From 78da0e0a0cf773dcb7d918a60e069a85986f47da Mon Sep 17 00:00:00 2001
From: Xianyi Zhang <xianyi@iscas.ac.cn>
Date: Sun, 20 Feb 2011 17:14:38 +0800
Subject: [PATCH] Fixed #6. Disable multi-thread swap when incx==0 or incy==0.

---
 interface/swap.c  | 7 ++++++-
 interface/zswap.c | 5 +++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/interface/swap.c b/interface/swap.c
index 7676246f9..271fa083a 100644
--- a/interface/swap.c
+++ b/interface/swap.c
@@ -78,7 +78,12 @@ void CNAME(blasint n, FLOAT *x, blasint incx, FLOAT *y, blasint incy){
 
 #ifdef SMP
   nthreads = num_cpu_avail(1);
-
+  
+  //disable multi-thread when incx==0 or incy==0
+  //In that case, the threads would be dependent.
+  if (incx == 0 || incy == 0)
+	  nthreads = 1;
+  
   if (nthreads == 1) {
 #endif
 
diff --git a/interface/zswap.c b/interface/zswap.c
index f4a03a550..06a889204 100644
--- a/interface/zswap.c
+++ b/interface/zswap.c
@@ -80,6 +80,11 @@ void CNAME(blasint n, FLOAT *x, blasint incx, FLOAT *y, blasint incy){
 #ifdef SMP
   nthreads = num_cpu_avail(1);
 
+  //disable multi-thread when incx==0 or incy==0
+  //In that case, the threads would be dependent.
+  if (incx == 0 || incy == 0)
+	  nthreads = 1;
+
   if (nthreads == 1) {
 #endif