diff options
Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/ggc-zone.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/gcc/ggc-zone.c | 2379 |
1 files changed, 2379 insertions, 0 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/ggc-zone.c b/gcc-4.2.1-5666.3/gcc/ggc-zone.c new file mode 100644 index 000000000..1d6edfb70 --- /dev/null +++ b/gcc-4.2.1-5666.3/gcc/ggc-zone.c @@ -0,0 +1,2379 @@ +/* "Bag-of-pages" zone garbage collector for the GNU compiler. + Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005 + Free Software Foundation, Inc. + + Contributed by Richard Henderson (rth@redhat.com) and Daniel Berlin + (dberlin@dberlin.org). Rewritten by Daniel Jacobowitz + <dan@codesourcery.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 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. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "rtl.h" +#include "tm_p.h" +#include "toplev.h" +#include "varray.h" +#include "flags.h" +#include "ggc.h" +#include "timevar.h" +#include "params.h" +#include "bitmap.h" + +#ifdef ENABLE_VALGRIND_CHECKING +# ifdef HAVE_VALGRIND_MEMCHECK_H +# include <valgrind/memcheck.h> +# elif defined HAVE_MEMCHECK_H +# include <memcheck.h> +# else +# include <valgrind.h> +# endif +#else +/* Avoid #ifdef:s when we can help it. */ +#define VALGRIND_DISCARD(x) +#define VALGRIND_MALLOCLIKE_BLOCK(w,x,y,z) +#define VALGRIND_FREELIKE_BLOCK(x,y) +#endif + +/* Prefer MAP_ANON(YMOUS) to /dev/zero, since we don't need to keep a + file open. Prefer either to valloc. */ +#ifdef HAVE_MMAP_ANON +# undef HAVE_MMAP_DEV_ZERO + +# include <sys/mman.h> +# ifndef MAP_FAILED +# define MAP_FAILED -1 +# endif +# if !defined (MAP_ANONYMOUS) && defined (MAP_ANON) +# define MAP_ANONYMOUS MAP_ANON +# endif +# define USING_MMAP +#endif + +#ifdef HAVE_MMAP_DEV_ZERO +# include <sys/mman.h> +# ifndef MAP_FAILED +# define MAP_FAILED -1 +# endif +# define USING_MMAP +#endif + +#ifndef USING_MMAP +#error Zone collector requires mmap +#endif + +#if (GCC_VERSION < 3001) +#define prefetch(X) ((void) X) +#define prefetchw(X) ((void) X) +#else +#define prefetch(X) __builtin_prefetch (X) +#define prefetchw(X) __builtin_prefetch (X, 1, 3) +#endif + +/* FUTURE NOTES: + + If we track inter-zone pointers, we can mark single zones at a + time. + + If we have a zone where we guarantee no inter-zone pointers, we + could mark that zone separately. + + The garbage zone should not be marked, and we should return 1 in + ggc_set_mark for any object in the garbage zone, which cuts off + marking quickly. */ + +/* Strategy: + + This garbage-collecting allocator segregates objects into zones. + It also segregates objects into "large" and "small" bins. Large + objects are greater than page size. + + Pages for small objects are broken up into chunks. The page has + a bitmap which marks the start position of each chunk (whether + allocated or free). Free chunks are on one of the zone's free + lists and contain a pointer to the next free chunk. Chunks in + most of the free lists have a fixed size determined by the + free list. Chunks in the "other" sized free list have their size + stored right after their chain pointer. + + Empty pages (of all sizes) are kept on a single page cache list, + and are considered first when new pages are required; they are + deallocated at the start of the next collection if they haven't + been recycled by then. The free page list is currently per-zone. */ + +/* Define GGC_DEBUG_LEVEL to print debugging information. + 0: No debugging output. + 1: GC statistics only. + 2: Page-entry allocations/deallocations as well. + 3: Object allocations as well. + 4: Object marks as well. */ +#define GGC_DEBUG_LEVEL (0) + +#ifndef HOST_BITS_PER_PTR +#define HOST_BITS_PER_PTR HOST_BITS_PER_LONG +#endif + +/* This structure manages small free chunks. The SIZE field is only + initialized if the chunk is in the "other" sized free list. Large + chunks are allocated one at a time to their own page, and so don't + come in here. */ + +struct alloc_chunk { + struct alloc_chunk *next_free; + unsigned int size; +}; + +/* The size of the fixed-size portion of a small page descriptor. */ +#define PAGE_OVERHEAD (offsetof (struct small_page_entry, alloc_bits)) + +/* The collector's idea of the page size. This must be a power of two + no larger than the system page size, because pages must be aligned + to this amount and are tracked at this granularity in the page + table. We choose a size at compile time for efficiency. + + We could make a better guess at compile time if PAGE_SIZE is a + constant in system headers, and PAGE_SHIFT is defined... */ +#define GGC_PAGE_SIZE 4096 +#define GGC_PAGE_MASK (GGC_PAGE_SIZE - 1) +#define GGC_PAGE_SHIFT 12 + +#if 0 +/* Alternative definitions which use the runtime page size. */ +#define GGC_PAGE_SIZE G.pagesize +#define GGC_PAGE_MASK G.page_mask +#define GGC_PAGE_SHIFT G.lg_pagesize +#endif + +/* The size of a small page managed by the garbage collector. This + must currently be GGC_PAGE_SIZE, but with a few changes could + be any multiple of it to reduce certain kinds of overhead. */ +#define SMALL_PAGE_SIZE GGC_PAGE_SIZE + +/* Free bin information. These numbers may be in need of re-tuning. + In general, decreasing the number of free bins would seem to + increase the time it takes to allocate... */ + +/* FIXME: We can't use anything but MAX_ALIGNMENT for the bin size + today. */ + +#define NUM_FREE_BINS 64 +#define FREE_BIN_DELTA MAX_ALIGNMENT +#define SIZE_BIN_DOWN(SIZE) ((SIZE) / FREE_BIN_DELTA) + +/* Allocation and marking parameters. */ + +/* The smallest allocatable unit to keep track of. */ +#define BYTES_PER_ALLOC_BIT MAX_ALIGNMENT + +/* The smallest markable unit. If we require each allocated object + to contain at least two allocatable units, we can use half as many + bits for the mark bitmap. But this adds considerable complexity + to sweeping. */ +#define BYTES_PER_MARK_BIT BYTES_PER_ALLOC_BIT + +#define BYTES_PER_MARK_WORD (8 * BYTES_PER_MARK_BIT * sizeof (mark_type)) + +/* We use this structure to determine the alignment required for + allocations. + + There are several things wrong with this estimation of alignment. + + The maximum alignment for a structure is often less than the + maximum alignment for a basic data type; for instance, on some + targets long long must be aligned to sizeof (int) in a structure + and sizeof (long long) in a variable. i386-linux is one example; + Darwin is another (sometimes, depending on the compiler in use). + + Also, long double is not included. Nothing in GCC uses long + double, so we assume that this is OK. On powerpc-darwin, adding + long double would bring the maximum alignment up to 16 bytes, + and until we need long double (or to vectorize compiler operations) + that's painfully wasteful. This will need to change, some day. */ + +struct max_alignment { + char c; + union { + HOST_WIDEST_INT i; + double d; + } u; +}; + +/* The biggest alignment required. */ + +#define MAX_ALIGNMENT (offsetof (struct max_alignment, u)) + +/* Compute the smallest multiple of F that is >= X. */ + +#define ROUND_UP(x, f) (CEIL (x, f) * (f)) + +/* Types to use for the allocation and mark bitmaps. It might be + a good idea to add ffsl to libiberty and use unsigned long + instead; that could speed us up where long is wider than int. */ + +typedef unsigned int alloc_type; +typedef unsigned int mark_type; +#define alloc_ffs(x) ffs(x) + +/* A page_entry records the status of an allocation page. This is the + common data between all three kinds of pages - small, large, and + PCH. */ +typedef struct page_entry +{ + /* The address at which the memory is allocated. */ + char *page; + + /* The zone that this page entry belongs to. */ + struct alloc_zone *zone; + +#ifdef GATHER_STATISTICS + /* How many collections we've survived. */ + size_t survived; +#endif + + /* Does this page contain small objects, or one large object? */ + bool large_p; + + /* Is this page part of the loaded PCH? */ + bool pch_p; +} page_entry; + +/* Additional data needed for small pages. */ +struct small_page_entry +{ + struct page_entry common; + + /* The next small page entry, or NULL if this is the last. */ + struct small_page_entry *next; + + /* If currently marking this zone, a pointer to the mark bits + for this page. If we aren't currently marking this zone, + this pointer may be stale (pointing to freed memory). */ + mark_type *mark_bits; + + /* The allocation bitmap. This array extends far enough to have + one bit for every BYTES_PER_ALLOC_BIT bytes in the page. */ + alloc_type alloc_bits[1]; +}; + +/* Additional data needed for large pages. */ +struct large_page_entry +{ + struct page_entry common; + + /* The next large page entry, or NULL if this is the last. */ + struct large_page_entry *next; + + /* The number of bytes allocated, not including the page entry. */ + size_t bytes; + + /* The previous page in the list, so that we can unlink this one. */ + struct large_page_entry *prev; + + /* During marking, is this object marked? */ + bool mark_p; +}; + +/* A two-level tree is used to look up the page-entry for a given + pointer. Two chunks of the pointer's bits are extracted to index + the first and second levels of the tree, as follows: + + HOST_PAGE_SIZE_BITS + 32 | | + msb +----------------+----+------+------+ lsb + | | | + PAGE_L1_BITS | + | | + PAGE_L2_BITS + + The bottommost HOST_PAGE_SIZE_BITS are ignored, since page-entry + pages are aligned on system page boundaries. The next most + significant PAGE_L2_BITS and PAGE_L1_BITS are the second and first + index values in the lookup table, respectively. + + For 32-bit architectures and the settings below, there are no + leftover bits. For architectures with wider pointers, the lookup + tree points to a list of pages, which must be scanned to find the + correct one. */ + +#define PAGE_L1_BITS (8) +#define PAGE_L2_BITS (32 - PAGE_L1_BITS - GGC_PAGE_SHIFT) +#define PAGE_L1_SIZE ((size_t) 1 << PAGE_L1_BITS) +#define PAGE_L2_SIZE ((size_t) 1 << PAGE_L2_BITS) + +#define LOOKUP_L1(p) \ + (((size_t) (p) >> (32 - PAGE_L1_BITS)) & ((1 << PAGE_L1_BITS) - 1)) + +#define LOOKUP_L2(p) \ + (((size_t) (p) >> GGC_PAGE_SHIFT) & ((1 << PAGE_L2_BITS) - 1)) + +#if HOST_BITS_PER_PTR <= 32 + +/* On 32-bit hosts, we use a two level page table, as pictured above. */ +typedef page_entry **page_table[PAGE_L1_SIZE]; + +#else + +/* On 64-bit hosts, we use the same two level page tables plus a linked + list that disambiguates the top 32-bits. There will almost always be + exactly one entry in the list. */ +typedef struct page_table_chain +{ + struct page_table_chain *next; + size_t high_bits; + page_entry **table[PAGE_L1_SIZE]; +} *page_table; + +#endif + +/* The global variables. */ +static struct globals +{ + /* The linked list of zones. */ + struct alloc_zone *zones; + + /* Lookup table for associating allocation pages with object addresses. */ + page_table lookup; + + /* The system's page size, and related constants. */ + size_t pagesize; + size_t lg_pagesize; + size_t page_mask; + + /* The size to allocate for a small page entry. This includes + the size of the structure and the size of the allocation + bitmap. */ + size_t small_page_overhead; + +#if defined (HAVE_MMAP_DEV_ZERO) + /* A file descriptor open to /dev/zero for reading. */ + int dev_zero_fd; +#endif + + /* Allocate pages in chunks of this size, to throttle calls to memory + allocation routines. The first page is used, the rest go onto the + free list. */ + size_t quire_size; + + /* The file descriptor for debugging output. */ + FILE *debug_file; +} G; + +/* A zone allocation structure. There is one of these for every + distinct allocation zone. */ +struct alloc_zone +{ + /* The most recent free chunk is saved here, instead of in the linked + free list, to decrease list manipulation. It is most likely that we + will want this one. */ + char *cached_free; + size_t cached_free_size; + + /* Linked lists of free storage. Slots 1 ... NUM_FREE_BINS have chunks of size + FREE_BIN_DELTA. All other chunks are in slot 0. */ + struct alloc_chunk *free_chunks[NUM_FREE_BINS + 1]; + + /* The highest bin index which might be non-empty. It may turn out + to be empty, in which case we have to search downwards. */ + size_t high_free_bin; + + /* Bytes currently allocated in this zone. */ + size_t allocated; + + /* Linked list of the small pages in this zone. */ + struct small_page_entry *pages; + + /* Doubly linked list of large pages in this zone. */ + struct large_page_entry *large_pages; + + /* If we are currently marking this zone, a pointer to the mark bits. */ + mark_type *mark_bits; + + /* Name of the zone. */ + const char *name; + + /* The number of small pages currently allocated in this zone. */ + size_t n_small_pages; + + /* Bytes allocated at the end of the last collection. */ + size_t allocated_last_gc; + + /* Total amount of memory mapped. */ + size_t bytes_mapped; + + /* A cache of free system pages. */ + struct small_page_entry *free_pages; + + /* Next zone in the linked list of zones. */ + struct alloc_zone *next_zone; + + /* True if this zone was collected during this collection. */ + bool was_collected; + + /* True if this zone should be destroyed after the next collection. */ + bool dead; + +#ifdef GATHER_STATISTICS + struct + { + /* Total memory allocated with ggc_alloc. */ + unsigned long long total_allocated; + /* Total overhead for memory to be allocated with ggc_alloc. */ + unsigned long long total_overhead; + + /* Total allocations and overhead for sizes less than 32, 64 and 128. + These sizes are interesting because they are typical cache line + sizes. */ + + unsigned long long total_allocated_under32; + unsigned long long total_overhead_under32; + + unsigned long long total_allocated_under64; + unsigned long long total_overhead_under64; + + unsigned long long total_allocated_under128; + unsigned long long total_overhead_under128; + } stats; +#endif +} main_zone; + +/* Some default zones. */ +struct alloc_zone rtl_zone; +struct alloc_zone tree_zone; +struct alloc_zone tree_id_zone; + +/* The PCH zone does not need a normal zone structure, and it does + not live on the linked list of zones. */ +struct pch_zone +{ + /* The start of the PCH zone. NULL if there is none. */ + char *page; + + /* The end of the PCH zone. NULL if there is none. */ + char *end; + + /* The size of the PCH zone. 0 if there is none. */ + size_t bytes; + + /* The allocation bitmap for the PCH zone. */ + alloc_type *alloc_bits; + + /* If we are currently marking, the mark bitmap for the PCH zone. + When it is first read in, we could avoid marking the PCH, + because it will not contain any pointers to GC memory outside + of the PCH; however, the PCH is currently mapped as writable, + so we must mark it in case new pointers are added. */ + mark_type *mark_bits; +} pch_zone; + +#ifdef USING_MMAP +static char *alloc_anon (char *, size_t, struct alloc_zone *); +#endif +static struct small_page_entry * alloc_small_page (struct alloc_zone *); +static struct large_page_entry * alloc_large_page (size_t, struct alloc_zone *); +static void free_chunk (char *, size_t, struct alloc_zone *); +static void free_small_page (struct small_page_entry *); +static void free_large_page (struct large_page_entry *); +static void release_pages (struct alloc_zone *); +static void sweep_pages (struct alloc_zone *); +static bool ggc_collect_1 (struct alloc_zone *, bool); +static void new_ggc_zone_1 (struct alloc_zone *, const char *); + +/* Traverse the page table and find the entry for a page. + Die (probably) if the object wasn't allocated via GC. */ + +static inline page_entry * +lookup_page_table_entry (const void *p) +{ + page_entry ***base; + size_t L1, L2; + +#if HOST_BITS_PER_PTR <= 32 + base = &G.lookup[0]; +#else + page_table table = G.lookup; + size_t high_bits = (size_t) p & ~ (size_t) 0xffffffff; + while (table->high_bits != high_bits) + table = table->next; + base = &table->table[0]; +#endif + + /* Extract the level 1 and 2 indices. */ + L1 = LOOKUP_L1 (p); + L2 = LOOKUP_L2 (p); + + return base[L1][L2]; +} + +/* Set the page table entry for the page that starts at P. If ENTRY + is NULL, clear the entry. */ + +static void +set_page_table_entry (void *p, page_entry *entry) +{ + page_entry ***base; + size_t L1, L2; + +#if HOST_BITS_PER_PTR <= 32 + base = &G.lookup[0]; +#else + page_table table; + size_t high_bits = (size_t) p & ~ (size_t) 0xffffffff; + for (table = G.lookup; table; table = table->next) + if (table->high_bits == high_bits) + goto found; + + /* Not found -- allocate a new table. */ + table = xcalloc (1, sizeof(*table)); + table->next = G.lookup; + table->high_bits = high_bits; + G.lookup = table; +found: + base = &table->table[0]; +#endif + + /* Extract the level 1 and 2 indices. */ + L1 = LOOKUP_L1 (p); + L2 = LOOKUP_L2 (p); + + if (base[L1] == NULL) + base[L1] = xcalloc (PAGE_L2_SIZE, sizeof (page_entry *)); + + base[L1][L2] = entry; +} + +/* Find the page table entry associated with OBJECT. */ + +static inline struct page_entry * +zone_get_object_page (const void *object) +{ + return lookup_page_table_entry (object); +} + +/* Find which element of the alloc_bits array OBJECT should be + recorded in. */ +static inline unsigned int +zone_get_object_alloc_word (const void *object) +{ + return (((size_t) object & (GGC_PAGE_SIZE - 1)) + / (8 * sizeof (alloc_type) * BYTES_PER_ALLOC_BIT)); +} + +/* Find which bit of the appropriate word in the alloc_bits array + OBJECT should be recorded in. */ +static inline unsigned int +zone_get_object_alloc_bit (const void *object) +{ + return (((size_t) object / BYTES_PER_ALLOC_BIT) + % (8 * sizeof (alloc_type))); +} + +/* Find which element of the mark_bits array OBJECT should be recorded + in. */ +static inline unsigned int +zone_get_object_mark_word (const void *object) +{ + return (((size_t) object & (GGC_PAGE_SIZE - 1)) + / (8 * sizeof (mark_type) * BYTES_PER_MARK_BIT)); +} + +/* Find which bit of the appropriate word in the mark_bits array + OBJECT should be recorded in. */ +static inline unsigned int +zone_get_object_mark_bit (const void *object) +{ + return (((size_t) object / BYTES_PER_MARK_BIT) + % (8 * sizeof (mark_type))); +} + +/* Set the allocation bit corresponding to OBJECT in its page's + bitmap. Used to split this object from the preceding one. */ +static inline void +zone_set_object_alloc_bit (const void *object) +{ + struct small_page_entry *page + = (struct small_page_entry *) zone_get_object_page (object); + unsigned int start_word = zone_get_object_alloc_word (object); + unsigned int start_bit = zone_get_object_alloc_bit (object); + + page->alloc_bits[start_word] |= 1L << start_bit; +} + +/* Clear the allocation bit corresponding to OBJECT in PAGE's + bitmap. Used to coalesce this object with the preceding + one. */ +static inline void +zone_clear_object_alloc_bit (struct small_page_entry *page, + const void *object) +{ + unsigned int start_word = zone_get_object_alloc_word (object); + unsigned int start_bit = zone_get_object_alloc_bit (object); + + /* Would xor be quicker? */ + page->alloc_bits[start_word] &= ~(1L << start_bit); +} + +/* Find the size of the object which starts at START_WORD and + START_BIT in ALLOC_BITS, which is at most MAX_SIZE bytes. + Helper function for ggc_get_size and zone_find_object_size. */ + +static inline size_t +zone_object_size_1 (alloc_type *alloc_bits, + size_t start_word, size_t start_bit, + size_t max_size) +{ + size_t size; + alloc_type alloc_word; + int indx; + + /* Load the first word. */ + alloc_word = alloc_bits[start_word++]; + + /* If that was the last bit in this word, we'll want to continue + with the next word. Otherwise, handle the rest of this word. */ + if (start_bit) + { + indx = alloc_ffs (alloc_word >> start_bit); + if (indx) + /* indx is 1-based. We started at the bit after the object's + start, but we also ended at the bit after the object's end. + It cancels out. */ + return indx * BYTES_PER_ALLOC_BIT; + + /* The extra 1 accounts for the starting unit, before start_bit. */ + size = (sizeof (alloc_type) * 8 - start_bit + 1) * BYTES_PER_ALLOC_BIT; + + if (size >= max_size) + return max_size; + + alloc_word = alloc_bits[start_word++]; + } + else + size = BYTES_PER_ALLOC_BIT; + + while (alloc_word == 0) + { + size += sizeof (alloc_type) * 8 * BYTES_PER_ALLOC_BIT; + if (size >= max_size) + return max_size; + alloc_word = alloc_bits[start_word++]; + } + + indx = alloc_ffs (alloc_word); + return size + (indx - 1) * BYTES_PER_ALLOC_BIT; +} + +/* Find the size of OBJECT on small page PAGE. */ + +static inline size_t +zone_find_object_size (struct small_page_entry *page, + const void *object) +{ + const char *object_midptr = (const char *) object + BYTES_PER_ALLOC_BIT; + unsigned int start_word = zone_get_object_alloc_word (object_midptr); + unsigned int start_bit = zone_get_object_alloc_bit (object_midptr); + size_t max_size = (page->common.page + SMALL_PAGE_SIZE + - (char *) object); + + return zone_object_size_1 (page->alloc_bits, start_word, start_bit, + max_size); +} + +/* Allocate the mark bits for every zone, and set the pointers on each + page. */ +static void +zone_allocate_marks (void) +{ + struct alloc_zone *zone; + + for (zone = G.zones; zone; zone = zone->next_zone) + { + struct small_page_entry *page; + mark_type *cur_marks; + size_t mark_words, mark_words_per_page; +#ifdef ENABLE_CHECKING + size_t n = 0; +#endif + + mark_words_per_page + = (GGC_PAGE_SIZE + BYTES_PER_MARK_WORD - 1) / BYTES_PER_MARK_WORD; + mark_words = zone->n_small_pages * mark_words_per_page; + zone->mark_bits = (mark_type *) xcalloc (sizeof (mark_type), + mark_words); + cur_marks = zone->mark_bits; + for (page = zone->pages; page; page = page->next) + { + page->mark_bits = cur_marks; + cur_marks += mark_words_per_page; +#ifdef ENABLE_CHECKING + n++; +#endif + } +#ifdef ENABLE_CHECKING + gcc_assert (n == zone->n_small_pages); +#endif + } + + /* We don't collect the PCH zone, but we do have to mark it + (for now). */ + if (pch_zone.bytes) + pch_zone.mark_bits + = (mark_type *) xcalloc (sizeof (mark_type), + CEIL (pch_zone.bytes, BYTES_PER_MARK_WORD)); +} + +/* After marking and sweeping, release the memory used for mark bits. */ +static void +zone_free_marks (void) +{ + struct alloc_zone *zone; + + for (zone = G.zones; zone; zone = zone->next_zone) + if (zone->mark_bits) + { + free (zone->mark_bits); + zone->mark_bits = NULL; + } + + if (pch_zone.bytes) + { + free (pch_zone.mark_bits); + pch_zone.mark_bits = NULL; + } +} + +#ifdef USING_MMAP +/* Allocate SIZE bytes of anonymous memory, preferably near PREF, + (if non-null). The ifdef structure here is intended to cause a + compile error unless exactly one of the HAVE_* is defined. */ + +static inline char * +alloc_anon (char *pref ATTRIBUTE_UNUSED, size_t size, struct alloc_zone *zone) +{ +#ifdef HAVE_MMAP_ANON + char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); +#endif +#ifdef HAVE_MMAP_DEV_ZERO + char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE, G.dev_zero_fd, 0); +#endif + + if (page == (char *) MAP_FAILED) + { + perror ("virtual memory exhausted"); + exit (FATAL_EXIT_CODE); + } + + /* Remember that we allocated this memory. */ + zone->bytes_mapped += size; + + /* Pretend we don't have access to the allocated pages. We'll enable + access to smaller pieces of the area in ggc_alloc. Discard the + handle to avoid handle leak. */ + VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (page, size)); + + return page; +} +#endif + +/* Allocate a new page for allocating small objects in ZONE, and + return an entry for it. */ + +static struct small_page_entry * +alloc_small_page (struct alloc_zone *zone) +{ + struct small_page_entry *entry; + + /* Check the list of free pages for one we can use. */ + entry = zone->free_pages; + if (entry != NULL) + { + /* Recycle the allocated memory from this page ... */ + zone->free_pages = entry->next; + } + else + { + /* We want just one page. Allocate a bunch of them and put the + extras on the freelist. (Can only do this optimization with + mmap for backing store.) */ + struct small_page_entry *e, *f = zone->free_pages; + int i; + char *page; + + page = alloc_anon (NULL, GGC_PAGE_SIZE * G.quire_size, zone); + + /* This loop counts down so that the chain will be in ascending + memory order. */ + for (i = G.quire_size - 1; i >= 1; i--) + { + e = xcalloc (1, G.small_page_overhead); + e->common.page = page + (i << GGC_PAGE_SHIFT); + e->common.zone = zone; + e->next = f; + f = e; + set_page_table_entry (e->common.page, &e->common); + } + + zone->free_pages = f; + + entry = xcalloc (1, G.small_page_overhead); + entry->common.page = page; + entry->common.zone = zone; + set_page_table_entry (page, &entry->common); + } + + zone->n_small_pages++; + + if (GGC_DEBUG_LEVEL >= 2) + fprintf (G.debug_file, + "Allocating %s page at %p, data %p-%p\n", + entry->common.zone->name, (PTR) entry, entry->common.page, + entry->common.page + SMALL_PAGE_SIZE - 1); + + return entry; +} + +/* Allocate a large page of size SIZE in ZONE. */ + +static struct large_page_entry * +alloc_large_page (size_t size, struct alloc_zone *zone) +{ + struct large_page_entry *entry; + char *page; + size_t needed_size; + + needed_size = size + sizeof (struct large_page_entry); + page = xmalloc (needed_size); + + entry = (struct large_page_entry *) page; + + entry->next = NULL; + entry->common.page = page + sizeof (struct large_page_entry); + entry->common.large_p = true; + entry->common.pch_p = false; + entry->common.zone = zone; +#ifdef GATHER_STATISTICS + entry->common.survived = 0; +#endif + entry->mark_p = false; + entry->bytes = size; + entry->prev = NULL; + + set_page_table_entry (entry->common.page, &entry->common); + + if (GGC_DEBUG_LEVEL >= 2) + fprintf (G.debug_file, + "Allocating %s large page at %p, data %p-%p\n", + entry->common.zone->name, (PTR) entry, entry->common.page, + entry->common.page + SMALL_PAGE_SIZE - 1); + + return entry; +} + + +/* For a page that is no longer needed, put it on the free page list. */ + +static inline void +free_small_page (struct small_page_entry *entry) +{ + if (GGC_DEBUG_LEVEL >= 2) + fprintf (G.debug_file, + "Deallocating %s page at %p, data %p-%p\n", + entry->common.zone->name, (PTR) entry, + entry->common.page, entry->common.page + SMALL_PAGE_SIZE - 1); + + gcc_assert (!entry->common.large_p); + + /* Mark the page as inaccessible. Discard the handle to + avoid handle leak. */ + VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (entry->common.page, + SMALL_PAGE_SIZE)); + + entry->next = entry->common.zone->free_pages; + entry->common.zone->free_pages = entry; + entry->common.zone->n_small_pages--; +} + +/* Release a large page that is no longer needed. */ + +static inline void +free_large_page (struct large_page_entry *entry) +{ + if (GGC_DEBUG_LEVEL >= 2) + fprintf (G.debug_file, + "Deallocating %s page at %p, data %p-%p\n", + entry->common.zone->name, (PTR) entry, + entry->common.page, entry->common.page + SMALL_PAGE_SIZE - 1); + + gcc_assert (entry->common.large_p); + + set_page_table_entry (entry->common.page, NULL); + free (entry); +} + +/* Release the free page cache to the system. */ + +static void +release_pages (struct alloc_zone *zone) +{ +#ifdef USING_MMAP + struct small_page_entry *p, *next; + char *start; + size_t len; + + /* Gather up adjacent pages so they are unmapped together. */ + p = zone->free_pages; + + while (p) + { + start = p->common.page; + next = p->next; + len = SMALL_PAGE_SIZE; + set_page_table_entry (p->common.page, NULL); + p = next; + + while (p && p->common.page == start + len) + { + next = p->next; + len += SMALL_PAGE_SIZE; + set_page_table_entry (p->common.page, NULL); + p = next; + } + + munmap (start, len); + zone->bytes_mapped -= len; + } + + zone->free_pages = NULL; +#endif +} + +/* Place the block at PTR of size SIZE on the free list for ZONE. */ + +static inline void +free_chunk (char *ptr, size_t size, struct alloc_zone *zone) +{ + struct alloc_chunk *chunk = (struct alloc_chunk *) ptr; + size_t bin = 0; + + bin = SIZE_BIN_DOWN (size); + gcc_assert (bin != 0); + if (bin > NUM_FREE_BINS) + { + bin = 0; + VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk))); + chunk->size = size; + chunk->next_free = zone->free_chunks[bin]; + VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (ptr + sizeof (struct alloc_chunk), + size - sizeof (struct alloc_chunk))); + } + else + { + VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk *))); + chunk->next_free = zone->free_chunks[bin]; + VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (ptr + sizeof (struct alloc_chunk *), + size - sizeof (struct alloc_chunk *))); + } + + zone->free_chunks[bin] = chunk; + if (bin > zone->high_free_bin) + zone->high_free_bin = bin; + if (GGC_DEBUG_LEVEL >= 3) + fprintf (G.debug_file, "Deallocating object, chunk=%p\n", (void *)chunk); +} + +/* Allocate a chunk of memory of at least ORIG_SIZE bytes, in ZONE. */ + +void * +ggc_alloc_zone_stat (size_t orig_size, struct alloc_zone *zone + MEM_STAT_DECL) +{ + size_t bin; + size_t csize; + struct small_page_entry *entry; + struct alloc_chunk *chunk, **pp; + void *result; + size_t size = orig_size; + + /* Make sure that zero-sized allocations get a unique and freeable + pointer. */ + if (size == 0) + size = MAX_ALIGNMENT; + else + size = (size + MAX_ALIGNMENT - 1) & -MAX_ALIGNMENT; + + /* Try to allocate the object from several different sources. Each + of these cases is responsible for setting RESULT and SIZE to + describe the allocated block, before jumping to FOUND. If a + chunk is split, the allocate bit for the new chunk should also be + set. + + Large objects are handled specially. However, they'll just fail + the next couple of conditions, so we can wait to check for them + below. The large object case is relatively rare (< 1%), so this + is a win. */ + + /* First try to split the last chunk we allocated. For best + fragmentation behavior it would be better to look for a + free bin of the appropriate size for a small object. However, + we're unlikely (1% - 7%) to find one, and this gives better + locality behavior anyway. This case handles the lion's share + of all calls to this function. */ + if (size <= zone->cached_free_size) + { + result = zone->cached_free; + + zone->cached_free_size -= size; + if (zone->cached_free_size) + { + zone->cached_free += size; + zone_set_object_alloc_bit (zone->cached_free); + } + + goto found; + } + + /* Next, try to find a free bin of the exactly correct size. */ + + /* We want to round SIZE up, rather than down, but we know it's + already aligned to at least FREE_BIN_DELTA, so we can just + shift. */ + bin = SIZE_BIN_DOWN (size); + + if (bin <= NUM_FREE_BINS + && (chunk = zone->free_chunks[bin]) != NULL) + { + /* We have a chunk of the right size. Pull it off the free list + and use it. */ + + zone->free_chunks[bin] = chunk->next_free; + + /* NOTE: SIZE is only guaranteed to be right if MAX_ALIGNMENT + == FREE_BIN_DELTA. */ + result = chunk; + + /* The allocation bits are already set correctly. HIGH_FREE_BIN + may now be wrong, if this was the last chunk in the high bin. + Rather than fixing it up now, wait until we need to search + the free bins. */ + + goto found; + } + + /* Next, if there wasn't a chunk of the ideal size, look for a chunk + to split. We can find one in the too-big bin, or in the largest + sized bin with a chunk in it. Try the largest normal-sized bin + first. */ + + if (zone->high_free_bin > bin) + { + /* Find the highest numbered free bin. It will be at or below + the watermark. */ + while (zone->high_free_bin > bin + && zone->free_chunks[zone->high_free_bin] == NULL) + zone->high_free_bin--; + + if (zone->high_free_bin > bin) + { + size_t tbin = zone->high_free_bin; + chunk = zone->free_chunks[tbin]; + + /* Remove the chunk from its previous bin. */ + zone->free_chunks[tbin] = chunk->next_free; + + result = (char *) chunk; + + /* Save the rest of the chunk for future allocation. */ + if (zone->cached_free_size) + free_chunk (zone->cached_free, zone->cached_free_size, zone); + + chunk = (struct alloc_chunk *) ((char *) result + size); + zone->cached_free = (char *) chunk; + zone->cached_free_size = (tbin - bin) * FREE_BIN_DELTA; + + /* Mark the new free chunk as an object, so that we can + find the size of the newly allocated object. */ + zone_set_object_alloc_bit (chunk); + + /* HIGH_FREE_BIN may now be wrong, if this was the last + chunk in the high bin. Rather than fixing it up now, + wait until we need to search the free bins. */ + + goto found; + } + } + + /* Failing that, look through the "other" bucket for a chunk + that is large enough. */ + pp = &(zone->free_chunks[0]); + chunk = *pp; + while (chunk && chunk->size < size) + { + pp = &chunk->next_free; + chunk = *pp; + } + + if (chunk) + { + /* Remove