From 199ed39abef153c69434112b7868766bf37725e8 Mon Sep 17 00:00:00 2001
From: Cary R <cygcary@yahoo.com>
Date: Sun, 2 Aug 2020 23:34:52 -0700
Subject: [PATCH] Report when the array pattern is larger than the maximum
 queue size

---
 tgt-vvp/stmt_assign.c | 23 +++++++++++++++++++++--
 vvp/codes.h           |  1 +
 vvp/compile.cc        |  1 +
 vvp/vthread.cc        | 20 ++++++++++++++++++++
 vvp/vvp_darray.cc     | 21 +++++++++++++++++++++
 vvp/vvp_darray.h      |  4 ++++
 6 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/tgt-vvp/stmt_assign.c b/tgt-vvp/stmt_assign.c
index 5fde4ba29..c31528019 100644
--- a/tgt-vvp/stmt_assign.c
+++ b/tgt-vvp/stmt_assign.c
@@ -1055,8 +1055,19 @@ static int show_stmt_assign_queue_pattern(ivl_signal_t var, ivl_expr_t rval,
 {
       int errors = 0;
       unsigned idx;
+      unsigned max_size;
+      unsigned max_elems;
       assert(ivl_expr_type(rval) == IVL_EX_ARRAY_PATTERN);
-      for (idx = 0 ; idx < ivl_expr_parms(rval) ; idx += 1) {
+      max_size = ivl_signal_array_count(var);
+      max_elems = ivl_expr_parms(rval);
+      if ((max_size != 0) && (max_elems > max_size)) {
+	    fprintf(stderr, "Warning: Array pattern assignment has more elements "
+	                    "(%u) than bounded queue '%s' supports (%u).\n"
+	                    "         Only using first %u elements.\n",
+	                    max_elems, ivl_signal_basename(var), max_size, max_size);
+	    max_elems = max_size;
+      }
+      for (idx = 0 ; idx < max_elems ; idx += 1) {
 	    switch (ivl_type_base(element_type)) {
 		case IVL_VT_BOOL:
 		case IVL_VT_LOGIC:
@@ -1086,6 +1097,15 @@ static int show_stmt_assign_queue_pattern(ivl_signal_t var, ivl_expr_t rval,
 	    }
       }
 
+      if ((max_size == 0) || (max_elems < max_size)) {
+	    int del_idx = allocate_word();
+	    assert(del_idx >= 0);
+	      /* Save the first queue element to delete. */
+	    fprintf(vvp_out, "    %%ix/load %u, %u, 0;\n", del_idx, max_elems);
+	    fprintf(vvp_out, "    %%delete/tail v%p_0, %u;\n", var, del_idx);
+	    clr_word(del_idx);
+      }
+
       return errors;
 }
 
@@ -1139,7 +1159,6 @@ static int show_stmt_assign_sig_queue(ivl_statement_t net)
 	      /* There is no l-value mux, but the r-value is an array
 		 pattern. This is a special case of an assignment to
 		 elements of the l-value. */
-	    fprintf(vvp_out, "    %%delete/obj v%p_0;\n", var);
 	    errors += show_stmt_assign_queue_pattern(var, rval, element_type, idx);
       } else {
 	    fprintf(stderr, "Sorry: I don't know how to handle expr_type=%d "
diff --git a/vvp/codes.h b/vvp/codes.h
index a1a71b9a7..b715019d4 100644
--- a/vvp/codes.h
+++ b/vvp/codes.h
@@ -101,6 +101,7 @@ extern bool of_DELAY(vthread_t thr, vvp_code_t code);
 extern bool of_DELAYX(vthread_t thr, vvp_code_t code);
 extern bool of_DELETE_ELEM(vthread_t thr, vvp_code_t code);
 extern bool of_DELETE_OBJ(vthread_t thr, vvp_code_t code);
+extern bool of_DELETE_TAIL(vthread_t thr, vvp_code_t code);
 extern bool of_DISABLE(vthread_t thr, vvp_code_t code);
 extern bool of_DISABLE_FORK(vthread_t thr, vvp_code_t code);
 extern bool of_DIV(vthread_t thr, vvp_code_t code);
diff --git a/vvp/compile.cc b/vvp/compile.cc
index a89312d88..e07d1ae48 100644
--- a/vvp/compile.cc
+++ b/vvp/compile.cc
@@ -153,6 +153,7 @@ static const struct opcode_table_s opcode_table[] = {
       { "%delayx", of_DELAYX, 1,  {OA_NUMBER,   OA_NONE,     OA_NONE} },
       { "%delete/elem",of_DELETE_ELEM,1,{OA_FUNC_PTR,OA_NONE,OA_NONE} },
       { "%delete/obj",of_DELETE_OBJ,1,{OA_FUNC_PTR,OA_NONE,  OA_NONE} },
+      { "%delete/tail",of_DELETE_TAIL,2,{OA_FUNC_PTR,OA_BIT1,OA_NONE} },
       { "%disable",  of_DISABLE, 1, {OA_VPI_PTR,OA_NONE,     OA_NONE} },
       { "%disable/fork",of_DISABLE_FORK,0,{OA_NONE,OA_NONE,  OA_NONE} },
       { "%div",      of_DIV,     0, {OA_NONE,   OA_NONE,     OA_NONE} },
diff --git a/vvp/vthread.cc b/vvp/vthread.cc
index c2a3cddf2..6446ccb4b 100644
--- a/vvp/vthread.cc
+++ b/vvp/vthread.cc
@@ -2468,6 +2468,26 @@ bool of_DELETE_OBJ(vthread_t thr, vvp_code_t cp)
       return true;
 }
 
