diff options
Diffstat (limited to 'src/alloc.c')
| -rw-r--r-- | src/alloc.c | 103 |
1 files changed, 67 insertions, 36 deletions
diff --git a/src/alloc.c b/src/alloc.c index de73ce9bae0..847b3c88bbe 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -2001,6 +2001,35 @@ INIT must be an integer that represents a character. */) return val; } +verify (sizeof (size_t) * CHAR_BIT == BITS_PER_SIZE_T); +verify ((BITS_PER_SIZE_T & (BITS_PER_SIZE_T - 1)) == 0); + +static +ptrdiff_t +bool_vector_payload_bytes (ptrdiff_t nr_bits, + ptrdiff_t* exact_needed_bytes_out) +{ + ptrdiff_t exact_needed_bytes; + ptrdiff_t needed_bytes; + + eassert_and_assume (nr_bits >= 0); + + exact_needed_bytes = ROUNDUP ((size_t) nr_bits, CHAR_BIT) / CHAR_BIT; + needed_bytes = ROUNDUP ((size_t) nr_bits, BITS_PER_SIZE_T) / CHAR_BIT; + + if (needed_bytes == 0) + { + /* Always allocate at least one machine word of payload so that + bool-vector operations in data.c don't need a special case + for empty vectors. */ + needed_bytes = sizeof (size_t); + } + + if (exact_needed_bytes_out != NULL) + *exact_needed_bytes_out = exact_needed_bytes; + + return needed_bytes; +} DEFUN ("make-bool-vector", Fmake_bool_vector, Smake_bool_vector, 2, 2, 0, doc: /* Return a new bool-vector of length LENGTH, using INIT for each element. @@ -2009,37 +2038,43 @@ LENGTH must be a number. INIT matters only in whether it is t or nil. */) { register Lisp_Object val; struct Lisp_Bool_Vector *p; - ptrdiff_t length_in_chars; - EMACS_INT length_in_elts; - int bits_per_value; - int extra_bool_elts = ((bool_header_size - header_size + word_size - 1) - / word_size); + ptrdiff_t exact_payload_bytes; + ptrdiff_t total_payload_bytes; + ptrdiff_t needed_elements; CHECK_NATNUM (length); + if (PTRDIFF_MAX < XFASTINT (length)) + memory_full (SIZE_MAX); - bits_per_value = sizeof (EMACS_INT) * BOOL_VECTOR_BITS_PER_CHAR; + total_payload_bytes = bool_vector_payload_bytes + (XFASTINT (length), &exact_payload_bytes); - length_in_elts = (XFASTINT (length) + bits_per_value - 1) / bits_per_value; + eassert_and_assume (exact_payload_bytes <= total_payload_bytes); + eassert_and_assume (0 <= exact_payload_bytes); - val = Fmake_vector (make_number (length_in_elts + extra_bool_elts), Qnil); + needed_elements = ROUNDUP ((size_t) ((bool_header_size - header_size) + + total_payload_bytes), + word_size) / word_size; - /* No Lisp_Object to trace in there. */ + p = (struct Lisp_Bool_Vector* ) allocate_vector (needed_elements); + XSETVECTOR (val, p); XSETPVECTYPESIZE (XVECTOR (val), PVEC_BOOL_VECTOR, 0, 0); - p = XBOOL_VECTOR (val); p->size = XFASTINT (length); - - length_in_chars = ((XFASTINT (length) + BOOL_VECTOR_BITS_PER_CHAR - 1) - / BOOL_VECTOR_BITS_PER_CHAR); - if (length_in_chars) + if (exact_payload_bytes) { - memset (p->data, ! NILP (init) ? -1 : 0, length_in_chars); + memset (p->data, ! NILP (init) ? -1 : 0, exact_payload_bytes); /* Clear any extraneous bits in the last byte. */ - p->data[length_in_chars - 1] + p->data[exact_payload_bytes - 