示例#1
0
 def check_false(element):
     if element.get_precision() is ML_Bool:
         return LogicalNot(element, precision=ML_Bool)
     else:
         return Equal(
             element, Constant(0,
                               precision=element.get_precision()))
示例#2
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def get_output_check_statement(output_signal, output_tag, output_value):
    """ Generate output value check statement """
    test_pass_cond = Comparison(
        output_signal,
        output_value,
        specifier=Comparison.Equal,
        precision=ML_Bool
    )

    check_statement = ConditionBlock(
        LogicalNot(
            test_pass_cond,
            precision = ML_Bool
        ),
        Report(
            Concatenation(
                " result for {}: ".format(output_tag),
                Conversion(
                    output_signal if output_signal.get_precision() is ML_StdLogic else
                    TypeCast(
                        output_signal,
                        precision=ML_StdLogicVectorFormat(
                            output_signal.get_precision().get_bit_size()
                        )
                     ),
                    precision = ML_String
                    ),
                precision = ML_String
            )
        )
    )
    return test_pass_cond, check_statement
示例#3
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def simplify_logical_or_not(node, leaf_transform):
    """ Simplify a tree of LogicalOr nodes, whose
        leaf are LogicalNot nodes """

    # the leaf_function transforms a leaf by extracting
    # its single input (decapsulating LogicalNot) and
    # calling leaf_transform on this input
    def leaf_function(op):
        return leaf_transform(op.get_input(0))

    result = simplify_logical_tree(
        node,
        op_predicate=(lambda op: isinstance(op, LogicalOr)),
        leaf_predicate=(lambda op: isinstance(op, LogicalNot)),
        result_ctor=lambda op, op_list: LogicalNot(
            logical_reduce(list(map(leaf_transform, op_list)),
                           LogicalAnd,
                           precision=node.get_precision()),
            precision=node.get_precision()))
    forward_attributes(node, result)
    return result
    def generate_scheme(self):
        """ main scheme generation """
        input_precision = self.precision
        output_precision = self.precision

        # declaring main input variable
        x_interval = Interval(-10.3, 10.7)
        var_x = self.implementation.add_input_variable("x",
                                                       input_precision,
                                                       interval=x_interval)

        y_interval = Interval(-17.9, 17.2)
        var_y = self.implementation.add_input_variable("y",
                                                       input_precision,
                                                       interval=y_interval)

        z_interval = Interval(-70.3, -57.7)
        var_z = self.implementation.add_input_variable("z",
                                                       input_precision,
                                                       interval=z_interval)

        min_yz = Min(var_z, var_y)

        cst0 = Constant(42.5, tag="cst0", precision=self.precision)
        cst1 = Constant(2.5, tag="cst1", precision=self.precision)
        cst2 = Constant(12.5, tag="cst2", precision=self.precision)

        new_cst = cst0 + cst1 * cst2

        result = min_yz + new_cst

        scheme = ConditionBlock(
            LogicalAnd(
                LogicalOr(cst0 > cst1, LogicalNot(cst1 > cst0)),
                var_x > var_y,
            ), Return(result), Return(cst2))
        return scheme
示例#5
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    def generate_scalar_scheme(self, vx):
        Log.set_dump_stdout(True)

        Log.report(Log.Info, "\033[33;1m generating implementation scheme \033[0m")
        if self.debug_flag:
            Log.report(Log.Info, "\033[31;1m debug has been enabled \033[0;m")

        # local overloading of RaiseReturn operation
        def ExpRaiseReturn(*args, **kwords):
            kwords["arg_value"] = vx
            kwords["function_name"] = self.function_name
            if self.libm_compliant:
                return RaiseReturn(*args, precision=self.precision, **kwords)
            else:
                return Return(kwords["return_value"], precision=self.precision)

        test_nan_or_inf = Test(
            vx, specifier=Test.IsInfOrNaN, likely=False,
            debug=debug_multi, tag="nan_or_inf")
        test_nan = Test(
            vx, specifier=Test.IsNaN, debug=debug_multi, tag="is_nan_test")
        test_positive = Comparison(
            vx, 0, specifier=Comparison.GreaterOrEqual, debug=debug_multi,
            tag="inf_sign")

        test_signaling_nan = Test(
            vx, specifier=Test.IsSignalingNaN, debug=debug_multi,
            tag="is_signaling_nan")
        return_snan = Statement(
            ExpRaiseReturn(ML_FPE_Invalid, return_value=FP_QNaN(self.precision))
        )

        # return in case of infinity input
        infty_return = Statement(
            ConditionBlock(
                test_positive,
                Return(FP_PlusInfty(self.precision), precision=self.precision),
                Return(FP_PlusZero(self.precision), precision=self.precision)
            )
        )
        # return in case of specific value input (NaN or inf)
        specific_return = ConditionBlock(
            test_nan,
            ConditionBlock(
                test_signaling_nan,
                return_snan,
                Return(FP_QNaN(self.precision), precision=self.precision)
            ),
            infty_return)
        # return in case of standard (non-special) input

        # exclusion of early overflow and underflow cases
        precision_emax      = self.precision.get_emax()
        precision_max_value = S2 * S2**precision_emax
        exp_overflow_bound  = sollya.ceil(log(precision_max_value))
        early_overflow_test = Comparison(
            vx, exp_overflow_bound,
            likely=False, specifier=Comparison.Greater)
        early_overflow_return = Statement(
            ClearException() if self.libm_compliant else Statement(),
            ExpRaiseReturn(
                ML_FPE_Inexact, ML_FPE_Overflow,
                return_value=FP_PlusInfty(self.precision)
            )
        )

        precision_emin = self.precision.get_emin_subnormal()
        precision_min_value = S2 ** precision_emin
        exp_underflow_bound = floor(log(precision_min_value))

        early_underflow_test = Comparison(
            vx, exp_underflow_bound,
            likely=False, specifier=Comparison.Less)
        early_underflow_return = Statement(
            ClearException() if self.libm_compliant else Statement(),
            ExpRaiseReturn(
                ML_FPE_Inexact, ML_FPE_Underflow,
                return_value=FP_PlusZero(self.precision)))

        # constant computation
        invlog2 = self.precision.round_sollya_object(1/log(2), sollya.RN)

        interval_vx = Interval(exp_underflow_bound, exp_overflow_bound)
        interval_fk = interval_vx * invlog2
        interval_k = Interval(floor(inf(interval_fk)), sollya.ceil(sup(interval_fk)))


        log2_hi_precision = self.precision.get_field_size() - (sollya.ceil(log2(sup(abs(interval_k)))) + 2)
        Log.report(Log.Info, "log2_hi_precision: %d" % log2_hi_precision)
        invlog2_cst = Constant(invlog2, precision = self.precision)
        log2_hi = round(log(2), log2_hi_precision, sollya.RN)
        log2_lo = self.precision.round_sollya_object(log(2) - log2_hi, sollya.RN)

        # argument reduction
        unround_k = vx * invlog2
        unround_k.set_attributes(tag = "unround_k", debug = debug_multi)
        k = NearestInteger(unround_k, precision = self.precision, debug = debug_multi, tag="k")
        ik = NearestInteger(unround_k, precision = self.precision.get_integer_format(), debug = debug_multi, tag="ik")
        exact_pre_mul = (k * log2_hi)
        exact_pre_mul.set_attributes(exact= True)
        exact_hi_part = vx - exact_pre_mul
        exact_hi_part.set_attributes(exact = True, tag = "exact_hi", debug = debug_multi, prevent_optimization = True)
        exact_lo_part = - k * log2_lo
        exact_lo_part.set_attributes(tag = "exact_lo", debug = debug_multi, prevent_optimization = True)
        r =  exact_hi_part + exact_lo_part
        r.set_tag("r")
        r.set_attributes(debug = debug_multi)

        approx_interval = Interval(-log(2)/2, log(2)/2)

        approx_interval_half = approx_interval / 2
        approx_interval_split = [Interval(-log(2)/2, inf(approx_interval_half)), approx_interval_half, Interval(sup(approx_interval_half), log(2)/2)]

