According to gcc-4.3.0/gcc/config/rs6000/crtsavres.asm R13 is volatile

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4779 c046a42c-6fe2-441c-8c8c-71466251a162

tcg/ppc/tcg-target.c

@@ -118,7 +118,6 @@ static const int tcg_target_call_oarg_regs[2] = {
 };
 
 static const int tcg_target_callee_save_regs[] = {
-    TCG_REG_R13,                /* should r13 be saved? */
     TCG_REG_R14,
     TCG_REG_R15,
     TCG_REG_R16,