[Bug rtl-optimization/46114] [4.6 regression] g++ SEGV when built with gld on Solaris 10+/x86

["ro at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46114

Rainer Orth <ro at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.10.21 20:36:21
     Ever Confirmed|0                           |1

--- Comment #3 from Rainer Orth <ro at gcc dot gnu.org> 2010-10-21 20:36:21 UTC ---
I could reproduce the bug with the attached testcase (go.c with main,
pr46114.c reduced from g++spec.c).

Compile with

% gcc -O2 -o go go.c pr46114.c

After the culprit patch, the program prints

opt_index = 902 arg = 8049253 value = 1 lang_mask = 65536 decoded = 1
opt_index = 902 arg = 8049264 value = 1 lang_mask = 65536 decoded = 804a90c
opt_index = 1019 arg = 0 value = 1 lang_mask = 65536 decoded = 804a938

i.e. decoded (a pointer) is invalid.  Before, one gets

opt_index = 902 arg = 8049273 value = 1 lang_mask = 65536 decoded = 804a900
opt_index = 902 arg = 8049284 value = 1 lang_mask = 65536 decoded = 804a92c
opt_index = 1019 arg = 0 value = 1 lang_mask = 65536 decoded = 804a958

The bug is extremely sensitive to the details of the input, so I didn't try
to reduce it further.

Please fix, this is really ugly and makes gcc with gld completely useless.