Merge pull request #19 from fukatani/master

Thank you for your pull request. This modification might be useful for the future extension, and seems that it does not affect the current behavior. 
"Provisional commit for issue #14. Implemented function for detecting reset."

Author: shtaxxx

pyverilog/dataflow/bindvisitor.py

@@ -256,6 +256,11 @@ def _createAlwaysinfo(self, node, scope):
         reset_name = None
         reset_bit = None
 
+        #TODO unimplemented
+        #print('load: ' + str(self._first_lvalue_is_const(node)))
+        #print('if_branch: ' + str(self._has_if_branch(node)))
+        #print('reset_info: ' + str(self._get_rst_info(node)))
+
         for l in node.sens_list.list:
             if l.sig is None:
                 continue
@@ -283,6 +288,134 @@ def _createAlwaysinfo(self, node, scope):
 
         return (clock_name, clock_edge, clock_bit, reset_name, reset_edge, reset_bit, senslist)
 
+    #TODO This function is implemented for https://github.com/PyHDI/Pyverilog/issues/14.
+    #Be incorporated into formally in lator commit.
+    def _first_lvalue_is_const(self, node):
+        """ [FUNCTIONS]
+        Walk until lvalue and judge whether it is constant or not.
+
+        ex.
+        if(RST)
+          reg1 <= 1'd0: //const: judged as rst branch
+
+        if(RST)
+          reg1 <= {1'd0, 1'd0}: //const: judged as rst branch
+
+        if(RST)
+          reg1 <= reg2: //variable: judged as not rst branch
+
+        if(RST)
+          reg1 <= {1'd0, reg2}: //variable: judged as not rst branch
+        """
+        if isinstance(node, Always):
+            return self._first_lvalue_is_const(node.statement)
+        elif isinstance(node, Block):
+            return self._first_lvalue_is_const(node.statements[0])
+        elif isinstance(node, IfStatement):
+            return self._first_lvalue_is_const(node.true_statement)
+        elif isinstance(node, NonblockingSubstitution):
+            print(node.left.var)# for debug
+            return self._first_lvalue_is_const(node.right)
+        elif isinstance(node, Identifier):
+            node_chain = self.get_scopechain(node)
+            if node_chain in self.dataflow.terms.keys():
+                #Parameter is regard as constant.
+                return 'Parameter' in self.dataflow.terms[node_chain].termtype
+            return False
+        elif hasattr(node, 'children'):
+            for child in node.children():
+                if not self._first_lvalue_is_const(child):
+                    return False
+            return True
+        elif isinstance(node, Rvalue):
+            return self._first_lvalue_is_const(node.var)
+        elif hasattr(node, 'value'):
+            return True
+        else:
+            raise Exception('Pyverilog unknown error')
+
+    def get_scopechain(self, node):
+        assert isinstance(node, Identifier), 'Node type should be Identifier.'
+        scope_list = self.frames.current.get_module_list() + [util.ScopeLabel(str(node)),]
+        return util.ScopeChain(scope_list)
+
+    #TODO This function is implemented for https://github.com/PyHDI/Pyverilog/issues/14.
+    #Be incorporated into formally in lator commit.
+    def _get_rst_info(self, node, rst_name='', is_posedge=True, rst_bit=0):
+        """ [FUNCTIONS]
+        get reset information from first if statement.
+
+        ex1.
