restore back, bag with none aligged vertical block

/*
 * Copyright (c) 2016 AMD Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and/or associated documentation files (the
 * "Materials"), to deal in the Materials without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Materials, and to
 * permit persons to whom the Materials are furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Materials.
 *
 * THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
 */

#define _FLOAT					float
#define _FLOAT2					float2
#define _FLOAT4					float4
#define _FLOAT8					float8

#ifndef FLT_MAX
#define FLT_MAX         3.402823466e+38F        /* max value */
#endif

#define MLO_N_OUT_HORIZ_READS ((MLO_OUT_WIDTH + MLO_IN_TILE0 - 1) / MLO_IN_TILE0)
#define MLO_N_SPANS_PER_SCAN (MLO_N_OUT_HORIZ_READS)
#define MLO_N_OUT_HORIZ_PIX_READS (MLO_N_OUT_HORIZ_READS * MLO_IN_TILE0)
#define MLO_OUT_N_PIXS_OFF (MLO_OUT_WIDTH - ((MLO_OUT_WIDTH / MLO_IN_TILE0)*MLO_IN_TILE0))
#define MLO_N_OUT_VERTICAL_READS (MLO_FILTER_SIZE1)
// won't run non-border blocks if  MLO_IN_N_VERT_LOOPS < 2
#if MLO_FILTER_PAD1 > 0

#if  MLO_IN_N_VERT_LOOPS >= 2
#define MLO_N_GENERIC_LOOPS ((int)(MLO_IN_N_VERT_LOOPS - 2))
#define MLO_IN_VERT_READS (MLO_IN_EXTENT1 + MLO_FILTER_PAD1)
#else
#define MLO_N_GENERIC_LOOPS 0
#define MLO_IN_VERT_READS MLO_IN_EXTENT1
#endif

#else
#define MLO_N_GENERIC_LOOPS (MLO_IN_N_VERT_LOOPS)
#define MLO_IN_VERT_READS MLO_IN_EXTENT1
#endif

// there is an assumption that the scanline fits into LDS
#define MLO_N_IN_HORIZ_PIX_READS (MLO_IN_WIDTH)
#define MLO_N_IN_HORIZ_READS ((MLO_N_IN_HORIZ_PIX_READS + MLO_READ_UNIT - 1) / MLO_READ_UNIT)
#define MLO_IN_N_PIXS_OFF  (MLO_N_IN_HORIZ_PIX_READS - (MLO_N_IN_HORIZ_PIX_READS/MLO_READ_UNIT)*MLO_READ_UNIT)
#define MLO_IN_LCL_WIDTH (MLO_N_IN_HORIZ_READS * MLO_READ_UNIT + 2* MLO_FILTER_PAD0)
#define MLO_IN_LCL_HEIGHT MLO_IN_VERT_READS
#define MLO_IN_LCL_SZ (MLO_IN_LCL_WIDTH * MLO_IN_LCL_HEIGHT)
#define MLO_TOTAL_IN_LCL_SZ (MLO_N_LCL_BATCHS*MLO_N_LCL_IN_MAPS*MLO_IN_LCL_SZ)

#define MLO_WEI_LCL_SZ (MLO_GRP_SZ * MLO_FILTER_SIZE0)
#if MLO_TOTAL_IN_LCL_SZ > MLO_WEI_LCL_SZ
#define MLO_LCL_SZ (MLO_TOTAL_IN_LCL_SZ)
#else
#define MLO_LCL_SZ (MLO_WEI_LCL_SZ)
#endif

#define MLO_HW_WAVE_ID_SETTING 0

#if MLO_HW_WAVE_ID_SETTING
extern __attribute__((const)) uint __hsail_get_dynwave_id(void);
static inline int getWaveId()
{
	int wave_id = 0;

	wave_id = __hsail_get_dynwave_id();
	wave_id = wave_id & MLO_N_PHYS_WAVES_MASK;
	return(wave_id);
}
#else
static inline int getWaveId()
{
	int wave_id = 0;

	wave_id = (get_local_id(0) >> MLO_LG2_PHYS_WAVE_SZ);

	return(wave_id);
}
#endif

static inline int gePhysLocalId()
{
	int lcl_wave_id = get_local_id(0) - ((get_local_id(0) >> MLO_LG2_PHYS_WAVE_SZ) << MLO_LG2_PHYS_WAVE_SZ);
	return(lcl_wave_id);
}

static inline int iDiv(int v, int d)
{
	int r = (int)((float)v / d + 0.00001f);
	return(r);
}

static inline int iMod(int v, int u, int d)
{
	int r = v - mul24((int)u, (int)d);
	return(r);
}

static inline void ReduceKernel(__local _FLOAT * lcl_blob, __private _FLOAT *weights_accum, int lcl_id, int scan_lcl, int sum_stride, int unit_len, bool debug)
{
// read first half
	if (scan_lcl < (sum_stride >> 1))
	{
		for (int i = 0; i < unit_len; ++i)
		{
			weights_accum[i] = lcl_blob[(lcl_id + scan_lcl) * unit_len + i];

		}

	}
// add second half
// appload accumulated value so far
	for (int j = (sum_stride >> 1); j > 0; j >>= 1)
	{
		barrier(CLK_LOCAL_MEM_FENCE);
		if (scan_lcl < j)
		{
			for (int i = 0; i < unit_len; ++i)
			{
				weights_accum[i] += lcl_blob[(lcl_id + j) * unit_len + i];

				lcl_blob[lcl_id * unit_len + i] = weights_accum[i];
			}

		}
	}
}

static inline void  Kahan_summation(__private _FLOAT *sum, __private _FLOAT * c, _FLOAT v)
{
	_FLOAT y = v - *c;    //So far, so good: c is zero.
	_FLOAT t = *sum + y;         //Alas, sum is big, y small, so low-order digits of y are lost.
	*c = (t - *sum) - y;   //(t - sum) recovers the high-order part of y; subtracting y recovers -(low part of y)
	*sum = t;             //Algebraically, c should always be zero. Beware eagerly optimising compilers!
}

/*
	group cooperative read
	read by MLO_READ_UNIT
	handle out of range both horizontally and vertically (by fixed number of veryical reads)

	no guard against number of inputs
*/
static inline void readInput(int lcl_id, int gbl_in_scan_off, int n_v_reads, const __global _FLOAT * bot, __local _FLOAT *lcl_bot)
{
	for (int p4 = lcl_id; p4 < MLO_N_LCL_IN_MAPS * MLO_N_IN_HORIZ_READS * n_v_reads;
		p4 += MLO_GRP_SZ)
	{
		__private _FLOAT in_rd_data[MLO_READ_UNIT];
// TODO : more than 1 input
		int c = 0;
		int c_scan = iDiv(p4, (MLO_N_IN_HORIZ_READS));

		int c_pix4 = iMod(p4, c_scan, (MLO_N_IN_HORIZ_READS));

//		if (c < MLO_N_INPUTS)

