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authorbstarynk <bstarynk@138bc75d-0d04-0410-961f-82ee72b054a4>2012-08-29 12:37:05 +0000
committerbstarynk <bstarynk@138bc75d-0d04-0410-961f-82ee72b054a4>2012-08-29 12:37:05 +0000
commit12cb78d1cca1387a092ec0bd49c250340bff4afc (patch)
tree1eab97da96906e0a2786d51d9f25f20de02befcf /gcc/hash-table.c
parent31879e18aea3222fe3e56f2c0319c9f230645ff3 (diff)
downloadgcc-12cb78d1cca1387a092ec0bd49c250340bff4afc.tar.gz
2012-08-29 Basile Starynkevitch <basile@starynkevitch.net>
MELT branch merged with trunk rev 190745 using svnmerge, notably C++ conversion. [gcc/] 2012-08-29 Basile Starynkevitch <basile@starynkevitch.net> {{merging with trunk, converted to C++}} * melt-runtime.h (MELT_FLEXIBLE_DIM): Set when C++. * melt-runtime.c (melt_tempdir_path): Don't use choose_tmpdir from libiberty. (meltgc_start_module_by_index): Use address-of & on VEC_index. (melt_really_initialize): When printing builtin settings, handle GCC 4.8 as with implicit ENABLE_BUILD_WITH_CXX. (meltgc_out_edge): Provide additional flag TDF_DETAILS for dump_edge_info. (melt_val2passflag): Handle PROP_referenced_vars only when defined. * melt-module.mk: Use GCCMELT_COMPILER instead of GCCMELT_CC. * melt-build-script.tpl: Transmit GCCMELT_COMPILER on every make using melt-module.mk and improve the error message. * melt-build-script.sh: Regenerate. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/melt-branch@190778 138bc75d-0d04-0410-961f-82ee72b054a4
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+/* A type-safe hash table template.
+ Copyright (C) 2012
+ Free Software Foundation, Inc.
+ Contributed by Lawrence Crowl <crowl@google.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+
+/* This file implements a typed hash table.
+ The implementation borrows from libiberty's hashtab. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "hash-table.h"
+
+
+/* Table of primes and multiplicative inverses.
+
+ Note that these are not minimally reduced inverses. Unlike when generating
+ code to divide by a constant, we want to be able to use the same algorithm
+ all the time. All of these inverses (are implied to) have bit 32 set.
+
+ For the record, here's the function that computed the table; it's a
+ vastly simplified version of the function of the same name from gcc. */
+
+#if 0
+unsigned int
+ceil_log2 (unsigned int x)
+{
+ int i;
+ for (i = 31; i >= 0 ; --i)
+ if (x > (1u << i))
+ return i+1;
+ abort ();
+}
+
+unsigned int
+choose_multiplier (unsigned int d, unsigned int *mlp, unsigned char *shiftp)
+{
+ unsigned long long mhigh;
+ double nx;
+ int lgup, post_shift;
+ int pow, pow2;
+ int n = 32, precision = 32;
+
+ lgup = ceil_log2 (d);
+ pow = n + lgup;
+ pow2 = n + lgup - precision;
+
+ nx = ldexp (1.0, pow) + ldexp (1.0, pow2);
+ mhigh = nx / d;
+
+ *shiftp = lgup - 1;
+ *mlp = mhigh;
+ return mhigh >> 32;
+}
+#endif
+
+struct prime_ent const prime_tab[] = {
+ { 7, 0x24924925, 0x9999999b, 2 },
+ { 13, 0x3b13b13c, 0x745d1747, 3 },
+ { 31, 0x08421085, 0x1a7b9612, 4 },
+ { 61, 0x0c9714fc, 0x15b1e5f8, 5 },
+ { 127, 0x02040811, 0x0624dd30, 6 },
+ { 251, 0x05197f7e, 0x073260a5, 7 },
+ { 509, 0x01824366, 0x02864fc8, 8 },
