[Bug pch/53880] [4.8 Regression] compile time regression when generating precompiled headers for boost

["markus at trippelsdorf dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53880

--- Comment #3 from Markus Trippelsdorf <markus at trippelsdorf dot de> 2012-07-08 07:08:13 UTC ---
Unfortunately jimis' patch from Bug 53525 doesn't help much:

c++ -c -o pch.hpp.gch /usr/include/boost/math/special_functions.hpp  156.69s
user 0.33s system 99% cpu 2:37.50 total

From "perf top":

 99.78%  cc1plus       [.] gt_pch_p_9line_maps
  0.04%  cc1plus       [.] htab_find_with_hash
  0.02%  cc1plus       [.] gt_pch_p_14lang_tree_node
  0.02%  libc-2.16.so  [.] fwrite_unlocked   â
  0.01%  libc-2.16.so  [.] __mempcpy
  0.01%  [kernel]      [k] do_timer 

Zoom into gt_pch_p_9line_maps:

       â         size_t l3 = (size_t)(((*x).info_macro).used);
       â         if ((*x).info_macro.maps != NULL) {
       â           size_t i3;
       â           for (i3 = 0; i3 != (size_t)(l3); i3++) {
  3.89 â109:   cmp    %rcx,%rbx
  3.69 â       nop
  3.15 â     â je     188
  3.11 â112:   mov    0x18(%rbp),%rax
  3.04 â       add    $0x1,%rbx
       â           break;
       â         }
       â     }
       â
       â     void
       â     gt_pch_p_9line_maps (ATTRIBUTE_UNUSED void *this_obj,
  2.76 â11a:   lea    (%rbx,%rbx,4),%r15
  3.53 â       shl    $0x3,%r15
       â       {
       â         size_t l3 = (size_t)(((*x).info_macro).used);
       â         if ((*x).info_macro.maps != NULL) {
       â           size_t i3;
       â           for (i3 = 0; i3 != (size_t)(l3); i3++) {
       â             switch (((*x).info_macro.maps[i3]).reason ==
LC_ENTER_MACRO)
  3.46 â       lea    (%rax,%r15,1),%rdi
  3.42 â       cmpb   $0x4,0x4(%rdi)
  4.40 â     â jne    100
       â               case 1:
       â                 {
       â                   size_t l4 = (size_t)(2 *
((*x).info_macro.maps[i3].d.macro).n_tokens);
       â                   {
       â                     union tree_node * x5 =
       â                       ((*x).info_macro.maps[i3].d.macro.macro) ?
HT_IDENT_TO_GCC_IDENT (HT_NODE (((*x).info_macro.maps[i3].d.macro.macro)))
  4.38 â       mov    0x8(%rdi),%rsi
  4.25 â       xor    %edx,%edx
  2.22 â       lea    -0x18(%rsi),%r8
  2.16 â       test   %rsi,%rsi
  2.68 â       cmovne %r8,%rdx
       â                     if ((void *)((*x).info_macro.maps) == this_obj)
  2.72 â       cmp    %rax,%r14
       â                 break;
       â               case 1:
       â                 {
       â                   size_t l4 = (size_t)(2 *
((*x).info_macro.maps[i3].d.macro).n_tokens);
       â                   {
       â                     union tree_node * x5 =
  2.62 â       mov    %rdx,0x18(%rsp)
       â                       ((*x).info_macro.maps[i3].d.macro.macro) ?
HT_IDENT_TO_GCC_IDENT (HT_NODE (((*x).info_macro.maps[i3].d.macro.macro)))
       â                     if ((void *)((*x).info_macro.maps) == this_obj)
  2.68 â     â je     1a0
       â                       op (&(x5), cookie);
       â                     (*x).info_macro.maps[i3].d.macro.macro = (x5) ?
CPP_HASHNODE (GCC_IDENT_TO_HT_IDENT ((x5))) : NULL;
  2.68 â147:   lea    0x18(%rdx),%rsi
  2.85 â       xor    %eax,%eax
  3.39 â       test   %rdx,%rdx
  3.11 â       cmovne %rsi,%rax
  3.23 â       mov    %rax,0x8(%rdi)
       â                   }
       â                   if ((*x).info_macro.maps[i3].d.macro.macro_locations
!= NULL) {
  5.10 â       mov    0x18(%rbp),%rax
  4.93 â       add    %rax,%r15
  5.48 â       cmpq   $0x0,0x18(%r15)
  3.57 â     â je     109
       â                     size_t i4;
       â                     for (i4 = 0; i4 != (size_t)(l4); i4++) {
       â                     }
       â                     if ((void *)((*x).info_macro.maps) == this_obj)
  3.20 â       cmp    %rax,%r14
  2.82 â     â jne    109
       â                       op
(&((*x).info_macro.maps[i3].d.macro.macro_locations), cookie);
       â       mov    %rcx,0x8(%rsp)
       â       lea    0x18(%r15),%rdi
       â       mov    %r13,%rsi
       â     â callq  *%r12
       â       mov    0x8(%rsp),%rcx
       â       }