* config/rs6000/rs6000-opts.h (enum processor_type): Add
        PROCESSOR_PPC8548.
        * config/rs6000/rs6000-cpus.def: Reference it for cpu="8548".
        * config/rs6000/rs6000.md (cpu attribute definition): Add ppc8548.
        * config/rs6000/8540.md: indicate that the units/patterns apply to
        ppc8548 as well.

        * config/rs6000/rs6000.c (rs6000_option_override_internal): Rename
        default_cpu into implicit_cpu, conveying what --with-cpu was passed at
        configure time. Treat implicit_cpu as have_CPU. Pick defaults for SPE
        related flags,  check that what is queried is supported by the selected
        configuration. Rework the single/double_float and MASK_STRING resets to
        hit for all the E500 cores (854x + E500MC variants). Select the ppc8540
        costs for PROCESSOR_PPC8548 as well.
        (rs6000_issue_rate): case CPU_PPC8548 together with CPU_PPC8540.
        (rs6000_use_sched_lookahead): Likewise, rewriting function as a case
        statement instead of a sequence of ifs.

        * config/rs6000/rs6000.h (TARGET_E500): Remove.
        (TARGET_NO_LWSYNC): Adjust accordingly.
        * config/rs6000/e500.h (TARGET_E500): Remove.
        (CHECK_E500_OPTIONS): Adjust accordingly.
        * config/rs6000/eabispe.h (SUBSUBTARGET_OVERRIDE_OPTIONS): Remove.
        (TARGET_DEFAULT): Reformat definition to match the one in linuxspe.h.
        * config/rs6000/linuxspe.h: Likewise.
        * config/rs6000/vxworks.h: Remove bogus TARGET_E500 overrides and
        superfluous comments.
        * config/rs6000/e500-double.h: Remove.

        * config.gcc (pick a default with_cpu): For powerpc*-*-*spe*,
        default to with_cpu=8548 if --enable-e500-double, and to 8540
        otherwise.
        (set misc flags section): For powerpc*|rs6000*, remove inclusion
        of e500-double.h for --enable-e500-double.

From-SVN: r187581