		{

#if MLO_IN_N_PIXS_OFF > 0

			if (c_pix4 == MLO_N_IN_HORIZ_READS - 1)
			{
				for (int i = 0; i < MLO_IN_N_PIXS_OFF; ++i)
				{

					in_rd_data[i] = bot[gbl_in_scan_off + c*MLO_IN_CHANNEL_STRIDE + c_scan* MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT + i];
				}

				for (int i = MLO_IN_N_PIXS_OFF; i < MLO_READ_UNIT; ++i)
				{
					in_rd_data[i] = 0;
				}

			}
			else
#endif
			{
				*(MLO_READ_TYPE*)in_rd_data = *(__global MLO_READ_TYPE*)&bot[gbl_in_scan_off + c*MLO_IN_CHANNEL_STRIDE + c_scan* MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT];
			}

// MLO_N_LCL_IN_MAPS inputs
			for (int i = 0; i < MLO_READ_UNIT; ++i)
			{
				int lcl_in_off = c*MLO_IN_LCL_SZ + c_scan* MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT + i;
				lcl_bot[lcl_in_off] = in_rd_data[i];
			}
		}

	} // for (int p4 = lcl_id; p4 < MLO_N_LCL_IN_MAPS * MLO_N_IN_HORIZ_READS * MLO_IN_VERT_READS;

	barrier(CLK_LOCAL_MEM_FENCE);

}

/*
	core processing loop
	bot - input, from local (1 span)
	top - output diff, from global (array of spans, filters vertical size)

	loop over filter vertical size

*/
static inline void Processing(int sc, int sc_lcl_off, int top_lim, int bot_lim, __private _FLOAT * pvt_accum, __local _FLOAT * lcl_bot, __private _FLOAT * top_dat)
{
	for (int l = top_lim; l >= bot_lim; --l)
	{
		for (int m = 0; m < MLO_IN_TILE0; ++m)
		{
			for (int n = 0; n < MLO_FILTER_SIZE0; ++n)
			{
				_FLOAT bot_val = lcl_bot[sc_lcl_off + n + m];
				for(int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
				{
					int pvt_top_off =  k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + (top_lim - l) * MLO_IN_TILE0 + m;
					int pvt_accum_off = k*MLO_FILTER_SIZE1*MLO_FILTER_SIZE0 + l*MLO_FILTER_SIZE0 + n;

					_FLOAT top_val = top_dat[pvt_top_off];

					pvt_accum[pvt_accum_off]
						// each wk-it process an input
						+= bot_val*top_val;
#if 0
					if (bot_val * top_val != 0 && get_global_id(1) == 0 && get_global_id(2) == 0 && (get_local_id(0) == 0  || get_local_id(0) == 1 )&& k == 0 && l == 0 && n == 0)
					{
						printf("G: %d %d %d %d  %f %f %f %f\n",
							get_local_id(0),
							sc,
							sc_lcl_off + n + m,
							pvt_top_off,
							pvt_accum[pvt_accum_off],
							bot_val * top_val,
							bot_val,
							top_val
						);
					}
#endif
				}
			}

		}

	}

}

static inline void moveOutputUp(__private _FLOAT * top_dat)
{
	// move up output to reduce overfetch
	for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
	{
		for (int j = 0; j < MLO_FILTER_SIZE1 - 1; ++j)
		{
			for (int i = 0; i < MLO_IN_TILE0; ++i)
			{
				int pvt_off_n = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + j *MLO_IN_TILE0 + i;
				int pvt_off_o = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + (j + 1) *MLO_IN_TILE0 + i;
				top_dat[pvt_off_n] = top_dat[pvt_off_o];
			}
		}
	}
}

static inline void spanRightSiding5x5(int k, int top_df_off, int j, _FLOAT mask, __private _FLOAT * top_dat, __global const _FLOAT * top_df)
{
	int i = 0;
	int pvt_off = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + j *MLO_IN_TILE0;
	for (; i < MLO_OUT_N_PIXS_OFF; ++i)
	{
		top_dat[pvt_off + i] = top_df[top_df_off + i] * mask;
	}
	for (; i < MLO_IN_TILE0; ++i)
	{
		top_dat[pvt_off + i] = 0;
	}

}
#if 1
#if (MLO_IN_TILE0 - MLO_OUT_N_PIXS_OFF <= MLO_FILTER_PAD0)
#define MLO_OUT_MASK_SZ (MLO_IN_TILE0 - MLO_OUT_N_PIXS_OFF)
#else
#define MLO_OUT_MASK_SZ (MLO_FILTER_PAD0)
#endif
#endif

//#define MLO_OUT_MASK_SZ (1)
static inline void spanReadingOutput3x3(int k, int j, int top_df_off, _FLOAT mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
	__private _FLOAT * out_mask,
#endif
	__private _FLOAT * top_dat, const __global _FLOAT * top_df)
{
	int pvt_off = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + j *MLO_IN_TILE0;
	for (int i = 0; i < MLO_IN_TILE0; ++i)
	{
		top_dat[pvt_off + i] = top_df[top_df_off + i] * mask
			;
	}
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16

	for (int i = MLO_OUT_N_PIXS_OFF; i < MLO_OUT_N_PIXS_OFF + MLO_OUT_MASK_SZ; ++i)
	{
		top_dat[pvt_off + i] *= out_mask[i - MLO_OUT_N_PIXS_OFF];

	}
#endif
}

/*********************************************************************************************************
// wrw algorithm for large filters
// idea:
// split output scan-line on number of spans by the  MLO_IN_TILE0 (2 for example)
// 1 scan-line has ((MLO_OUT_WIDTH + MLO_IN_TILE0 - 1/MLO_IN_TILE0) spans
// group will process MLO_GRP_SZ/((MLO_OUT_WIDTH + MLO_IN_TILE0 - 1/MLO_IN_TILE0) output maps

// alg
// load a block of input map (or full map) into LDS
// loop
// read MLO_FILTER_SIZE1 number of spans from output map into VGPRs (for example 5 *2 = 10)
// read 1 input line for  maps into LDS
// accumulate

// accumulate all spans at the end
// start new loop for the next batch (if defined)
// write out

// kerenl handles 5x5, 3x3 with padding
// small images in 1 short- MLO_N_GENERIC_LOOPS == 0
// big images  in 2 blocks - MLO_IN_N_VERT_LOOPS == 2 or multiple blocks - MLO_IN_N_VERT_LOOPS > 2
// there are prolog and apilog that deal with top/bottom padding.
// left/right padding handles as a LDS border pixels zeroed at the beginning.