+        always @(posedge CLK or posedge RST) begin
+            if(RST)
+                reg1 <= 0;
+            else
+                reg1 <= !reg1;
+        end
+        ->RST is posedge RST.
+
+        ex2.
+        always @(posedge CLK or posedge RST) begin
+            if(!RSTN[1])
+                reg1 <= 0;
+            else
+                reg1 <= !reg1;
+        end
+        ->RSTN[1] is negedge RST.
+
+        ex3.
+        always @(posedge CLK or posedge RST) begin
+            if(RST && RST2)
+                reg1 <= 0;
+            else
+                reg1 <= !reg1;
+        end
+        -> reg1 has no reset. (too complex condition)
+        """
+        if isinstance(node, Always):
+            return self._get_rst_info(node.statement, rst_name, is_posedge, rst_bit)
+        elif isinstance(node, Block):
+            return self._get_rst_info(node.statements[0], rst_name, is_posedge, rst_bit)
+        elif isinstance(node, IfStatement):
+            return self._get_rst_info(node.cond, rst_name, is_posedge, rst_bit)
+        elif isinstance(node, pyverilog.vparser.ast.Ulnot):
+            is_posedge = not is_posedge
+            return self._get_rst_info(node.children()[0], rst_name, is_posedge, rst_bit)
+        elif isinstance(node, pyverilog.vparser.ast.Pointer):
+            #TODO if identifier
+            if isinstance(node.ptr, Identifier):
+                ptr_chain = self.get_scopechain(node.ptr)
+                if 'Parameter' in self.dataflow.terms[ptr_chain].termtype:
+                    rst_bit = self.dataflow.binddict[ptr_chain][0].tree.eval()
+                    return self._get_rst_info(node.var, rst_name, is_posedge, rst_bit)
+                else:
+                    return (None, None, None)
+            elif hasattr(node.ptr, 'value'):
+                return self._get_rst_info(node.var, rst_name, is_posedge, int(node.ptr.value))
+        elif isinstance(node, pyverilog.vparser.ast.Identifier):
+            return (node, is_posedge, rst_bit)
+        return (None, None, None)
+
+    #TODO This function is implemented for https://github.com/PyHDI/Pyverilog/issues/14.
+    #Be incorporated into formally in lator commit.
+    def _has_if_branch(self, node):
+        """ [FUNCTIONS]
+        Return always block have 'if branch' or not.
+        ex.
+        always @(posedge CLK or posedge RST) begin
+            reg1 <= 0;
+        end
+        -> reg1 has no reset. (If statement isn't exists.)
+        """
+        if isinstance(node, Always):
+            return self._has_if_branch(node.statement)
+        elif isinstance(node, Block):
+            return self._has_if_branch(node.statements[0])
+        elif isinstance(node, IfStatement):
+            return True
+        else:
+            return  False
+
     def visit_IfStatement(self, node):
         if self.frames.isFunctiondef() and not self.frames.isFunctioncall(): return
         if self.frames.isTaskdef() and not self.frames.isTaskcall(): return
@@ -828,7 +961,7 @@ def addTerm(self, node, rscope=None):
         else:
             msb = DFIntConst('0') if node.width is None else self.makeDFTree(node.width.msb, scope)
         lsb = DFIntConst('0') if node.width is None else self.makeDFTree(node.width.lsb, scope)
-        
+
         lenmsb = None
         lenlsb = None
         if isinstance(node, RegArray) or isinstance(node, WireArray):