        # TODO: should be computed automatically
        exact_hi_interval = approx_interval
        exact_lo_interval = - interval_k * log2_lo

        opt_r = self.optimise_scheme(r, copy = {})

        tag_map = {}
        self.opt_engine.register_nodes_by_tag(opt_r, tag_map)

        cg_eval_error_copy_map = {
            vx: Variable("x", precision=self.precision, interval=interval_vx),
            tag_map["k"]: Variable("k", interval=interval_k, precision=self.precision)
        }

        #try:
        if gappa_utils.is_gappa_installed():
            eval_error = self.gappa_engine.get_eval_error_v2(
                self.opt_engine, opt_r, cg_eval_error_copy_map,
                gappa_filename=gappa_utils.generate_gappa_filename("red_arg.g"))
        else:
            eval_error = 0.0
            Log.report(Log.Warning, "gappa is not installed in this environnement")
        Log.report(Log.Info, "eval error: %s" % eval_error)


        local_ulp = sup(ulp(sollya.exp(approx_interval), self.precision))
        # FIXME refactor error_goal from accuracy
        Log.report(Log.Info, "accuracy: %s" % self.accuracy)
        if isinstance(self.accuracy, ML_Faithful):
            error_goal = local_ulp
        elif isinstance(self.accuracy, ML_CorrectlyRounded):
            error_goal = S2**-1 * local_ulp
        elif isinstance(self.accuracy, ML_DegradedAccuracyAbsolute):
            error_goal = self.accuracy.goal
        elif isinstance(self.accuracy, ML_DegradedAccuracyRelative):
            error_goal = self.accuracy.goal
        else:
            Log.report(Log.Error, "unknown accuracy: %s" % self.accuracy)


        # error_goal = local_ulp #S2**-(self.precision.get_field_size()+1)
        error_goal_approx = S2**-1 * error_goal

        Log.report(Log.Info, "\033[33;1m building mathematical polynomial \033[0m\n")
        poly_degree = max(sup(guessdegree(expm1(sollya.x)/sollya.x, approx_interval, error_goal_approx)) - 1, 2)
        init_poly_degree = poly_degree

        error_function = lambda p, f, ai, mod, t: dirtyinfnorm(f - p, ai)

        polynomial_scheme_builder = PolynomialSchemeEvaluator.generate_estrin_scheme
        #polynomial_scheme_builder = PolynomialSchemeEvaluator.generate_horner_scheme

        MAX_NUM_ITERATION = 20

        for _ in range(MAX_NUM_ITERATION):
            Log.report(Log.Info, "attempting poly degree: %d" % poly_degree)
            precision_list = [1] + [self.precision] * (poly_degree)
            poly_object, poly_approx_error = Polynomial.build_from_approximation_with_error(expm1(sollya.x), poly_degree, precision_list, approx_interval, sollya.absolute, error_function = error_function)
            Log.report(Log.Info, "polynomial: %s " % poly_object)
            sub_poly = poly_object.sub_poly(start_index = 2)
            Log.report(Log.Info, "polynomial: %s " % sub_poly)

            Log.report(Log.Info, "poly approx error: %s" % poly_approx_error)

            Log.report(Log.Info, "\033[33;1m generating polynomial evaluation scheme \033[0m")
            pre_poly = polynomial_scheme_builder(poly_object, r, unified_precision = self.precision)
            pre_poly.set_attributes(tag = "pre_poly", debug = debug_multi)

            pre_sub_poly = polynomial_scheme_builder(sub_poly, r, unified_precision = self.precision)
            pre_sub_poly.set_attributes(tag = "pre_sub_poly", debug = debug_multi)

            poly = 1 + (exact_hi_part + (exact_lo_part + pre_sub_poly))
            poly.set_tag("poly")

            # optimizing poly before evaluation error computation
            #opt_poly = self.opt_engine.optimization_process(poly, self.precision, fuse_fma = fuse_fma)
            #opt_sub_poly = self.opt_engine.optimization_process(pre_sub_poly, self.precision, fuse_fma = fuse_fma)
            opt_poly = self.optimise_scheme(poly)
            opt_sub_poly = self.optimise_scheme(pre_sub_poly)

            # evaluating error of the polynomial approximation
            r_gappa_var        = Variable("r", precision = self.precision, interval = approx_interval)
            exact_hi_gappa_var = Variable("exact_hi", precision = self.precision, interval = exact_hi_interval)
            exact_lo_gappa_var = Variable("exact_lo", precision = self.precision, interval = exact_lo_interval)
            vx_gappa_var       = Variable("x", precision = self.precision, interval = interval_vx)
            k_gappa_var        = Variable("k", interval = interval_k, precision = self.precision)


            #print "exact_hi interval: ", exact_hi_interval

            sub_poly_error_copy_map = {
                #r.get_handle().get_node(): r_gappa_var,
                #vx.get_handle().get_node():  vx_gappa_var,
                exact_hi_part.get_handle().get_node(): exact_hi_gappa_var,
                exact_lo_part.get_handle().get_node(): exact_lo_gappa_var,
                #k.get_handle().get_node(): k_gappa_var,
            }

            poly_error_copy_map = {
                exact_hi_part.get_handle().get_node(): exact_hi_gappa_var,
                exact_lo_part.get_handle().get_node(): exact_lo_gappa_var,
            }


            if gappa_utils.is_gappa_installed():
                sub_poly_eval_error = -1.0
                gappa_sub_poly_filename = gappa_utils.generate_gappa_filename("{}_gappa_sub_poly.g".format(self.function_name))
                sub_poly_eval_error = self.gappa_engine.get_eval_error_v2(self.opt_engine, opt_sub_poly, sub_poly_error_copy_map, gappa_filename =gappa_sub_poly_filename)

                dichotomy_map = [
                    {
                        exact_hi_part.get_handle().get_node(): approx_interval_split[0],
                    },
                    {
                        exact_hi_part.get_handle().get_node(): approx_interval_split[1],
                    },
                    {
                        exact_hi_part.get_handle().get_node(): approx_interval_split[2],
                    },
                ]
                gappa_poly_filename = gappa_utils.generate_gappa_filename("gappa_poly.g")
                poly_eval_error_dico = self.gappa_engine.get_eval_error_v3(self.opt_engine, opt_poly, poly_error_copy_map, gappa_filename=gappa_poly_filename, dichotomy = dichotomy_map)

                poly_eval_error = max([sup(abs(err)) for err in poly_eval_error_dico])
            else:
                poly_eval_error = 0.0
                sub_poly_eval_error = 0.0
                Log.report(Log.Warning, "gappa is not installed in this environnement")
                Log.report(Log.Info, "stopping autonomous degree research")
                # incrementing polynomial degree to counteract initial decrementation effect
                poly_degree += 1
                break
            Log.report(Log.Info, "poly evaluation error: %s" % poly_eval_error)
            Log.report(Log.Info, "sub poly evaluation error: %s" % sub_poly_eval_error)

            global_poly_error     = None
            global_rel_poly_error = None

            for case_index in range(3):
                poly_error = poly_approx_error + poly_eval_error_dico[case_index]
                rel_poly_error = sup(abs(poly_error / sollya.exp(approx_interval_split[case_index])))
                if global_rel_poly_error == None or rel_poly_error > global_rel_poly_error:
                    global_rel_poly_error = rel_poly_error
                    global_poly_error = poly_error
            flag = error_goal > global_rel_poly_error


            if flag:
                break
            else:
                poly_degree += 1

        late_overflow_test = Comparison(
            ik, self.precision.get_emax(),
            specifier=Comparison.Greater, likely=False,
            debug=debug_multi, tag="late_overflow_test")
        overflow_exp_offset = int(self.precision.get_emax() - self.precision.get_field_size() / 2)
        cst_overflow_exp_offset = Constant(overflow_exp_offset, precision=self.precision.get_integer_format())
        diff_k = Subtraction(
            ik,
            cst_overflow_exp_offset,
            precision=self.precision.get_integer_format(),
            debug=debug_multi,
            tag="diff_k",
        )
        late_overflow_result = (ExponentInsertion(diff_k, precision = self.precision) * poly) * ExponentInsertion(cst_overflow_exp_offset, precision = self.precision)
        late_overflow_result.set_attributes(silent = False, tag = "late_overflow_result", debug = debug_multi, precision = self.precision)
        late_overflow_return = ConditionBlock(Test(late_overflow_result, specifier = Test.IsInfty, likely = False), ExpRaiseReturn(ML_FPE_Overflow, return_value = FP_PlusInfty(self.precision)), Return(late_overflow_result, precision=self.precision))

