gcc/libgo/runtime/go-new-map.c

/* go-new-map.c -- allocate a new map.

   Copyright 2009 The Go Authors. All rights reserved.
   Use of this source code is governed by a BSD-style
   license that can be found in the LICENSE file.  */

#include "runtime.h"
#include "go-alloc.h"
#include "map.h"

/* List of prime numbers, copied from libstdc++/src/hashtable.c.  */

static const unsigned long prime_list[] = /* 256 + 1 or 256 + 48 + 1 */
{
  2ul, 3ul, 5ul, 7ul, 11ul, 13ul, 17ul, 19ul, 23ul, 29ul, 31ul,
  37ul, 41ul, 43ul, 47ul, 53ul, 59ul, 61ul, 67ul, 71ul, 73ul, 79ul,
  83ul, 89ul, 97ul, 103ul, 109ul, 113ul, 127ul, 137ul, 139ul, 149ul,
  157ul, 167ul, 179ul, 193ul, 199ul, 211ul, 227ul, 241ul, 257ul,
  277ul, 293ul, 313ul, 337ul, 359ul, 383ul, 409ul, 439ul, 467ul,
  503ul, 541ul, 577ul, 619ul, 661ul, 709ul, 761ul, 823ul, 887ul,
  953ul, 1031ul, 1109ul, 1193ul, 1289ul, 1381ul, 1493ul, 1613ul,
  1741ul, 1879ul, 2029ul, 2179ul, 2357ul, 2549ul, 2753ul, 2971ul,
  3209ul, 3469ul, 3739ul, 4027ul, 4349ul, 4703ul, 5087ul, 5503ul,
  5953ul, 6427ul, 6949ul, 7517ul, 8123ul, 8783ul, 9497ul, 10273ul,
  11113ul, 12011ul, 12983ul, 14033ul, 15173ul, 16411ul, 17749ul,
  19183ul, 20753ul, 22447ul, 24281ul, 26267ul, 28411ul, 30727ul,
  33223ul, 35933ul, 38873ul, 42043ul, 45481ul, 49201ul, 53201ul,
  57557ul, 62233ul, 67307ul, 72817ul, 78779ul, 85229ul, 92203ul,
  99733ul, 107897ul, 116731ul, 126271ul, 136607ul, 147793ul,
  159871ul, 172933ul, 187091ul, 202409ul, 218971ul, 236897ul,
  256279ul, 277261ul, 299951ul, 324503ul, 351061ul, 379787ul,
  410857ul, 444487ul, 480881ul, 520241ul, 562841ul, 608903ul,
  658753ul, 712697ul, 771049ul, 834181ul, 902483ul, 976369ul,
  1056323ul, 1142821ul, 1236397ul, 1337629ul, 1447153ul, 1565659ul,
  1693859ul, 1832561ul, 1982627ul, 2144977ul, 2320627ul, 2510653ul,
  2716249ul, 2938679ul, 3179303ul, 3439651ul, 3721303ul, 4026031ul,
  4355707ul, 4712381ul, 5098259ul, 5515729ul, 5967347ul, 6456007ul,
  6984629ul, 7556579ul, 8175383ul, 8844859ul, 9569143ul, 10352717ul,
  11200489ul, 12117689ul, 13109983ul, 14183539ul, 15345007ul,
  16601593ul, 17961079ul, 19431899ul, 21023161ul, 22744717ul,
  24607243ul, 26622317ul, 28802401ul, 31160981ul, 33712729ul,
  36473443ul, 39460231ul, 42691603ul, 46187573ul, 49969847ul,
  54061849ul, 58488943ul, 63278561ul, 68460391ul, 74066549ul,
  80131819ul, 86693767ul, 93793069ul, 101473717ul, 109783337ul,
  118773397ul, 128499677ul, 139022417ul, 150406843ul, 162723577ul,
  176048909ul, 190465427ul, 206062531ul, 222936881ul, 241193053ul,
  260944219ul, 282312799ul, 305431229ul, 330442829ul, 357502601ul,
  386778277ul, 418451333ul, 452718089ul, 489790921ul, 529899637ul,
  573292817ul, 620239453ul, 671030513ul, 725980837ul, 785430967ul,
  849749479ul, 919334987ul, 994618837ul, 1076067617ul, 1164186217ul,
  1259520799ul, 1362662261ul, 1474249943ul, 1594975441ul, 1725587117ul,
  1866894511ul, 2019773507ul, 2185171673ul, 2364114217ul, 2557710269ul,
  2767159799ul, 2993761039ul, 3238918481ul, 3504151727ul, 3791104843ul,
  4101556399ul, 4294967291ul,
#if __SIZEOF_LONG__ >= 8
  6442450933ul, 8589934583ul, 12884901857ul, 17179869143ul,
  25769803693ul, 34359738337ul, 51539607367ul, 68719476731ul,
  103079215087ul, 137438953447ul, 206158430123ul, 274877906899ul,
  412316860387ul, 549755813881ul, 824633720731ul, 1099511627689ul,
  1649267441579ul, 2199023255531ul, 3298534883309ul, 4398046511093ul,
  6597069766607ul, 8796093022151ul, 13194139533241ul, 17592186044399ul,
  26388279066581ul, 35184372088777ul, 52776558133177ul, 70368744177643ul,
  105553116266399ul, 140737488355213ul, 211106232532861ul, 281474976710597ul,
  562949953421231ul, 1125899906842597ul, 2251799813685119ul,
  4503599627370449ul, 9007199254740881ul, 18014398509481951ul,
  36028797018963913ul, 72057594037927931ul, 144115188075855859ul,
  288230376151711717ul, 576460752303423433ul,
  1152921504606846883ul, 2305843009213693951ul,
  4611686018427387847ul, 9223372036854775783ul,
  18446744073709551557ul
#endif
};