**********************************************************************************************************/

__attribute__((reqd_work_group_size(MLO_GRP_SZ0, MLO_GRP_SZ1, MLO_GRP_SZ2)))
__kernel void MLOpenCvBwdWrW(
	const __global _FLOAT * top_df,
	const __global _FLOAT * bot,
	__global _FLOAT * weights_df,
#if MLO_CONV_BIAS
	__global _FLOAT * bias_df,
#endif
	_FLOAT padding_val
)
{

	// input/output tiles + reduce buffer

	__local _FLOAT lcl[(MLO_LCL_SZ)];
	__local _FLOAT * lcl_bot = lcl;

	// guarnteeing an uniformity over a wave
	int wave_id = getWaveId();
	int lcl_id = get_local_id(0);
	int lcl_wv_id = gePhysLocalId();

	int c_idx_base = get_group_id(1); // input map index base

	int o_idx_base = iDiv(get_group_id(2), (MLO_BATCH_SZ / (MLO_N_BATCH_LOOPS*MLO_N_LCL_BATCHS))); // output map index base
	int ib_base = iMod(get_group_id(2), o_idx_base, (MLO_BATCH_SZ / (MLO_N_BATCH_LOOPS*MLO_N_LCL_BATCHS)));

	int ib = ib_base*MLO_N_LCL_BATCHS;

	int c_idx = c_idx_base * MLO_N_LCL_IN_MAPS; // input map index

	int o_idx = o_idx_base * (MLO_N_LCL_OUT_MAPS * MLO_OUT_STACKS); // output map index

	int gbl_in_off = c_idx * MLO_IN_CHANNEL_STRIDE + ib * MLO_IN_BATCH_STRIDE;
	int gbl_out_off = o_idx * MLO_OUT_CHANNEL_STRIDE + ib * MLO_OUT_BATCH_STRIDE;
	// 1 span per wk_item, total scanline with MLO_N_SPANS_PER_SCAN spans
	// TODO: more than 1 input
	int o = iDiv(lcl_id, MLO_N_SPANS_PER_SCAN);
	//	bool scan_lead = (o*MLO_N_SPANS_PER_SCAN == lcl_id);
	int spn = iMod(lcl_id, o, MLO_N_SPANS_PER_SCAN);

	int lcl_bot_off = spn * MLO_IN_TILE0;
	int out_wk_item_off = o * MLO_OUT_CHANNEL_STRIDE + lcl_bot_off;
	gbl_out_off += out_wk_item_off;

#define MLO_TOP_DAT_SZ (MLO_N_LCL_OUT_MAPS * MLO_IN_TILE0 * MLO_FILTER_SIZE1)

	__private _FLOAT top_dat[MLO_TOP_DAT_SZ];

	for (int i = 0; i < MLO_TOP_DAT_SZ; ++i)
	{
		top_dat[i] = 0;
	}

#define MLO_ACCUM_SZ (MLO_N_LCL_OUT_MAPS * MLO_FILTER_SIZE1*MLO_FILTER_SIZE0)

	__private _FLOAT pvt_accum[MLO_ACCUM_SZ];

	for (int i = 0; i < MLO_ACCUM_SZ; ++i)
	{
		pvt_accum[i] = 0;
	}

	// zero out LDS
	for (int i = lcl_id; i < (MLO_LCL_SZ); i += MLO_GRP_SZ)
	{
		lcl[i] = 0;
	}

// 3x3 out mask
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16

	_FLOAT out_mask[MLO_OUT_MASK_SZ];
	if (spn == MLO_N_SPANS_PER_SCAN - 1)
	{
		for (int i = 0; i < MLO_OUT_MASK_SZ; ++i)
		{
			out_mask[i] = 0;
		}
	}
	else
	{
		for (int i = 0; i < MLO_OUT_MASK_SZ; ++i)
		{
			out_mask[i] = 1;
		}
	}

#endif

	// over all batches
	for (int b = 0;
		b < MLO_N_BATCH_LOOPS;
		++b,
		gbl_in_off += MLO_N_LCL_BATCHS*MLO_IN_BATCH_STRIDE,
		gbl_out_off += MLO_N_LCL_BATCHS*MLO_OUT_BATCH_STRIDE
		)
	{
		barrier(CLK_LOCAL_MEM_FENCE);
		// top border input block
		int gbl_in_scan_off = gbl_in_off;
		int gbl_out_scan_off = gbl_out_off;

		// read input map
		readInput(lcl_id, gbl_in_scan_off, MLO_IN_VERT_READS, bot, lcl_bot);
		// move input pointer
		gbl_in_scan_off += MLO_IN_STRIDE * MLO_IN_EXTENT1;

		for (int i = 0; i < MLO_TOP_DAT_SZ; ++i)
		{
			top_dat[i] = 0;
		}

		// prefetch output

		int gbl_out_scan_off1 = gbl_out_scan_off;
		for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k, gbl_out_scan_off1 += MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE)
		{
			for (int j = 0; j < MLO_FILTER_SIZE1 - 1; ++j)
			{
				// loop around all output maps
				int top_df_off = gbl_out_scan_off1 + j*MLO_OUT_STRIDE;
				_FLOAT mask = 1;
#if MLO_FILTER_SIZE1 - 1 > MLO_OUT_HEIGHT
				top_df_off = (j < MLO_OUT_HEIGHT) ? top_df_off : 0;
				mask = (j < MLO_OUT_HEIGHT) ? 1 : 0;
#endif

// 5x5 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) > 16
				if (spn == MLO_N_SPANS_PER_SCAN - 1)
				{

					spanRightSiding5x5(k, top_df_off, j, mask, top_dat, top_df);

				}
				else
#endif
				{
					spanReadingOutput3x3(k, j, top_df_off, mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
						out_mask,
#endif
						top_dat, top_df);
				}

			}
		}

		barrier(CLK_LOCAL_MEM_FENCE);

		gbl_out_scan_off += (MLO_FILTER_SIZE1 - 1) * MLO_OUT_STRIDE;

		int sc = 0;
		int sc_lcl_off = lcl_bot_off;

		// prolog
		// handling padding

		// pad0
		for (; sc < MLO_FILTER_PAD1; ++sc, sc_lcl_off += MLO_IN_LCL_WIDTH)
		{
			Processing(sc, sc_lcl_off, sc + MLO_FILTER_PAD1, 0, pvt_accum, lcl_bot, top_dat);
		}

		for (; sc < MLO_IN_EXTENT1
#if MLO_IN_N_VERT_LOOPS == 1
			- MLO_FILTER_PAD1
			// 3x3 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
			- 1
#endif
#endif
			; ++sc, gbl_out_scan_off += MLO_OUT_STRIDE, sc_lcl_off += MLO_IN_LCL_WIDTH)
		{
			for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
			{
				int top_df_off = gbl_out_scan_off + k*MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE;
				_FLOAT mask = 1;

#if MLO_FILTER_SIZE1 > MLO_OUT_HEIGHT
				top_df_off = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? top_df_off : 0;
				mask = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? 1 : 0;
#endif
				// move in the last output scans
// 5x5 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) > 16
				if (spn == MLO_N_SPANS_PER_SCAN - 1)
				{
					spanRightSiding5x5(k, top_df_off, (MLO_FILTER_SIZE1 - 1), mask, top_dat, top_df);
				}
				else
#endif
				{
					spanReadingOutput3x3(k, (MLO_FILTER_SIZE1 - 1), top_df_off, mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
						out_mask,
#endif
						top_dat, top_df);
				}

			}

			// processing
			Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, 0, pvt_accum, lcl_bot, top_dat);