        late_underflow_test = Comparison(k, self.precision.get_emin_normal(), specifier = Comparison.LessOrEqual, likely=False, tag="late_underflow_test")
        underflow_exp_offset = 2 * self.precision.get_field_size()
        corrected_exp = Addition(
          ik,
          Constant(
            underflow_exp_offset,
            precision=self.precision.get_integer_format()
          ),
          precision=self.precision.get_integer_format(),
          tag="corrected_exp"
        )
        late_underflow_result = (ExponentInsertion(corrected_exp, precision = self.precision) * poly) * ExponentInsertion(-underflow_exp_offset, precision = self.precision)
        late_underflow_result.set_attributes(debug = debug_multi, tag = "late_underflow_result", silent = False)
        test_subnormal = Test(late_underflow_result, specifier = Test.IsSubnormal)
        late_underflow_return = Statement(ConditionBlock(test_subnormal, ExpRaiseReturn(ML_FPE_Underflow, return_value = late_underflow_result)), Return(late_underflow_result, precision=self.precision))

        twok = ExponentInsertion(ik, tag = "exp_ik", debug = debug_multi, precision = self.precision)
        #std_result = twok * ((1 + exact_hi_part * pre_poly) + exact_lo_part * pre_poly) 
        std_result = twok * poly
        std_result.set_attributes(tag = "std_result", debug = debug_multi)
        std_cond = LogicalNot(LogicalOr(late_overflow_test, late_underflow_test), likely=True)

        result_scheme = ConditionBlock(
            std_cond,
            Return(std_result, precision=self.precision),
            ConditionBlock(
                late_overflow_test,
                late_overflow_return,
                late_underflow_return,
            )
        )
        std_return = ConditionBlock(early_overflow_test, early_overflow_return, ConditionBlock(early_underflow_test, early_underflow_return, result_scheme))

        # main scheme
        Log.report(Log.Info, "\033[33;1m MDL scheme \033[0m")
        scheme = ConditionBlock(
            test_nan_or_inf,
            Statement(
                ClearException() if self.libm_compliant else Statement(),
                specific_return
            ),
            std_return
        )

        return scheme
示例#6
0
    def generate_scalar_scheme(self, vx, vy):
        # fixing inputs' node tag
        vx.set_attributes(tag="x")
        vy.set_attributes(tag="y")

        int_precision = self.precision.get_integer_format()

        # assuming x = m.2^e (m in [1, 2[)
        #          n, positive or null integers
        #
        # pow(x, n) = x^(y)
        #             = exp(y * log(x))
        #             = 2^(y * log2(x))
        #             = 2^(y * (log2(m) + e))
        #
        e = ExponentExtraction(vx, tag="e", precision=int_precision)
        m = MantissaExtraction(vx, tag="m", precision=self.precision)

        # approximation log2(m)

        # retrieving processor inverse approximation table
        dummy_var = Variable("dummy", precision = self.precision)
        dummy_div_seed = ReciprocalSeed(dummy_var, precision = self.precision)
        inv_approx_table = self.processor.get_recursive_implementation(
            dummy_div_seed, language=None,
            table_getter= lambda self: self.approx_table_map)

        log_f = sollya.log(sollya.x) # /sollya.log(self.basis)



        ml_log_args = ML_GenericLog.get_default_args(precision=self.precision, basis=2)
        ml_log = ML_GenericLog(ml_log_args)
        log_table, log_table_tho, table_index_range = ml_log.generate_log_table(log_f, inv_approx_table)
        log_approx = ml_log.generate_reduced_log_split(Abs(m, precision=self.precision), log_f, inv_approx_table, log_table)

        log_approx = Select(Equal(vx, 0), FP_MinusInfty(self.precision), log_approx)
        log_approx.set_attributes(tag="log_approx", debug=debug_multi)
        r = Multiplication(log_approx, vy, tag="r", debug=debug_multi)


        # 2^(y * (log2(m) + e)) = 2^(y * log2(m)) * 2^(y * e)
        #
        # log_approx = log2(Abs(m))
        # r = y * log_approx ~ y * log2(m)
        #
        # NOTES: manage cases where e is negative and
        # (y * log2(m)) AND (y * e) could cancel out
        # if e positive, whichever the sign of y (y * log2(m)) and (y * e) CANNOT
        # be of opposite signs

        # log2(m) in [0, 1[ so cancellation can occur only if e == -1
        # we split 2^x in 2^x = 2^t0 * 2^t1
        # if e < 0: t0 = y * (log2(m) + e), t1=0
        # else:     t0 = y * log2(m), t1 = y * e

        t_cond = e < 0

        # e_y ~ e * y
        e_f = Conversion(e, precision=self.precision)
        #t0 = Select(t_cond, (e_f + log_approx) * vy, Multiplication(e_f, vy), tag="t0")
        #NearestInteger(t0, precision=self.precision, tag="t0_int")

        EY = NearestInteger(e_f * vy, tag="EY", precision=self.precision)
        LY = NearestInteger(log_approx * vy, tag="LY", precision=self.precision)
        t0_int = Select(t_cond, EY + LY, EY, tag="t0_int")
        t0_frac = Select(t_cond, FMA(e_f, vy, -EY) + FMA(log_approx, vy, -LY) ,EY - t0_int, tag="t0_frac")
        #t0_frac.set_attributes(tag="t0_frac")

        ml_exp2_args = ML_Exp2.get_default_args(precision=self.precision)
        ml_exp2 = ML_Exp2(ml_exp2_args)

        exp2_t0_frac = ml_exp2.generate_scalar_scheme(t0_frac, inline_select=True)
        exp2_t0_frac.set_attributes(tag="exp2_t0_frac", debug=debug_multi)

        exp2_t0_int = ExponentInsertion(Conversion(t0_int, precision=int_precision), precision=self.precision, tag="exp2_t0_int")

        t1 = Select(t_cond, Constant(0, precision=self.precision), r)
        exp2_t1 = ml_exp2.generate_scalar_scheme(t1, inline_select=True)
        exp2_t1.set_attributes(tag="exp2_t1", debug=debug_multi)

        result_sign = Constant(1.0, precision=self.precision) # Select(n_is_odd, CopySign(vx, Constant(1.0, precision=self.precision)), 1)

        y_int = NearestInteger(vy, precision=self.precision)
        y_is_integer = Equal(y_int, vy)
        y_is_even = LogicalOr(
            # if y is a number (exc. inf) greater than 2**mantissa_size * 2,
            # then it is an integer multiple of 2 => even
            Abs(vy) >= 2**(self.precision.get_mantissa_size()+1),
            LogicalAnd(
                y_is_integer and Abs(vy) < 2**(self.precision.get_mantissa_size()+1),
                # we want to limit the modulo computation to an integer input
                Equal(Modulo(Conversion(y_int, precision=int_precision), 2), 0)
            )
        )
        y_is_odd = LogicalAnd(
            LogicalAnd(
                Abs(vy) < 2**(self.precision.get_mantissa_size()+1),
                y_is_integer
            ),
            Equal(Modulo(Conversion(y_int, precision=int_precision), 2), 1)
        )