the chunk from its previous bin. */ + *pp = chunk->next_free; + + result = (char *) chunk; + + /* Save the rest of the chunk for future allocation, if there's any + left over. */ + csize = chunk->size; + if (csize > size) + { + if (zone->cached_free_size) + free_chunk (zone->cached_free, zone->cached_free_size, zone); + + chunk = (struct alloc_chunk *) ((char *) result + size); + zone->cached_free = (char *) chunk; + zone->cached_free_size = csize - size; + + /* Mark the new free chunk as an object. */ + zone_set_object_alloc_bit (chunk); + } + + goto found; + } + + /* Handle large allocations. We could choose any threshold between + GGC_PAGE_SIZE - sizeof (struct large_page_entry) and + GGC_PAGE_SIZE. It can't be smaller, because then it wouldn't + be guaranteed to have a unique entry in the lookup table. Large + allocations will always fall through to here. */ + if (size > GGC_PAGE_SIZE) + { + struct large_page_entry *entry = alloc_large_page (size, zone); + +#ifdef GATHER_STATISTICS + entry->common.survived = 0; +#endif + + entry->next = zone->large_pages; + if (zone->large_pages) + zone->large_pages->prev = entry; + zone->large_pages = entry; + + result = entry->common.page; + + goto found; + } + + /* Failing everything above, allocate a new small page. */ + + entry = alloc_small_page (zone); + entry->next = zone->pages; + zone->pages = entry; + + /* Mark the first chunk in the new page. */ + entry->alloc_bits[0] = 1; + + result = entry->common.page; + if (size < SMALL_PAGE_SIZE) + { + if (zone->cached_free_size) + free_chunk (zone->cached_free, zone->cached_free_size, zone); + + zone->cached_free = (char *) result + size; + zone->cached_free_size = SMALL_PAGE_SIZE - size; + + /* Mark the new free chunk as an object. */ + zone_set_object_alloc_bit (zone->cached_free); + } + + found: + + /* We could save TYPE in the chunk, but we don't use that for + anything yet. If we wanted to, we could do it by adding it + either before the beginning of the chunk or after its end, + and adjusting the size and pointer appropriately. */ + + /* We'll probably write to this after we return. */ + prefetchw (result); + +#ifdef ENABLE_GC_CHECKING + /* `Poison' the entire allocated object. */ + VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (result, size)); + memset (result, 0xaf, size); + VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (result + orig_size, + size - orig_size)); +#endif + + /* Tell Valgrind that the memory is there, but its content isn't + defined. The bytes at the end of the object are still marked + unaccessible. */ + VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (result, orig_size)); + + /* Keep track of how many bytes are being allocated. This + information is used in deciding when to collect. */ + zone->allocated += size; + + timevar_ggc_mem_total += size; + +#ifdef GATHER_STATISTICS + ggc_record_overhead (orig_size, size - orig_size, result PASS_MEM_STAT); + + { + size_t object_size = size; + size_t overhead = object_size - orig_size; + + zone->stats.total_overhead += overhead; + zone->stats.total_allocated += object_size; + + if (orig_size <= 32) + { + zone->stats.total_overhead_under32 += overhead; + zone->stats.total_allocated_under32 += object_size; + } + if (orig_size <= 64) + { + zone->stats.total_overhead_under64 += overhead; + zone->stats.total_allocated_under64 += object_size; + } + if (orig_size <= 128) + { + zone->stats.total_overhead_under128 += overhead; + zone->stats.total_allocated_under128 += object_size; + } + } +#endif + + if (GGC_DEBUG_LEVEL >= 3) + fprintf (G.debug_file, "Allocating object, size=%lu at %p\n", + (unsigned long) size, result); + + return result; +} + +/* Allocate a SIZE of chunk memory of GTE type, into an appropriate zone + for that type. */ + +void * +ggc_alloc_typed_stat (enum gt_types_enum gte, size_t size + MEM_STAT_DECL) +{ + switch (gte) + { + case gt_ggc_e_14lang_tree_node: + return ggc_alloc_zone_pass_stat (size, &tree_zone); + + case gt_ggc_e_7rtx_def: + return ggc_alloc_zone_pass_stat (size, &rtl_zone); + + case gt_ggc_e_9rtvec_def: + return ggc_alloc_zone_pass_stat (size, &rtl_zone); + + default: + return ggc_alloc_zone_pass_stat (size, &main_zone); + } +} + +/* Normal ggc_alloc simply allocates into the main zone. */ + +void * +ggc_alloc_stat (size_t size MEM_STAT_DECL) +{ + return ggc_alloc_zone_pass_stat (size, &main_zone); +} + +/* Poison the chunk. */ +#ifdef ENABLE_GC_CHECKING +#define poison_region(PTR, SIZE) \ + memset ((PTR), 0xa5, (SIZE)) +#else +#define poison_region(PTR, SIZE) +#endif + +/* Free the object at P. */ + +void +ggc_free (void *p) +{ + struct page_entry *page; + +#ifdef GATHER_STATISTICS + ggc_free_overhead (p); +#endif + + poison_region (p, ggc_get_size (p)); + + page = zone_get_object_page (p); + + if (page->large_p) + { + struct large_page_entry *large_page + = (struct large_page_entry *) page; + + /* Remove the page from the linked list. */ + if (large_page->prev) + large_page->prev->next = large_page->next; + else + { + gcc_assert (large_page->common.zone->large_pages == large_page); + large_page->common.zone->large_pages = large_page->next; + } + if (large_page->next) + large_page->next->prev = large_page->prev; + + large_page->common.zone->allocated -= large_page->bytes; + + /* Release the memory associated with this object. */ + free_large_page (large_page); + } + else if (page->pch_p) + /* Don't do anything. We won't allocate a new object from the + PCH zone so there's no point in releasing anything. */ + ; + else + { + size_t size = ggc_get_size (p); + + page->zone->allocated -= size; + + /* Add the chunk to the free list. We don't bother with coalescing, + since we are likely to want a chunk of this size again. */ + free_chunk (p, size, page->zone); + } +} + +/* If P is not marked, mark it and return false. Otherwise return true. + P must have been allocated by the GC allocator; it mustn't point to + static objects, stack variables, or memory allocated with malloc. */ + +int +ggc_set_mark (const void *p) +{ + struct page_entry *page; + const char *ptr = (const char *) p; + + page = zone_get_object_page (p); + + if (page->pch_p) + { + size_t mark_word, mark_bit, offset; + offset = (ptr - pch_zone.page) / BYTES_PER_MARK_BIT; + mark_word = offset / (8 * sizeof (mark_type)); + mark_bit = offset % (8 * sizeof (mark_type)); + + if (pch_zone.mark_bits[mark_word] & (1 << mark_bit)) + return 1; + pch_zone.mark_bits[mark_word] |= (1 << mark_bit); + } + else if (page->large_p) + { + struct large_page_entry *large_page + = (struct large_page_entry *) page; + + if (large_page->mark_p) + return 1; + large_page->mark_p = true; + } + else + { + struct small_page_entry *small_page + = (struct small_page_entry *) page; + + if (small_page->mark_bits[zone_get_object_mark_word (p)] + & (1 << zone_get_object_mark_bit (p))) + return 1; + small_page->mark_bits[zone_get_object_mark_word (p)] + |= (1 << zone_get_object_mark_bit (p)); + } + + if (GGC_DEBUG_LEVEL >= 4) + fprintf (G.debug_file, "Marking %p\n", p); + + return 0; +} + +/* Return 1 if P has been marked, zero otherwise. + P must have been allocated by the GC allocator; it mustn't point to + static objects, stack variables, or memory allocated with malloc. */ + +int +ggc_marked_p (const void *p) +{ + struct page_entry *page; + const char *ptr = p; + + page = zone_get_object_page (p); + + if (page->pch_p) + { + size_t mark_word, mark_bit, offset; + offset = (ptr - pch_zone.page) / BYTES_PER_MARK_BIT; + mark_word = offset / (8 * sizeof (mark_type)); + mark_bit = offset % (8 * sizeof (mark_type)); + + return (pch_zone.mark_bits[mark_word] & (1 << mark_bit)) != 0; + } + + if (page->large_p) + { + struct large_page_entry *large_page + = (struct large_page_entry *) page; + + return large_page->mark_p; + } + else + { + struct small_page_entry *small_page + = (struct small_page_entry *) page; + + return 0 != (small_page->mark_bits[zone_get_object_mark_word (p)] + & (1 << zone_get_object_mark_bit (p))); + } +} + +/* Return the size of the gc-able object P. */ + +size_t +ggc_get_size (const void *p) +{ + struct page_entry *page; + const char *ptr = (const char *) p; + + page = zone_get_object_page (p); + + if (page->pch_p) + { + size_t alloc_word, alloc_bit, offset, max_size; + offset = (ptr - pch_zone.page) / BYTES_PER_ALLOC_BIT + 1; + alloc_word = offset / (8 * sizeof (alloc_type)); + alloc_bit = offset % (8 * sizeof (alloc_type)); + max_size = pch_zone.bytes - (ptr - pch_zone.page); + return zone_object_size_1 (pch_zone.alloc_bits, alloc_word, alloc_bit, + max_size); + } + + if (page->large_p) + return ((struct large_page_entry *)page)->bytes; + else + return zone_find_object_size ((struct small_page_entry *) page, p); +} + +/* Initialize the ggc-zone-mmap allocator. */ +void +init_ggc (void) +{ + /* The allocation size must be greater than BYTES_PER_MARK_BIT, and + a multiple of both BYTES_PER_ALLOC_BIT and FREE_BIN_DELTA, for + the current assumptions to hold. */ + + gcc_assert (FREE_BIN_DELTA == MAX_ALIGNMENT); + + /* Set up the main zone by hand. */ + main_zone.name = "Main zone"; + G.zones = &main_zone; + + /* Allocate the default zones. */ + new_ggc_zone_1 (&rtl_zone, "RTL zone"); + new_ggc_zone_1 (&tree_zone, "Tree zone"); + new_ggc_zone_1 (&tree_id_zone, "Tree identifier zone"); + + G.pagesize = getpagesize(); + G.lg_pagesize = exact_log2 (G.pagesize); + G.page_mask = ~(G.pagesize - 1); + + /* Require the system page size to be a multiple of GGC_PAGE_SIZE. */ + gcc_assert ((G.pagesize & (GGC_PAGE_SIZE - 1)) == 0); + + /* Allocate 16 system pages at a time. */ + G.quire_size = 16 * G.pagesize / GGC_PAGE_SIZE; + + /* Calculate the size of the allocation bitmap and other overhead. */ + /* Right now we allocate bits for the page header and bitmap. These + are wasted, but a little tricky to eliminate. */ + G.small_page_overhead + = PAGE_OVERHEAD + (GGC_PAGE_SIZE / BYTES_PER_ALLOC_BIT / 8); + /* G.small_page_overhead = ROUND_UP (G.small_page_overhead, MAX_ALIGNMENT); */ + +#ifdef HAVE_MMAP_DEV_ZERO + G.dev_zero_fd = open ("/dev/zero", O_RDONLY); + gcc_assert (G.dev_zero_fd != -1); +#endif + +#if 0 + G.debug_file = fopen ("ggc-mmap.debug", "w"); + setlinebuf (G.debug_file); +#else + G.debug_file = stdout; +#endif + +#ifdef USING_MMAP + /* StunOS has an amazing off-by-one error for the first mmap allocation + after fiddling with RLIMIT_STACK. The result, as hard as it is to + believe, is an unaligned page allocation, which would cause us to + hork badly if we tried to use it. */ + { + char *p = alloc_anon (NULL, G.pagesize, &main_zone); + struct small_page_entry *e; + if ((size_t)p & (G.pagesize - 1)) + { + /* How losing. Discard this one and try another. If we still + can't get something useful, give up. */ + + p = alloc_anon (NULL, G.pagesize, &main_zone); + gcc_assert (!((size_t)p & (G.pagesize - 1))); + } + + if (GGC_PAGE_SIZE == G.pagesize) + { + /* We have a good page, might as well hold onto it... */ + e = xcalloc (1, G.small_page_overhead); + e->common.page = p; + e->common.zone = &main_zone; + e->next = main_zone.free_pages; + set_page_table_entry (e->common.page, &e->common); + main_zone.free_pages = e; + } + else + { + munmap (p, G.pagesize); + } + } +#endif +} + +/* Start a new GGC zone. */ + +static void +new_ggc_zone_1 (struct alloc_zone *new_zone, const char * name) +{ + new_zone->name = name; + new_zone->next_zone = G.zones->next_zone; + G.zones->next_zone = new_zone; +} + +struct alloc_zone * +new_ggc_zone (const char * name) +{ + struct alloc_zone *new_zone = xcalloc (1, sizeof (struct alloc_zone)); + new_ggc_zone_1 (new_zone, name); + return new_zone; +} + +/* Destroy a GGC zone. */ +void +destroy_ggc_zone (struct alloc_zone * dead_zone) +{ + struct alloc_zone *z; + + for (z = G.zones; z && z->next_zone != dead_zone; z = z->next_zone) + /* Just find that zone. */ + continue; + + /* We should have found the zone in the list. Anything else is fatal. */ + gcc_assert (z); + + /* z is dead, baby. z is dead. */ + z->dead = true; +} + +/* Free all empty pages and objects within a page for a given zone */ + +static void +sweep_pages (struct alloc_zone *zone) +{ + struct large_page_entry **lpp, *lp, *lnext; + struct small_page_entry **spp, *sp, *snext; + char *last_free; + size_t allocated = 0; + bool nomarksinpage; + + /* First, reset the free_chunks lists, since we are going to + re-free free chunks in hopes of coalescing them into large chunks. */ + memset (zone->free_chunks, 0, sizeof (zone->free_chunks)); + zone->high_free_bin = 0; + zone->cached_free = NULL; + zone->cached_free_size = 0; + + /* Large pages are all or none affairs. Either they are completely + empty, or they are completely full. */ + lpp = &zone->large_pages; + for (lp = zone->large_pages; lp != NULL; lp = lnext) + { + gcc_assert (lp->common.large_p); + + lnext = lp->next; + +#ifdef GATHER_STATISTICS + /* This page has now survived another collection. */ + lp->common.survived++; +#endif + + if (lp->mark_p) + { + lp->mark_p = false; + allocated += lp->bytes; + lpp = &lp->next; + } + else + { + *lpp = lnext; +#ifdef ENABLE_GC_CHECKING + /* Poison the page. */ + memset (lp->common.page, 0xb5, SMALL_PAGE_SIZE); +#endif + if (lp->prev) + lp->prev->next = lp->next; + if (lp->next) + lp->next->prev = lp->prev; + free_large_page (lp); + } + } + + spp = &zone->pages; + for (sp = zone->pages; sp != NULL; sp = snext) + { + char *object, *last_object; + char *end; + alloc_type *alloc_word_p; + mark_type *mark_word_p; + + gcc_assert (!sp->common.large_p); + + snext = sp->next; + +#ifdef GATHER_STATISTICS + /* This page has now survived another collection. */ + sp->common.survived++; +#endif + + /* Step through all chunks, consolidate those that are free and + insert them into the free lists. Note that consolidation + slows down collection slightly. */ + + last_object = object = sp->common.page; + end = sp->common.page + SMALL_PAGE_SIZE; + last_free = NULL; + nomarksinpage = true; + mark_word_p = sp->mark_bits; + alloc_word_p = sp->alloc_bits; + + gcc_assert (BYTES_PER_ALLOC_BIT == BYTES_PER_MARK_BIT); + + object = sp->common.page; + do + { + unsigned int i, n; + alloc_type alloc_word; + mark_type mark_word; + + alloc_word = *alloc_word_p++; + mark_word = *mark_word_p++; + + if (mark_word) + nomarksinpage = false; + + /* There ought to be some way to do this without looping... */ + i = 0; + while ((n = alloc_ffs (alloc_word)) != 0) + { + /* Extend the current state for n - 1 bits. We can't + shift alloc_word by n, even though it isn't used in the + loop, in case only the highest bit was set. */ + alloc_word >>= n - 1; + mark_word >>= n - 1; + object += BYTES_PER_MARK_BIT * (n - 1); + + if (mark_word & 1) + { + if (last_free) + { + VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (last_free, + object + - last_free)); + poison_region (last_free, object - last_free); + free_chunk (last_free, object - last_free, zone); + last_free = NULL; + } + else + allocated += object - last_object; + last_object = object; + } + else + { + if (last_free == NULL) + { + last_free = object; + allocated += object - last_object; + } + else + zone_clear_object_alloc_bit (sp, object); + } + + /* Shift to just after the alloc bit we handled. */ + alloc_word >>= 1; + mark_word >>= 1; + object += BYTES_PER_MARK_BIT; + + i += n; + } + + object += BYTES_PER_MARK_BIT * (8 * sizeof (alloc_type) - i); + } + while (object < end); + + if (nomarksinpage) + { + *spp = snext; +#ifdef ENABLE_GC_CHECKING + VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (sp->common.page, SMALL_PAGE_SIZE)); + /* Poison the page. */ + memset (sp->common.page, 0xb5, SMALL_PAGE_SIZE); +#endif + free_small_page (sp); + continue; + } + else if (last_free) + { + VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (last_free, + object - last_free)); + poison_region (last_free, object - last_free); + free_chunk (last_free, object - last_free, zone); + } + else + allocated += object - last_object; + + spp = &sp->next; + } + + zone->allocated = allocated; +} + +/* mark-and-sweep routine for collecting a single zone. NEED_MARKING + is true if we need to mark before sweeping, false if some other + zone collection has already performed marking for us. Returns true + if we collected, false otherwise. */ + +static bool +ggc_collect_1 (struct alloc_zone *zone, bool need_marking) +{ +#if 0 + /* */ + { + int i; + for (i = 0; i < NUM_FREE_BINS + 1; i++) + { + struct