[Beignet] [PATCH 2/3] GBE: Do not change vertical stride when it is 0

[Ruiling Song]

It will change scalar register g3<0,1,0> into g3<16,1,0> which illegally
crosses more than 2 adjacent rows.

Signed-off-by: Ruiling Song <ruiling.song at intel.com>
---
 backend/src/backend/gen_register.hpp |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/backend/src/backend/gen_register.hpp b/backend/src/backend/gen_register.hpp
index 47b0515..8f06435 100644
--- a/backend/src/backend/gen_register.hpp
+++ b/backend/src/backend/gen_register.hpp
@@ -277,7 +277,8 @@ namespace gbe
       GBE_ASSERT(isint64());
       GenRegister r = h2(*this);
       r.type = type == GEN_TYPE_UL ? GEN_TYPE_UD : GEN_TYPE_D;
-      r.vstride = GEN_VERTICAL_STRIDE_16;
+      if(r.vstride != GEN_VERTICAL_STRIDE_0)
+       r.vstride = GEN_VERTICAL_STRIDE_16;
       return r;
     }
 
-- 
1.7.9.5