        # special cases management
        special_case_results = Statement(
            # x is sNaN OR y is sNaN
            ConditionBlock(
                LogicalOr(Test(vx, specifier=Test.IsSignalingNaN), Test(vy, specifier=Test.IsSignalingNaN)),
                Return(FP_QNaN(self.precision))
            ),
            # pow(x, ±0) is 1 if x is not a signaling NaN
            ConditionBlock(
                Test(vy, specifier=Test.IsZero),
                Return(Constant(1.0, precision=self.precision))
            ),
            # pow(±0, y) is ±∞ and signals the divideByZero exception for y an odd integer <0
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsZero), LogicalAnd(y_is_odd, vy < 0)),
                Return(Select(Test(vx, specifier=Test.IsPositiveZero), FP_PlusInfty(self.precision), FP_MinusInfty(self.precision))),
            ),
            # pow(±0, −∞) is +∞ with no exception
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsZero), Test(vy, specifier=Test.IsNegativeInfty)),
                Return(FP_MinusInfty(self.precision)),
            ),
            # pow(±0, +∞) is +0 with no exception
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsZero), Test(vy, specifier=Test.IsPositiveInfty)),
                Return(FP_PlusInfty(self.precision)),
            ),
            # pow(±0, y) is ±0 for finite y>0 an odd integer
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsZero), LogicalAnd(y_is_odd, vy > 0)),
                Return(vx),
            ),
            # pow(−1, ±∞) is 1 with no exception
            ConditionBlock(
                LogicalAnd(Equal(vx, -1), Test(vy, specifier=Test.IsInfty)),
                Return(Constant(1.0, precision=self.precision)),
            ),
            # pow(+1, y) is 1 for any y (even a quiet NaN)
            ConditionBlock(
                vx == 1,
                Return(Constant(1.0, precision=self.precision)),
            ),
            # pow(x, +∞) is +0 for −1<x<1
            ConditionBlock(
                LogicalAnd(Abs(vx) < 1, Test(vy, specifier=Test.IsPositiveInfty)),
                Return(FP_PlusZero(self.precision))
            ),
            # pow(x, +∞) is +∞ for x<−1 or for 1<x (including ±∞)
            ConditionBlock(
                LogicalAnd(Abs(vx) > 1, Test(vy, specifier=Test.IsPositiveInfty)),
                Return(FP_PlusInfty(self.precision))
            ),
            # pow(x, −∞) is +∞ for −1<x<1
            ConditionBlock(
                LogicalAnd(Abs(vx) < 1, Test(vy, specifier=Test.IsNegativeInfty)),
                Return(FP_PlusInfty(self.precision))
            ),
            # pow(x, −∞) is +0 for x<−1 or for 1<x (including ±∞)
            ConditionBlock(
                LogicalAnd(Abs(vx) > 1, Test(vy, specifier=Test.IsNegativeInfty)),
                Return(FP_PlusZero(self.precision))
            ),
            # pow(+∞, y) is +0 for a number y < 0
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsPositiveInfty), vy < 0),
                Return(FP_PlusZero(self.precision))
            ),
            # pow(+∞, y) is +∞ for a number y > 0
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsPositiveInfty), vy > 0),
                Return(FP_PlusInfty(self.precision))
            ),
            # pow(−∞, y) is −0 for finite y < 0 an odd integer
            # TODO: check y is finite
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsNegativeInfty), LogicalAnd(y_is_odd, vy < 0)),
                Return(FP_MinusZero(self.precision)),
            ),
            # pow(−∞, y) is −∞ for finite y > 0 an odd integer
            # TODO: check y is finite
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsNegativeInfty), LogicalAnd(y_is_odd, vy > 0)),
                Return(FP_MinusInfty(self.precision)),
            ),
            # pow(−∞, y) is +0 for finite y < 0 and not an odd integer
            # TODO: check y is finite
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsNegativeInfty), LogicalAnd(LogicalNot(y_is_odd), vy < 0)),
                Return(FP_PlusZero(self.precision)),
            ),
            # pow(−∞, y) is +∞ for finite y > 0 and not an odd integer
            # TODO: check y is finite
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsNegativeInfty), LogicalAnd(LogicalNot(y_is_odd), vy > 0)),
                Return(FP_PlusInfty(self.precision)),
            ),
            # pow(±0, y) is +∞ and signals the divideByZero exception for finite y<0 and not an odd integer
            # TODO: signal divideByZero exception
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsZero), LogicalAnd(LogicalNot(y_is_odd), vy < 0)),
                Return(FP_PlusInfty(self.precision)),
            ),
            # pow(±0, y) is +0 for finite y>0 and not an odd integer
            ConditionBlock(
                LogicalAnd(Test(vx, specifier=Test.IsZero), LogicalAnd(LogicalNot(y_is_odd), vy > 0)),
                Return(FP_PlusZero(self.precision)),
            ),
        )

        # manage n=1 separately to avoid catastrophic propagation of errors
        # between log2 and exp2 to eventually compute the identity function
        # test-case #3
        result = Statement(
            special_case_results,
            # fallback default cases
            Return(result_sign * exp2_t1 * exp2_t0_int * exp2_t0_frac))
        return result
示例#7
0
    def generic_atan2_generate(self, _vx, vy=None):
        """ if vy is None, compute atan(_vx), else compute atan2(vy / vx) """

        if vy is None:
            # approximation
            # if abs_vx <= 1.0 then atan(abx_vx) is directly approximated
            # if abs_vx > 1.0 then atan(abs_vx) = pi/2 - atan(1 / abs_vx)
            #
            # for vx >= 0, atan(vx) = atan(abs_vx)
            #
            # for vx < 0, atan(vx) = -atan(abs_vx) for vx < 0
            #                      = -pi/2 + atan(1 / abs_vx)
            vx = _vx
            sign_cond = vx < 0
            abs_vx = Select(vx < 0, -vx, vx, tag="abs_vx", debug=debug_multi)
            bound_cond = abs_vx > 1
            inv_abs_vx = 1 / abs_vx

            # condition to select subtraction
            cond = LogicalOr(LogicalAnd(vx < 0, LogicalNot(bound_cond)),
                             vx > 1,
                             tag="cond",
                             debug=debug_multi)

            # reduced argument
            red_vx = Select(bound_cond,
                            inv_abs_vx,
                            abs_vx,
                            tag="red_vx",
                            debug=debug_multi)

            offset = None
        else:
            # bound_cond is True iff Abs(vy / _vx) > 1.0
            bound_cond = Abs(vy) > Abs(_vx)
            bound_cond.set_attributes(tag="bound_cond", debug=debug_multi)
            # vx and vy are of opposite signs
            #sign_cond = (_vx * vy) < 0
            # using cast to int(signed) and bitwise xor
            # to determine if _vx and vy are of opposite sign rapidly
            fast_sign_cond = BitLogicXor(
                TypeCast(_vx, precision=self.precision.get_integer_format()),
                TypeCast(vy, precision=self.precision.get_integer_format()),
                precision=self.precision.get_integer_format()) < 0
            # sign_cond = (_vx * vy) < 0
            sign_cond = fast_sign_cond
            sign_cond.set_attributes(tag="sign_cond", debug=debug_multi)

            # condition to select subtraction
            # TODO: could be accelerated if LogicalXor existed
            slow_cond = LogicalOr(
                LogicalAnd(sign_cond,
                           LogicalNot(bound_cond)),  # 1 < (vy / _vx) < 0
                LogicalAnd(bound_cond,
                           LogicalNot(sign_cond)),  # (vy / _vx) > 1
                tag="cond",
                debug=debug_multi)
            cond = slow_cond

            numerator = Select(bound_cond,
                               _vx,
                               vy,
                               tag="numerator",
                               debug=debug_multi)
            denominator = Select(bound_cond,
                                 vy,
                                 _vx,
                                 tag="denominator",
                                 debug=debug_multi)
            # reduced argument
            red_vx = Abs(numerator) / Abs(denominator)
            red_vx.set_attributes(tag="red_vx", debug=debug_multi)

            offset = Select(
                _vx > 0,
                Constant(0, precision=self.precision),
                # vx < 0
                Select(
                    sign_cond,
                    # vy > 0
                    Constant(sollya.pi, precision=self.precision),
                    Constant(-sollya.pi, precision=self.precision),
                    precision=self.precision),
                precision=self.precision,
                tag="offset")

        approx_fct = sollya.atan(sollya.x)

        if self.method == "piecewise":
            sign_vx = Select(cond,
                             -1,
                             1,
                             precision=self.precision,
                             tag="sign_vx",
                             debug=debug_multi)

