If the operands of a select instruction are identical, then this select can be replaced by its operand. If the condition of a select is a constant, the this select can be replaced by one of its condition, depending on the truth value of the condition. This simplification is already done but: * when src1 == src2, the condition's value is tested although it may not be a constant. It's kinda OK because in all case one of the operand will be selected and both are identical but it's a bit weird and unclean. * since the instruction will be replaced, the usage of its condition and operands must be removed. This is done here but the kill_instruction() inside replace_with_pseudo() take already care of this. So, separate the two cases and simply use replace_with_pseudo() for both without bothering killing the operands. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>