			// move up output to reduce overfetch
			moveOutputUp(top_dat);
		}

// non-border input blocks
		for (int i_loop = 0;i_loop < MLO_N_GENERIC_LOOPS; ++i_loop, gbl_in_scan_off += MLO_IN_STRIDE * MLO_IN_EXTENT1)
		{
			barrier(CLK_LOCAL_MEM_FENCE);

			readInput(lcl_id, gbl_in_scan_off, MLO_IN_VERT_READS, bot, lcl_bot);

// point to the start of the local buffer

			sc_lcl_off = lcl_bot_off;

			barrier(CLK_LOCAL_MEM_FENCE);

			for (; sc < (i_loop + 2) * MLO_IN_EXTENT1
				// 3x3 out of range
				; ++sc, gbl_out_scan_off += MLO_OUT_STRIDE, sc_lcl_off += MLO_IN_LCL_WIDTH)
			{

				for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
				{
					int top_df_off = gbl_out_scan_off + k*MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE;
					_FLOAT mask = 1;

#if MLO_FILTER_SIZE1 > MLO_OUT_HEIGHT
					top_df_off = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? top_df_off : 0;
					mask = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? 1 : 0;
#endif
					// move in the last output scans
					// 5x5 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) > 16
					if (spn == MLO_N_SPANS_PER_SCAN - 1)
					{
						spanRightSiding5x5(k, top_df_off, (MLO_FILTER_SIZE1 - 1), mask, top_dat, top_df);
					}
					else
#endif
					{
						spanReadingOutput3x3(k, (MLO_FILTER_SIZE1 - 1), top_df_off, mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
							out_mask,
#endif
							top_dat, top_df);

					}

				}

				// processing
				Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, 0, pvt_accum, lcl_bot, top_dat);

				// move up output to reduce overfetch
				moveOutputUp(top_dat);

			}
		}

// bottom border block

		for (int i_loop = 0; i_loop < (MLO_IN_N_VERT_LOOPS - MLO_N_GENERIC_LOOPS - 1); ++i_loop, gbl_in_scan_off += MLO_IN_STRIDE * MLO_IN_EXTENT1)
		{
			barrier(CLK_LOCAL_MEM_FENCE);
// read 1 scan line less
// padding processing takes care of the bottom border.
// TO DD: verify it with 5x5
			readInput(lcl_id, gbl_in_scan_off, MLO_IN_EXTENT1, bot, lcl_bot);

			// point to the start of the local buffer

			sc_lcl_off = lcl_bot_off;

			barrier(CLK_LOCAL_MEM_FENCE);

			for (; sc < MLO_OUT_HEIGHT - MLO_FILTER_PAD1
				// 3x3 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
				- 1
#endif
				; ++sc, gbl_out_scan_off += MLO_OUT_STRIDE, sc_lcl_off += MLO_IN_LCL_WIDTH)
			{

				for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
				{
					int top_df_off = gbl_out_scan_off + k*MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE;
					_FLOAT mask = 1;

#if MLO_FILTER_SIZE1 > MLO_OUT_HEIGHT
					top_df_off = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? top_df_off : 0;
					mask = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? 1 : 0;
#endif
					// move in the last output scans
					// 5x5 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) > 16
					if (spn == MLO_N_SPANS_PER_SCAN - 1)
					{
						spanRightSiding5x5(k, top_df_off, (MLO_FILTER_SIZE1 - 1), mask, top_dat, top_df);
					}
					else
#endif
					{
						spanReadingOutput3x3(k, (MLO_FILTER_SIZE1 - 1), top_df_off, mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
							out_mask,
#endif
							top_dat, top_df);
					}

				}

				// processing
				Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, 0, pvt_accum, lcl_bot, top_dat);

				// move up output to reduce overfetch
				moveOutputUp(top_dat);

			}
		}

// handling 3x3 out of range
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
		{
			for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
			{
				int top_df_off = gbl_out_scan_off + k*MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE;
				_FLOAT mask = 1;

#if MLO_FILTER_SIZE1 > MLO_OUT_HEIGHT
				top_df_off = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? top_df_off : 0;
				mask = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? 1 : 0;
#endif
				// move in the last output scans

				if (spn == MLO_N_SPANS_PER_SCAN - 1 )
				{
					spanRightSiding5x5(k, top_df_off, (MLO_FILTER_SIZE1 - 1), mask, top_dat, top_df);
				}
				else
				{
					int pvt_off = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + (MLO_FILTER_SIZE1 - 1) *MLO_IN_TILE0;
					for (int i = 0; i < MLO_IN_TILE0; ++i)
					{
						top_dat[pvt_off + i] = top_df[top_df_off + i] * mask;
					}
				}

			}

			// processing
			Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, 0, pvt_accum, lcl_bot, top_dat);

			// move up output to reduce overfetch
			moveOutputUp(top_dat);

		}

		++sc; gbl_out_scan_off += MLO_OUT_STRIDE; sc_lcl_off += MLO_IN_LCL_WIDTH;
#endif

		// epilog
		// handling padding
		// pad0/1

		for (; sc < MLO_OUT_HEIGHT; ++sc, sc_lcl_off += MLO_IN_LCL_WIDTH)
		{
			// processing
			Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, (MLO_FILTER_PAD1 + 1 - (MLO_OUT_HEIGHT - sc)), pvt_accum, lcl_bot, top_dat);
			// move up output to reduce overfetch
			moveOutputUp(top_dat);

		} // for (; sc < MLO_OUT_HEIGHT - MLO_FILTER_PAD1 + 2; ++sc, gbl_out_scan_off += MLO_OUT_CHANNEL_STRIDE, gbl_in_scan_off += MLO_IN_CHANNEL_STRIDE)

	} // 	for (int b = 0;

	// final summation over all output maps and each filter row
	// this coudl be done with log but it negligeble anyway
	for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
	{
		for (int l = 0; l < MLO_FILTER_SIZE1; ++l)
		{

			barrier(CLK_LOCAL_MEM_FENCE);
			for (int n = 0; n < MLO_FILTER_SIZE0; ++n)
			{
				int pvt_off = k*MLO_FILTER_SIZE0 * MLO_FILTER_SIZE1 + l*MLO_FILTER_SIZE0 + n;
				lcl[lcl_id * MLO_FILTER_SIZE0 + n] =
					pvt_accum[pvt_off];

			}

			barrier(CLK_LOCAL_MEM_FENCE);

			if (spn == 0)
			{
				for (int s = 0; s < MLO_N_SPANS_PER_SCAN - 1; ++s)
				{

					for (int n = 0; n < MLO_FILTER_SIZE0; ++n)
					{
						int pvt_off = k*MLO_FILTER_SIZE0 * MLO_FILTER_SIZE1 + l*MLO_FILTER_SIZE0 + n;
						pvt_accum[pvt_off]
							+= lcl[(lcl_id + s + 1) * MLO_FILTER_SIZE0 + n];
#if 0
						if (/*fabs(pvt_accum[pvt_off] - 0.020364f) < 0.0001f*/ pvt_off == 12 && get_global_id(1) == 0 && get_global_id(2) == 0 && get_local_id(0) == 0 && k == 0/* && l == 2 && n == 2*/)
						{
							printf("G:s: %d %d %d  %f %f\n",
								get_local_id(0),
								(lcl_id + s + 1) * MLO_FILTER_SIZE0 + n,
								pvt_off,
								pvt_accum[pvt_off],
								lcl[(lcl_id + s + 1) * MLO_FILTER_SIZE0 + n]
							);
						}
#endif

