void *data, int size);
void obstack_1grow (struct obstack *obstack, int data_char);
void obstack_ptr_grow (struct obstack *obstack, void *data);
void obstack_int_grow (struct obstack *obstack, int data);
void * obstack_finish (struct obstack *obstack);
int obstack_object_size (struct obstack *obstack);
int obstack_room (struct obstack *obstack);
void obstack_make_room (struct obstack *obstack, int size);
void obstack_1grow_fast (struct obstack *obstack, int data_char);
void obstack_ptr_grow_fast (struct obstack *obstack, void *data);
void obstack_int_grow_fast (struct obstack *obstack, int data);
void obstack_blank_fast (struct obstack *obstack, int size);
void * obstack_base (struct obstack *obstack);
void * obstack_next_free (struct obstack *obstack);
int obstack_alignment_mask (struct obstack *obstack);
int obstack_chunk_size (struct obstack *obstack);
int obstack_memory_used (struct obstack *obstack);
/* Error handler called when `obstack_chunk_alloc' failed to allocate
more memory. This can be set to a user defined function. The
default action is to print a message and abort. */
extern void (*obstack_alloc_failed_handler) (void);
/* Exit value used when `print_and_abort' is used. */
extern int obstack_exit_failure;
/* Pointer to beginning of object being allocated or to be allocated next.
Note that this might not be the final address of the object
because a new chunk might be needed to hold the final size. */
#define obstack_base(h) ((h)->object_base)
/* Size for allocating ordinary chunks. */
#define obstack_chunk_size(h) ((h)->chunk_size)
/* Pointer to next byte not yet allocated in current chunk. */
#define obstack_next_free(h) ((h)->next_free)
/* Mask specifying low bits that should be clear in address of an object. */
#define obstack_alignment_mask(h) ((h)->alignment_mask)
/* To prevent prototype warnings provide complete argument list in
standard C version. */
# define obstack_init(h) \
_obstack_begin ((h), 0, 0, \
(void *(*) (long)) obstack_chunk_alloc, (void (*) (void *)) obstack_chunk_free)
# define obstack_begin(h, size) \
_obstack_begin ((h), (size), 0, \
(void *(*) (long)) obstack_chunk_alloc, (void (*) (void *)) obstack_chunk_free)
# define obstack_specify_allocation(h, size, alignment, chunkfun, freefun) \
_obstack_begin ((h), (size), (alignment), \
(void *(*) (long)) (chunkfun), (void (*) (void *)) (freefun))
# define obstack_specify_allocation_with_arg(h, size, alignment, chunkfun, freefun, arg) \
_obstack_begin_1 ((h), (size), (alignment), \
(void *(*) (void *, long)) (chunkfun), \
(void (*) (void *, void *)) (freefun), (arg))
# define obstack_chunkfun(h, newchunkfun) \
((h) -> chunkfun = (struct _obstack_chunk *(*)(void *, long)) (newchunkfun))
# define obstack_freefun(h, newfreefun) \
((h) -> freefun = (void (*)(void *, struct _obstack_chunk *)) (newfreefun))
#define obstack_1grow_fast(h,achar) (*((h)->next_free)++ = (achar))
#define obstack_blank_fast(h,n) ((h)->next_free += (n))
#define obstack_memory_used(h) _obstack_memory_used (h)
#if defined __GNUC__ && defined __STDC__ && __STDC__
/* NextStep 2.0 cc is really gcc 1.93 but it defines __GNUC__ = 2 and
does not implement __extension__. But that compiler doesn't define
__GNUC_MINOR__. */
# if __GNUC__ < 2 || (__NeXT__ && !__GNUC_MINOR__)
# define __extension__
# endif
/* For GNU C, if not -traditional,
we can define these macros to compute all args only once
without using a global variable.