            cst_sign = Select(sign_cond,
                              -1,
                              1,
                              precision=self.precision,
                              tag="cst_sign",
                              debug=debug_multi)
            cst = cst_sign * Select(
                bound_cond, sollya.pi / 2, 0, precision=self.precision)
            cst.set_attributes(tag="cst", debug=debug_multi)

            bound_low = 0.0
            bound_high = 1.0
            num_intervals = self.num_sub_intervals
            error_threshold = S2**-(self.precision.get_mantissa_size() + 8)

            approx, eval_error = piecewise_approximation(
                approx_fct,
                red_vx,
                self.precision,
                bound_low=bound_low,
                bound_high=bound_high,
                max_degree=None,
                num_intervals=num_intervals,
                error_threshold=error_threshold,
                odd=True)

            result = cst + sign_vx * approx
            result.set_attributes(tag="result",
                                  precision=self.precision,
                                  debug=debug_multi)

        elif self.method == "single":
            approx_interval = Interval(0, 1.0)
            # determining the degree of the polynomial approximation
            poly_degree_range = sollya.guessdegree(
                approx_fct / sollya.x, approx_interval,
                S2**-(self.precision.get_field_size() + 2))
            poly_degree = int(sollya.sup(poly_degree_range)) + 4
            Log.report(Log.Info, "poly_degree={}".format(poly_degree))

            # arctan is an odd function, so only odd coefficient must be non-zero
            poly_degree_list = list(range(1, poly_degree + 1, 2))
            poly_object, poly_error = Polynomial.build_from_approximation_with_error(
                approx_fct, poly_degree_list,
                [1] + [self.precision.get_sollya_object()] *
                (len(poly_degree_list) - 1), approx_interval)

            odd_predicate = lambda index, _: ((index - 1) % 4 != 0)
            even_predicate = lambda index, _: (index != 1 and
                                               (index - 1) % 4 == 0)

            poly_odd_object = poly_object.sub_poly_cond(odd_predicate,
                                                        offset=1)
            poly_even_object = poly_object.sub_poly_cond(even_predicate,
                                                         offset=1)

            sollya.settings.display = sollya.hexadecimal
            Log.report(Log.Info, "poly_error: {}".format(poly_error))
            Log.report(Log.Info, "poly_odd: {}".format(poly_odd_object))
            Log.report(Log.Info, "poly_even: {}".format(poly_even_object))

            poly_odd = PolynomialSchemeEvaluator.generate_horner_scheme(
                poly_odd_object, abs_vx)
            poly_odd.set_attributes(tag="poly_odd", debug=debug_multi)
            poly_even = PolynomialSchemeEvaluator.generate_horner_scheme(
                poly_even_object, abs_vx)
            poly_even.set_attributes(tag="poly_even", debug=debug_multi)
            exact_sum = poly_odd + poly_even
            exact_sum.set_attributes(tag="exact_sum", debug=debug_multi)

            # poly_even should be (1 + poly_even)
            result = vx + vx * exact_sum
            result.set_attributes(tag="result",
                                  precision=self.precision,
                                  debug=debug_multi)

        else:
            raise NotImplementedError

        if not offset is None:
            result = result + offset

        std_scheme = Statement(Return(result))
        scheme = std_scheme

        return scheme
示例#8
0
    def generate_scalar_scheme(self, vx, n):
        # fixing inputs' node tag
        vx.set_attributes(tag="x")
        n.set_attributes(tag="n")

        int_precision = self.precision.get_integer_format()

        # assuming x = m.2^e (m in [1, 2[)
        #          n, positive or null integers
        #
        # rootn(x, n) = x^(1/n)
        #             = exp(1/n * log(x))
        #             = 2^(1/n * log2(x))
        #             = 2^(1/n * (log2(m) + e))
        #

        # approximation log2(m)

        # retrieving processor inverse approximation table
        dummy_var = Variable("dummy", precision=self.precision)
        dummy_div_seed = ReciprocalSeed(dummy_var, precision=self.precision)
        inv_approx_table = self.processor.get_recursive_implementation(
            dummy_div_seed,
            language=None,
            table_getter=lambda self: self.approx_table_map)

        log_f = sollya.log(sollya.x)  # /sollya.log(self.basis)

        use_reciprocal = False

        # non-scaled vx used to compute vx^1
        unmodified_vx = vx

        is_subnormal = Test(vx, specifier=Test.IsSubnormal, tag="is_subnormal")
        exp_correction_factor = self.precision.get_mantissa_size()
        mantissa_factor = Constant(2**exp_correction_factor,
                                   tag="mantissa_factor")
        vx = Select(is_subnormal, vx * mantissa_factor, vx, tag="corrected_vx")

        m = MantissaExtraction(vx, tag="m", precision=self.precision)
        e = ExponentExtraction(vx, tag="e", precision=int_precision)
        e = Select(is_subnormal,
                   e - exp_correction_factor,
                   e,
                   tag="corrected_e")

        ml_log_args = ML_GenericLog.get_default_args(precision=self.precision,
                                                     basis=2)
        ml_log = ML_GenericLog(ml_log_args)
        log_table, log_table_tho, table_index_range = ml_log.generate_log_table(
            log_f, inv_approx_table)
        log_approx = ml_log.generate_reduced_log_split(
            Abs(m, precision=self.precision), log_f, inv_approx_table,
            log_table)
        # floating-point version of n
        n_f = Conversion(n, precision=self.precision, tag="n_f")
        inv_n = Division(Constant(1, precision=self.precision), n_f)

        log_approx = Select(Equal(vx, 0), FP_MinusInfty(self.precision),
                            log_approx)
        log_approx.set_attributes(tag="log_approx", debug=debug_multi)
        if use_reciprocal:
            r = Multiplication(log_approx, inv_n, tag="r", debug=debug_multi)
        else:
            r = Division(log_approx, n_f, tag="r", debug=debug_multi)

        # e_n ~ e / n
        e_f = Conversion(e, precision=self.precision, tag="e_f")
        if use_reciprocal:
            e_n = Multiplication(e_f, inv_n, tag="e_n")
        else:
            e_n = Division(e_f, n_f, tag="e_n")
        error_e_n = FMA(e_n, -n_f, e_f, tag="error_e_n")
        e_n_int = NearestInteger(e_n, precision=self.precision, tag="e_n_int")
        pre_e_n_frac = e_n - e_n_int
        pre_e_n_frac.set_attributes(tag="pre_e_n_frac")
        e_n_frac = pre_e_n_frac + error_e_n * inv_n
        e_n_frac.set_attributes(tag="e_n_frac")

        ml_exp2_args = ML_Exp2.get_default_args(precision=self.precision)
        ml_exp2 = ML_Exp2(ml_exp2_args)
        exp2_r = ml_exp2.generate_scalar_scheme(r, inline_select=True)
        exp2_r.set_attributes(tag="exp2_r", debug=debug_multi)

        exp2_e_n_frac = ml_exp2.generate_scalar_scheme(e_n_frac,
                                                       inline_select=True)
        exp2_e_n_frac.set_attributes(tag="exp2_e_n_frac", debug=debug_multi)

        exp2_e_n_int = ExponentInsertion(Conversion(e_n_int,
                                                    precision=int_precision),
                                         precision=self.precision,
                                         tag="exp2_e_n_int")

        n_is_even = Equal(Modulo(n, 2), 0, tag="n_is_even", debug=debug_multi)
        n_is_odd = LogicalNot(n_is_even, tag="n_is_odd")
        result_sign = Select(
            n_is_odd, CopySign(vx, Constant(1.0, precision=self.precision)), 1)

        # managing n == -1
        if self.expand_div:
            ml_division_args = ML_Division.get_default_args(
                precision=self.precision, input_formats=[self.precision] * 2)
            ml_division = ML_Division(ml_division_args)
            self.division_implementation = ml_division.implementation
            self.division_implementation.set_scheme(
                ml_division.generate_scheme())
            ml_division_fct = self.division_implementation.get_function_object(
            )
        else:
            ml_division_fct = Division

