* expr.c (compress_float_constant): New.
        (emit_move_insn): Use it.
        (float_extend_from_mem): New.
        (init_expr_once): Initialize it.
        * real.c (exact_real_truncate): New.

        * config/i386/i386.h (CONST_COSTS): Assume CONST_DOUBLE gets
        dropped into memory; penalize for size.
        (RTX_COSTS): FLOAT_EXTEND is free.
        * config/i386/i386.md (extendsfdf2, extendsfxf2, extendsftf2,
        extenddfxf2, extenddftf2): Accept constants and drop them to memory.

From-SVN: r53401