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#ifndef __PExpr_H
#define __PExpr_H
/*
* Copyright (c) 1998-2008 Stephen Williams <steve@icarus.com>
*
* 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
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* 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 <string>
# include <vector>
# include "netlist.h"
# include "verinum.h"
# include "LineInfo.h"
# include "pform_types.h"
class Design;
class Module;
class NetNet;
class NetExpr;
class NetScope;
/*
* The PExpr class hierarchy supports the description of
* expressions. The parser can generate expression objects from the
* source, possibly reducing things that it knows how to reduce.
*
* The elaborate_net method is used by structural elaboration to build
* up a netlist interpretation of the expression.
*/
class PExpr : public LineInfo {
public:
PExpr();
virtual ~PExpr();
virtual void dump(ostream&) const;
// This method tests the width that the expression wants to
// be. It is used by elaboration of assignments to figure out
// the width of the expression.
//
// The "min" is the width of the local context, so it the
// minimum width that this function should return. Initially
// this is the same as the lval width.
//
// The "lval" is the width of the destination where this
// result is going to go. This can be used to constrain the
// amount that an expression can reasonably expand. For
// example, there is no point expanding an addition to beyond
// the lval. This extra bit of information allows the
// expression to optimize itself a bit. If the lval==0, then
// the subexpression should not make l-value related
// optimizations.
//
// The unsigned_flag is set to true if the expression is
// unsized and therefore expandable. This happens if a
// sub-expression is an unsized literal. Some expressions make
// special use of that.
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const;
// During the elaborate_sig phase, we may need to scan
// expressions to find implicit net declarations.
virtual bool elaborate_sig(Design*des, NetScope*scope) const;
// Procedural elaboration of the expression. The expr_width is
// the width of the context of the expression (i.e. the
// l-value width of an assignment),
//
// ... or -1 if the expression is self-determined. or
// ... or -2 if the expression is losslessly
// self-determined. This can happen in situations where the
// result is going to a pseudo-infinitely wide context.
//
// The sys_task_arg flag is true if expressions are allowed to
// be incomplete.
virtual NetExpr*elaborate_expr(Design*des, NetScope*scope,
int expr_width, bool sys_task_arg) const;
// Elaborate expressions that are the r-value of parameter
// assignments. This elaboration follows the restrictions of
// constant expressions and supports later overriding and
// evaluation of parameters.
virtual NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
// This method elaborate the expression as gates, for use in a
// continuous assign or other wholly structural context.
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0 =Link::STRONG,
Link::strength_t drive1 =Link::STRONG)
const;
// This method elaborates the expression as gates, but
// restricted for use as l-values of continuous assignments.
virtual NetNet* elaborate_lnet(Design*des, NetScope*scope) const;
// This is similar to elaborate_lnet, except that the
// expression is evaluated to be bi-directional. This is
// useful for arguments to inout ports of module instances and
// ports of tran primitives.
virtual NetNet* elaborate_bi_net(Design*des, NetScope*scope) const;
// Expressions that can be in the l-value of procedural
// assignments can be elaborated with this method. If the
// is_force flag is true, then the set of valid l-value types
// is slightly modified to accommodate the Verilog force
// statement
virtual NetAssign_* elaborate_lval(Design*des,
NetScope*scope,
bool is_force) const;
// This attempts to evaluate a constant expression, and return
// a verinum as a result. If the expression cannot be
// evaluated, return 0.
virtual verinum* eval_const(Design*des, NetScope*sc) const;
// This method returns true if that expression is the same as
// this expression. This method is used for comparing
// expressions that must be structurally "identical".
virtual bool is_the_same(const PExpr*that) const;
// Return true if this expression is a valid constant
// expression. the Module pointer is needed to find parameter
// identifiers and any other module specific interpretations
// of expressions.
