From 4b7dbbf43bb51e33810759cda268440b9785a7f6 Mon Sep 17 00:00:00 2001
From: Evghenii <egaburov@dds.nl>
Date: Mon, 18 Nov 2013 12:46:30 +0100
Subject: [PATCH] added cuda kernel

---
 .../mandelbrot_tasks3d/mandelbrot_tasks3d.cu  | 104 ++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 examples_cuda/mandelbrot_tasks3d/mandelbrot_tasks3d.cu

diff --git a/examples_cuda/mandelbrot_tasks3d/mandelbrot_tasks3d.cu b/examples_cuda/mandelbrot_tasks3d/mandelbrot_tasks3d.cu
new file mode 100644
index 00000000..e642042a
--- /dev/null
+++ b/examples_cuda/mandelbrot_tasks3d/mandelbrot_tasks3d.cu
@@ -0,0 +1,104 @@
+/*
+  Copyright (c) 2010-2012, Intel Corporation
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are
+  met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+
+    * Neither the name of Intel Corporation nor the names of its
+      contributors may be used to endorse or promote products derived from
+      this software without specific prior written permission.
+
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+   IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+   TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+   PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
+*/
+
+#define programCount 32
+#define programIndex (threadIdx.x & 31)
+#define taskIndex0 (blockIdx.x*4 + (threadIdx.x >> 5))
+#define taskCount0 (gridDim.x*4)
+#define taskIndex1 (blockIdx.y)
+#define taskCount1 (gridDim.y)
+#define warpIdx (threadIdx.x >> 5)
+
+
+__device__
+static inline int
+mandel(float c_re, float c_im, int count) {
+    float z_re = c_re, z_im = c_im;
+    int i;
+    for (i = 0; i < count; ++i) {
+        if (z_re * z_re + z_im * z_im > 4.0f)
+            break;
+
+        float new_re = z_re*z_re - z_im*z_im;
+        float new_im = 2.f * z_re * z_im;
+        z_re = c_re + new_re;
+        z_im = c_im + new_im;
+    }
+
+    return i;
+}
+
+
+/* Task to compute the Mandelbrot iterations for a single scanline.
+ */
+__global__ void
+mandelbrot_scanline( float x0,  float dx, 
+                     float y0,  float dy,
+                     int width,  int height, 
+                     int xspan,  int yspan,
+                     int maxIterations,  int output[]) {
+    const  int xstart = taskIndex0 * xspan;
+    const  int xend   = min(xstart  + xspan, width);
+
+    const  int ystart = taskIndex1 * yspan;
+    const  int yend   = min(ystart  + yspan, height);
+   
+  for ( int yi = ystart; yi < yend; yi++)
+    for ( int xi = xstart; xi < xend; xi += programCount)
+    {
+      const float x = x0 + (xi + programIndex) * dx;
+      const float y = y0 +  yi              * dy;
+
+      const int res = mandel(x,y,maxIterations);
+      const int index = yi * width + (xi + programIndex);
+      if (xi + programIndex < xend)
+        output[index] = res;
+    }
+}
+
+extern "C" __global__ void
+mandelbrot_ispc( float x0,  float y0, 
+                 float x1,  float y1,
+                 int width,  int height, 
+                 int maxIterations,  int output[]) {
+     float dx = (x1 - x0) / width;
+     float dy = (y1 - y0) / height;
+    const  int xspan = 64;  /* make sure it is big enough to avoid false-sharing */
+    const  int yspan = 8; 
+
+
+    if (programIndex == 0)
+      mandelbrot_scanline<<<dim3((width+4-1)/xspan/4,height/yspan),128>>>
+        (x0, dx, y0, dy, width, height, xspan, yspan,  maxIterations, output);
+    cudaDeviceSynchronize();
+}