From dfaed128c0d953ea681b165b9ba56fc2040b08e2 Mon Sep 17 00:00:00 2001
From: Stephen Williams <steve@icarus.com>
Date: Wed, 15 Jan 2014 16:30:34 -0800
Subject: [PATCH] Fix %store/vec4 overlap of vectors written with extreme
 indices.

---
 vvp/vthread.cc | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/vvp/vthread.cc b/vvp/vthread.cc
index 3910ed770..5648d54ee 100644
--- a/vvp/vthread.cc
+++ b/vvp/vthread.cc
@@ -1281,6 +1281,7 @@ bool of_ASSIGN_VEC4_OFF_D(vthread_t thr, vvp_code_t cp)
       unsigned off_index = cp->bit_idx[0];
       unsigned del_index = cp->bit_idx[1];
       vvp_vector4_t val = thr->pop_vec4();
+      unsigned wid = val.size();
 
       int off = thr->words[off_index].w_int;
       int del = thr->words[del_index].w_int;
@@ -1300,6 +1301,9 @@ bool of_ASSIGN_VEC4_OFF_D(vthread_t thr, vvp_code_t cp)
 		  return true;
 	    assert(0); // XXXX Not implemented yet.
       }
+      if (off+wid > sig->value_size()) {
+	    assert(0); // XXXX Not implemented yet.
+      }
 
       schedule_assign_vector(ptr, off, sig->value_size(), val, del);
       return true;
@@ -5875,6 +5879,29 @@ bool of_STORE_VEC4(vthread_t thr, vvp_code_t cp)
       if (off_index!=0 && thr->flags[4] == BIT4_1)
 	    return true;
 
+      if (off <= -(int)wid)
+	    return true;
+      if (off >= (int)sig->value_size())
+	    return true;
+
+	// If the index is below the vector, then only assign the high
+	// bits that overlap with the target.
+      if (off < 0) {
+	    int use_off = -off;
+	    wid -= use_off;
+	    val = val.subvalue(use_off, wid);
+	    off = 0;
+      }
+
+	// If the value is partly above the target, then only assign
+	// the bits that overlap.
+      if ((off+wid) > sig->value_size()) {
+	    wid = sig->value_size()-off;
+	    val = val.subvalue(0, wid);
+	    val.resize(wid);
+      }
+
+
       if (off==0 && val.size()==sig->value_size())
 	    vvp_send_vec4(ptr, val, thr->wt_context);
       else