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Content-Language: en-US From: =?UTF-8?Q?Martin_Li=c5=a1ka?= To: dwz@sourceware.org References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-9.9 required=5.0 tests=BAYES_00, BODY_8BITS, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_ASCII_DIVIDERS, NICE_REPLY_A, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: dwz@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Dwz mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 31 Mar 2022 11:29:50 -0000 PING^1 On 1/5/22 09:17, Martin Liška wrote: > The algorithm provides the following speed-up with -O2: > > - 1/5: sysdig (60M) > dwz_O2                : 9.7 > dwz_O2_xxhash         : 8.5 (87.7%) > - 2/5: rtags (58M) > dwz_O2                : 17.6 > dwz_O2_xxhash         : 15.8 (89.5%) > - 3/5: libetonyek (91M) > dwz_O2                : 10.8 > dwz_O2_xxhash         : 9.4 (86.7%) > - 4/5: krita (685M) > dwz_O2                : 96.0 > dwz_O2_xxhash         : 85.6 (89.1%) > - 5/5: gcc (1.2G) > dwz_O2                : 58.6 > dwz_O2_xxhash         : 54.1 (92.4%) > --- >  Makefile  |   4 +- >  dwz.c     | 103 +++++++++++++++++++++++----------------- >  hashtab.c | 139 ------------------------------------------------------ >  hashtab.h |   6 ++- >  4 files changed, 65 insertions(+), 187 deletions(-) > > diff --git a/Makefile b/Makefile > index 9394ef4..89546c2 100644 > --- a/Makefile > +++ b/Makefile > @@ -8,7 +8,7 @@ CFLAGS = -O2 -g >  DWZ_VERSION := $(shell cat $(srcdir)/VERSION) >  CFLAGS_VERSION = -DDWZ_VERSION='"$(DWZ_VERSION)"' >  CFLAGS_COPYRIGHT = $(shell cat $(srcdir)/COPYRIGHT_YEARS) > -CFLAGS_COMMON = -Wall -W -D_FILE_OFFSET_BITS=64 > +CFLAGS_COMMON = -Wall -W -D_FILE_OFFSET_BITS=64 -DXXH_INLINE_ALL=1 >  override CFLAGS += $(CFLAGS_COMMON) $(CFLAGS_VERSION) $(CFLAGS_COPYRIGHT) > >  prefix = /usr > @@ -17,7 +17,7 @@ bindir = $(exec_prefix)/bin >  datarootdir = $(prefix)/share >  mandir = $(datarootdir)/man >  OBJECTS = args.o dwz.o hashtab.o pool.o sha1.o dwarfnames.o > -LIBS=-lelf > +LIBS=-lelf -lxxhash >  dwz: $(OBJECTS) >      $(CC) $(LDFLAGS) -o $@ $^ $(LIBS) >  args.o: native.o > diff --git a/dwz.c b/dwz.c > index a3b289f..cc68f4a 100644 > --- a/dwz.c > +++ b/dwz.c > @@ -112,6 +112,21 @@ >  # define NT_GNU_BUILD_ID 3 >  #endif > > +/* xxHash state object.  */ > +static XXH64_state_t state; > + > +/* Clear xxHash state to zero.  */ > +#define hash_init_state() XXH64_reset(&state, 0) > + > +/* Update hash STATE with VALUE.  */ > +#define hash_update_state(value) XXH64_update(&state, &value, sizeof value) > + > +/* Update hash STATE with OBJECT that has a provided SIZE.  */ > +#define hash_update_state_object(object, size) XXH64_update(&state, object, size) > + > +/* Get digest once we are done with a state.  */ > +#define hash_digest() XXH64_digest(&state) > + >  /* Print memory amount M (in kb) in both exact and human readable, like so: >     1382508 (1.3G).  */ >  static void > @@ -1187,16 +1202,18 @@ compute_abbrev_hash (struct abbrev_tag *t) >  { >    unsigned int i; > > -  t->hash = iterative_hash_object (t->tag, 0); > -  t->hash = iterative_hash_object (t->nattr, t->hash); > -  t->hash = iterative_hash_object (t->children, t->hash); > +  hash_init_state (); > +  hash_update_state (t->tag); > +  hash_update_state (t->nattr); > +  hash_update_state (t->children); >    for (i = 0; i < t->nattr; i++) >      { > -      t->hash = iterative_hash_object (t->attr[i].attr, t->hash); > -      t->hash = iterative_hash_object (t->attr[i].form, t->hash); > +      hash_update_state (t->attr[i].attr); > +      hash_update_state (t->attr[i].form); >        if (t->attr[i].form == DW_FORM_implicit_const) > -    t->hash = iterative_hash_object (t->values[i], t->hash); > +    hash_update_state (t->values[i]); >      } > +  t->hash = hash_digest (); >  } > >  /* Maximum number of attributes in a DIE.  */ > @@ -3402,22 +3419,17 @@ checksum_die (DSO *dso, dw_cu_ref cu, dw_die_ref top_die, dw_die_ref die) >            struct dw_file *cu_file = &cu->cu_files[value - 1]; >            size_t file_len = strlen (cu_file->file); >            s = t->attr[i].attr; > -          die->u.p1.die_hash > -            = iterative_hash_object (s, die->u.p1.die_hash); > -          die->u.p1.die_hash > -            = iterative_hash_object (cu_file->time, > -                         die->u.p1.die_hash); > -          die->u.p1.die_hash > -            = iterative_hash_object (cu_file->size, > -                         die->u.p1.die_hash); > -          die->u.p1.die_hash > -            = iterative_hash (cu_file->file, file_len + 1, > -                      die->u.p1.die_hash); > +          hash_init_state (); > +          hash_update_state (die->u.p1.die_hash); > +          hash_update_state (s); > +          hash_update_state (cu_file->time); > +          hash_update_state (cu_file->size); > +          hash_update_state_object (cu_file->file, file_len + 1); >            if (cu_file->dir) > -            die->u.p1.die_hash > -              = iterative_hash (cu_file->dir, > -                    strlen (cu_file->dir) + 1, > -                    die->u.p1.die_hash); > +            { > +              hash_update_state_object (cu_file->dir, > +                        strlen (cu_file->dir) + 1); > +            } >            /* Ignore DW_AT_comp_dir for DW_AT_*_file >               etc. if immediately followed by DW_AT_*_line 0.  */ >            else if (cu_file->file_angle_brackets_encapsulated_no_slash > @@ -3427,7 +3439,13 @@ checksum_die (DSO *dso, dw_cu_ref cu, dw_die_ref top_die, dw_die_ref die) >                    ? DW_AT_decl_line : DW_AT_call_line) >                 && t->attr[i + 1].form == DW_FORM_data1 >                 && *new_ptr == 0) > -            break; > +            { > +              die->u.p1.die_hash = hash_digest (); > +              break; > +            } > + > +          die->u.p1.die_hash = hash_digest (); > + >            if (cu->cu_comp_dir >                && (cu_file->dir ? cu_file->dir[0] >                         : cu_file->file[0]) != '/') > @@ -5541,7 +5559,7 @@ strp_eq2 (const void *p, const void *q) >  static hashval_t >  strp_hash3 (const void *p) >  { > -  return iterative_hash (p, strlen (p), 0); > +  return hash (p, strlen (p)); >  } > >  /* Corresponding equality function in strp_htab.  */ > @@ -5571,7 +5589,7 @@ note_strp_offset (unsigned int off) > >        p = debug_sections[DEBUG_STR].data + off; >        len = strlen ((char *) p); > -      hash = iterative_hash (p, len, 0); > +      hash = hash (p, len); >        if (alt_strp_htab) >      { >        if (htab_find_with_hash (alt_strp_htab, p, hash)) > @@ -5653,7 +5671,7 @@ lookup_strp_offset (unsigned int off) > >        p = debug_sections[DEBUG_STR].data + off; >        len = strlen ((char *) p); > -      hash = iterative_hash (p, len, 0); > +      hash = hash (p, len); >        if (alt_strp_htab) >      { >        unsigned char *q = (unsigned char *) > @@ -5694,7 +5712,7 @@ note_strp_offset2 (unsigned int off) >      { >        p = debug_sections[DEBUG_STR].data + off; >        len = strlen ((char *) p); > -      hash = iterative_hash (p, len, 0); > +      hash = hash (p, len); >        if (htab_find_with_hash (alt_strp_htab, p, hash)) >          return dwarf_5 ? DW_FORM_strp_sup : DW_FORM_GNU_strp_alt; >      } > @@ -5704,7 +5722,7 @@ note_strp_offset2 (unsigned int off) >      return DW_FORM_strp; >    p = debug_sections[DEBUG_STR].data + off; >    q = (unsigned char *) strchr ((char *) p, '\0'); > -  