+ { 1021, 0x00c0906d, 0x014191f7, 9 },
+ { 2039, 0x0121456f, 0x0161e69e, 10 },
+ { 4093, 0x00300902, 0x00501908, 11 },
+ { 8191, 0x00080041, 0x00180241, 12 },
+ { 16381, 0x000c0091, 0x00140191, 13 },
+ { 32749, 0x002605a5, 0x002a06e6, 14 },
+ { 65521, 0x000f00e2, 0x00110122, 15 },
+ { 131071, 0x00008001, 0x00018003, 16 },
+ { 262139, 0x00014002, 0x0001c004, 17 },
+ { 524287, 0x00002001, 0x00006001, 18 },
+ { 1048573, 0x00003001, 0x00005001, 19 },
+ { 2097143, 0x00004801, 0x00005801, 20 },
+ { 4194301, 0x00000c01, 0x00001401, 21 },
+ { 8388593, 0x00001e01, 0x00002201, 22 },
+ { 16777213, 0x00000301, 0x00000501, 23 },
+ { 33554393, 0x00001381, 0x00001481, 24 },
+ { 67108859, 0x00000141, 0x000001c1, 25 },
+ { 134217689, 0x000004e1, 0x00000521, 26 },
+ { 268435399, 0x00000391, 0x000003b1, 27 },
+ { 536870909, 0x00000019, 0x00000029, 28 },
+ { 1073741789, 0x0000008d, 0x00000095, 29 },
+ { 2147483647, 0x00000003, 0x00000007, 30 },
+ /* Avoid "decimal constant so large it is unsigned" for 4294967291. */
+ { 0xfffffffb, 0x00000006, 0x00000008, 31 }
+};
+
+/* The following function returns an index into the above table of the
+ nearest prime number which is greater than N, and near a power of two. */
+
+unsigned int
+hash_table_higher_prime_index (unsigned long n)
+{
+ unsigned int low = 0;
+ unsigned int high = sizeof(prime_tab) / sizeof(prime_tab[0]);
+
+ while (low != high)
+ {
+ unsigned int mid = low + (high - low) / 2;
+ if (n > prime_tab[mid].prime)
+ low = mid + 1;
+ else
+ high = mid;
+ }
+
+ /* If we've run out of primes, abort. */
+ if (n > prime_tab[low].prime)
+ {
+ fprintf (stderr, "Cannot find prime bigger than %lu\n", n);
+ abort ();
+ }
+
+ return low;
+}
+
+/* Return X % Y using multiplicative inverse values INV and SHIFT.
+
+ The multiplicative inverses computed above are for 32-bit types,
+ and requires that we be able to compute a highpart multiply.
+
+ FIX: I am not at all convinced that
+ 3 loads, 2 multiplications, 3 shifts, and 3 additions
+ will be faster than
+ 1 load and 1 modulus
+ on modern systems running a compiler. */
+
+#ifdef UNSIGNED_64BIT_TYPE
+static inline hashval_t
+mul_mod (hashval_t x, hashval_t y, hashval_t inv, int shift)
+{
+ __extension__ typedef UNSIGNED_64BIT_TYPE ull;
+ hashval_t t1, t2, t3, t4, q, r;
+
+ t1 = ((ull)x * inv) >> 32;
+ t2 = x - t1;
+ t3 = t2 >> 1;
+ t4 = t1 + t3;
+ q = t4 >> shift;
+ r = x - (q * y);
+
+ return r;
+}
+#endif
+
+/* Compute the primary table index for HASH given current prime index. */
+
+hashval_t
+hash_table_mod1 (hashval_t hash, unsigned int index)
+{
+ const struct prime_ent *p = &prime_tab[index];
+#ifdef UNSIGNED_64BIT_TYPE
+ if (sizeof (hashval_t) * CHAR_BIT <= 32)
+ return mul_mod (hash, p->prime, p->inv, p->shift);
+#endif
+ return hash % p->prime;
+}
+
+
+/* Compute the secondary table index for HASH given current prime index. */
+
+hashval_t
+hash_table_mod2 (hashval_t hash, unsigned int index)
+{
+ const struct prime_ent *p = &prime_tab[index];
+#ifdef UNSIGNED_64BIT_TYPE
+ if (sizeof (hashval_t) * CHAR_BIT <= 32)
+ return 1 + mul_mod (hash, p->prime - 2, p->inv_m2, p->shift);
+#endif
+ return 1 + hash % (p->prime - 2);
+}