virtual bool is_constant(Module*) const;
private: // not implemented
PExpr(const PExpr&);
PExpr& operator= (const PExpr&);
};
ostream& operator << (ostream&, const PExpr&);
class PEConcat : public PExpr {
public:
PEConcat(const svector<PExpr*>&p, PExpr*r =0);
~PEConcat();
virtual verinum* eval_const(Design*des, NetScope*sc) const;
virtual void dump(ostream&) const;
virtual bool elaborate_sig(Design*des, NetScope*scope) const;
virtual NetNet* elaborate_lnet(Design*des, NetScope*scope) const;
virtual NetNet* elaborate_bi_net(Design*des, NetScope*scope) const;
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual NetExpr*elaborate_expr(Design*des, NetScope*,
int expr_width, bool sys_task_arg) const;
virtual NetEConcat*elaborate_pexpr(Design*des, NetScope*) const;
virtual NetAssign_* elaborate_lval(Design*des,
NetScope*scope,
bool is_force) const;
virtual bool is_constant(Module*) const;
private:
NetNet* elaborate_lnet_common_(Design*des, NetScope*scope,
bool bidirectional_flag) const;
private:
svector<PExpr*>parms_;
PExpr*repeat_;
};
/*
* Event expressions are expressions that can be combined with the
* event "or" operator. These include "posedge foo" and similar, and
* also include named events. "edge" events are associated with an
* expression, whereas named events simply have a name, which
* represents an event variable.
*/
class PEEvent : public PExpr {
public:
enum edge_t {ANYEDGE, POSEDGE, NEGEDGE, POSITIVE};
// Use this constructor to create events based on edges or levels.
PEEvent(edge_t t, PExpr*e);
~PEEvent();
edge_t type() const;
PExpr* expr() const;
virtual void dump(ostream&) const;
private:
edge_t type_;
PExpr *expr_;
};
/*
* This holds a floating point constant in the source.
*/
class PEFNumber : public PExpr {
public:
explicit PEFNumber(verireal*vp);
~PEFNumber();
const verireal& value() const;
/* The eval_const method as applied to a floating point number
gets the *integer* value of the number. This accounts for
any rounding that is needed to get the value. */
virtual verinum* eval_const(Design*des, NetScope*sc) const;
/* A PEFNumber is a constant, so this returns true. */
virtual bool is_constant(Module*) const;
virtual NetExpr*elaborate_expr(Design*des, NetScope*,
int expr_width, bool sys_task_arg) const;
virtual NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual void dump(ostream&) const;
private:
verireal*value_;
};
class PEIdent : public PExpr {
public:
explicit PEIdent(perm_string);
explicit PEIdent(const pform_name_t&);
~PEIdent();
// Add another name to the string of hierarchy that is the
// current identifier.
void append_name(perm_string);
virtual void dump(ostream&) const;
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const;
virtual bool elaborate_sig(Design*des, NetScope*scope) const;
// Identifiers are allowed (with restrictions) is assign l-values.
virtual NetNet* elaborate_lnet(Design*des, NetScope*scope) const;
virtual NetNet* elaborate_bi_net(Design*des, NetScope*scope) const;
// Identifiers are also allowed as procedural assignment l-values.
virtual NetAssign_* elaborate_lval(Design*des,
NetScope*scope,
bool is_force) const;
// Structural r-values are OK.
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual NetExpr*elaborate_expr(Design*des, NetScope*,
int expr_width, bool sys_task_arg) const;
virtual NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
// Elaborate the PEIdent as a port to a module. This method
// only applies to Ident expressions.
NetNet* elaborate_port(Design*des, NetScope*sc) const;
virtual bool is_constant(Module*) const;
verinum* eval_const(Design*des, NetScope*sc) const;
const pform_name_t& path() const { return path_; }
private:
pform_name_t path_;
private:
// Common functions to calculate parts of part/bit selects.