hash = iterative_hash (p, q - p, 0); > +  hash = hash (p, q - p); >    se.off = off; >    se.new_off = hash & ~1U; >    struct strp_entry *s = (struct strp_entry *) > @@ -5860,7 +5878,7 @@ finalize_strp (bool build_tail_offset_list) > >      memcpy (p, debug_sections[DEBUG_STR].data + arr[i]->off, len); >      slot = htab_find_slot_with_hash (strp_htab, p, > -                     iterative_hash (p, len - 1, 0), > +                     hash (p, len - 1), >                       INSERT); >      if (slot == NULL) >        dwz_oom (); > @@ -5876,7 +5894,7 @@ finalize_strp (bool build_tail_offset_list) >            if (tail_offset_list != NULL) >          tail_offset_list[k++] = arr[j]->new_off; >            slot = htab_find_slot_with_hash (strp_htab, q, > -                           iterative_hash (q, l - 1, 0), > +                           hash (q, l - 1), >                             INSERT); >            if (slot == NULL) >          dwz_oom (); > @@ -9849,17 +9867,16 @@ line_htab_lookup (dw_cu_ref cu, unsigned int id) >  { >    void **slot; >    struct line_entry le; > -  hashval_t h; > - >    if (id == 0) >      return 0; >    assert (id <= cu->cu_nfiles); >    le.file = &cu->cu_files[id - 1]; > -  h = iterative_hash_object (le.file->time, 0); > -  h = iterative_hash_object (le.file->size, h); > -  h = iterative_hash (le.file->file, strlen (le.file->file) + 1, h); > +  hash_init_state (); > +  hash_update_state (le.file->time); > +  hash_update_state (le.file->size); > +  hash_update_state_object (le.file->file, strlen (le.file->file) + 1); >    if (le.file->dir) > -    h = iterative_hash (le.file->dir, strlen (le.file->dir) + 1, h); > +    hash_update_state_object (le.file->dir, strlen (le.file->dir) + 1); >    if (line_htab == NULL) >      { >        line_htab = htab_try_create (50, line_hash, line_eq, NULL); > @@ -9867,15 +9884,15 @@ line_htab_lookup (dw_cu_ref cu, unsigned int id) >      dwz_oom (); >        max_line_id = 1; >      } > -  le.hash = h; > -  slot = htab_find_slot_with_hash (line_htab, &le, h, INSERT); > +  le.hash = hash_digest ();; > +  slot = htab_find_slot_with_hash (line_htab, &le, le.hash, INSERT); >    if (slot == NULL) >      dwz_oom (); >    if (*slot == NULL) >      { >        struct line_entry *l = pool_alloc (line_entry, sizeof (*l)); >        l->file = le.file; > -      l->hash = h; > +      l->hash = le.hash; >        l->new_id = max_line_id++; >        *slot = (void *) l; >        return l->new_id; > @@ -10347,7 +10364,7 @@ handle_macro (void) >            /* This should only happen if there were multiple >               same transparent units within a single object file.  */ >            && htab_find_with_hash (strp_htab, p, > -                      iterative_hash (p, len, 0)) == NULL) > +                      hash (p, len)) == NULL) >          can_share = false; >            s = ptr; >            break; > @@ -15756,7 +15773,7 @@ optimize_multifile (unsigned int *die_count) >        hashval_t hash; > >        q = (unsigned char *) strchr ((char *) p, '\0'); > -      hash = iterative_hash (p, q - p, 0); > +      hash = hash (p, q - p); >        se.off = p - debug_sections[DEBUG_STR].data; >        se.new_off = hash & ~1U; >        slot = htab_find_slot_with_hash (strp_htab, &se, se.new_off, INSERT); > @@ -16076,8 +16093,7 @@ read_multifile (int fd, unsigned int die_count) >          { >            q = (unsigned char *) strchr ((char *) p, '\0') + 1; >            slot = htab_find_slot_with_hash (strp_htab, p, > -                           iterative_hash (p, q - p - 1, > -                                   0), INSERT); > +                           hash (p, q - p - 1), INSERT); >            if (slot == NULL) >          dwz_oom (); >            assert (*slot == NULL); > @@ -16090,8 +16106,7 @@ read_multifile (int fd, unsigned int die_count) >            p = debug_sections[DEBUG_STR].data + *pi; >            q = (unsigned char *) strchr ((char *) p, '\0'); >            slot = htab_find_slot_with_hash (strp_htab, p, > -                           iterative_hash (p, q - p, > -                                   0), INSERT); > +                           hash (p, q - p), INSERT); >            if (slot == NULL) >              dwz_oom (); >            assert (*slot == NULL); > diff --git a/hashtab.c b/hashtab.c > index 41eab30..a9b9d13 100644 > --- a/hashtab.c > +++ b/hashtab.c > @@ -626,142 +626,3 @@ htab_restore (htab, name, restorefn) >    fclose (f); >  } >  #endif > - > -/* DERIVED FROM: > --------------------------------------------------------------------- > -lookup2.c, by Bob Jenkins, December 1996, Public Domain. > -hash(), hash2(), hash3, and mix() are externally useful functions. > -Routines to test the hash are included if SELF_TEST is defined. > -You can use this free for any purpose.  It has no warranty. > --------------------------------------------------------------------- > -*/ > - > -/* > --------------------------------------------------------------------- > -mix -- mix 3 32-bit values reversibly. > -For every delta with one or two bit set, and the deltas of all three > -  high bits or all three low bits, whether the original value of a,b,c > -  is almost all zero or is uniformly distributed, > -* If mix() is run forward or backward, at least 32 bits in a,b,c > -  have at least 1/4 probability of changing. > -* If mix() is run forward, every bit of c will change between 1/3 and > -  2/3 of the time.  (Well, 22/100 and 78/100 for some 2-bit deltas.) > -mix() was built out of 36 single-cycle latency instructions in a > -  structure that could supported 2x parallelism, like so: > -      a -= b; > -      a -= c; x = (c>>13); > -      b -= c; a ^= x; > -      b -= a; x = (a<<8); > -      c -= a; b ^= x; > -      c -= b; x = (b>>13); > -      ... > -  Unfortunately, superscalar Pentiums and Sparcs can't take advantage > -  of that parallelism.  They've also turned some of those single-cycle > -  latency instructions into multi-cycle latency instructions.  Still, > -  this is the fastest good hash I could find.  There were about 2^^68 > -  to choose from.  I only looked at a billion or so. > --------------------------------------------------------------------- > -*/ > -/* same, but slower, works on systems that might have 8 byte hashval_t's */ > -#define mix(a,b,c) \ > -{ \ > -  a -= b; a -= c; a ^= (c>>13); \ > -  b -= c; b -= a; b ^= (a<< 8); \ > -  c -= a; c -= b; c ^= ((b&0xffffffff)>>13); \ > -  a -= b; a -= c; a ^= ((c&0xffffffff)>>12); \ > -  b -= c; b -= a; b = (b ^ (a<<16)) & 0xffffffff; \ > -  c -= a; c -= b; c = (c ^ (b>> 5)) & 0xffffffff; \ > -  a -= b; a -= c; a = (a ^ (c>> 3)) & 0xffffffff; \ > -  b -= c; b -= a; b = (b ^ (a<<10)) & 0xffffffff; \ > -  c -= a; c -= b; c = (c ^ (b>>15)) & 0xffffffff; \ > -} > - > -/* > --------------------------------------------------------------------- > -hash() -- hash a variable-length key into a 32-bit value > -  k     : the key (the unaligned variable-length array of bytes) > -  len   : the length of the key, counting by bytes > -  level : can be any 4-byte value > -Returns a 32-bit value.  Every bit of the key affects every bit of > -the return value.  Every 1-bit and 2-bit delta achieves avalanche. > -About 36+6len instructions. > - > -The best hash table sizes are powers of 2.  There is no need to do > -mod a prime (mod is sooo slow!).  If you need less than 32 bits, > -use a bitmask.  