alloc_chunk *chunk; + int n, tot; + + n = 0; + tot = 0; + chunk = zone->free_chunks[i]; + while (chunk) + { + n++; + tot += chunk->size; + chunk = chunk->next_free; + } + fprintf (stderr, "Bin %d: %d free chunks (%d bytes)\n", + i, n, tot); + } + } + /* */ +#endif + + if (!quiet_flag) + fprintf (stderr, " {%s GC %luk -> ", + zone->name, (unsigned long) zone->allocated / 1024); + + /* Zero the total allocated bytes. This will be recalculated in the + sweep phase. */ + zone->allocated = 0; + + /* Release the pages we freed the last time we collected, but didn't + reuse in the interim. */ + release_pages (zone); + + if (need_marking) + { + zone_allocate_marks (); + ggc_mark_roots (); +#ifdef GATHER_STATISTICS + ggc_prune_overhead_list (); +#endif + } + + sweep_pages (zone); + zone->was_collected = true; + zone->allocated_last_gc = zone->allocated; + + if (!quiet_flag) + fprintf (stderr, "%luk}", (unsigned long) zone->allocated / 1024); + return true; +} + +#ifdef GATHER_STATISTICS +/* Calculate the average page survival rate in terms of number of + collections. */ + +static float +calculate_average_page_survival (struct alloc_zone *zone) +{ + float count = 0.0; + float survival = 0.0; + struct small_page_entry *p; + struct large_page_entry *lp; + for (p = zone->pages; p; p = p->next) + { + count += 1.0; + survival += p->common.survived; + } + for (lp = zone->large_pages; lp; lp = lp->next) + { + count += 1.0; + survival += lp->common.survived; + } + return survival/count; +} +#endif + +/* Top level collection routine. */ + +void +ggc_collect (void) +{ + struct alloc_zone *zone; + bool marked = false; + + timevar_push (TV_GC); + + if (!ggc_force_collect) + { + float allocated_last_gc = 0, allocated = 0, min_expand; + + for (zone = G.zones; zone; zone = zone->next_zone) + { + allocated_last_gc += zone->allocated_last_gc; + allocated += zone->allocated; + } + + allocated_last_gc = + MAX (allocated_last_gc, + (size_t) PARAM_VALUE (GGC_MIN_HEAPSIZE) * 1024); + min_expand = allocated_last_gc * PARAM_VALUE (GGC_MIN_EXPAND) / 100; + + if (allocated < allocated_last_gc + min_expand) + { + timevar_pop (TV_GC); + return; + } + } + + /* Start by possibly collecting the main zone. */ + main_zone.was_collected = false; + marked |= ggc_collect_1 (&main_zone, true); + + /* In order to keep the number of collections down, we don't + collect other zones unless we are collecting the main zone. This + gives us roughly the same number of collections as we used to + have with the old gc. The number of collection is important + because our main slowdown (according to profiling) is now in + marking. So if we mark twice as often as we used to, we'll be + twice as slow. Hopefully we'll avoid this cost when we mark + zone-at-a-time. */ + /* NOTE drow/2004-07-28: We now always collect the main zone, but + keep this code in case the heuristics are further refined. */ + + if (main_zone.was_collected) + { + struct alloc_zone *zone; + + for (zone = main_zone.next_zone; zone; zone = zone->next_zone) + { + zone->was_collected = false; + marked |= ggc_collect_1 (zone, !marked); + } + } + +#ifdef GATHER_STATISTICS + /* Print page survival stats, if someone wants them. */ + if (GGC_DEBUG_LEVEL >= 2) + { + for (zone = G.zones; zone; zone = zone->next_zone) + { + if (zone->was_collected) + { + float f = calculate_average_page_survival (zone); + printf ("Average page survival in zone `%s' is %f\n", + zone->name, f); + } + } + } +#endif + + if (marked) + zone_free_marks (); + + /* Free dead zones. */ + for (zone = G.zones; zone && zone->next_zone; zone = zone->next_zone) + { + if (zone->next_zone->dead) + { + struct alloc_zone *dead_zone = zone->next_zone; + + printf ("Zone `%s' is dead and will be freed.\n", dead_zone->name); + + /* The zone must be empty. */ + gcc_assert (!dead_zone->allocated); + + /* Unchain the dead zone, release all its pages and free it. */ + zone->next_zone = zone->next_zone->next_zone; + release_pages (dead_zone); + free (dead_zone); + } + } + + timevar_pop (TV_GC); +} + +/* Print allocation statistics. */ +#define SCALE(x) ((unsigned long) ((x) < 1024*10 \ + ? (x) \ + : ((x) < 1024*1024*10 \ + ? (x) / 1024 \ + : (x) / (1024*1024)))) +#define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M')) + +void +ggc_print_statistics (void) +{ + struct alloc_zone *zone; + struct ggc_statistics stats; + size_t total_overhead = 0, total_allocated = 0, total_bytes_mapped = 0; + size_t pte_overhead, i; + + /* Clear the statistics. */ + memset (&stats, 0, sizeof (stats)); + + /* Make sure collection will really occur. */ + ggc_force_collect = true; + + /* Collect and print the statistics common across collectors. */ + ggc_print_common_statistics (stderr, &stats); + + ggc_force_collect = false; + + /* Release free pages so that we will not count the bytes allocated + there as part of the total allocated memory. */ + for (zone = G.zones; zone; zone = zone->next_zone) + release_pages (zone); + + /* Collect some information about the various sizes of + allocation. */ + fprintf (stderr, + "Memory still allocated at the end of the compilation process\n"); + + fprintf (stderr, "%20s %10s %10s %10s\n", + "Zone", "Allocated", "Used", "Overhead"); + for (zone = G.zones; zone; zone = zone->next_zone) + { + struct large_page_entry *large_page; + size_t overhead, allocated, in_use; + + /* Skip empty zones. */ + if (!zone->pages && !zone->large_pages) + continue; + + allocated = in_use = 0; + + overhead = sizeof (struct alloc_zone); + + for (large_page = zone->large_pages; large_page != NULL; + large_page = large_page->next) + { + allocated += large_page->bytes; + in_use += large_page->bytes; + overhead += sizeof (struct large_page_entry); + } + + /* There's no easy way to walk through the small pages finding + used and unused objects. Instead, add all the pages, and + subtract out the free list. */ + + allocated += GGC_PAGE_SIZE * zone->n_small_pages; + in_use += GGC_PAGE_SIZE * zone->n_small_pages; + overhead += G.small_page_overhead * zone->n_small_pages; + + for (i = 0; i <= NUM_FREE_BINS; i++) + { + struct alloc_chunk *chunk = zone->free_chunks[i]; + while (chunk) + { + in_use -= ggc_get_size (chunk); + chunk = chunk->next_free; + } + } + + fprintf (stderr, "%20s %10lu%c %10lu%c %10lu%c\n", + zone->name, + SCALE (allocated), LABEL (allocated), + SCALE (in_use), LABEL (in_use), + SCALE (overhead), LABEL (overhead)); + + gcc_assert (in_use == zone->allocated); + + total_overhead += overhead; + total_allocated += zone->allocated; + total_bytes_mapped += zone->bytes_mapped; + } + + /* Count the size of the page table as best we can. */ +#if HOST_BITS_PER_PTR <= 32 + pte_overhead = sizeof (G.lookup); + for (i = 0; i < PAGE_L1_SIZE; i++) + if (G.lookup[i]) + pte_overhead += PAGE_L2_SIZE * sizeof (struct page_entry *); +#else + { + page_table table = G.lookup; + pte_overhead = 0; + while (table) + { + pte_overhead += sizeof (*table); + for (i = 0; i < PAGE_L1_SIZE; i++) + if (table->table[i]) + pte_overhead += PAGE_L2_SIZE * sizeof (struct page_entry *); + table = table->next; + } + } +#endif + fprintf (stderr, "%20s %11s %11s %10lu%c\n", "Page Table", + "", "", SCALE (pte_overhead), LABEL (pte_overhead)); + total_overhead += pte_overhead; + + fprintf (stderr, "%20s %10lu%c %10lu%c %10lu%c\n", "Total", + SCALE (total_bytes_mapped), LABEL (total_bytes_mapped), + SCALE (total_allocated), LABEL(total_allocated), + SCALE (total_overhead), LABEL (total_overhead)); + +#ifdef GATHER_STATISTICS + { + unsigned long long all_overhead = 0, all_allocated = 0; + unsigned long long all_overhead_under32 = 0, all_allocated_under32 = 0; + unsigned long long all_overhead_under64 = 0, all_allocated_under64 = 0; + unsigned long long all_overhead_under128 = 0, all_allocated_under128 = 0; + + fprintf (stderr, "\nTotal allocations and overheads during the compilation process\n"); + + for (zone = G.zones; zone; zone = zone->next_zone) + { + all_overhead += zone->stats.total_overhead; + all_allocated += zone->stats.total_allocated; + + all_allocated_under32 += zone->stats.total_allocated_under32; + all_overhead_under32 += zone->stats.total_overhead_under32; + + all_allocated_under64 += zone->stats.total_allocated_under64; + all_overhead_under64 += zone->stats.total_overhead_under64; + + all_allocated_under128 += zone->stats.total_allocated_under128; + all_overhead_under128 += zone->stats.total_overhead_under128; + + fprintf (stderr, "%20s: %10lld\n", + zone->name, zone->stats.total_allocated); + } + + fprintf (stderr, "\n"); + + fprintf (stderr, "Total Overhead: %10lld\n", + all_overhead); + fprintf (stderr, "Total Allocated: %10lld\n", + all_allocated); + + fprintf (stderr, "Total Overhead under 32B: %10lld\n", + all_overhead_under32); + fprintf (stderr, "Total Allocated under 32B: %10lld\n", + all_allocated_under32); + fprintf (stderr, "Total Overhead under 64B: %10lld\n", + all_overhead_under64); + fprintf (stderr, "Total Allocated under 64B: %10lld\n", + all_allocated_under64); + fprintf (stderr, "Total Overhead under 128B: %10lld\n", + all_overhead_under128); + fprintf (stderr, "Total Allocated under 128B: %10lld\n", + all_allocated_under128); + } +#endif +} + +/* Precompiled header support. */ + +/* For precompiled headers, we sort objects based on their type. We + also sort various objects into their own buckets; currently this + covers strings and IDENTIFIER_NODE trees. The choices of how + to sort buckets have not yet been tuned. */ + +#define NUM_PCH_BUCKETS (gt_types_enum_last + 3) + +#define OTHER_BUCKET (gt_types_enum_last + 0) +#define IDENTIFIER_BUCKET (gt_types_enum_last + 1) +#define STRING_BUCKET (gt_types_enum_last + 2) + +struct ggc_pch_ondisk +{ + size_t total; + size_t type_totals[NUM_PCH_BUCKETS]; +}; + +struct ggc_pch_data +{ + struct ggc_pch_ondisk d; + size_t base; + size_t orig_base; + size_t alloc_size; + alloc_type *alloc_bits; + size_t type_bases[NUM_PCH_BUCKETS]; + size_t start_offset; +}; + +/* Initialize the PCH data structure. */ + +struct ggc_pch_data * +init_ggc_pch (void) +{ + return xcalloc (sizeof (struct ggc_pch_data), 1); +} + +/* Return which of the page-aligned buckets the object at X, with type + TYPE, should be sorted into in the PCH. Strings will have + IS_STRING set and TYPE will be gt_types_enum_last. Other objects + of unknown type will also have TYPE equal to gt_types_enum_last. */ + +static int +pch_bucket (void *x, enum gt_types_enum type, + bool is_string) +{ + /* Sort identifiers into their own bucket, to improve locality + when searching the identifier hash table. */ + if (type == gt_ggc_e_14lang_tree_node + && TREE_CODE ((tree) x) == IDENTIFIER_NODE) + return IDENTIFIER_BUCKET; + else if (type == gt_types_enum_last) + { + if (is_string) + return STRING_BUCKET; + return OTHER_BUCKET; + } + return type; +} + +/* Add the size of object X to the size of the PCH data. */ + +void +ggc_pch_count_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED, + size_t size, bool is_string, enum gt_types_enum type) +{ + /* NOTE: Right now we don't need to align up the size of any objects. + Strings can be unaligned, and everything else is allocated to a + MAX_ALIGNMENT boundary already. */ + + d->d.type_totals[pch_bucket (x, type, is_string)] += size; +} + +/* Return the total size of the PCH data. */ + +size_t +ggc_pch_total_size (struct ggc_pch_data *d) +{ + enum gt_types_enum i; + size_t alloc_size, total_size; + + total_size = 0; + for (i = 0; i < NUM_PCH_BUCKETS; i++) + { + d->d.type_totals[i] = ROUND_UP (d->d.type_totals[i], GGC_PAGE_SIZE); + total_size += d->d.type_totals[i]; + } + d->d.total = total_size; + + /* Include the size of the allocation bitmap. */ + alloc_size = CEIL (d->d.total, BYTES_PER_ALLOC_BIT * 8); + alloc_size = ROUND_UP (alloc_size, MAX_ALIGNMENT); + d->alloc_size = alloc_size; + + return d->d.total + alloc_size; +} + +/* Set the base address for the objects in the PCH file. */ + +void +ggc_pch_this_base (struct ggc_pch_data *d, void *base_) +{ + int i; + size_t base = (size_t) base_; + + d->base = d->orig_base = base; + for (i = 0; i < NUM_PCH_BUCKETS; i++) + { + d->type_bases[i] = base; + base += d->d.type_totals[i]; + } + + if (d->alloc_bits == NULL) + d->alloc_bits = xcalloc (1, d->alloc_size); +} + +/* Allocate a place for object X of size SIZE in the PCH file. */ + +char * +ggc_pch_alloc_object (struct ggc_pch_data *d, void *x, + size_t size, bool is_string, + enum gt_types_enum type) +{ + size_t alloc_word, alloc_bit; + char *result; + int bucket = pch_bucket (x, type, is_string); + + /* Record the start of the object in the allocation bitmap. We + can't assert that the allocation bit is previously clear, because + strings may violate the invariant that they are at least + BYTES_PER_ALLOC_BIT long. This is harmless - ggc_get_size + should not be called for strings. */ + alloc_word = ((d->type_bases[bucket] - d->orig_base) + / (8 * sizeof (alloc_type) * BYTES_PER_ALLOC_BIT)); + alloc_bit = ((d->type_bases[bucket] - d->orig_base) + / BYTES_PER_ALLOC_BIT) % (8 * sizeof (alloc_type)); + d->alloc_bits[alloc_word] |= 1L << alloc_bit; + + /* Place the object at the current pointer for this bucket. */ + result = (char *) d->type_bases[bucket]; + d->type_bases[bucket] += size; + return result; +} + +/* Prepare to write out the PCH data to file F. */ + +void +ggc_pch_prepare_write (struct ggc_pch_data *d, + FILE *f) +{ + /* We seek around a lot while writing. Record where the end + of the padding in the PCH file is, so that we can + locate each object's offset. */ + d->start_offset = ftell (f); +} + +/* Write out object X of SIZE to file F. */ + +void +ggc_pch_write_object (struct ggc_pch_data *d, + FILE *f, void *x, void *newx, + size_t size, bool is_string ATTRIBUTE_UNUSED) +{ + if (fseek (f, (size_t) newx - d->orig_base + d->start_offset, SEEK_SET) != 0) + fatal_error ("can't seek PCH file: %m"); + + if (fwrite (x, size, 1, f) != 1) + fatal_error ("can't write PCH file: %m"); +} + +void +ggc_pch_finish (struct ggc_pch_data *d, FILE *f) +{ + /* Write out the allocation bitmap. */ + if (fseek (f, d->start_offset + d->d.total, SEEK_SET) != 0) + fatal_error ("can't seek PCH file: %m"); + + if (fwrite (d->alloc_bits, d->alloc_size, 1, f) != 1) + fatal_error ("can't write PCH fle: %m"); + + /* Done with the PCH, so write out our footer. */ + if (fwrite (&d->d, sizeof (d->d), 1, f) != 1) + fatal_error ("can't write PCH file: %m"); + + free (d->alloc_bits); + free (d); +} + +/* The PCH file from F has been mapped at ADDR. Read in any + additional data from the file and set up the GC state. */ + +void +ggc_pch_read (FILE *f, void *addr) +{ + struct ggc_pch_ondisk d; + size_t alloc_size; + struct alloc_zone *zone; + struct page_entry *pch_page; + char *p; + + if (fread (&d, sizeof (d), 1, f) != 1) + fatal_error ("can't read PCH file: %m"); + + alloc_size = CEIL (d.total, BYTES_PER_ALLOC_BIT * 8); + alloc_size = ROUND_UP (alloc_size, MAX_ALIGNMENT); + + pch_zone.bytes = d.total; + pch_zone.alloc_bits = (alloc_type *) ((char *) addr + pch_zone.bytes); + pch_zone.page = (char *) addr; + pch_zone.end = (char *) pch_zone.alloc_bits; + + /* We've just read in a PCH file. So, every object that used to be + allocated is now free. */ + for (zone = G.zones; zone; zone = zone->next_zone) + { + struct small_page_entry *page, *next_page; + struct large_page_entry *large_page, *next_large_page; + + zone->allocated = 0; + + /* Clear the zone's free chunk list. */ + memset (zone->free_chunks, 0, sizeof (zone->free_chunks)); + zone->high_free_bin = 0; + zone->cached_free = NULL; + zone->cached_free_size = 0; + + /* Move all the small pages onto the free list. */ + for (page = zone->pages; page != NULL; page = next_page) + { + next_page = page->next; + memset (page->alloc_bits, 0, + G.small_page_overhead - PAGE_OVERHEAD); + free_small_page (page); + } + + /* Discard all the large pages. */ + for (large_page = zone->large_pages; large_page != NULL; + large_page = next_large_page) + { + next_large_page = large_page->next; + free_large_page (large_page); + } + + zone->pages = NULL; + zone->large_pages = NULL; + } + + /* Allocate the dummy page entry for the PCH, and set all pages + mapped into the PCH to reference it. */ + pch_page = xcalloc (1, sizeof (struct page_entry)); + pch_page->page = pch_zone.page; + pch_page->pch_p = true; + + for (p = pch_zone.page; p < pch_zone.end; p += GGC_PAGE_SIZE) + set_page_table_entry (p, pch_page); +} |