        # manage n=1 separately to avoid catastrophic propagation of errors
        # between log2 and exp2 to eventually compute the identity function
        # test-case #3
        result = ConditionBlock(
            LogicalOr(LogicalOr(Test(vx, specifier=Test.IsNaN), Equal(n, 0)),
                      LogicalAnd(n_is_even, vx < 0)),
            Return(FP_QNaN(self.precision)),
            Statement(
                ConditionBlock(
                    Equal(n, -1, tag="n_is_mone"),
                    #Return(Division(Constant(1, precision=self.precision), unmodified_vx, tag="div_res", precision=self.precision)),
                    Return(
                        ml_division_fct(Constant(1, precision=self.precision),
                                        unmodified_vx,
                                        tag="div_res",
                                        precision=self.precision)),
                ),
                ConditionBlock(
                    # rootn( ±inf, n) is +∞ for even n< 0.
                    Test(vx, specifier=Test.IsInfty),
                    Statement(
                        ConditionBlock(
                            n < 0,
                            #LogicalAnd(n_is_odd, n < 0),
                            Return(
                                Select(Test(vx,
                                            specifier=Test.IsPositiveInfty),
                                       Constant(FP_PlusZero(self.precision),
                                                precision=self.precision),
                                       Constant(FP_MinusZero(self.precision),
                                                precision=self.precision),
                                       precision=self.precision)),
                            Return(vx),
                        ), ),
                ),
                ConditionBlock(
                    # rootn(±0, n) is ±∞ for odd n < 0.
                    LogicalAnd(LogicalAnd(n_is_odd, n < 0),
                               Equal(vx, 0),
                               tag="n_is_odd_and_neg"),
                    Return(
                        Select(Test(vx, specifier=Test.IsPositiveZero),
                               Constant(FP_PlusInfty(self.precision),
                                        precision=self.precision),
                               Constant(FP_MinusInfty(self.precision),
                                        precision=self.precision),
                               precision=self.precision)),
                ),
                ConditionBlock(
                    # rootn( ±0, n) is +∞ for even n< 0.
                    LogicalAnd(LogicalAnd(n_is_even, n < 0), Equal(vx, 0)),
                    Return(FP_PlusInfty(self.precision))),
                ConditionBlock(
                    # rootn(±0, n) is +0 for even n > 0.
                    LogicalAnd(n_is_even, Equal(vx, 0)),
                    Return(vx)),
                ConditionBlock(
                    Equal(n, 1), Return(unmodified_vx),
                    Return(result_sign * exp2_r * exp2_e_n_int *
                           exp2_e_n_frac))))
        return result
示例#9
0
    def generate_auto_test(self,
                           test_num=10,
                           test_range=Interval(-1.0, 1.0),
                           debug=False,
                           time_step=10):
        """ time_step: duration of a stage (in ns) """
        # instanciating tested component
        # map of input_tag -> input_signal and output_tag -> output_signal
        io_map = {}
        # map of input_tag -> input_signal, excludind commodity signals
        # (e.g. clock and reset)
        input_signals = {}
        # map of output_tag -> output_signal
        output_signals = {}
        # excluding clock and reset signals from argument list
        # reduced_arg_list = [input_port for input_port in self.implementation.get_arg_list() if not input_port.get_tag() in ["clk", "reset"]]
        reduced_arg_list = self.implementation.get_arg_list()
        for input_port in reduced_arg_list:
            input_tag = input_port.get_tag()
            input_signal = Signal(input_tag + "_i",
                                  precision=input_port.get_precision(),
                                  var_type=Signal.Local)
            io_map[input_tag] = input_signal
            if not input_tag in ["clk", "reset"]:
                input_signals[input_tag] = input_signal
        for output_port in self.implementation.get_output_port():
            output_tag = output_port.get_tag()
            output_signal = Signal(output_tag + "_o",
                                   precision=output_port.get_precision(),
                                   var_type=Signal.Local)
            io_map[output_tag] = output_signal
            output_signals[output_tag] = output_signal

        # building list of test cases
        tc_list = []

        self_component = self.implementation.get_component_object()
        self_instance = self_component(io_map=io_map, tag="tested_entity")
        test_statement = Statement()

        # initializing random test case generator
        self.init_test_generator()

        # Appending standard test cases if required
        if self.auto_test_std:
            tc_list += self.standard_test_cases

        for i in range(test_num):
            input_values = self.generate_test_case(input_signals, io_map, i,
                                                   test_range)
            tc_list.append((input_values, None))

        def compute_results(tc):
            """ update test case with output values if required """
            input_values, output_values = tc
            if output_values is None:
                return input_values, self.numeric_emulate(input_values)
            else:
                return tc

        # filling output values
        tc_list = [compute_results(tc) for tc in tc_list]

        for input_values, output_values in tc_list:
            input_msg = ""

            # Adding input setting
            for input_tag in input_values:
                input_signal = io_map[input_tag]
                # FIXME: correct value generation depending on signal precision
                input_value = input_values[input_tag]
                test_statement.add(
                    ReferenceAssign(
                        input_signal,
                        Constant(input_value,
                                 precision=input_signal.get_precision())))
                value_msg = input_signal.get_precision().get_cst(
                    input_value, language=VHDL_Code).replace('"', "'")
                value_msg += " / " + hex(input_signal.get_precision(
                ).get_base_format().get_integer_coding(input_value))
                input_msg += " {}={} ".format(input_tag, value_msg)
            test_statement.add(Wait(time_step * self.stage_num))
            # Adding output value comparison
            for output_tag in output_signals:
                output_signal = output_signals[output_tag]
                output_value = Constant(
                    output_values[output_tag],
                    precision=output_signal.get_precision())
                output_precision = output_signal.get_precision()
                expected_dec = output_precision.get_cst(
                    output_values[output_tag],
                    language=VHDL_Code).replace('"', "'")
                expected_hex = " / " + hex(
                    output_precision.get_base_format().get_integer_coding(
                        output_values[output_tag]))
                value_msg = "{} / {}".format(expected_dec, expected_hex)

                test_pass_cond = Comparison(output_signal,
                                            output_value,
                                            specifier=Comparison.Equal,
                                            precision=ML_Bool)

                test_statement.add(
                    ConditionBlock(
                        LogicalNot(test_pass_cond, precision=ML_Bool),
                        Report(
                            Concatenation(
                                " result for {}: ".format(output_tag),
                                Conversion(TypeCast(
                                    output_signal,
                                    precision=ML_StdLogicVectorFormat(
                                        output_signal.get_precision(
                                        ).get_bit_size())),
                                           precision=ML_String),
                                precision=ML_String))))
                test_statement.add(
                    Assert(
                        test_pass_cond,
                        "\"unexpected value for inputs {input_msg}, output {output_tag}, expecting {value_msg}, got: \""
                        .format(input_msg=input_msg,
                                output_tag=output_tag,
                                value_msg=value_msg),
                        severity=Assert.Failure))

        testbench = CodeEntity("testbench")
        test_process = Process(
            test_statement,
            # end of test
            Assert(Constant(0, precision=ML_Bool),
                   " \"end of test, no error encountered \"",
                   severity=Assert.Failure))

        testbench_scheme = Statement(self_instance, test_process)

        if self.pipelined:
            half_time_step = time_step / 2
            assert (half_time_step * 2) == time_step
            # adding clock process for pipelined bench
            clk_process = Process(
                Statement(
                    ReferenceAssign(io_map["clk"],
                                    Constant(1, precision=ML_StdLogic)),
                    Wait(half_time_step),
                    ReferenceAssign(io_map["clk"],
                                    Constant(0, precision=ML_StdLogic)),
                    Wait(half_time_step),
                ))
            testbench_scheme.push(clk_process)

        testbench.add_process(testbench_scheme)

        return [testbench]
示例#10
0
    def generate_scheme(self):
        # declaring target and instantiating optimization engine

        vx = self.implementation.add_input_variable("x", self.precision)
        vx.set_attributes(precision=self.precision,
                          tag="vx",
                          debug=debug_multi)
        Log.set_dump_stdout(True)

        Log.report(Log.Info,
                   "\033[33;1m Generating implementation scheme \033[0m")
        if self.debug_flag:
            Log.report(Log.Info, "\033[31;1m debug has been enabled \033[0;m")

