Right shift by constant.

tgt-vvp/eval_expr.c

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: eval_expr.c,v 1.18 2001/04/21 01:49:17 steve Exp $"
+#ident "$Id: eval_expr.c,v 1.19 2001/04/21 03:26:23 steve Exp $"
 #endif
 
 # include  "vvp_priv.h"
@@ -314,13 +314,11 @@ static struct vector_info draw_binary_expr_ls(ivl_expr_t exp, unsigned wid)
       ivl_expr_t le = ivl_expr_oper1(exp);
       ivl_expr_t re = ivl_expr_oper2(exp);
 
-      unsigned shift;
+      unsigned shift = 0;
 
       struct vector_info lv;
       struct vector_info rs;
 
-      lv = draw_eval_expr_wid(le, wid);
-
 	/* XXXX support only constant right expressions. */
       switch (ivl_expr_type(re)) {
 	  case IVL_EX_NUMBER: {
@@ -355,6 +353,8 @@ static struct vector_info draw_binary_expr_ls(ivl_expr_t exp, unsigned wid)
 	    return rs;
       }
 
+      lv = draw_eval_expr_wid(le, wid);
+
       assert(lv.wid >= (wid - shift));
       rs.base = allocate_vector(wid);
       rs.wid = wid;
@@ -367,6 +367,77 @@ static struct vector_info draw_binary_expr_ls(ivl_expr_t exp, unsigned wid)
       return rs;
 }
 
+static struct vector_info draw_binary_expr_rs(ivl_expr_t exp, unsigned wid)
+{
+      ivl_expr_t le = ivl_expr_oper1(exp);
+      ivl_expr_t re = ivl_expr_oper2(exp);
+
+      unsigned shift = 0;
+
+      struct vector_info lv;
+      struct vector_info rs;
+
+	/* XXXX support only constant right expressions. */
+      switch (ivl_expr_type(re)) {
+	  case IVL_EX_NUMBER: {
+		unsigned idx, nbits = ivl_expr_width(re);
+		const char*bits = ivl_expr_bits(re);
+
+		for (idx = 0 ;  idx < nbits ;  idx += 1) switch (bits[idx]) {
+
+		    case '0':
+		      break;
+		    case '1':
+		      assert(idx < (8*sizeof shift));
+		      shift |= 1 << idx;
+		      break;
+		    default:
+		      assert(0);
+		}
+		break;
+	  }
+	    
+	  case IVL_EX_ULONG:
+	    shift = ivl_expr_uvalue(re);
+	    break;
+	  default:
+	    assert(0);
+	    break;
+      }
+
+      if (shift >= wid) {
+	    rs.base = 0;
+	    rs.wid  = wid;
+	    return rs;
+      }
+
+      lv = draw_eval_expr_wid(le, wid);
+
+
+      switch (lv.base) {
+	  case 0:
+	    return lv;
+	  case 1:
+	  case 2:
+	  case 3:
+	    rs.base = allocate_vector(wid);
+	    rs.wid = wid;
+	    fprintf(vvp_out, "    %%mov %u, %u, %u;\n", rs.base,
+		    lv.base, wid-shift);
+	    fprintf(vvp_out, "    %%mov %u, 0, %u;\n",
+		    rs.base+wid-shift, shift);
+	    return rs;
+
+	  default:
+	    assert(lv.wid == wid);
+	    fprintf(vvp_out, "    %%mov %u, %u, %u;\n", lv.base,
+		    lv.base+shift, wid-shift);
+	    fprintf(vvp_out, "    %%mov %u, 0, %u;\n",
+		    lv.base+wid-shift, shift);
+	    return lv;
+      }
+}
+
 static struct vector_info draw_binary_expr_plus(ivl_expr_t exp, unsigned wid)
 {
       ivl_expr_t le = ivl_expr_oper1(exp);
@@ -416,10 +487,14 @@ static struct vector_info draw_binary_expr(ivl_expr_t exp, unsigned wid)
 	    rv = draw_binary_expr_plus(exp, wid);
 	    break;
 
-	  case 'l':
+	  case 'l': /* << */
 	    rv = draw_binary_expr_ls(exp, wid);
 	    break;
 
+	  case 'r': /* >> */
+	    rv = draw_binary_expr_rs(exp, wid);
+	    break;
+
 	  case '&':
 	  case '|':
 	  case '^':
@@ -732,6 +807,9 @@ struct vector_info draw_eval_expr(ivl_expr_t exp)
 
 /*
  * $Log: eval_expr.c,v $
+ * Revision 1.19  2001/04/21 03:26:23  steve
+ *  Right shift by constant.
+ *
  * Revision 1.18  2001/04/21 01:49:17  steve
  *  Left shift by a constant amount.
  *

tgt-vvp/vvp_process.c

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: vvp_process.c,v 1.29 2001/04/21 00:55:46 steve Exp $"
+#ident "$Id: vvp_process.c,v 1.30 2001/04/21 03:26:23 steve Exp $"
 #endif
 
 # include  "vvp_priv.h"
@@ -141,8 +141,10 @@ static int show_stmt_assign(ivl_statement_t net)
 	if (ivl_lval_pins(lval) < wid)
 	      wid = ivl_lval_pins(lval);
 
-	for (idx = 0 ;  idx < wid ;  idx += 1)
+	for (idx = 0 ;  idx < wid ;  idx += 1) {
-	      set_to_nexus(ivl_lval_pin(lval, idx), res.base+idx);
+	      unsigned bidx = res.base < 4? res.base : (res.base+idx);
+	      set_to_nexus(ivl_lval_pin(lval, idx), bidx);
+	}
 
 	for (idx = wid ;  idx < ivl_lval_pins(lval) ;  idx += 1)
 	      set_to_nexus(ivl_lval_pin(lval, idx), 0);
@@ -749,6 +751,9 @@ int draw_func_definition(ivl_scope_t scope)
 
 /*
  * $Log: vvp_process.c,v $
+ * Revision 1.30  2001/04/21 03:26:23  steve
+ *  Right shift by constant.
+ *
  * Revision 1.29  2001/04/21 00:55:46  steve
  *  Generate code for disable.
  *