From 002a79bfc4522ef8e7466b5a4fe8ad8dbc79eb11 Mon Sep 17 00:00:00 2001
From: Ilya Lavrenov <ilya.lavrenov@itseez.com>
Date: Wed, 28 May 2014 18:39:02 +0400
Subject: [PATCH] optimized cv::countNonZero

---
 modules/core/src/opencl/reduce.cl | 40 ++++++++++++++++++++++++++++++++++++---
 modules/core/src/stat.cpp         |  9 +++++----
 2 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/modules/core/src/opencl/reduce.cl b/modules/core/src/opencl/reduce.cl
index 8fc2330..e24c82a 100644
--- a/modules/core/src/opencl/reduce.cl
+++ b/modules/core/src/opencl/reduce.cl
@@ -82,6 +82,10 @@
 
 #define noconvert
 
+#ifndef kercn
+#define kercn 1
+#endif
+
 #ifdef HAVE_MASK_CONT
 #define MASK_INDEX int mask_index = id + mask_offset;
 #else
@@ -176,9 +180,39 @@
     __local dstT localmem[WGS2_ALIGNED]
 #define DEFINE_ACCUMULATOR \
     dstT accumulator = (dstT)(0); \
-    srcT zero = (srcT)(0), one = (srcT)(1)
+    srcT1 zero = (srcT1)(0), one = (srcT1)(1)
+#if kercn == 1
 #define REDUCE_GLOBAL \
     accumulator += loadpix(srcptr + src_index) == zero ? zero : one
+#elif kercn == 4
+#define REDUCE_GLOBAL \
+    srcT value = loadpix(srcptr + src_index); \
+    accumulator += value.s0 == zero ? zero : one; \
+    accumulator += value.s1 == zero ? zero : one; \
+    accumulator += value.s2 == zero ? zero : one; \
+    accumulator += value.s3 == zero ? zero : one
+#elif kercn == 16
+#define REDUCE_GLOBAL \
+    srcT value = loadpix(srcptr + src_index); \
+    accumulator += value.s0 == zero ? zero : one; \
+    accumulator += value.s1 == zero ? zero : one; \
+    accumulator += value.s2 == zero ? zero : one; \
+    accumulator += value.s3 == zero ? zero : one; \
+    accumulator += value.s4 == zero ? zero : one; \
+    accumulator += value.s5 == zero ? zero : one; \
+    accumulator += value.s6 == zero ? zero : one; \
+    accumulator += value.s7 == zero ? zero : one; \
+    accumulator += value.s8 == zero ? zero : one; \
+    accumulator += value.s9 == zero ? zero : one; \
+    accumulator += value.sA == zero ? zero : one; \
+    accumulator += value.sB == zero ? zero : one; \
+    accumulator += value.sC == zero ? zero : one; \
+    accumulator += value.sD == zero ? zero : one; \
+    accumulator += value.sE == zero ? zero : one; \
+    accumulator += value.sF == zero ? zero : one
+#else
+#error "kercn should be either 1, 4 or 16"
+#endif
 #define SET_LOCAL_1 \
     localmem[lid] = accumulator
 #define REDUCE_LOCAL_1 \
@@ -316,14 +350,14 @@ __kernel void reduce(__global const uchar * srcptr, int src_step, int src_offset
 {
     int lid = get_local_id(0);
     int gid = get_group_id(0);
-    int  id = get_global_id(0);
+    int  id = get_global_id(0) * kercn;
 
     srcptr += src_offset;
 
     DECLARE_LOCAL_MEM;
     DEFINE_ACCUMULATOR;
 
-    for (int grain = groupnum * WGS; id < total; id += grain)
+    for (int grain = groupnum * WGS * kercn; id < total; id += grain)
     {
 #ifdef HAVE_SRC_CONT
         int src_index = mul24(id, srcTSIZE);
diff --git a/modules/core/src/stat.cpp b/modules/core/src/stat.cpp
index 37cd8eb..e9fc538 100644
--- a/modules/core/src/stat.cpp
+++ b/modules/core/src/stat.cpp
@@ -645,7 +645,7 @@ namespace cv {
 
 static bool ocl_countNonZero( InputArray _src, int & res )
 {
-    int type = _src.type(), depth = CV_MAT_DEPTH(type);
+    int type = _src.type(), depth = CV_MAT_DEPTH(type), kercn = ocl::predictOptimalVectorWidth(_src);
     bool doubleSupport = ocl::Device::getDefault().doubleFPConfig() > 0;
 
     if (depth == CV_64F && !doubleSupport)
@@ -660,9 +660,10 @@ static bool ocl_countNonZero( InputArray _src, int & res )
     wgs2_aligned >>= 1;
 
     ocl::Kernel k("reduce", ocl::core::reduce_oclsrc,
-                  format("-D srcT=%s -D OP_COUNT_NON_ZERO -D WGS=%d "
-                         "-D WGS2_ALIGNED=%d%s%s",
-                         ocl::typeToStr(type), (int)wgs,
+                  format("-D srcT=%s -D srcT1=%s -D cn=1 -D OP_COUNT_NON_ZERO -D WGS=%d "
+                         "-D kercn=%d -D WGS2_ALIGNED=%d%s%s",
+                         ocl::typeToStr(CV_MAKE_TYPE(depth, kercn)),
+                         ocl::typeToStr(depth), (int)wgs, kercn,
                          wgs2_aligned, doubleSupport ? " -D DOUBLE_SUPPORT" : "",
                          _src.isContinuous() ? " -D HAVE_SRC_CONT" : ""));
     if (k.empty())
-- 
2.7.4