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#ifndef __netmisc_H
#define __netmisc_H
* Copyright (c) 1999-2008 Stephen Williams (
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
* General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
# include "netlist.h"
* Search for a symbol using the "start" scope as the starting
* point. If the path includes a scope part, then locate the
* scope first.
* The return value is the scope where the symbol was found.
* If the symbol was not found, return 0. The output arguments
* get 0 except for the pointer to the object that represents
* the located symbol.
* The ex1 and ex2 output arguments are extended results. If the
* symbol is a parameter (par!=0) then ex1 is the msb expression and
* ex2 is the lsb expression for the range. If there is no range, then
* these values are set to 0.
extern NetScope* symbol_search(Design*des,
NetScope*start, pform_name_t path,
NetNet*&net, /* net/reg */
const NetExpr*&par,/* parameter */
NetEvent*&eve, /* named event */
const NetExpr*&ex1, const NetExpr*&ex2);
inline NetScope* symbol_search(Design*des,
NetScope*start, const pform_name_t&path,
NetNet*&net, /* net/reg */
const NetExpr*&par,/* parameter */
NetEvent*&eve /* named event */)
const NetExpr*ex1, *ex2;
return symbol_search(des, start, path, net, par, eve, ex1, ex2);
* This function transforms an expression by padding the high bits
* with V0 until the expression has the desired width. This may mean
* not transforming the expression at all, if it is already wide
* enough.
extern NetExpr*pad_to_width(NetExpr*expr, unsigned wid);
extern NetNet*pad_to_width(Design*des, NetNet*n, unsigned w);
extern NetNet*pad_to_width_signed(Design*des, NetNet*n, unsigned w);
* Generate the nodes necessary to cast an expression (a net) to a
* real value.
extern NetNet*cast_to_int(Design*des, NetScope*scope, NetNet*src, unsigned wid);
extern NetNet*cast_to_real(Design*des, NetScope*scope, NetNet*src);
* Take the input expression and return a variation that assures that
* the expression is 1-bit wide and logical. This reflects the needs
* of conditions i.e. for "if" statements or logical operators.
extern NetExpr*condition_reduce(NetExpr*expr);
* This function transforms an expression by cropping the high bits
* off with a part select. The result has the width w passed in. This
* function does not pad, use pad_to_width if padding is desired.
extern NetNet*crop_to_width(Design*des, NetNet*n, unsigned w);
* This function takes as input a NetNet signal and adds a constant
* value to it. If the val is 0, then simply return sig. Otherwise,
* return a new NetNet value that is the output of an addition.
extern NetNet*add_to_net(Design*des, NetNet*sig, long val);
* These functions make various sorts of expressions, given operands
* of certain type. The order of the operands is preserved in cases
* where order matters.
* make_add_expr
* Make a NetEBAdd expression with <expr> the first argument and
* <val> the second. This may get turned into a subtract if <val> is
* less than zero. If val is exactly zero, then return <expr> as is.
* make_sub_expr
* Make a NetEBAdd(subtract) node that subtracts the given
* expression from the integer value.
extern NetExpr*make_add_expr(NetExpr*expr, long val);
extern NetExpr*make_sub_expr(long val, NetExpr*expr);
* Make a NetEConst object that contains only X bits.
extern NetEConst*make_const_x(unsigned long wid);
* In some cases the lval is accessible as a pointer to the head of
* a list of NetAssign_ objects. This function returns the width of
* the l-value represented by this list.
extern unsigned count_lval_width(const class NetAssign_*first);
* This function elaborates an expression, and tries to evaluate it
* right away. If the expression can be evaluated, this returns a
* constant expression. If it cannot be evaluated, it returns whatever
* it can. If the expression cannot be elaborated, return 0.
* The expr_width is the width of the context where the expression is
* being elaborated, or -1 if the expression is self-determined width.
* Also, the prune_width is the maximum width of the result, and it
* passed to the eval_tree method of the expression to limit constant
* results if possible.
class PExpr;
extern NetExpr* elab_and_eval(Design*des, NetScope*scope,
const PExpr*pe, int expr_wid,
int prune_width =-1);
* This procedure elaborates an expression and if the elaboration is
* successful the original expression is replaced with the new one.
void eval_expr(NetExpr*&expr, int prune_width =-1);
* Get the long integer value for the passed in expression, if
* possible. If it is not possible (the expression is not evaluated
* down to a constant) then return false and leave value unchanged.
bool eval_as_long(long&value, NetExpr*expr);
bool eval_as_double(double&value, NetExpr*expr);
* Evaluate the component of a scope path to get an hname_t value. Do
* the evaluation in the context of the given scope.
extern hname_t eval_path_component(Design*des, NetScope*scope,
const name_component_t&comp);
* Evaluate an entire scope path in the context of the given scope.
extern std::list<hname_t> eval_scope_path(Design*des, NetScope*scope,
const pform_name_t&path);
* Return a human readable version of the operator.
const char *human_readable_op(const char op);
* Is the expression a constant value and if so what is its logical
* value.
* C_NON - the expression is not a constant value.
* C_0 - the expression is constant and it has a false value.
* C_1 - the expression is constant and it has a true value.
* C_X - the expression is constant and it has an 'bX value.
enum const_bool { C_NON, C_0, C_1, C_X };
const_bool const_logical(const NetExpr*expr);
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