pyverilog/utils/scope.py

@@ -1,6 +1,6 @@
 #-------------------------------------------------------------------------------
 # scope.py
-# 
+#
 # classes for definition of scope
 #
 # Copyright (C) 2013, Shinya Takamaeda-Yamazaki
@@ -12,7 +12,7 @@
 import os
 import copy
 
-scopetype_list_unprint = ('generate', 'always', 'function', #'functioncall', 
+scopetype_list_unprint = ('generate', 'always', 'function', #'functioncall',
                           'task', 'taskcall', 'initial', 'for', 'while', 'if')
 scopetype_list_print = ('module', 'block', 'signal', 'functioncall',)
 scopetype_list = scopetype_list_unprint + scopetype_list_print + ('any', )
@@ -88,6 +88,8 @@ def tocode(self):
                 it = None
         ret = ret[:-1]
         return ''.join(ret)
+    def get_module_list(self):
+        return [scope for scope in self.scopechain if scope.scopetype == 'module']
     def __repr__(self):
         ret = ''
         for scope in self.scopechain:

testcode/reset.v

@@ -0,0 +1,96 @@
+module TOP(CLK, RST);
+  input CLK, RST;
+  reg [7:0] cnt1,cnt2,cnt3,cnt4,cnt5,cnt6,cnt7,cnt8,cnt9,cnt10;
+  parameter zero = 0;
+
+  //reset
+  always @(posedge CLK) begin
+    if(RST[0]) begin
+      cnt1 <= 0;
+    end else begin
+      cnt1 <= 8'd1;
+    end
+  end
+
+  //reset
+  always @(posedge CLK or posedge RST)
+    if(RST)
+      cnt2 <= 0;
+    else
+      cnt2 <= 8'd1;
+
+  //not reset
+  always @(posedge CLK or posedge RST) begin
+    if(RST) begin
+      cnt3 <= cnt1[0];
+    end else begin
+      cnt3 <= 8'd1;
+    end
+  end
+
+  //not reset
+  always @(posedge CLK or posedge RST) begin
+    cnt4 <= 0;
+  end
+
+  //reset
+  always @(posedge CLK or posedge RST) begin
+    if(RST) begin
+      cnt5 <= {2'd0,6'd0};
+    end else begin
+      cnt5 <= 8'd1;
+    end
+  end
+
+  //not reset
+  always @(posedge CLK or posedge RST) begin
+    if(RST) begin
+      cnt6 <= 7'd0 + cnt1[1:0];
+    end else begin
+      cnt6 <= 8'd1;
+    end
+  end
+
+  //reset
+  always @(posedge CLK) begin
+    if(!RST) begin
+      cnt7 <= 0;
+    end else begin
+      cnt7 <= 8'd1;
+    end
+  end
+
+  //not reset
+  always @(posedge CLK) begin
+    if(RST && RST) begin
+      cnt8 <= 0;
+    end else begin
+      cnt8 <= 8'd1;
+    end
+  end
+
+  always @(posedge CLK) begin
+    if(RST[zero]) begin
+      cnt10 <= 0;
+    end else begin
+      cnt10 <= 8'd1;
+    end
+  end
+
+  SUB sub(CLK,RST);
+
+endmodule
+
+module SUB(CLK, RST);
+  input CLK, RST;
+  reg [7:0] cnt9;
+  parameter zero = 0;
+
+  always @(posedge CLK) begin
+    if(RST) begin
+      cnt9 <= zero;
+    end else begin
+      cnt9 <= 8'd1;
+    end
+  end
+endmodule

tests/dataflow_test/test_reset.py

@@ -0,0 +1,48 @@
+import os
+import sys
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
+from pyverilog.dataflow.dataflow_analyzer import VerilogDataflowAnalyzer
+
+codedir = '../../testcode/'
+
+expected = """\
+"""
+
+def test():
+    filelist = [codedir + 'reset.v']
+    topmodule = 'TOP'
+    noreorder = False
+    nobind = False
+    include = None
+    define = None
+
+    analyzer = VerilogDataflowAnalyzer(filelist, topmodule,
+                                       noreorder=noreorder,
+                                       nobind=nobind,
+                                       preprocess_include=include,
+                                       preprocess_define=define)
+    analyzer.generate()
+    #TODO Current version is for only display.
+##    directives = analyzer.get_directives()
+##    instances = analyzer.getInstances()
+##    terms = analyzer.getTerms()
+##    binddict = analyzer.getBinddict()
+##
+##    output = []
+##    output.append(list(binddict.values())[0][0].tostr())
+##    output.append('\n')
+##
+##    rslt = ''.join(output)
+##
+##    print(rslt)
+##    for key, verb in binddict.items():
+##        if verb[0].getResetName() is None:
+##            print(str(key) + ': None')
+##        else:
+##            print(str(key) + ': ' + verb[0].getResetEdge() + str(verb[0].getResetName()) +
+##              '[' + str(verb[0].getResetBit()) + ']')
+
+
+
+if __name__ == '__main__':
+    test()