From 30fdadc5252f1d9746ac76177af9959bacd4ef58 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Wed, 23 Jul 2008 13:40:42 +0100
Subject: [PATCH] Support delays in logic devices

---
 tgt-vhdl/scope.cc       | 21 +++++++++++++++++++--
 tgt-vhdl/vhdl_syntax.cc |  6 ++++++
 tgt-vhdl/vhdl_syntax.hh |  5 +++--
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/tgt-vhdl/scope.cc b/tgt-vhdl/scope.cc
index ac1202fff..69808076b 100644
--- a/tgt-vhdl/scope.cc
+++ b/tgt-vhdl/scope.cc
@@ -242,9 +242,26 @@ static void declare_logic(vhdl_arch *arch, ivl_scope_t scope)
                dynamic_cast<vhdl_var_ref*>(nexus_to_expr(arch->get_scope(), output));
             if (NULL == lhs)
                continue;  // Not suitable for continuous assignment
-            
+
             vhdl_expr *rhs = translate_logic(arch->get_scope(), log);
-            arch->add_stmt(new vhdl_cassign_stmt(lhs, rhs));
+            vhdl_cassign_stmt *ass = new vhdl_cassign_stmt(lhs, rhs);
+            
+            ivl_expr_t delay = ivl_logic_delay(log, 1);
+            vhdl_expr *after;
+            if (delay && (after = translate_expr(delay))) {
+               // Need to make 'after' a time value
+               // we can do this by multiplying by 1ns
+               vhdl_type integer(VHDL_TYPE_INTEGER);
+               after = after->cast(&integer);
+               
+               vhdl_expr *ns1 = new vhdl_const_time(1, TIME_UNIT_NS);
+               after = new vhdl_binop_expr(after, VHDL_BINOP_MULT, ns1,
+                                           vhdl_type::time());
+               
+               ass->set_after(after);
+            }
+            
+            arch->add_stmt(ass);
          }
       }
    }
diff --git a/tgt-vhdl/vhdl_syntax.cc b/tgt-vhdl/vhdl_syntax.cc
index a14f11e6d..2f5e9f56f 100644
--- a/tgt-vhdl/vhdl_syntax.cc
+++ b/tgt-vhdl/vhdl_syntax.cc
@@ -611,6 +611,12 @@ void vhdl_cassign_stmt::emit(std::ostream &of, int level) const
       of << "else ";
    }
    rhs_->emit(of, level);
+   
+   if (after_) {
+      of << " after ";
+      after_->emit(of, level);
+   }
+      
    of << ";";
 }
 
diff --git a/tgt-vhdl/vhdl_syntax.hh b/tgt-vhdl/vhdl_syntax.hh
index c6a2c727f..f7acf9762 100644
--- a/tgt-vhdl/vhdl_syntax.hh
+++ b/tgt-vhdl/vhdl_syntax.hh
@@ -227,14 +227,15 @@ typedef std::list<vhdl_conc_stmt*> conc_stmt_list_t;
 class vhdl_cassign_stmt : public vhdl_conc_stmt {
 public:
    vhdl_cassign_stmt(vhdl_var_ref *lhs, vhdl_expr *rhs)
-      : lhs_(lhs), rhs_(rhs) {}
+      : lhs_(lhs), rhs_(rhs), after_(NULL) {}
    ~vhdl_cassign_stmt();
 
    void emit(std::ostream &of, int level) const;
    void add_condition(vhdl_expr *value, vhdl_expr *cond);
+   void set_after(vhdl_expr *a) { after_ = a; }
 private:
    vhdl_var_ref *lhs_;
-   vhdl_expr *rhs_;
+   vhdl_expr *rhs_, *after_;
 
    struct when_part_t {
       vhdl_expr *value, *cond;