+/* %delete/tail <label>, idx
+ *
+ * Remove all elements after the one specified.
+ */
+bool of_DELETE_TAIL(vthread_t thr, vvp_code_t cp)
+{
+      vvp_net_t*net = cp->net;
+
+      vvp_fun_signal_object*obj = dynamic_cast<vvp_fun_signal_object*> (net->fun);
+      assert(obj);
+
+      vvp_queue*dqueue = obj->get_object().peek<vvp_queue>();
+      assert(dqueue);
+
+      unsigned idx = thr->words[cp->bit_idx[0]].w_int;
+      dqueue->erase_tail(idx);
+
+      return true;
+}
+
 static bool do_disable(vthread_t thr, vthread_t match)
 {
       bool flag = false;
diff --git a/vvp/vvp_darray.cc b/vvp/vvp_darray.cc
index 4f7a7d92d..868c082dc 100644
--- a/vvp/vvp_darray.cc
+++ b/vvp/vvp_darray.cc
@@ -582,6 +582,13 @@ void vvp_queue_real::erase(unsigned idx)
       queue.erase(pos);
 }
 
+void vvp_queue_real::erase_tail(unsigned idx)
+{
+      assert(queue.size() >= idx);
+      if (queue.size() > idx)
+	    queue.resize(idx);
+}
+
 vvp_queue_string::~vvp_queue_string()
 {
 }
@@ -694,6 +701,13 @@ void vvp_queue_string::erase(unsigned idx)
       queue.erase(pos);
 }
 
+void vvp_queue_string::erase_tail(unsigned idx)
+{
+      assert(queue.size() >= idx);
+      if (queue.size() > idx)
+	    queue.resize(idx);
+}
+
 vvp_queue_vec4::~vvp_queue_vec4()
 {
 }
@@ -805,3 +819,10 @@ void vvp_queue_vec4::erase(unsigned idx)
 
       queue.erase(pos);
 }
+
+void vvp_queue_vec4::erase_tail(unsigned idx)
+{
+      assert(queue.size() >= idx);
+      if (queue.size() > idx)
+	    queue.resize(idx);
+}
diff --git a/vvp/vvp_darray.h b/vvp/vvp_darray.h
index d0d40e9b1..1e7c0c29e 100644
--- a/vvp/vvp_darray.h
+++ b/vvp/vvp_darray.h
@@ -172,6 +172,7 @@ class vvp_queue : public vvp_darray {
       virtual void pop_back(void) =0;
       virtual void pop_front(void)=0;
       virtual void erase(unsigned idx)=0;
+      virtual void erase_tail(unsigned idx)=0;
 };
 
 class vvp_queue_real : public vvp_queue {
@@ -189,6 +190,7 @@ class vvp_queue_real : public vvp_queue {
       void pop_back(void) { queue.pop_back(); };
       void pop_front(void) { queue.pop_front(); };
       void erase(unsigned idx);
+      void erase_tail(unsigned idx);
 
     private:
       std::deque<double> queue;
@@ -209,6 +211,7 @@ class vvp_queue_string : public vvp_queue {
       void pop_back(void) { queue.pop_back(); };
       void pop_front(void) { queue.pop_front(); };
       void erase(unsigned idx);
+      void erase_tail(unsigned idx);
 
     private:
       std::deque<std::string> queue;
@@ -229,6 +232,7 @@ class vvp_queue_vec4 : public vvp_queue {
       void pop_back(void) { queue.pop_back(); };
       void pop_front(void) { queue.pop_front(); };
       void erase(unsigned idx);
+      void erase_tail(unsigned idx);
 
     private:
       std::deque<vvp_vector4_t> queue;