https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63892

--- Comment #18 from Iain Sandoe <iains at gcc dot gnu.org> ---

so - next increment - simplification of the previous. 
(don't try to redirect callers if we don't have any) 

diff --git a/gcc/ipa-icf.c b/gcc/ipa-icf.c
index e1af8bf..ca19967 100644
--- a/gcc/ipa-icf.c
+++ b/gcc/ipa-icf.c
@@ -660,7 +660,8 @@ sem_function::merge (sem_item *alias_item)
       /* When both alias and original are not overwritable, we can save
          the extra thunk wrapper for direct calls.  */
       redirect_callers
-       = (!original_discardable
+       = (alias->callers
+          && !original_discardable
           && !DECL_COMDAT_GROUP (alias->decl)
           && alias->get_availability () > AVAIL_INTERPOSABLE
           && original->get_availability () > AVAIL_INTERPOSABLE


Unfortunately, we're still not there.
I think that we can have a situation where we remove an alias which happens to
be the version that the vtable is pointing to (and so end up with an
unsatisfied reference from the vtable and link time).  

However, I still haven't figured out how to redirect those references…
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Subject: [Bug target/65161] ICE: in vec<_haifa_insn_data, va_heap, vl_embed>::operator[], at vec.h:736 with -O3 -fselective-scheduling2 -mtune=slm
Date: Sun, 22 Feb 2015 13:11:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?ide161

--- Comment #1 from Zdenek Sojka <zsojka at seznam dot cz> ---
Created attachment 34834
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id4834&actioníit
testcase that doesn't need --param on cmd line

Compiler output:
$ gcc -O3 -fselective-scheduling2 -mtune=slm testcase.c
testcase.c: In function 'foo':
testcase.c:11:1: internal compiler error: in operator[], at vec.h:736
 }
 ^
0x5abcde vec<_haifa_insn_data, va_heap, vl_embed>::operator[](unsigned int)
        /mnt/svn/gcc-trunk/gcc/vec.h:736
0xf304c6 vec<_haifa_insn_data, va_heap, vl_embed>::operator[](unsigned int)
        /mnt/svn/gcc-trunk/gcc/config/i386/i386.c:26672
0xf304c6 vec<_haifa_insn_data, va_heap, vl_ptr>::operator[](unsigned int)
        /mnt/svn/gcc-trunk/gcc/vec.h:1202
0xf304c6 swap_top_of_ready_list
        /mnt/svn/gcc-trunk/gcc/config/i386/i386.c:26661
0xf304c6 ix86_sched_reorder
        /mnt/svn/gcc-trunk/gcc/config/i386/i386.c:26740
0xc0e83d invoke_reorder_hooks
        /mnt/svn/gcc-trunk/gcc/sel-sched.c:4129
0xc0e83d find_best_expr
        /mnt/svn/gcc-trunk/gcc/sel-sched.c:4406
0xc0e83d fill_insns
        /mnt/svn/gcc-trunk/gcc/sel-sched.c:5568
0xc0f73a schedule_on_fences
        /mnt/svn/gcc-trunk/gcc/sel-sched.c:7393
0xc0f73a sel_sched_region_2
        /mnt/svn/gcc-trunk/gcc/sel-sched.c:7531
0xc11025 sel_sched_region_1
        /mnt/svn/gcc-trunk/gcc/sel-sched.c:7573
0xc11025 sel_sched_region(int)
        /mnt/svn/gcc-trunk/gcc/sel-sched.c:7674
0xc12021 run_selective_scheduling()
        /mnt/svn/gcc-trunk/gcc/sel-sched.c:7750
0xbea6e5 rest_of_handle_sched2
        /mnt/svn/gcc-trunk/gcc/sched-rgn.c:3647
0xbea6e5 execute
        /mnt/svn/gcc-trunk/gcc/sched-rgn.c:3791
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