bool calculate_parts_(Design*, NetScope*, long&msb, long&lsb) const;
bool calculate_up_do_width_(Design*, NetScope*, unsigned long&wid) const;
private:
NetAssign_*elaborate_lval_net_word_(Design*, NetScope*, NetNet*) const;
bool elaborate_lval_net_part_(Design*, NetScope*, NetAssign_*) const;
bool elaborate_lval_net_idx_(Design*, NetScope*, NetAssign_*,
index_component_t::ctype_t) const;
private:
NetExpr*elaborate_expr_param(Design*des,
NetScope*scope,
const NetExpr*par,
NetScope*found,
const NetExpr*par_msb,
const NetExpr*par_lsb) const;
NetExpr*elaborate_expr_net(Design*des,
NetScope*scope,
NetNet*net,
NetScope*found,
bool sys_task_arg) const;
NetExpr*elaborate_expr_net_word_(Design*des,
NetScope*scope,
NetNet*net,
NetScope*found,
bool sys_task_arg) const;
NetExpr*elaborate_expr_net_part_(Design*des,
NetScope*scope,
NetESignal*net,
NetScope*found) const;
NetExpr*elaborate_expr_net_idx_up_(Design*des,
NetScope*scope,
NetESignal*net,
NetScope*found) const;
NetExpr*elaborate_expr_net_idx_do_(Design*des,
NetScope*scope,
NetESignal*net,
NetScope*found) const;
NetExpr*elaborate_expr_net_bit_(Design*des,
NetScope*scope,
NetESignal*net,
NetScope*found) const;
public:
NetNet* elaborate_net_array_(Design*des, NetScope*scope,
NetNet*sig, unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
NetNet* elaborate_net_net_(Design*des, NetScope*scope,
NetNet*sig, unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
NetNet* elaborate_net_net_idx_up_(Design*des, NetScope*scope,
NetNet*sig, unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
NetNet* elaborate_net_bitmux_(Design*des, NetScope*scope,
NetNet*sig,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
private:
NetNet* elaborate_lnet_common_(Design*des, NetScope*scope,
bool bidirectional_flag) const;
NetNet*make_implicit_net_(Design*des, NetScope*scope) const;
bool eval_part_select_(Design*des, NetScope*scope, NetNet*sig,
long&midx, long&lidx) const;
NetNet*process_select_(Design*des, NetScope*scope, NetNet*sig) const;
};
class PENumber : public PExpr {
public:
explicit PENumber(verinum*vp);
~PENumber();
const verinum& value() const;
virtual void dump(ostream&) const;
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const;
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual NetEConst*elaborate_expr(Design*des, NetScope*,
int expr_width, bool) const;
virtual NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
virtual NetAssign_* elaborate_lval(Design*des,
NetScope*scope,
bool is_force) const;
virtual verinum* eval_const(Design*des, NetScope*sc) const;
virtual bool is_the_same(const PExpr*that) const;
virtual bool is_constant(Module*) const;
private:
verinum*const value_;
};
/*
* This represents a string constant in an expression.
*
* The s parameter to the PEString constructor is a C string that this
* class instance will take for its own. The caller should not delete
* the string, the destructor will do it.
*/
class PEString : public PExpr {
public:
explicit PEString(char*s);
~PEString();
string value() const;
virtual void dump(ostream&) const;
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const;
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual NetEConst*elaborate_expr(Design*des, NetScope*,
int expr_width, bool) const;
virtual NetEConst*elaborate_pexpr(Design*des, NetScope*sc) const;
verinum* eval_const(Design*, NetScope*) const;
virtual bool is_constant(Module*) const;
private:
char*text_;
};
class PEUnary : public PExpr {
public:
explicit PEUnary(char op, PExpr*ex);
~PEUnary();
virtual void dump(ostream&out) const;
virtual bool elaborate_sig(Design*des, NetScope*scope) const;
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual NetExpr*elaborate_expr(Design*des, NetScope*,
int expr_width, bool sys_task_arg) const;
virtual NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
virtual verinum* eval_const(Design*des, NetScope*sc) const;
virtual bool is_constant(Module*) const;
private:
NetNet* elab_net_uminus_const_logic_(Design*des, NetScope*scope,
NetEConst*expr,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
NetNet* elab_net_uminus_const_real_(Design*des, NetScope*scope,
NetECReal*expr,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
NetNet* elab_net_unary_real_(Design*des, NetScope*scope,
NetExpr*expr,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
private:
char op_;