For example, if you need only 10 bits, do > -  h = (h & hashmask(10)); > -In which case, the hash table should have hashsize(10) elements. > - > -If you are hashing n strings (ub1 **)k, do it like this: > -  for (i=0, h=0; i - > -By Bob Jenkins, 1996.  bob_jenkins@burtleburtle.net.  You may use this > -code any way you wish, private, educational, or commercial.  It's free. > - > -See http://burtleburtle.net/bob/hash/evahash.html > -Use for hash table lookup, or anything where one collision in 2^32 is > -acceptable.  Do NOT use for cryptographic purposes. > --------------------------------------------------------------------- > -*/ > - > -hashval_t > -iterative_hash (const void *k_in /* the key */, > -                register size_t  length /* the length of the key */, > -                register hashval_t initval /* the previous hash, or > -                                              an arbitrary value */) > -{ > -  register const unsigned char *k = (const unsigned char *)k_in; > -  register hashval_t a,b,c,len; > - > -  /* Set up the internal state */ > -  len = length; > -  a = b = 0x9e3779b9;  /* the golden ratio; an arbitrary value */ > -  c = initval;           /* the previous hash value */ > - > -  /*---------------------------------------- handle most of the key */ > -#ifndef WORDS_BIGENDIAN > -  /* On a little-endian machine, if the data is 4-byte aligned we can hash > -     by word for better speed.  This gives nondeterministic results on > -     big-endian machines.  */ > -  if (sizeof (hashval_t) == 4 && (((size_t)k)&3) == 0) > -    while (len >= 12)    /* aligned */ > -      { > -    a += *(hashval_t *)(k+0); > -    b += *(hashval_t *)(k+4); > -    c += *(hashval_t *)(k+8); > -    mix(a,b,c); > -    k += 12; len -= 12; > -      } > -  else /* unaligned */ > -#endif > -    while (len >= 12) > -      { > -    a += (k[0] +((hashval_t)k[1]<<8) +((hashval_t)k[2]<<16) +((hashval_t)k[3]<<24)); > -    b += (k[4] +((hashval_t)k[5]<<8) +((hashval_t)k[6]<<16) +((hashval_t)k[7]<<24)); > -    c += (k[8] +((hashval_t)k[9]<<8) +((hashval_t)k[10]<<16)+((hashval_t)k[11]<<24)); > -    mix(a,b,c); > -    k += 12; len -= 12; > -      } > - > -  /*------------------------------------- handle the last 11 bytes */ > -  c += length; > -  switch(len)              /* all the case statements fall through */ > -    { > -    case 11: c+=((hashval_t)k[10]<<24);    /* fall through */ > -    case 10: c+=((hashval_t)k[9]<<16);    /* fall through */ > -    case 9 : c+=((hashval_t)k[8]<<8);    /* fall through */ > -      /* the first byte of c is reserved for the length */ > -    case 8 : b+=((hashval_t)k[7]<<24);    /* fall through */ > -    case 7 : b+=((hashval_t)k[6]<<16);    /* fall through */ > -    case 6 : b+=((hashval_t)k[5]<<8);    /* fall through */ > -    case 5 : b+=k[4];            /* fall through */ > -    case 4 : a+=((hashval_t)k[3]<<24);    /* fall through */ > -    case 3 : a+=((hashval_t)k[2]<<16);    /* fall through */ > -    case 2 : a+=((hashval_t)k[1]<<8);    /* fall through */ > -    case 1 : a+=k[0]; > -      /* case 0: nothing left to add */ > -    } > -  mix(a,b,c); > -  /*-------------------------------------------- report the result */ > -  return c; > -} > diff --git a/hashtab.h b/hashtab.h > index cb3da01..509e627 100644 > --- a/hashtab.h > +++ b/hashtab.h > @@ -153,9 +153,11 @@ extern void    htab_restore (htab_t, const char *, htab_restorefn); > >  #endif > > -/* An iterative hash function for arbitrary data.  */ > -extern hashval_t iterative_hash (const void *, size_t, hashval_t); > +#include > + >  /* Shorthand for hashing something with an intrinsic size.  */ > +#define hash(IN,LEN) XXH64(IN, LEN, 0) > +#define iterative_hash(IN,LEN,INIT) XXH64(IN, LEN, INIT) >  #define iterative_hash_object(OB,INIT) iterative_hash (&OB, sizeof (OB), INIT) > >  #ifdef __cplusplus