Refactor LPM code

tgt-vhdl/lpm.cc

@@ -23,6 +23,53 @@
 #include <iostream>
 #include <cassert>
 
+/*
+ * Return the base of a part select.
+ */
+static vhdl_expr *part_select_base(vhdl_scope *scope, ivl_lpm_t lpm)
+{
+   vhdl_expr *off;
+   ivl_nexus_t base = ivl_lpm_data(lpm, 1);
+   if (base != NULL)
+      off = nexus_to_var_ref(scope, base);
+   else
+      off = new vhdl_const_int(ivl_lpm_base(lpm));
+
+   // Array indexes must be integers
+   vhdl_type integer(VHDL_TYPE_INTEGER);
+   return off->cast(&integer);
+}
+
+vhdl_var_ref *lpm_output(vhdl_scope *scope, ivl_lpm_t lpm)
+{
+   vhdl_var_ref *out = nexus_to_var_ref(scope, ivl_lpm_q(lpm, 0));
+   if (NULL == out) {
+      vhdl_type *type =
+         vhdl_type::type_for(ivl_lpm_width(lpm),
+                             ivl_lpm_signed(lpm) != 0);
+      string name("LPM");
+      name += ivl_lpm_basename(lpm);
+      name += "_Out";
+
+      if (!scope->have_declared(name)) {
+         scope->add_decl
+            (new vhdl_signal_decl(name.c_str(), new vhdl_type(*type)));
+      }
+      
+      out = new vhdl_var_ref(name.c_str(), type);
+   }
+
+   if (ivl_lpm_type(lpm) == IVL_LPM_PART_PV) {
+      vhdl_expr *off = part_select_base(scope, lpm);
+      assert(off);
+
+      out->set_slice(off, ivl_lpm_width(lpm) - 1);
+   }
+   
+   return out;
+}
+
+
 static vhdl_expr *concat_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
 {
    vhdl_type *result_type =
@@ -71,23 +118,6 @@ static vhdl_expr *binop_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm, vhdl_binop
       return expr;
 }
 
-/*
- * Return the base of a part select.
- */
-static vhdl_expr *part_select_base(vhdl_scope *scope, ivl_lpm_t lpm)
-{
-   vhdl_expr *off;
-   ivl_nexus_t base = ivl_lpm_data(lpm, 1);
-   if (base != NULL)
-      off = nexus_to_var_ref(scope, base);
-   else
-      off = new vhdl_const_int(ivl_lpm_base(lpm));
-
-   // Array indexes must be integers
-   vhdl_type integer(VHDL_TYPE_INTEGER);
-   return off->cast(&integer);
-}
-
 static vhdl_expr *part_select_vp_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
 {
    vhdl_var_ref *selfrom = nexus_to_var_ref(scope, ivl_lpm_data(lpm, 0));
@@ -102,37 +132,10 @@ static vhdl_expr *part_select_vp_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
    return selfrom;
 }
 
+
 static vhdl_expr *part_select_pv_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
 {   
-   vhdl_expr *off = part_select_base(scope, lpm);;
+   return nexus_to_var_ref(scope, ivl_lpm_data(lpm, 0));
-   if (NULL == off)
-      return NULL;
-   
-   vhdl_var_ref *out = nexus_to_var_ref(scope, ivl_lpm_q(lpm, 0));
-   if (NULL == out)
-      return NULL;
-
-   out->set_slice(off, ivl_lpm_width(lpm) - 1);
-   return out;
-}
-
-static int draw_part_select_pv_lpm(vhdl_arch *arch, ivl_lpm_t lpm)
-{
-   vhdl_var_ref *out;
-   vhdl_var_ref *selfrom;
-   if (NULL == (out = nexus_to_var_ref(arch->get_scope(), ivl_lpm_q(lpm, 0)))
-       || NULL == (selfrom = nexus_to_var_ref(arch->get_scope(), ivl_lpm_data(lpm, 0)))) {
-      // Not continuous assignment to signal: ignore it
-      return 0;
-   }
-
-   vhdl_expr *off = part_select_base(arch->get_scope(), lpm);;
-   if (NULL == off)
-      return 1;
-
-   out->set_slice(off, ivl_lpm_width(lpm) - 1);
-   arch->add_stmt(new vhdl_cassign_stmt(out, selfrom));
-   return 0;
 }
 
 static vhdl_expr *ufunc_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
@@ -200,7 +203,7 @@ static vhdl_expr *array_lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
    return ref;
 }
 
