2008-09-24  Michael J. Eager  <eager@eagercon.com>

        * config/rs6000/predicates.md (easy_fp_constant): Single FP consts
        are easy.
        * config/rs6000/rs6000.c (rs6000_override_options): Move
        rs6000_init_hard_regno_mode_ok after all options changed.
        Set rs6000_single_float, rs6000_double_float if TARGET_HARD_FLOAT.
        (rs6000_handle_option): Process -msingle-float, -mdouble-float,
        -msimple-fpu flags.  Add warning messages if single FP not configured.
        (rs6000_file_start): Output gnu_attribute for single-float.
        (legitimate_lo_sum_address_p): Condition on TARGET_DOUBLE_FLOAT.
        (rs6000_legitimize_address): Likewise.
        (rs6000_legitimize_reload_address): Likewise.
        (rs6000_emit_move): Condition on TARGET_DOUBLE_FLOAT,
        TARGET_SINGLE_FLOAT.
        (function_arg_advance): Likewise.
        (function_arg): Likewise.
        (setup_incoming_varargs): Condition on TARGET_DOUBLE_FLOAT.
        (rs6000_gimplify_va_arg): Condition on TARGET_DOUBLE_FLOAT,
        TARGET_SINGLE_FLOAT.
        (rs6000_split_multireg_move): Condition on TARGET_DOUBLE_FLOAT.
        (rs6000_emit_prologue): Likewise.
        (rs6000_function_value): Condition on TARGET_DOUBLE_FLOAT,
        TARGET_SINGLE_FLOAT.
        (rs6000_libcall_value): Likewise.
        * config/rs6000/rs6000.h (TARGET_SINGLE_FLOAT): New default to 1.
        (TARGET_DOUBLE_FLOAT): New default to 1
        (TARGET_SIMPLE_FPU): New default to 0
        (TARGET_SINGLE_FPU): New default to 0
        (TARGET_SINGLE_FLOAT_MODE): New.
        (TARGET_DOUBLE_FLOAT_MODE): New.
        * config/rs6000/singlefp.h: New; redefine TARGET_SINGLE_FLOAT,
        TARGET_DOUBLE_FLOAT, TARGET_SIMPLE_FPU, TARGET_SINGLE_FPU,
        UNITS_PER_FP_WORD
        * config/rs6000/rs6000.md (define_mode_iterator): Condition on
        TARGET_DOUBLE_FLOAT, TARGET_SINGLE_FLOAT.
        (extendsfdf2, extendsfdf2_fpr, truncdfsf2, truncdfsf2_fpr,
        copysigndf3,fseldfsf4, negdf2, negdf2_fpr, absdf2, absdf2_fpr,
        nabsdf2_fpr, adddf3, adddf3_fpr, subdf3, subdf3_fpr, muldf3,
        muldf3_fpr, divdf3, divdf3_fpr, sqrtdf2, smaxdf3, smindf3,
        movdfcc, *fseldfdf4, floatsidf2, *floatsidf2_internal,
        floatunssidf2, *floatunssidf2_internal, fix_truncdfsi2,
        *fix_truncdfsi2_internal, fix_truncdfsi2_internal_gfxopt,
        fix_truncdfsi2_mfpgpr, fctiwz, btruncdf2, ceildf2, floordf2,
        rounddf2, floatdidf2, floatsidf_ppc64_mfpgpr, floatsidf_ppc64,
        floatunssidf_ppc64, fix_truncdfdi2, movdf_hardfloat32,
        movdf_hardfloat64_mfpgpr, movdf_hardfloat64, extenddftf2_fprs,
        extenddftf2_internal, trunctfdf2_internal2, fix_trunc_helper,
        abstf2_internal, movdf_update1, movdf_update2, cmpdf_internal1,
        cmptf_internal1, *cmptf_internal2): Condition on
        TARGET_DOUBLE_FLOAT.
        (aux_truncdfsf2, negsf2, *negsf2, abssf2, *abssf2, addsf3, subsf3,
        mulsf3, divsf3, sqrtsf2, copysignsf3, smaxsf3, sminsf3, movsfcc,
        *fselsfsf4, fixuns_truncsfsi2, fix_truncsfsi2, floatunssisf2,
        btruncsf2, ceilsf2, floorsf2, roundsf2, floatdisf2_internal1,
        floatdisf2_internal2, *movsf_hardfloat, trunctfsf2_fprs,
        *movsf_update1, *movsf_update2, *cmpsf_internal1): Condition on
        TARGET_SINGLE_FLOAT.
        (divsf3, sqrtsf2, divdf3, divdf3_fpr): Condition on TARGET_SIMPLE_FPU.
        * config/rs6000/rs6000.opt (-msingle-float): New.
        (-mdouble-float): New.
        (-msimple-fpu): New.
        * doc/invoke.texi (RS/6000 and PowerPC Options): Add
        -msingle-float, -mdouble-float, -msimple-fpu options.
        * config/rs6000/rs6000-c.c (rs6000_cpu_cpp_builtins): Set
        _SOFT_DOUBLE for -msingle-float.
        * config.gcc: New config for target=powerpc-xilinx-eabi.

From-SVN: r140632