Also, we can avoid using the `temp' slot, to make faster code. */
# define obstack_object_size(OBSTACK) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
(unsigned) (__o->next_free - __o->object_base); })
# define obstack_room(OBSTACK) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
(unsigned) (__o->chunk_limit - __o->next_free); })
# define obstack_make_room(OBSTACK,length) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
int __len = (length); \
if (__o->chunk_limit - __o->next_free < __len) \
_obstack_newchunk (__o, __len); \
(void) 0; })
# define obstack_empty_p(OBSTACK) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
(__o->chunk->prev == 0 && __o->next_free - __o->chunk->contents == 0); })
# define obstack_grow(OBSTACK,where,length) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
int __len = (length); \
if (__o->next_free + __len > __o->chunk_limit) \
_obstack_newchunk (__o, __len); \
_obstack_memcpy (__o->next_free, (where), __len); \
__o->next_free += __len; \
(void) 0; })
# define obstack_grow0(OBSTACK,where,length) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
int __len = (length); \
if (__o->next_free + __len + 1 > __o->chunk_limit) \
_obstack_newchunk (__o, __len + 1); \
_obstack_memcpy (__o->next_free, (where), __len); \
__o->next_free += __len; \
*(__o->next_free)++ = 0; \
(void) 0; })
# define obstack_1grow(OBSTACK,datum) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
if (__o->next_free + 1 > __o->chunk_limit) \
_obstack_newchunk (__o, 1); \
obstack_1grow_fast (__o, datum); \
(void) 0; })
/* These assume that the obstack alignment is good enough for pointers or ints,
and that the data added so far to the current object
shares that much alignment. */
# define obstack_ptr_grow(OBSTACK,datum) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
if (__o->next_free + sizeof (void *) > __o->chunk_limit) \
_obstack_newchunk (__o, sizeof (void *)); \
obstack_ptr_grow_fast (__o, datum); })
# define obstack_int_grow(OBSTACK,datum) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
if (__o->next_free + sizeof (int) > __o->chunk_limit) \
_obstack_newchunk (__o, sizeof (int)); \
obstack_int_grow_fast (__o, datum); })
# define obstack_ptr_grow_fast(OBSTACK,aptr) \
__extension__ \
({ struct obstack *__o1 = (OBSTACK); \
*(const void **) __o1->next_free = (aptr); \
__o1->next_free += sizeof (const void *); \
(void) 0; })
# define obstack_int_grow_fast(OBSTACK,aint) \
__extension__ \
({ struct obstack *__o1 = (OBSTACK); \
*(int *) __o1->next_free = (aint); \
__o1->next_free += sizeof (int); \
(void) 0; })
# define obstack_blank(OBSTACK,length) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
int __len = (length); \
if (__o->chunk_limit - __o->next_free < __len) \
_obstack_newchunk (__o, __len); \
obstack_blank_fast (__o, __len); \
(void) 0; })
# define obstack_alloc(OBSTACK,length) \
__extension__ \
({ struct obstack *__h = (OBSTACK); \
obstack_blank (__h, (length)); \
obstack_finish (__h); })
# define obstack_copy(OBSTACK,where,length) \
__extension__ \
({ struct obstack *__h = (OBSTACK); \
obstack_grow (__h, (where), (length)); \
obstack_finish (__h); })
# define obstack_copy0(OBSTACK,where,length) \
__extension__ \
({ struct obstack *__h = (OBSTACK); \
obstack_grow0 (__h, (where), (length)); \
obstack_finish (__h); })
/* The local variable is named __o1 to avoid a name conflict
when obstack_blank is called. */
# define obstack_finish(OBSTACK) \
__extension__ \
({ struct obstack *__o1 = (OBSTACK); \
void *value; \
value = (void *) __o1->object_base; \
if (__o1->next_free == value) \
__o1->maybe_empty_object = 1; \
__o1->next_free \
= __INT_TO_PTR ((__PTR_TO_INT (__o1->next_free)+__o1->alignment_mask)\
& ~ (__o1->alignment_mask)); \
if (__o1->next_free - (char *)__o1->chunk \
> __o1->chunk_limit - (char *)__o1->chunk) \
__o1->next_free = __o1->chunk_limit; \
__o1->object_base = __o1->next_free; \
value; })
# define obstack_free(OBSTACK, OBJ) \
__extension__ \
({ struct obstack *__o = (OBSTACK); \
void *__obj = (void *) (OBJ); \
if (__obj > (void *)__o->chunk && __obj < (void *)__o->chunk_limit) \
__o->next_free = __o->object_base = (char *) __obj; \
else (obstack_free) (__o, __obj); })
#else /* not __GNUC__ or not __STDC__ */
# define obstack_object_size(h) \
(unsigned) ((h)->next_free - (h)->object_base)
# define obstack_room(h) \
(unsigned) ((h)->chunk_limit - (h)->next_free)
# define obstack_empty_p(h) \
((h)->chunk->prev == 0 && (h)->next_free - (h)->chunk->contents == 0)
/* Note that the call to _obstack_newchunk is enclosed in (..., 0)
so that we can avoid having void expressions
in the arms of the conditional expression.
