From 68a9526fec3f3dc29dc40a5b79a9a5428efe159b Mon Sep 17 00:00:00 2001
From: Stephen Williams <steve@icarus.com>
Date: Sun, 2 Dec 2007 19:00:12 -0800
Subject: [PATCH] Minor performance tweak of vector_to_array function.

---
 vvp/vthread.cc |  3 ++-
 vvp/vvp_net.cc | 12 +++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/vvp/vthread.cc b/vvp/vthread.cc
index 878418e17..3fe8e53e6 100644
--- a/vvp/vthread.cc
+++ b/vvp/vthread.cc
@@ -170,16 +170,17 @@ void vthread_put_real(struct vthread_s*thr, unsigned addr, double val)
 static unsigned long* vector_to_array(struct vthread_s*thr,
 				      unsigned addr, unsigned wid)
 {
-      unsigned awid = (wid + CPU_WORD_BITS - 1) / (CPU_WORD_BITS);
 
 
       if (addr == 0) {
+	    unsigned awid = (wid + CPU_WORD_BITS - 1) / (CPU_WORD_BITS);
 	    unsigned long*val = new unsigned long[awid];
 	    for (unsigned idx = 0 ;  idx < awid ;  idx += 1)
 		  val[idx] = 0;
 	    return val;
       }
       if (addr == 1) {
+	    unsigned awid = (wid + CPU_WORD_BITS - 1) / (CPU_WORD_BITS);
 	    unsigned long*val = new unsigned long[awid];
 	    for (unsigned idx = 0 ;  idx < awid ;  idx += 1)
 		  val[idx] = -1UL;
diff --git a/vvp/vvp_net.cc b/vvp/vvp_net.cc
index e1eade218..aed907fe7 100644
--- a/vvp/vvp_net.cc
+++ b/vvp/vvp_net.cc
@@ -355,6 +355,9 @@ unsigned long* vvp_vector4_t::subarray(unsigned adr, unsigned wid) const
 	    unsigned long tmp = bits_ptr_[adr/BITS_PER_WORD];
 	    tmp >>= 2UL * (adr%BITS_PER_WORD);
 
+	    unsigned long mask1 = 1;
+	    const unsigned long mask1_last = 1UL << (BIT2_PER_WORD-1);
+	    unsigned long*val_ptr = val;
 	    for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
 		    /* Starting a new word? */
 		  if (adr%BITS_PER_WORD == 0)
@@ -363,10 +366,17 @@ unsigned long* vvp_vector4_t::subarray(unsigned adr, unsigned wid) const
 		  if (tmp&2)
 			goto x_out;
 		  if (tmp&1)
-			val[idx/BIT2_PER_WORD] |= 1UL << (idx % BIT2_PER_WORD);
+			*val_ptr |= mask1;
 
 		  adr += 1;
 		  tmp >>= 2UL;
+
+		  if (mask1 == mask1_last) {
+			val_ptr += 1;
+			mask1 = 1;
+		  } else {
+			mask1 <<= 1;
+		  }
 	    }
       }