From 8e30bc9f9e68940b32e0639711f2e7ec990e2e42 Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Fri, 22 Nov 2002 00:01:50 +0000
Subject: [PATCH]  Careful of left operands to shift that are constant.

---
 tgt-vvp/eval_expr.c | 31 ++++++++++++++++++++++++++++++-
 vvp/vthread.cc      |  7 ++++++-
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/tgt-vvp/eval_expr.c b/tgt-vvp/eval_expr.c
index d382596e5..caf75fc40 100644
--- a/tgt-vvp/eval_expr.c
+++ b/tgt-vvp/eval_expr.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: eval_expr.c,v 1.85 2002/11/21 22:42:48 steve Exp $"
+#ident "$Id: eval_expr.c,v 1.86 2002/11/22 00:01:50 steve Exp $"
 #endif
 
 # include  "vvp_priv.h"
@@ -666,6 +666,19 @@ static struct vector_info draw_binary_expr_lrs(ivl_expr_t exp, unsigned wid)
 
 	  case 'l': /* << (left shift) */
 	    lv = draw_eval_expr_wid(le, wid, 0);
+
+	      /* shifting 0 gets 0. */
+	    if (lv.base == 0)
+		  break;
+
+	    if (lv.base < 4) {
+		  struct vector_info tmp;
+		  tmp.base = allocate_vector(lv.wid);
+		  tmp.wid = lv.wid;
+		  fprintf(vvp_out, "    %%mov %u, %u, %u;\n",
+			  tmp.base, lv.base, lv.wid);
+		  lv = tmp;
+	    }
 	    fprintf(vvp_out, "    %%shiftl/i0  %u, %u;\n", lv.base, lv.wid);
 	    break;
 
@@ -680,6 +693,19 @@ static struct vector_info draw_binary_expr_lrs(ivl_expr_t exp, unsigned wid)
 	    } else {
 		  lv = draw_eval_expr_wid(le, ivl_expr_width(le), 0);
 	    }
+
+	      /* shifting 0 gets 0. */
+	    if (lv.base == 0)
+		  break;
+
+	    if (lv.base < 4) {
+		  struct vector_info tmp;
+		  tmp.base = allocate_vector(lv.wid);
+		  tmp.wid = lv.wid;
+		  fprintf(vvp_out, "    %%mov %u, %u, %u;\n",
+			  tmp.base, lv.base, lv.wid);
+		  lv = tmp;
+	    }
 	    fprintf(vvp_out, "    %%shiftr/i0  %u, %u;\n", lv.base, lv.wid);
 	    break;
 
@@ -1937,6 +1963,9 @@ struct vector_info draw_eval_expr(ivl_expr_t exp, int stuff_ok_flag)
 
 /*
  * $Log: eval_expr.c,v $
+ * Revision 1.86  2002/11/22 00:01:50  steve
+ *  Careful of left operands to shift that are constant.
+ *
  * Revision 1.85  2002/11/21 22:42:48  steve
  *  Allow right values of right shift to shift in.
  *
diff --git a/vvp/vthread.cc b/vvp/vthread.cc
index a58c4eccd..91e24e6ed 100644
--- a/vvp/vthread.cc
+++ b/vvp/vthread.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vthread.cc,v 1.94 2002/11/21 22:43:14 steve Exp $"
+#ident "$Id: vthread.cc,v 1.95 2002/11/22 00:01:50 steve Exp $"
 #endif
 
 # include  "vthread.h"
@@ -2221,6 +2221,8 @@ bool of_SHIFTL_I0(vthread_t thr, vvp_code_t cp)
       unsigned wid = cp->number;
       unsigned long shift = thr->index[0];
 
+      assert(base >= 4);
+
       if (shift >= wid) {
 	    for (unsigned idx = 0 ;  idx < wid ;  idx += 1)
 		  thr_put_bit(thr, base+idx, 0);
@@ -2494,6 +2496,9 @@ bool of_CALL_UFUNC(vthread_t thr, vvp_code_t cp)
 
 /*
  * $Log: vthread.cc,v $
+ * Revision 1.95  2002/11/22 00:01:50  steve
+ *  Careful of left operands to shift that are constant.
+ *
  * Revision 1.94  2002/11/21 22:43:14  steve
  *  %set/x0 instruction to support bounds checking.
  *