Casting the third operand to void was tried before,
but some compilers won't accept it. */
# define obstack_make_room(h,length) \
( (h)->temp = (length), \
(((h)->next_free + (h)->temp > (h)->chunk_limit) \
? (_obstack_newchunk ((h), (h)->temp), 0) : 0))
# define obstack_grow(h,where,length) \
( (h)->temp = (length), \
(((h)->next_free + (h)->temp > (h)->chunk_limit) \
? (_obstack_newchunk ((h), (h)->temp), 0) : 0), \
_obstack_memcpy ((h)->next_free, (where), (h)->temp), \
(h)->next_free += (h)->temp)
# define obstack_grow0(h,where,length) \
( (h)->temp = (length), \
(((h)->next_free + (h)->temp + 1 > (h)->chunk_limit) \
? (_obstack_newchunk ((h), (h)->temp + 1), 0) : 0), \
_obstack_memcpy ((h)->next_free, (where), (h)->temp), \
(h)->next_free += (h)->temp, \
*((h)->next_free)++ = 0)
# define obstack_1grow(h,datum) \
( (((h)->next_free + 1 > (h)->chunk_limit) \
? (_obstack_newchunk ((h), 1), 0) : 0), \
obstack_1grow_fast (h, datum))
# define obstack_ptr_grow(h,datum) \
( (((h)->next_free + sizeof (char *) > (h)->chunk_limit) \
? (_obstack_newchunk ((h), sizeof (char *)), 0) : 0), \
obstack_ptr_grow_fast (h, datum))
# define obstack_int_grow(h,datum) \
( (((h)->next_free + sizeof (int) > (h)->chunk_limit) \
? (_obstack_newchunk ((h), sizeof (int)), 0) : 0), \
obstack_int_grow_fast (h, datum))
# define obstack_ptr_grow_fast(h,aptr) \
(((const void **) ((h)->next_free += sizeof (void *)))[-1] = (aptr))
# define obstack_int_grow_fast(h,aint) \
(((int *) ((h)->next_free += sizeof (int)))[-1] = (aptr))
# define obstack_blank(h,length) \
( (h)->temp = (length), \
(((h)->chunk_limit - (h)->next_free < (h)->temp) \
? (_obstack_newchunk ((h), (h)->temp), 0) : 0), \
obstack_blank_fast (h, (h)->temp))
# define obstack_alloc(h,length) \
(obstack_blank ((h), (length)), obstack_finish ((h)))
# define obstack_copy(h,where,length) \
(obstack_grow ((h), (where), (length)), obstack_finish ((h)))
# define obstack_copy0(h,where,length) \
(obstack_grow0 ((h), (where), (length)), obstack_finish ((h)))
# define obstack_finish(h) \
( ((h)->next_free == (h)->object_base \
? (((h)->maybe_empty_object = 1), 0) \
: 0), \
(h)->temp = __PTR_TO_INT ((h)->object_base), \
(h)->next_free \
= __INT_TO_PTR ((__PTR_TO_INT ((h)->next_free)+(h)->alignment_mask) \
& ~ ((h)->alignment_mask)), \
(((h)->next_free - (char *) (h)->chunk \
> (h)->chunk_limit - (char *) (h)->chunk) \
? ((h)->next_free = (h)->chunk_limit) : 0), \
(h)->object_base = (h)->next_free, \
__INT_TO_PTR ((h)->temp))
# define obstack_free(h,obj) \
( (h)->temp = (char *) (obj) - (char *) (h)->chunk, \
(((h)->temp > 0 && (h)->temp < (h)->chunk_limit - (char *) (h)->chunk)\
? (int) ((h)->next_free = (h)->object_base \
= (h)->temp + (char *) (h)->chunk) \
: (((obstack_free) ((h), (h)->temp + (char *) (h)->chunk), 0), 0)))
#endif /* not __GNUC__ or not __STDC__ */
#ifdef __cplusplus
} /* C++ */
#endif
#endif /* obstack.h */
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