        C0 = Constant(0, precision=self.precision)

        C0_plus = Constant(FP_PlusZero(self.precision))
        C0_minus = Constant(FP_MinusZero(self.precision))

        def local_test(specifier, tag):
            """ Local wrapper to generate Test operations """
            return Test(vx,
                        specifier=specifier,
                        likely=False,
                        debug=debug_multi,
                        tag="is_%s" % tag,
                        precision=ML_Bool)

        test_NaN = local_test(Test.IsNaN, "is_NaN")
        test_inf = local_test(Test.IsInfty, "is_Inf")
        test_NaN_or_Inf = local_test(Test.IsInfOrNaN, "is_Inf_Or_Nan")

        test_negative = Comparison(vx,
                                   C0,
                                   specifier=Comparison.Less,
                                   debug=debug_multi,
                                   tag="is_Negative",
                                   precision=ML_Bool,
                                   likely=False)
        test_NaN_or_Neg = LogicalOr(test_NaN, test_negative, precision=ML_Bool)

        test_std = LogicalNot(LogicalOr(test_NaN_or_Inf,
                                        test_negative,
                                        precision=ML_Bool,
                                        likely=False),
                              precision=ML_Bool,
                              likely=True)

        test_zero = Comparison(vx,
                               C0,
                               specifier=Comparison.Equal,
                               likely=False,
                               debug=debug_multi,
                               tag="Is_Zero",
                               precision=ML_Bool)

        return_NaN_or_neg = Statement(Return(FP_QNaN(self.precision)))
        return_inf = Statement(Return(FP_PlusInfty(self.precision)))

        return_PosZero = Return(C0_plus)
        return_NegZero = Return(C0_minus)

        NR_init = ReciprocalSquareRootSeed(vx,
                                           precision=self.precision,
                                           tag="sqrt_seed",
                                           debug=debug_multi)

        result = compute_sqrt(vx,
                              NR_init,
                              int(self.num_iter),
                              precision=self.precision)

        return_non_std = ConditionBlock(
            test_NaN_or_Neg, return_NaN_or_neg,
            ConditionBlock(
                test_inf, return_inf,
                ConditionBlock(test_zero, return_PosZero, return_NegZero)))
        return_std = Return(result)

        scheme = ConditionBlock(test_std, return_std, return_non_std)
        return scheme
示例#11
0
def booth_radix4_multiply(lhs, rhs, pos_bit_heap, neg_bit_heap):
    """ Compute the multiplication @p lhs x @p rhs using radix 4 Booth
        recoding and drop the generated partial product in @p
        pos_bit_heap and @p neg_bit_heap based on their sign """
    # booth recoded partial product for n-th digit
    # is based on digit from n-1 to n+1
    #    (n+1) | (n) | (n-1) |  PP  |
    #    ------|-----|-------|------|
    #      0   |  0  |   0   |  +0  |
    #      0   |  0  |   1   |  +X  |
    #      0   |  1  |   0   |  +X  |
    #      0   |  1  |   1   |  +2x |
    #      1   |  0  |   0   |  -2X |
    #      1   |  0  |   1   |  -X  |
    #      1   |  1  |   0   |  -X  |
    #      1   |  1  |   1   |  +0  |
    #    ------|-----|-------|------|
    assert lhs.get_precision().get_bit_size() >= 2

    # lhs is the recoded operand
    # RECODING DIGITS
    # first recoded digit is padded right by 0
    first_digit = Concatenation(SubSignalSelection(
        lhs, 0, 1, precision=ML_StdLogicVectorFormat(2)),
                                Constant(0, precision=ML_StdLogic),
                                precision=ML_StdLogicVectorFormat(3),
                                debug=debug_std,
                                tag="booth_digit_0")
    digit_list = [(first_digit, 0)]

    for digit_index in range(2, lhs.get_precision().get_bit_size(), 2):
        if digit_index + 1 < lhs.get_precision().get_bit_size():
            # digits exist completely in lhs
            digit = SubSignalSelection(lhs,
                                       digit_index - 1,
                                       digit_index + 1,
                                       tag="booth_digit_%d" % digit_index,
                                       debug=debug_std)
        else:
            # MSB padding required
            sign_ext = Constant(0, precision=ML_StdLogic) if not (
                lhs.get_precision().get_signed()) else BitSelection(
                    lhs,
                    lhs.get_precision().get_bit_size() - 1)
            digit = Concatenation(sign_ext,
                                  SubSignalSelection(lhs, digit_index - 1,
                                                     digit_index),
                                  precision=ML_StdLogicVectorFormat(3),
                                  debug=debug_std,
                                  tag="booth_digit_%d" % digit_index)
        digit_list.append((digit, digit_index))
    # if lhs size is a mutiple of two and it is unsigned
    # than an extra digit must be generated to ensure a positive result
    if lhs.get_precision().get_bit_size() % 2 == 0 and not (
            lhs.get_precision().get_signed()):
        digit_index = lhs.get_precision().get_bit_size() - 1
        digit = Concatenation(Constant(0,
                                       precision=ML_StdLogicVectorFormat(2)),
                              BitSelection(lhs, digit_index),
                              precision=ML_StdLogicVectorFormat(3),
                              debug=debug_std,
                              tag="booth_digit_%d" % (digit_index + 1))
        digit_list.append((digit, digit_index + 1))

    def DCV(value):
        """ Digit Constante Value """
        return Constant(value, precision=ML_StdLogicVectorFormat(3))

    # PARTIAL PRODUCT GENERATION
    # Radix-4 booth recoding requires the following Partial Products
    # -2.rhs, -rhs, 0, rhs and 2.rhs
    # Negative PP are obtained by 1's complement of the value correctly shifted
    # adding a positive one to the LSB (inserted separately) and assuming
    # MSB digit has a negative weight
    for digit, index in digit_list:
        pp_zero = LogicalOr(Equal(digit, DCV(0), precision=ML_Bool),
                            Equal(digit, DCV(7), precision=ML_Bool),
                            precision=ML_Bool)
        pp_shifted = LogicalOr(Equal(digit, DCV(3), precision=ML_Bool),
                               Equal(digit, DCV(4), precision=ML_Bool),
                               precision=ML_Bool)
        # excluding zero case
        pp_neg_bit = BitSelection(digit, 2)
        pp_neg = equal_to(pp_neg_bit, 1)
        pp_neg_lsb_carryin = Select(LogicalAnd(pp_neg, LogicalNot(pp_zero)),
                                    Constant(1, precision=ML_StdLogic),
                                    Constant(0, precision=ML_StdLogic),
                                    tag="pp_%d_neg_lsb_carryin" % index,
                                    debug=debug_std)

        # LSB digit
        lsb_pp_digit = Select(pp_shifted,
                              Constant(0, precision=ML_StdLogic),
                              BitSelection(rhs, 0),
                              precision=ML_StdLogic)
        lsb_local_pp = Select(pp_zero,
                              Constant(0, precision=ML_StdLogic),
                              Select(pp_neg,
                                     BitLogicNegate(lsb_pp_digit),
                                     lsb_pp_digit,
                                     precision=ML_StdLogic),
                              debug=debug_std,
                              tag="lsb_local_pp_%d" % index,
                              precision=ML_StdLogic)
        pos_bit_heap.insert_bit(index, lsb_local_pp)
        pos_bit_heap.insert_bit(index, pp_neg_lsb_carryin)