/* Return the next number from PRIME_LIST >= N.  */

uintptr_t
__go_map_next_prime (uintptr_t n)
{
  size_t low;
  size_t high;

  low = 0;
  high = sizeof prime_list / sizeof prime_list[0];
  while (low < high)
    {
      size_t mid;

      mid = (low + high) / 2;

      /* Here LOW <= MID < HIGH.  */

      if (prime_list[mid] < n)
	low = mid + 1;
      else if (prime_list[mid] > n)
	high = mid;
      else
	return n;
    }
  if (low >= sizeof prime_list / sizeof prime_list[0])
    return n;
  return prime_list[low];
}

/* Allocate a new map.  */

struct __go_map *
__go_new_map (const struct __go_map_descriptor *descriptor, uintptr_t entries)
{
  int32 ientries;
  struct __go_map *ret;

  /* The master library limits map entries to int32, so we do too.  */
  ientries = (int32) entries;
  if (ientries < 0 || (uintptr_t) ientries != entries)
    runtime_panicstring ("map size out of range");

  if (entries == 0)
    entries = 5;
  else
    entries = __go_map_next_prime (entries);
  ret = (struct __go_map *) __go_alloc (sizeof (struct __go_map));
  ret->__descriptor = descriptor;
  ret->__element_count = 0;
  ret->__bucket_count = entries;
  ret->__buckets = (void **) __go_alloc (entries * sizeof (void *));
  __builtin_memset (ret->__buckets, 0, entries * sizeof (void *));
  return ret;
}

/* Allocate a new map when the argument to make is a large type.  */

struct __go_map *
__go_new_map_big (const struct __go_map_descriptor *descriptor,
		  uint64_t entries)
{
  uintptr_t sentries;

  sentries = (uintptr_t) entries;
  if ((uint64_t) sentries != entries)
    runtime_panicstring ("map size out of range");
  return __go_new_map (descriptor, sentries);
}