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elf/dl-lookup.c: Use __glibc_likely and __glibc_unlikely 

Convert all uses of __builtin_expect to __glibc_likely and
__glibc_unlikely. Most of these are trivial boolean expressions
but a few were not. In particular the use of __builtin_expect in
the switch expression in do_lookup_x has been removed. Verified
that there are no code changes on x86_64 and ARM aside from line
numbers.

ChangeLog:

2014-06-23  Will Newton  <will.newton@linaro.org>

	* elf/dl-lookup.c: Use __glibc_unlikely and __glibc_likely
	rather than __builtin_expect.
hjl/release/2.20/master
Will Newton 12 years ago
parent
d6d0622554
commit
cc7d044752
2 changed files with 22 additions and 20 deletions
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  1. 3
      ChangeLog
  2. 39
      elf/dl-lookup.c

3
ChangeLog
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@ -1,5 +1,8 @@
2014-06-23 Will Newton <will.newton@linaro.org>
* elf/dl-lookup.c: Use __glibc_unlikely and __glibc_likely
rather than __builtin_expect.
* elf/dl-lookup.c (undefined_msg): Remove variable.
(_dl_lookup_symbol_x): Replace undefined_msg with string
literal.

39
elf/dl-lookup.c
View File

@ -92,11 +92,10 @@ check_match (const char *const undef_name,
{
unsigned int stt = ELFW(ST_TYPE) (sym->st_info);
assert (ELF_RTYPE_CLASS_PLT == 1);
if (__builtin_expect ((sym->st_value == 0 /* No value. */
if (__glibc_unlikely ((sym->st_value == 0 /* No value. */
&& stt != STT_TLS)
|| ELF_MACHINE_SYM_NO_MATCH (sym)
|| (type_class & (sym->st_shndx == SHN_UNDEF)),
0))
|| (type_class & (sym->st_shndx == SHN_UNDEF))))
return NULL;
/* Ignore all but STT_NOTYPE, STT_OBJECT, STT_FUNC,
@ -405,8 +404,8 @@ do_lookup_x (const char *undef_name, uint_fast32_t new_hash,
unsigned int hashbit2 = ((new_hash >> map->l_gnu_shift)
& (__ELF_NATIVE_CLASS - 1));
if (__builtin_expect ((bitmask_word >> hashbit1)
& (bitmask_word >> hashbit2) & 1, 0))
if (__glibc_unlikely ((bitmask_word >> hashbit1)
& (bitmask_word >> hashbit2) & 1))
{
Elf32_Word bucket = map->l_gnu_buckets[new_hash
% map->l_nbuckets];
@ -461,7 +460,7 @@ do_lookup_x (const char *undef_name, uint_fast32_t new_hash,
if (sym != NULL)
{
found_it:
switch (__builtin_expect (ELFW(ST_BIND) (sym->st_info), STB_GLOBAL))
switch (ELFW(ST_BIND) (sym->st_info))
{
case STB_WEAK:
/* Weak definition. Use this value if we don't find another. */
@ -495,7 +494,7 @@ do_lookup_x (const char *undef_name, uint_fast32_t new_hash,
/* If this current map is the one mentioned in the verneed entry
and we have not found a weak entry, it is a bug. */
if (symidx == STN_UNDEF && version != NULL && version->filename != NULL
&& __builtin_expect (_dl_name_match_p (version->filename, map), 0))
&& __glibc_unlikely (_dl_name_match_p (version->filename, map)))
return -1;
}
while (++i < n);
@ -776,7 +775,7 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map,
if (res > 0)
break;
if (__builtin_expect (res, 0) < 0 && skip_map == NULL)
if (__glibc_unlikely (res < 0) && skip_map == NULL)
{
/* Oh, oh. The file named in the relocation entry does not
contain the needed symbol. This code is never reached
@ -857,7 +856,7 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map,
in the global scope which was dynamically loaded. In this case
we have to prevent the latter from being unloaded unless the
UNDEF_MAP object is also unloaded. */
if (__builtin_expect (current_value.m->l_type == lt_loaded, 0)
if (__glibc_unlikely (current_value.m->l_type == lt_loaded)
/* Don't do this for explicit lookups as opposed to implicit
runtime lookups. */
&& (flags & DL_LOOKUP_ADD_DEPENDENCY) != 0
@ -874,8 +873,8 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map,
if (__glibc_unlikely (current_value.m->l_used == 0))
current_value.m->l_used = 1;
if (__builtin_expect (GLRO(dl_debug_mask)
& (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK), 0))
if (__glibc_unlikely (GLRO(dl_debug_mask)
& (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK)))
_dl_debug_bindings (undef_name, undef_map, ref,
&current_value, version, type_class, protected);
@ -892,9 +891,9 @@ _dl_setup_hash (struct link_map *map)
{
Elf_Symndx *hash;
if (__builtin_expect (map->l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM
if (__glibc_likely (map->l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM
+ DT_THISPROCNUM + DT_VERSIONTAGNUM
+ DT_EXTRANUM + DT_VALNUM] != NULL, 1))
+ DT_EXTRANUM + DT_VALNUM] != NULL))
{
Elf32_Word *hash32
= (void *) D_PTR (map, l_info[DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM
@ -973,10 +972,10 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map,
type_class, undef_map);
if (val.s != value->s || val.m != value->m)
conflict = 1;
else if (__builtin_expect (undef_map->l_symbolic_in_local_scope, 0)
else if (__glibc_unlikely (undef_map->l_symbolic_in_local_scope)
&& val.s
&& __builtin_expect (ELFW(ST_BIND) (val.s->st_info),
STB_GLOBAL) == STB_GNU_UNIQUE)
&& __glibc_unlikely (ELFW(ST_BIND) (val.s->st_info)
== STB_GNU_UNIQUE))
{
/* If it is STB_GNU_UNIQUE and undef_map's l_local_scope
contains any DT_SYMBOLIC libraries, unfortunately there
@ -1010,11 +1009,11 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map,
if (value->s)
{
if (__builtin_expect (ELFW(ST_TYPE) (value->s->st_info)
== STT_TLS, 0))
if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info)
== STT_TLS))
type_class = 4;
else if (__builtin_expect (ELFW(ST_TYPE) (value->s->st_info)
== STT_GNU_IFUNC, 0))
else if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info)
== STT_GNU_IFUNC))
type_class |= 8;
}

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