1] &= (1 << ((XFASTINT (length) - 1) % BOOL_VECTOR_BITS_PER_CHAR + 1)) - 1; } + /* Clear padding at the end. */ + memset (p->data + exact_payload_bytes, + 0, + total_payload_bytes - exact_payload_bytes); + return val; } @@ -2565,24 +2600,22 @@ enum roundup_size = COMMON_MULTIPLE (word_size, USE_LSB_TAG ? GCALIGNMENT : 1) }; -/* ROUNDUP_SIZE must be a power of 2. */ -verify ((roundup_size & (roundup_size - 1)) == 0); - /* Verify assumptions described above. */ verify ((VECTOR_BLOCK_SIZE % roundup_size) == 0); verify (VECTOR_BLOCK_SIZE <= (1 << PSEUDOVECTOR_SIZE_BITS)); -/* Round up X to nearest mult-of-ROUNDUP_SIZE. */ - -#define vroundup(x) (((x) + (roundup_size - 1)) & ~(roundup_size - 1)) +/* Round up X to nearest mult-of-ROUNDUP_SIZE --- use at compile time. */ +#define vroundup_ct(x) ROUNDUP((size_t)(x), roundup_size) +/* Round up X to nearest mult-of-ROUNDUP_SIZE --- use at runtime. */ +#define vroundup(x) (assume((x) >= 0), vroundup_ct(x)) /* Rounding helps to maintain alignment constraints if USE_LSB_TAG. */ -#define VECTOR_BLOCK_BYTES (VECTOR_BLOCK_SIZE - vroundup (sizeof (void *))) +#define VECTOR_BLOCK_BYTES (VECTOR_BLOCK_SIZE - vroundup_ct (sizeof (void *))) /* Size of the minimal vector allocated from block. */ -#define VBLOCK_BYTES_MIN vroundup (header_size + sizeof (Lisp_Object)) +#define VBLOCK_BYTES_MIN vroundup_ct (header_size + sizeof (Lisp_Object)) /* Size of the largest vector allocated from block. */ @@ -2642,7 +2675,7 @@ struct large_vector struct large_vector *vector; #if USE_LSB_TAG /* We need to maintain ROUNDUP_SIZE alignment for the vector member. */ - unsigned char c[vroundup (sizeof (struct large_vector *))]; + unsigned char c[vroundup_ct (sizeof (struct large_vector *))]; #endif } next; struct Lisp_Vector v; @@ -2783,10 +2816,14 @@ vector_nbytes (struct Lisp_Vector *v) if (size & PSEUDOVECTOR_FLAG) { if (PSEUDOVECTOR_TYPEP (&v->header, PVEC_BOOL_VECTOR)) - size = (bool_header_size - + (((struct Lisp_Bool_Vector *) v)->size - + BOOL_VECTOR_BITS_PER_CHAR - 1) - / BOOL_VECTOR_BITS_PER_CHAR); + { + struct Lisp_Bool_Vector *bv = (struct Lisp_Bool_Vector *) v; + ptrdiff_t payload_bytes = + bool_vector_payload_bytes (bv->size, NULL); + + eassert_and_assume (payload_bytes >= 0); + size = bool_header_size + ROUNDUP (payload_bytes, word_size); + } else size = (header_size + ((size & PSEUDOVECTOR_SIZE_MASK) @@ -2886,17 +2923,11 @@ sweep_vectors (void) total_vectors++; if (vector->header.size & PSEUDOVECTOR_FLAG) { - struct Lisp_Bool_Vector *b = (struct Lisp_Bool_Vector *) vector; - /* All non-bool pseudovectors are small enough to be allocated from vector blocks. This code should be redesigned if some pseudovector type grows beyond VBLOCK_BYTES_MAX. */ eassert (PSEUDOVECTOR_TYPEP (&vector->header, PVEC_BOOL_VECTOR)); - - total_vector_slots - += (bool_header_size - + ((b->size + BOOL_VECTOR_BITS_PER_CHAR - 1) - / BOOL_VECTOR_BITS_PER_CHAR)) / word_size; + total_vector_slots += vector_nbytes (vector) / word_size; } else total_vector_slots |