					}

				}
			}

//			barrier(CLK_LOCAL_MEM_FENCE);
		}
	}

// output
// inputs are outputs
// TODO : for more than 1 input
	int c = 0;

	int wei_df_off = ((ib * MLO_N_OUTPUTS + o_idx + o) * (int)MLO_WEI_BATCH_STRIDE)
		// this input channel
		+ mul24((c_idx + c), (int)MLO_WEI_CHANNEL_STRIDE);
	for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
	{
		if (spn == 0 && o_idx + o + k*MLO_OUT_STACKS < MLO_N_OUTPUTS && o < MLO_OUT_STACKS)
		{

			for (int i = 0; i < (MLO_FILTER_SIZE1 * MLO_FILTER_SIZE0); ++i)
			{
				weights_df[wei_df_off + k*MLO_OUT_STACKS*MLO_WEI_BATCH_STRIDE + i] = pvt_accum[k*MLO_FILTER_SIZE0 * MLO_FILTER_SIZE1 + i];
#if 0
				if (wei_df_off + k*MLO_OUT_STACKS*MLO_WEI_BATCH_STRIDE + i == 12)
				{
					printf("G:o: %d %d  %f\n",
						get_local_id(0),
						k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + i,
						pvt_accum[k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + i]
					);
				}
#endif
			}

		}
	}

}

// final reduction kernel
// add filters over batches
__attribute__((reqd_work_group_size(MLO_UT_GRP_SZ0, 1, 1)))
__kernel void MLOpenCvBwdWrW_rdc(
	const __global _FLOAT * weight_df_tmp,
	__global _FLOAT * weights_df
)
{
	int gbl_id = get_global_id(0);
	int wei_idx0 = gbl_id * MLO_UT_READ_UNIT;

	int wei_blk_idx = iDiv(wei_idx0, MLO_WEI_CHANNEL_STRIDE);
	int wei_idx = iMod(wei_idx0, wei_blk_idx, MLO_WEI_CHANNEL_STRIDE);

	_FLOAT pvt_accum_wei[MLO_UT_READ_UNIT];
	for (int i = 0; i < MLO_UT_READ_UNIT; ++i)
	{
		pvt_accum_wei[i] = 0;
	}

	int batch_loop = (MLO_BATCH_SZ + (MLO_N_BATCH_LOOPS*MLO_N_LCL_BATCHS) - 1) / (MLO_N_BATCH_LOOPS*MLO_N_LCL_BATCHS);
	for (int i = 0; i < batch_loop; ++i)
	{
		*(MLO_UT_READ_TYPE*)pvt_accum_wei
			+= *(__global MLO_UT_READ_TYPE*)&weight_df_tmp[(wei_blk_idx * MLO_WEI_CHANNEL_STRIDE + i* MLO_N_OUTPUTS*MLO_WEI_BATCH_STRIDE)  + wei_idx];
	}

	*(__global MLO_UT_READ_TYPE*)&weights_df[wei_idx0] = *(MLO_UT_READ_TYPE*)pvt_accum_wei;

}

/*
 * Copyright (c) 2016 AMD Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and/or associated documentation files (the
 * "Materials"), to deal in the Materials without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Materials, and to
 * permit persons to whom the Materials are furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Materials.
 *
 * THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
 */

#define _FLOAT					float
#define _FLOAT2					float2
#define _FLOAT4					float4
#define _FLOAT8					float8

#ifndef FLT_MAX
#define FLT_MAX         3.402823466e+38F        /* max value */
#endif

#define MLO_N_OUT_HORIZ_READS ((MLO_OUT_WIDTH + MLO_IN_TILE0 - 1) / MLO_IN_TILE0)
#define MLO_N_SPANS_PER_SCAN (MLO_N_OUT_HORIZ_READS)
#define MLO_N_OUT_HORIZ_PIX_READS (MLO_N_OUT_HORIZ_READS * MLO_IN_TILE0)
#define MLO_OUT_N_PIXS_OFF (MLO_OUT_WIDTH - ((MLO_OUT_WIDTH / MLO_IN_TILE0)*MLO_IN_TILE0))
#define MLO_N_OUT_VERTICAL_READS (MLO_FILTER_SIZE1)
// won't run non-border blocks if  MLO_IN_N_VERT_LOOPS < 2
#if MLO_FILTER_PAD1 > 0

#if  MLO_IN_N_VERT_LOOPS >= 2
#define MLO_N_GENERIC_LOOPS ((int)(MLO_IN_N_VERT_LOOPS - 2))
#define MLO_IN_VERT_READS (MLO_IN_EXTENT1 + MLO_FILTER_PAD1)
#else
#define MLO_N_GENERIC_LOOPS 0
#define MLO_IN_VERT_READS MLO_IN_EXTENT1
#endif

#else
#define MLO_N_GENERIC_LOOPS (MLO_IN_N_VERT_LOOPS)
#define MLO_IN_VERT_READS MLO_IN_EXTENT1
#endif

// there is an assumption that the scanline fits into LDS
#define MLO_N_IN_HORIZ_PIX_READS (MLO_IN_WIDTH)
#define MLO_N_IN_HORIZ_READS ((MLO_N_IN_HORIZ_PIX_READS + MLO_READ_UNIT - 1) / MLO_READ_UNIT)
#define MLO_IN_N_PIXS_OFF  (MLO_N_IN_HORIZ_PIX_READS - (MLO_N_IN_HORIZ_PIX_READS/MLO_READ_UNIT)*MLO_READ_UNIT)
#define MLO_IN_LCL_WIDTH (MLO_N_IN_HORIZ_READS * MLO_READ_UNIT + 2* MLO_FILTER_PAD0)
#define MLO_IN_LCL_HEIGHT MLO_IN_VERT_READS
#define MLO_IN_LCL_SZ (MLO_IN_LCL_WIDTH * MLO_IN_LCL_HEIGHT)
#define MLO_TOTAL_IN_LCL_SZ (MLO_N_LCL_BATCHS*MLO_N_LCL_IN_MAPS*MLO_IN_LCL_SZ)

#define MLO_WEI_LCL_SZ (MLO_GRP_SZ * MLO_FILTER_SIZE0)
#if MLO_TOTAL_IN_LCL_SZ > MLO_WEI_LCL_SZ
#define MLO_LCL_SZ (MLO_TOTAL_IN_LCL_SZ)
#else
#define MLO_LCL_SZ (MLO_WEI_LCL_SZ)
#endif

