[c/c++] i686 codegen bugs in tinfo2.cc

[Benjamin Kosnik <bkoz at redhat dot com>]

The following c++ testfailures only occur with i686, and not on
i586. I'm hoping that the x86 port maintainers can help me out....

-r 8    0.175   16064   1948    356330  22_locale/operators.cc
 __throw_type_match_rtti_2

-r 6    0.128   18896   2044    320303  27_io/ios_base_callbacks.cc
std::locale::_Impl::_Impl(std::locale::_Impl const&,
                          std::string const&, unsigned, unsigned)
std::string::compare(char const*) const
std::string::_M_mutate(unsigned, unsigned, unsigned) // strlen len2 == toobig

-r 7    0.000   28064   2588    423303  27_io/ios_manip_fmtflags.cc
__throw_type_match_rtti_2 

-r 9    0.227   40464   3580    428996  27_io/istream_extractor_arith.cc
 __throw_type_match_rtti_2

Of these, most die in __throw_type_match_rtti_2. Comparing the
assembly of this file (tinfo2.cc in libsupc++, part of libstdc++-v3)
tinfo2.cc:226

extern "C" int
__throw_type_match_rtti_2 (const void *catch_type_r, const void *throw_type_r,
			 void *objptr, void **valp)
{
  const type_info &catch_type = *(const type_info *)catch_type_r;
  const type_info &throw_type = *(const type_info *)throw_type_r;

  *valp = objptr;

#if !defined(__GXX_ABI_VERSION) || __GXX_ABI_VERSION < 100
// old abi
[skip]
#else
// new abi  
  return catch_type.__do_catch (&throw_type, valp, 1);
#endif
  return 0;
}

I get:

// i585
00000000 <__throw_type_match_rtti_2>:
   0:   55                      push   %ebp
   1:   89 e5                   mov    %esp,%ebp
   3:   51                      push   %ecx
   4:   51                      push   %ecx
   5:   8b 4d 08                mov    0x8(%ebp),%ecx
   8:   8b 55 14                mov    0x14(%ebp),%edx
   b:   8b 45 10                mov    0x10(%ebp),%eax
   e:   89 02                   mov    %eax,(%edx)
  10:   8b 01                   mov    (%ecx),%eax
  12:   6a 01                   push   $0x1
  14:   52                      push   %edx
  15:   8b 55 0c                mov    0xc(%ebp),%edx
  18:   52                      push   %edx
  19:   51                      push   %ecx
  1a:   ff 50 10                call   *0x10(%eax)
  1d:   25 ff 00 00 00          and    $0xff,%eax
  22:   89 ec                   mov    %ebp,%esp
  24:   5d                      pop    %ebp
  25:   c3                      ret    
  26:   8d 76 00                lea    0x0(%esi),%esi
  29:   8d bc 27 00 00 00 00    lea    0x0(%edi,1),%edi

// i686
Disassembly of section .text.__throw_type_match_rtti_2:
00000000 <__throw_type_match_rtti_2>:
   0:   55                      push   %ebp
   1:   89 e5                   mov    %esp,%ebp
   3:   83 ec 08                sub    $0x8,%esp
   6:   8b 45 10                mov    0x10(%ebp),%eax
   9:   8b 4d 08                mov    0x8(%ebp),%ecx <---missing push %ecx
   c:   8b 55 14                mov    0x14(%ebp),%edx
   f:   89 02                   mov    %eax,(%edx)
  11:   8b 01                   mov    (%ecx),%eax
  13:   6a 01                   push   $0x1
  15:   52                      push   %edx
  16:   8b 55 0c                mov    0xc(%ebp),%edx
  19:   52                      push   %edx
  1a:   51                      push   %ecx
  1b:   ff 50 10                call   *0x10(%eax)
  1e:   89 ec                   mov    %ebp,%esp
  20:   5d                      pop    %ebp
  21:   0f b6 c0                movzbl %al,%eax
  24:   c3                      ret    
  25:   8d 74 26 00             lea    0x0(%esi,1),%esi
  29:   8d bc 27 00 00 00 00    lea    0x0(%edi,1),%edi

These fails have been present for some time now,
unfortunately. Looking back through my testresults, I see that

+ 20001030-mkcheck.txt 
+ 20001112-mkcheck.txt 
+ 20001127-mkcheck.txt
(results in between here for shared go + and -) 
- 20001231-mkcheck.txt-gcc 

so that sometime in the last month something happened where
i686 started getting weird with c++ code...

any ideas?

-benjamin