mandelbrot_imp.h

/*
  Copyright (c) 2010-2011, Intel Corporation
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	  notice, this list of conditions and the following disclaimer in the
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	  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,
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   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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*/

using namespace CPPSPMD;

// Must use unique struct/class names, or put them into uniquely named namespaces, otherwise the linker will get confused between the different variants. (At least with MSVC.)
namespace CPPSPMD_NAME(mandel_kernel_namespace)
{

struct mandelbrot_kernel : spmd_kernel
{
	inline vint_t mandel(const vfloat & c_re, const vfloat & c_im, const vint_t & count)
	{
		vfloat z_re = c_re, z_im = c_im;

		vint_t i = 0;
		SPMD_WHILE(i < count)
		{
			spmd_if_break(vfma(z_re, z_re, z_im * z_im) > 4.0f);

			vfloat new_re = vfms(z_re, z_re, z_im * z_im);
			vfloat new_im = 2.f * z_re * z_im;

			store_all(z_re, c_re + new_re);
			store_all(z_im, c_im + new_im);

			store(i, i + 1);
		}
		SPMD_WEND

		return i;
	}

	void _call(
		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;

		for (int j = 0; j < height; j++) 
		{
			// Note that we'll be doing PROGRAM_COUNT computations in parallel,
			// so increment orig_index by that much.  This assumes that width evenly
			// divides PROGRAM_COUNT.
			SPMD_FOREACH(orig_index, 0, width)
			{
				// Figure out the position on the complex plane to compute the
				// number of iterations at.  Note that the x values are
				// different across different program instances, since its
				// initializer incorporates the value of the program_index
				// variable.
				vfloat x = x0 + orig_index * dx;
				vfloat y = y0 + j * dy;

	#if CPPSPMD_INT16
				int* p = output + orig_index.get_first_value() + j * width;
				lint_t index = program_index;

				store((vint_t(index) * 2)[(int16_t*)p], mandel(x, y, maxIterations));
				store((vint_t(index) * 2 + 1)[(int16_t*)p], vint_t(0));
	#else
				lint_t index = j * width + orig_index;
				store(index[output], mandel(x, y, maxIterations));
	#endif
			}
			SPMD_FOREACH_END(orig_index);
		}
	}
};

} // namespace

using namespace CPPSPMD_NAME(mandel_kernel_namespace);

void CPPSPMD_NAME(mandelbrot)(
	float x0, float y0,
	float x1, float y1,
	int width, int height,
	int maxIterations,
	int output[])
{
	spmd_call< mandelbrot_kernel >(x0, y0, x1, y1, width, height, maxIterations, output);
}