The following patch fixes

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56184

The problem was in that reg equiv was not corrected for a split pseudo 
because of incorrect code for recognition of situation when a split 
pseudo was created.

The patch was successfully bootstrapped and tested on x86/x86-64.

Committed as rev. 196019.

2013-02-13  Vladimir Makarov  <vmakarov@redhat.com>

         PR target/56184
         * ira.c (max_regno_before_ira): Move from ...
         (ira): ... here.
         (fix_reg_equiv_init): Use max_regno_before_ira instead of
         vec_safe_length.

2013-02-13  Vladimir Makarov  <vmakarov@redhat.com>

         PR target/56184
         * gcc.target/arm/pr56184.C: New test.