#define MLO_HW_WAVE_ID_SETTING 0

#if MLO_HW_WAVE_ID_SETTING
extern __attribute__((const)) uint __hsail_get_dynwave_id(void);
static inline int getWaveId()
{
	int wave_id = 0;

	wave_id = __hsail_get_dynwave_id();
	wave_id = wave_id & MLO_N_PHYS_WAVES_MASK;
	return(wave_id);
}
#else
static inline int getWaveId()
{
	int wave_id = 0;

	wave_id = (get_local_id(0) >> MLO_LG2_PHYS_WAVE_SZ);

	return(wave_id);
}
#endif

static inline int gePhysLocalId()
{
	int lcl_wave_id = get_local_id(0) - ((get_local_id(0) >> MLO_LG2_PHYS_WAVE_SZ) << MLO_LG2_PHYS_WAVE_SZ);
	return(lcl_wave_id);
}

static inline int iDiv(int v, int d)
{
	int r = (int)((float)v / d + 0.00001f);
	return(r);
}

static inline int iMod(int v, int u, int d)
{
	int r = v - mul24((int)u, (int)d);
	return(r);
}

static inline void ReduceKernel(__local _FLOAT * lcl_blob, __private _FLOAT *weights_accum, int lcl_id, int scan_lcl, int sum_stride, int unit_len, bool debug)
{
// read first half
	if (scan_lcl < (sum_stride >> 1))
	{
		for (int i = 0; i < unit_len; ++i)
		{
			weights_accum[i] = lcl_blob[(lcl_id + scan_lcl) * unit_len + i];

		}

	}
// add second half
// appload accumulated value so far
	for (int j = (sum_stride >> 1); j > 0; j >>= 1)
	{
		barrier(CLK_LOCAL_MEM_FENCE);
		if (scan_lcl < j)
		{
			for (int i = 0; i < unit_len; ++i)
			{
				weights_accum[i] += lcl_blob[(lcl_id + j) * unit_len + i];

				lcl_blob[lcl_id * unit_len + i] = weights_accum[i];
			}

		}
	}
}

static inline void  Kahan_summation(__private _FLOAT *sum, __private _FLOAT * c, _FLOAT v)
{
	_FLOAT y = v - *c;    //So far, so good: c is zero.
	_FLOAT t = *sum + y;         //Alas, sum is big, y small, so low-order digits of y are lost.
	*c = (t - *sum) - y;   //(t - sum) recovers the high-order part of y; subtracting y recovers -(low part of y)
	*sum = t;             //Algebraically, c should always be zero. Beware eagerly optimising compilers!
}

/*
	group cooperative read
	read by MLO_READ_UNIT
	handle out of range both horizontally and vertically (by fixed number of veryical reads)

	no guard against number of inputs
*/
static inline void readInput(int lcl_id, int gbl_in_scan_off, int n_v_reads, const __global _FLOAT * bot, __local _FLOAT *lcl_bot)
{
	for (int p4 = lcl_id; p4 < MLO_N_LCL_IN_MAPS * MLO_N_IN_HORIZ_READS * n_v_reads;
		p4 += MLO_GRP_SZ)
	{
		__private _FLOAT in_rd_data[MLO_READ_UNIT];
// TODO : more than 1 input
		int c = 0;
		int c_scan = iDiv(p4, (MLO_N_IN_HORIZ_READS));

		int c_pix4 = iMod(p4, c_scan, (MLO_N_IN_HORIZ_READS));

//		if (c < MLO_N_INPUTS)

		{

#if MLO_IN_N_PIXS_OFF > 0

			if (c_pix4 == MLO_N_IN_HORIZ_READS - 1)
			{
				for (int i = 0; i < MLO_IN_N_PIXS_OFF; ++i)
				{

					in_rd_data[i] = bot[gbl_in_scan_off + c*MLO_IN_CHANNEL_STRIDE + c_scan* MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT + i];
				}

				for (int i = MLO_IN_N_PIXS_OFF; i < MLO_READ_UNIT; ++i)
				{
					in_rd_data[i] = 0;
				}

			}
			else
#endif
			{
				*(MLO_READ_TYPE*)in_rd_data = *(__global MLO_READ_TYPE*)&bot[gbl_in_scan_off + c*MLO_IN_CHANNEL_STRIDE + c_scan* MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT];
			}

// MLO_N_LCL_IN_MAPS inputs
			for (int i = 0; i < MLO_READ_UNIT; ++i)
			{
				int lcl_in_off = c*MLO_IN_LCL_SZ + c_scan* MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT + i;
				lcl_bot[lcl_in_off] = in_rd_data[i];
			}
		}

	} // for (int p4 = lcl_id; p4 < MLO_N_LCL_IN_MAPS * MLO_N_IN_HORIZ_READS * MLO_IN_VERT_READS;

	barrier(CLK_LOCAL_MEM_FENCE);

}

/*
	core processing loop
	bot - input, from local (1 span)
	top - output diff, from global (array of spans, filters vertical size)

	loop over filter vertical size

*/
static inline void Processing(int sc, int sc_lcl_off, int top_lim, int bot_lim, __private _FLOAT * pvt_accum, __local _FLOAT * lcl_bot, __private _FLOAT * top_dat)
{
	for (int l = top_lim; l >= bot_lim; --l)
	{
		for (int m = 0; m < MLO_IN_TILE0; ++m)
		{
			for (int n = 0; n < MLO_FILTER_SIZE0; ++n)
			{
				_FLOAT bot_val = lcl_bot[sc_lcl_off + n + m];
				for(int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
				{
					int pvt_top_off =  k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + (top_lim - l) * MLO_IN_TILE0 + m;
					int pvt_accum_off = k*MLO_FILTER_SIZE1*MLO_FILTER_SIZE0 + l*MLO_FILTER_SIZE0 + n;

					_FLOAT top_val = top_dat[pvt_top_off];

					pvt_accum[pvt_accum_off]
						// each wk-it process an input
						+= bot_val*top_val;
#if 0
					if (bot_val * top_val != 0 && get_global_id(1) == 0 && get_global_id(2) == 0 && (get_local_id(0) == 0 || get_local_id(0) == 1) && k == 0 && l == 0 && n == 0)
					{
						printf("G: %d %d %d %d  %f %f %f %f\n",
							get_local_id(0),
							sc,
							sc_lcl_off + n + m,
							pvt_top_off,
							pvt_accum[pvt_accum_off],
							bot_val * top_val,
							bot_val,
							top_val
						);
					}
#endif
				}
			}

		}

	}

}

static inline void moveOutputUp(__private _FLOAT * top_dat)
{
	// move up output to reduce overfetch
	for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
	{
		for (int j = 0; j < MLO_FILTER_SIZE1 - 1; ++j)
		{
			for (int i = 0; i < MLO_IN_TILE0; ++i)
			{
				int pvt_off_n = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + j *MLO_IN_TILE0 + i;
				int pvt_off_o = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + (j + 1) *MLO_IN_TILE0 + i;
				top_dat[pvt_off_n] = top_dat[pvt_off_o];
			}
		}
	}
}

static inline void spanRightSiding5x5(int k, int top_df_off, int j, _FLOAT mask, __private _FLOAT * top_dat, __global const _FLOAT * top_df)
{
	int i = 0;
	int pvt_off = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + j *MLO_IN_TILE0;
	for (; i < MLO_OUT_N_PIXS_OFF; ++i)
	{
		top_dat[pvt_off + i] = top_df[top_df_off + i] * mask;
	}
	for (; i < MLO_IN_TILE0; ++i)
	{
		top_dat[pvt_off + i] = 0;
	}