        # other digits
        rhs_size = rhs.get_precision().get_bit_size()
        for k in range(1, rhs_size):
            pp_digit = Select(pp_shifted,
                              BitSelection(rhs, k - 1),
                              BitSelection(rhs, k),
                              precision=ML_StdLogic)
            local_pp = Select(pp_zero,
                              Constant(0, precision=ML_StdLogic),
                              Select(pp_neg,
                                     BitLogicNegate(pp_digit),
                                     pp_digit,
                                     precision=ML_StdLogic),
                              debug=debug_std,
                              tag="local_pp_%d_%d" % (index, k),
                              precision=ML_StdLogic)
            pos_bit_heap.insert_bit(index + k, local_pp)
        # MSB digit
        msb_pp_digit = pp_digit = Select(
            pp_shifted,
            BitSelection(rhs, rhs_size - 1),
            # TODO: fix for signed rhs
            Constant(0, precision=ML_StdLogic)
            if not (rhs.get_precision().get_signed()) else BitSelection(
                rhs, rhs_size - 1),
            precision=ML_StdLogic)
        msb_pp = Select(pp_zero,
                        Constant(0, precision=ML_StdLogic),
                        Select(pp_neg,
                               BitLogicNegate(msb_pp_digit),
                               msb_pp_digit,
                               precision=ML_StdLogic),
                        debug=debug_std,
                        tag="msb_pp_%d" % (index),
                        precision=ML_StdLogic)
        if rhs.get_precision().get_signed():
            neg_bit_heap.insert_bit(index + rhs_size, msb_pp)
        else:
            pos_bit_heap.insert_bit(index + rhs_size, msb_pp)
            # MSB negative digit,
            # 'rhs_size + index) is the position of the MSB digit of rhs shifted by 1
            # we add +1 to get to the sign position
            neg_bit_heap.insert_bit(index + rhs_size + 1, pp_neg_lsb_carryin)
示例#12
0
 def LogicalXor(a, b):
     return LogicalOr(LogicalAnd(a, LogicalNot(b)), LogicalAnd(LogicalNot(a), b))
示例#13
0
  def generate_datafile_testbench(self, tc_list, io_map, input_signals, output_signals, time_step, test_fname="test.input"):
    """ Generate testbench with input and output data externalized in
        a data file """
    # textio function to read hexadecimal text
    def FCT_HexaRead_gen(input_format):
        legalized_input_format = input_format
        FCT_HexaRead = FunctionObject("hread", [HDL_LINE, legalized_input_format], ML_Void, FunctionOperator("hread", void_function=True, arity=2))
        return FCT_HexaRead
    # textio function to read binary text
    FCT_Read = FunctionObject("read", [HDL_LINE, ML_StdLogic], ML_Void, FunctionOperator("read", void_function=True, arity=2))
    input_line = Variable("input_line", precision=HDL_LINE, var_type=Variable.Local)

    # building ordered list of input and output signal names
    input_signal_list = [sname for sname in input_signals.keys()]
    input_statement = Statement()
    for input_name in input_signal_list:
        input_format = input_signals[input_name].precision
        input_var = Variable(
            "v_" + input_name,
            precision=input_format,
            var_type=Variable.Local)
        if input_format is ML_StdLogic:
            input_statement.add(FCT_Read(input_line, input_var))
        else:
            input_statement.add(FCT_HexaRead_gen(input_format)(input_line, input_var))
        input_statement.add(ReferenceAssign(input_signals[input_name], input_var))

    output_signal_list = [sname for sname in output_signals.keys()]
    output_statement = Statement()
    for output_name in output_signal_list:
        output_format = output_signals[output_name].precision
        output_var = Variable(
            "v_" + output_name,
            precision=output_format,
            var_type=Variable.Local)
        if output_format is ML_StdLogic:
            output_statement.add(FCT_Read(input_line, output_var))
        else:
            output_statement.add(FCT_HexaRead_gen(output_format)(input_line, output_var))

        output_signal = output_signals[output_name]
        #value_msg = get_output_value_msg(output_signal, output_value)
        test_pass_cond, check_statement = get_output_check_statement(output_signal, output_name, output_var)

        input_msg = multi_Concatenation(*tuple(sum([[" %s=" % input_tag, signal_str_conversion(input_signals[input_tag], input_signals[input_tag].precision)] for input_tag in input_signal_list], [])))

        output_statement.add(check_statement)
        assert_statement = Assert(
            test_pass_cond,
            multi_Concatenation(
                "unexpected value for inputs ",
                input_msg,
                " expecting :",
                signal_str_conversion(output_var, output_format),
                " got :",
                signal_str_conversion(output_signal, output_format),
               precision = ML_String
            ),
            severity=Assert.Failure
        )
        output_statement.add(assert_statement)

    self_component = self.implementation.get_component_object()
    self_instance = self_component(io_map = io_map, tag = "tested_entity")
    test_statement = Statement()

    DATA_FILE_NAME = test_fname

    with open(DATA_FILE_NAME, "w") as data_file:
        # dumping column tags
        data_file.write("# " + " ".join(input_signal_list + output_signal_list) + "\n")

        def get_raw_cst_string(cst_format, cst_value):
            size = int((cst_format.get_bit_size() + 3) / 4)
            return ("{:x}").format(cst_format.get_base_format().get_integer_coding(cst_value)).zfill(size)

        for input_values, output_values in tc_list:
            # TODO; generate test data file
            cst_list = []
            for input_name in input_signal_list:
                input_value = input_values[input_name]
                input_format = input_signals[input_name].get_precision()
                cst_list.append(get_raw_cst_string(input_format, input_value))

            for output_name in output_signal_list:
                output_value = output_values[output_name]
                output_format = output_signals[output_name].get_precision()
                cst_list.append(get_raw_cst_string(output_format, output_value))
            # dumping line into file
            data_file.write(" ".join(cst_list) + "\n")

    input_stream = Variable("data_file", precision=HDL_FILE, var_type=Variable.Local)
    file_status = Variable("file_status", precision=HDL_OPEN_FILE_STATUS, var_type=Variable.Local)
    FCT_EndFile = FunctionObject("endfile", [HDL_FILE], ML_Bool, FunctionOperator("endfile", arity=1)) 
    FCT_OpenFile = FunctionObject(
        "FILE_OPEN", [HDL_OPEN_FILE_STATUS, HDL_FILE, ML_String], ML_Void,
        FunctionOperator(
            "FILE_OPEN",
            arg_map={0: FO_Arg(0), 1: FO_Arg(1), 2: FO_Arg(2), 3: "READ_MODE"},
            void_function=True))
    FCT_ReadLine =  FunctionObject(
        "readline", [HDL_FILE, HDL_LINE], ML_Void,
        FunctionOperator("readline", void_function=True, arity=2))

    reset_statement = self.get_reset_statement(io_map, time_step)
    OPEN_OK = Constant("OPEN_OK", precision=HDL_OPEN_FILE_STATUS)

    testbench = CodeEntity("testbench")
    test_process = Process(
        reset_statement,
        FCT_OpenFile(file_status, input_stream, DATA_FILE_NAME),
        ConditionBlock(
            Comparison(file_status, OPEN_OK, specifier=Comparison.NotEqual),
          Assert(
            Constant(0, precision=ML_Bool),
            " \"failed to open file {}\"".format(DATA_FILE_NAME),
            severity=Assert.Failure
          )
        ),
        # consume legend line
        FCT_ReadLine(input_stream, input_line),
        WhileLoop(
            LogicalNot(FCT_EndFile(input_stream)),
            Statement(
                FCT_ReadLine(input_stream, input_line),
                input_statement,
                Wait(time_step * (self.stage_num + 2)),
                output_statement,
            ),
        ),
      # end of test
      Assert(
        Constant(0, precision = ML_Bool),
        " \"end of test, no error encountered \"",
        severity = Assert.Warning
      ),
      # infinite end loop
        WhileLoop(
            Constant(1, precision=ML_Bool),
            Statement(
                Wait(time_step * (self.stage_num + 2)),
            )
        )
    )

    testbench_scheme = Statement(
      self_instance,
      test_process
    )

    if self.pipelined:
        half_time_step = time_step / 2
        assert (half_time_step * 2) == time_step
        # adding clock process for pipelined bench
        clk_process = Process(
            Statement(
                ReferenceAssign(
                    io_map["clk"],
                    Constant(1, precision = ML_StdLogic)
                ),
                Wait(half_time_step),
                ReferenceAssign(
                    io_map["clk"],
                    Constant(0, precision = ML_StdLogic)
                ),
                Wait(half_time_step),
            )
        )
        testbench_scheme.push(clk_process)

    testbench.add_process(testbench_scheme)

    return [testbench]