-vhdl_expr *lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
+static vhdl_expr *lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
 {
    switch (ivl_lpm_type(lpm)) {
    case IVL_LPM_ADD:
@@ -241,18 +244,13 @@ vhdl_expr *lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm)
 
 int draw_lpm(vhdl_arch *arch, ivl_lpm_t lpm)
 {
-   if (ivl_lpm_type(lpm) == IVL_LPM_PART_PV)
+   vhdl_expr *f = lpm_to_expr(arch->get_scope(), lpm);
-      return draw_part_select_pv_lpm(arch, lpm);
+   if (NULL == f)
-   else {
-      vhdl_expr *f = lpm_to_expr(arch->get_scope(), lpm);
-      if (NULL == f)
-         return 1;
-        
-      vhdl_var_ref *out = nexus_to_var_ref(arch->get_scope(), ivl_lpm_q(lpm, 0));
-      if (out)
-         arch->add_stmt(new vhdl_cassign_stmt(out, f));
-      
       return 0;
-   }
+   
+   vhdl_var_ref *out = lpm_output(arch->get_scope(), lpm);
+   arch->add_stmt(new vhdl_cassign_stmt(out, f));
+   
+   return 0;
 }
 

tgt-vhdl/scope.cc

@@ -77,7 +77,7 @@ static vhdl_expr *nexus_to_expr(vhdl_scope *arch_scope, ivl_nexus_t nexus,
       }
       else if ((allowed & NEXUS_TO_OTHER) &&
                (lpm = ivl_nexus_ptr_lpm(nexus_ptr))) {
-         return lpm_to_expr(arch_scope, lpm);
+         return lpm_output(arch_scope, lpm);
       }
       else if ((allowed & NEXUS_TO_CONST) &&
                (con = ivl_nexus_ptr_con(nexus_ptr))) {
@@ -370,8 +370,9 @@ static void declare_lpm(vhdl_arch *arch, ivl_scope_t scope)
 {
    int nlpms = ivl_scope_lpms(scope);
    for (int i = 0; i < nlpms; i++) {
-      if (draw_lpm(arch, ivl_scope_lpm(scope, i)) != 0)
+      ivl_lpm_t lpm = ivl_scope_lpm(scope, i);
-         error("Failed to translate LPM");
+      if (draw_lpm(arch, lpm) != 0)
+         error("Failed to translate LPM %s", ivl_lpm_name(lpm));
    }
 }
 
@@ -564,12 +565,22 @@ static int draw_module(ivl_scope_t scope, ivl_scope_t parent)
          }
          
          // And an instantiation statement
-         std::string inst_name(ivl_scope_basename(scope));
+         string inst_name(ivl_scope_basename(scope));
          if (inst_name == ent->get_name()) {
             // Cannot have instance name the same as type in VHDL
             inst_name += "_Inst";
          }
 
+         // Need to replace any [ and ] characters that result
+         // from generate statements
+         string::size_type loc = inst_name.find('[', 0);
+         if (loc != string::npos)
+            inst_name.erase(loc, 1);
+
+         loc = inst_name.find(']', 0);
+         if (loc != string::npos)
+            inst_name.erase(loc, 1);         
+                     
          vhdl_comp_inst *inst =
             new vhdl_comp_inst(inst_name.c_str(), ent->get_name().c_str());
          port_map(scope, parent_ent, inst);         

tgt-vhdl/stmt.cc

@@ -289,7 +289,9 @@ static int draw_assign(vhdl_procedural *proc, stmt_container *container,
                        ivl_statement_t stmt)
 {
    if (proc->get_scope()->allow_signal_assignment()) {
-      // TODO: Explain blocking assignment here
+      // Blocking assignment is implemented as non-blocking assignment
+      // followed by a zero-time wait
+      // This follows the Verilog semantics fairly closely.
 
       vhdl_nbassign_stmt *a =
          make_assignment<vhdl_nbassign_stmt>(proc, container, stmt, false);

tgt-vhdl/vhdl_target.h

@@ -19,8 +19,8 @@ int draw_stmt(vhdl_procedural *proc, stmt_container *container,
               ivl_statement_t stmt);
 int draw_lpm(vhdl_arch *arch, ivl_lpm_t lpm);
 
-vhdl_expr *lpm_to_expr(vhdl_scope *scope, ivl_lpm_t lpm);
 vhdl_expr *translate_expr(ivl_expr_t e);
+vhdl_var_ref *lpm_output(vhdl_scope *scope, ivl_lpm_t lpm);
 
 void remember_entity(vhdl_entity *ent);
 vhdl_entity *find_entity(const string &tname);