}
#if 1
#if (MLO_IN_TILE0 - MLO_OUT_N_PIXS_OFF <= MLO_FILTER_PAD0)
#define MLO_OUT_MASK_SZ (MLO_IN_TILE0 - MLO_OUT_N_PIXS_OFF)
#else
#define MLO_OUT_MASK_SZ (MLO_FILTER_PAD0)
#endif
#endif

//#define MLO_OUT_MASK_SZ (1)
static inline void spanReadingOutput3x3(int k, int j, int top_df_off, _FLOAT mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
	__private _FLOAT * out_mask,
#endif
	__private _FLOAT * top_dat, const __global _FLOAT * top_df)
{
	int pvt_off = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + j *MLO_IN_TILE0;
	for (int i = 0; i < MLO_IN_TILE0; ++i)
	{
		top_dat[pvt_off + i] = top_df[top_df_off + i] * mask
			;
	}
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16

	for (int i = MLO_OUT_N_PIXS_OFF; i < MLO_OUT_N_PIXS_OFF + MLO_OUT_MASK_SZ; ++i)
	{
		top_dat[pvt_off + i] *= out_mask[i - MLO_OUT_N_PIXS_OFF];

	}
#endif
}

/*********************************************************************************************************
// wrw algorithm for large filters
// idea:
// split output scan-line on number of spans by the  MLO_IN_TILE0 (2 for example)
// 1 scan-line has ((MLO_OUT_WIDTH + MLO_IN_TILE0 - 1/MLO_IN_TILE0) spans
// group will process MLO_GRP_SZ/((MLO_OUT_WIDTH + MLO_IN_TILE0 - 1/MLO_IN_TILE0) output maps

// alg
// load a block of input map (or full map) into LDS
// loop
// read MLO_FILTER_SIZE1 number of spans from output map into VGPRs (for example 5 *2 = 10)
// read 1 input line for  maps into LDS
// accumulate

// accumulate all spans at the end
// start new loop for the next batch (if defined)
// write out

// kerenl handles 5x5, 3x3 with padding
// small images in 1 short- MLO_N_GENERIC_LOOPS == 0
// big images  in 2 blocks - MLO_IN_N_VERT_LOOPS == 2 or multiple blocks - MLO_IN_N_VERT_LOOPS > 2
// there are prolog and apilog that deal with top/bottom padding.
// left/right padding handles as a LDS border pixels zeroed at the beginning.

**********************************************************************************************************/

__attribute__((reqd_work_group_size(MLO_GRP_SZ0, MLO_GRP_SZ1, MLO_GRP_SZ2)))
__kernel void MLOpenCvBwdWrW(
	const __global _FLOAT * top_df,
	const __global _FLOAT * bot,
	__global _FLOAT * weights_df,
#if MLO_CONV_BIAS
	__global _FLOAT * bias_df,
#endif
	_FLOAT padding_val
)
{

	// input/output tiles + reduce buffer

	__local _FLOAT lcl[(MLO_LCL_SZ)];
	__local _FLOAT * lcl_bot = lcl;

	// guarnteeing an uniformity over a wave
	int wave_id = getWaveId();
	int lcl_id = get_local_id(0);
	int lcl_wv_id = gePhysLocalId();

	int c_idx_base = get_group_id(1); // input map index base

	int o_idx_base = iDiv(get_group_id(2), (MLO_BATCH_SZ / (MLO_N_BATCH_LOOPS*MLO_N_LCL_BATCHS))); // output map index base
	int ib_base = iMod(get_group_id(2), o_idx_base, (MLO_BATCH_SZ / (MLO_N_BATCH_LOOPS*MLO_N_LCL_BATCHS)));

	int ib = ib_base*MLO_N_LCL_BATCHS;

	int c_idx = c_idx_base * MLO_N_LCL_IN_MAPS; // input map index

	int o_idx = o_idx_base * (MLO_N_LCL_OUT_MAPS * MLO_OUT_STACKS); // output map index

	int gbl_in_off = c_idx * MLO_IN_CHANNEL_STRIDE + ib * MLO_IN_BATCH_STRIDE;
	int gbl_out_off = o_idx * MLO_OUT_CHANNEL_STRIDE + ib * MLO_OUT_BATCH_STRIDE;
	// 1 span per wk_item, total scanline with MLO_N_SPANS_PER_SCAN spans
	// TODO: more than 1 input
	int o = iDiv(lcl_id, MLO_N_SPANS_PER_SCAN);
	//	bool scan_lead = (o*MLO_N_SPANS_PER_SCAN == lcl_id);
	int spn = iMod(lcl_id, o, MLO_N_SPANS_PER_SCAN);

	int lcl_bot_off = spn * MLO_IN_TILE0;
	int out_wk_item_off = o * MLO_OUT_CHANNEL_STRIDE + lcl_bot_off;
	gbl_out_off += out_wk_item_off;

#define MLO_TOP_DAT_SZ (MLO_N_LCL_OUT_MAPS * MLO_IN_TILE0 * MLO_FILTER_SIZE1)

	__private _FLOAT top_dat[MLO_TOP_DAT_SZ];

	for (int i = 0; i < MLO_TOP_DAT_SZ; ++i)
	{
		top_dat[i] = 0;
	}

#define MLO_ACCUM_SZ (MLO_N_LCL_OUT_MAPS * MLO_FILTER_SIZE1*MLO_FILTER_SIZE0)

	__private _FLOAT pvt_accum[MLO_ACCUM_SZ];

	for (int i = 0; i < MLO_ACCUM_SZ; ++i)
	{
		pvt_accum[i] = 0;
	}

	// zero out LDS
	for (int i = lcl_id; i < (MLO_LCL_SZ); i += MLO_GRP_SZ)
	{
		lcl[i] = 0;
	}

// 3x3 out mask
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16

	_FLOAT out_mask[MLO_OUT_MASK_SZ];
	if (spn == MLO_N_SPANS_PER_SCAN - 1)
	{
		for (int i = 0; i < MLO_OUT_MASK_SZ; ++i)
		{
			out_mask[i] = 0;
		}
	}
	else
	{
		for (int i = 0; i < MLO_OUT_MASK_SZ; ++i)
		{
			out_mask[i] = 1;
		}
	}

#endif

	// over all batches
	for (int b = 0;
		b < MLO_N_BATCH_LOOPS;
		++b,
		gbl_in_off += MLO_N_LCL_BATCHS*MLO_IN_BATCH_STRIDE,
		gbl_out_off += MLO_N_LCL_BATCHS*MLO_OUT_BATCH_STRIDE
		)
	{
		barrier(CLK_LOCAL_MEM_FENCE);
		// top border input block
		int gbl_in_scan_off = gbl_in_off;
		int gbl_out_scan_off = gbl_out_off;

