[Beignet] [PATCH] Change CL_DEVICE_PREFERRED_VECTOR_WIDTH_CHAR from 8 to 16.

[Chuanbo Weng]

Because accessing global memory by uchar16/char16 will fully utilize
memory bandwidth, so change CL_DEVICE_PREFERRED_VECTOR_WIDTH_CHAR from
8 to 16. Three OpenCV cases will speedup from this patch:
OCL_ThreshFixture_Threshold, 25% improvement
OCL_MaxFixture_Max, 105% improvement
OCL_MinFixture_Min, 105% improvement.

Signed-off-by: Chuanbo Weng <chuanbo.weng at intel.com>
---
 src/cl_gt_device.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/cl_gt_device.h b/src/cl_gt_device.h
index 37abfd2..ed19f10 100644
--- a/src/cl_gt_device.h
+++ b/src/cl_gt_device.h
@@ -24,7 +24,7 @@
 .max_1d_global_work_sizes = {1024 * 1024 * 256, 1, 1},
 .max_2d_global_work_sizes = {8192, 8192, 1},
 .max_3d_global_work_sizes = {8192, 8192, 2048},
-.preferred_vector_width_char = 8,
+.preferred_vector_width_char = 16,
 .preferred_vector_width_short = 8,
 .preferred_vector_width_int = 4,
 .preferred_vector_width_long = 2,
-- 
1.9.1