PExpr*expr_;
};
class PEBinary : public PExpr {
public:
explicit PEBinary(char op, PExpr*l, PExpr*r);
~PEBinary();
virtual bool is_constant(Module*) const;
virtual void dump(ostream&out) const;
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const;
virtual bool elaborate_sig(Design*des, NetScope*scope) const;
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual NetExpr*elaborate_expr(Design*des, NetScope*,
int expr_width, bool sys_task_arg) const;
virtual NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
virtual verinum* eval_const(Design*des, NetScope*sc) const;
protected:
char op_;
PExpr*left_;
PExpr*right_;
NetExpr*elaborate_expr_base_(Design*, NetExpr*lp, NetExpr*rp, int use_wid) const;
NetExpr*elaborate_eval_expr_base_(Design*, NetExpr*lp, NetExpr*rp, int use_wid) const;
static void suppress_operand_sign_if_needed_(NetExpr*lp, NetExpr*rp);
private:
NetNet* elaborate_net_add_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
NetNet* elaborate_net_bit_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
NetNet* elaborate_net_cmp_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
NetNet* elaborate_net_div_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
NetNet* elaborate_net_mod_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
NetNet* elaborate_net_log_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
NetNet* elaborate_net_mul_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
NetNet* elaborate_net_pow_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
NetNet* elaborate_net_shift_(Design*des, NetScope*scope,
unsigned lwidth,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay) const;
};
/*
* Here are a few specialized classes for handling specific binary
* operators.
*/
class PEBComp : public PEBinary {
public:
explicit PEBComp(char op, PExpr*l, PExpr*r);
~PEBComp();
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&flag) const;
NetExpr* elaborate_expr(Design*des, NetScope*scope,
int expr_width, bool sys_task_arg) const;
};
class PEBShift : public PEBinary {
public:
explicit PEBShift(char op, PExpr*l, PExpr*r);
~PEBShift();
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval, bool&flag) const;
};
/*
* This class supports the ternary (?:) operator. The operator takes
* three expressions, the test, the true result and the false result.
*/
class PETernary : public PExpr {
public:
explicit PETernary(PExpr*e, PExpr*t, PExpr*f);
~PETernary();
virtual bool is_constant(Module*) const;
virtual void dump(ostream&out) const;
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const;
virtual bool elaborate_sig(Design*des, NetScope*scope) const;
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual NetETernary*elaborate_expr(Design*des, NetScope*,
int expr_width, bool sys_task_arg) const;
virtual NetETernary*elaborate_pexpr(Design*des, NetScope*sc) const;
virtual verinum* eval_const(Design*des, NetScope*sc) const;
private:
PExpr*expr_;
PExpr*tru_;
PExpr*fal_;
};
/*
* This class represents a parsed call to a function, including calls
* to system functions. The parameters in the parms list are the
* expressions that are passed as input to the ports of the function.
*/
class PECallFunction : public PExpr {
public:
explicit PECallFunction(const pform_name_t&n, const svector<PExpr *> &parms);
// Call of system function (name is not hierarchical)
explicit PECallFunction(perm_string n, const svector<PExpr *> &parms);
explicit PECallFunction(perm_string n);
~PECallFunction();
virtual void dump(ostream &) const;
virtual NetNet* elaborate_net(Design*des, NetScope*scope,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
virtual NetExpr*elaborate_expr(Design*des, NetScope*scope,
int expr_wid, bool sys_task_arg) const;
virtual unsigned test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const;
private:
pform_name_t path_;
svector<PExpr *> parms_;
bool check_call_matches_definition_(Design*des, NetScope*dscope) const;
NetExpr* elaborate_sfunc_(Design*des, NetScope*scope, int expr_wid) const;
NetNet* elaborate_net_sfunc_(Design*des, NetScope*scope,
unsigned width,
const NetExpr* rise,
const NetExpr* fall,
const NetExpr* decay,
Link::strength_t drive0,
Link::strength_t drive1) const;
unsigned test_width_sfunc_(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const;
};
#endif
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