		// read input map
		readInput(lcl_id, gbl_in_scan_off, MLO_IN_VERT_READS, bot, lcl_bot);
		// move input pointer
		gbl_in_scan_off += MLO_IN_STRIDE * MLO_IN_EXTENT1;

		for (int i = 0; i < MLO_TOP_DAT_SZ; ++i)
		{
			top_dat[i] = 0;
		}

		// prefetch output

		int gbl_out_scan_off1 = gbl_out_scan_off;
		for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k, gbl_out_scan_off1 += MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE)
		{
			for (int j = 0; j < MLO_FILTER_SIZE1 - 1; ++j)
			{
				// loop around all output maps
				int top_df_off = gbl_out_scan_off1 + j*MLO_OUT_STRIDE;
				_FLOAT mask = 1;
#if MLO_FILTER_SIZE1 - 1 > MLO_OUT_HEIGHT
				top_df_off = (j < MLO_OUT_HEIGHT) ? top_df_off : 0;
				mask = (j < MLO_OUT_HEIGHT) ? 1 : 0;
#endif

// 5x5 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) > 16
				if (spn == MLO_N_SPANS_PER_SCAN - 1)
				{

					spanRightSiding5x5(k, top_df_off, j, mask, top_dat, top_df);

				}
				else
#endif
				{
					spanReadingOutput3x3(k, j, top_df_off, mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
						out_mask,
#endif
						top_dat, top_df);
				}

			}
		}

		barrier(CLK_LOCAL_MEM_FENCE);

		gbl_out_scan_off += (MLO_FILTER_SIZE1 - 1) * MLO_OUT_STRIDE;

		int sc = 0;
		int sc_lcl_off = lcl_bot_off;

		// prolog
		// handling padding

		// pad0
		for (; sc < MLO_FILTER_PAD1; ++sc, sc_lcl_off += MLO_IN_LCL_WIDTH)
		{
			Processing(sc, sc_lcl_off, sc + MLO_FILTER_PAD1, 0, pvt_accum, lcl_bot, top_dat);
		}

		for (; sc < MLO_IN_EXTENT1
#if MLO_IN_N_VERT_LOOPS == 1
			- MLO_FILTER_PAD1
			// 3x3 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
			- 1
#endif
#endif
			; ++sc, gbl_out_scan_off += MLO_OUT_STRIDE, sc_lcl_off += MLO_IN_LCL_WIDTH)
		{
			for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
			{
				int top_df_off = gbl_out_scan_off + k*MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE;
				_FLOAT mask = 1;

#if MLO_FILTER_SIZE1 > MLO_OUT_HEIGHT
				top_df_off = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? top_df_off : 0;
				mask = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? 1 : 0;
#endif
				// move in the last output scans
// 5x5 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) > 16
				if (spn == MLO_N_SPANS_PER_SCAN - 1)
				{
					spanRightSiding5x5(k, top_df_off, (MLO_FILTER_SIZE1 - 1), mask, top_dat, top_df);
				}
				else
#endif
				{
					spanReadingOutput3x3(k, (MLO_FILTER_SIZE1 - 1), top_df_off, mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
						out_mask,
#endif
						top_dat, top_df);
				}

			}

			// processing
			Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, 0, pvt_accum, lcl_bot, top_dat);

			// move up output to reduce overfetch
			moveOutputUp(top_dat);
		}

// non-border input blocks
		for (int i_loop = 0;i_loop < MLO_N_GENERIC_LOOPS; ++i_loop, gbl_in_scan_off += MLO_IN_STRIDE * MLO_IN_EXTENT1)
		{
			barrier(CLK_LOCAL_MEM_FENCE);

			readInput(lcl_id, gbl_in_scan_off, MLO_IN_VERT_READS, bot, lcl_bot);

// point to the start of the local buffer

			sc_lcl_off = lcl_bot_off;

			barrier(CLK_LOCAL_MEM_FENCE);

			for (; sc < (i_loop + 2) * MLO_IN_EXTENT1
				// 3x3 out of range
				; ++sc, gbl_out_scan_off += MLO_OUT_STRIDE, sc_lcl_off += MLO_IN_LCL_WIDTH)
			{

				for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
				{
					int top_df_off = gbl_out_scan_off + k*MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE;
					_FLOAT mask = 1;

#if MLO_FILTER_SIZE1 > MLO_OUT_HEIGHT
					top_df_off = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? top_df_off : 0;
					mask = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? 1 : 0;
#endif
					// move in the last output scans
					// 5x5 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) > 16
					if (spn == MLO_N_SPANS_PER_SCAN - 1)
					{
						spanRightSiding5x5(k, top_df_off, (MLO_FILTER_SIZE1 - 1), mask, top_dat, top_df);
					}
					else
#endif
					{

						spanReadingOutput3x3(k, (MLO_FILTER_SIZE1 - 1), top_df_off, mask,
#if MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
							out_mask,
#endif
							top_dat, top_df);

					}

				}

				// processing
				Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, 0, pvt_accum, lcl_bot, top_dat);

				// move up output to reduce overfetch
				moveOutputUp(top_dat);

			}
		}

// bottom border block

		for (int i_loop = 0; i_loop < (MLO_IN_N_VERT_LOOPS - MLO_N_GENERIC_LOOPS - 1); ++i_loop, gbl_in_scan_off += MLO_IN_STRIDE * MLO_IN_EXTENT1)
		{
			barrier(CLK_LOCAL_MEM_FENCE);
			// read 1 scan line less
			// padding processing takes care of the bottom border.
			// do need sync with the real read: non intersecting areas.
#define MLO_LAST_VERT_READS (MLO_IN_HEIGHT - MLO_IN_EXTENT1 * (MLO_IN_N_VERT_LOOPS - 1))
#if 0 //MLO_IN_N_VERT_LOOPS > 1
			for (int c = 0; c < MLO_N_LCL_IN_MAPS; ++c)
			{
				for (int i = lcl_id; i < MLO_IN_VERT_READS - MLO_LAST_VERT_READS; i += MLO_GRP_SZ)
				{
					lcl_bot[c*MLO_IN_LCL_SZ + MLO_LAST_VERT_READS *MLO_IN_LCL_WIDTH + i] = 0;
				}
			}
#endif

			readInput(lcl_id, gbl_in_scan_off, MLO_LAST_VERT_READS, bot, lcl_bot);

			// point to the start of the local buffer

			sc_lcl_off = lcl_bot_off;

			barrier(CLK_LOCAL_MEM_FENCE);

			for (; sc < MLO_OUT_HEIGHT - MLO_FILTER_PAD1
				// 3x3 out of range
#if MLO_OUT_N_PIXS_OFF > 0 && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
				- 1
#endif
				; ++sc, gbl_out_scan_off += MLO_OUT_STRIDE, sc_lcl_off += MLO_IN_LCL_WIDTH)
			{

				for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
				{
					int top_df_off = gbl_out_scan_off + k*MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE;
					_FLOAT mask = 1;

#if MLO_FILTER_SIZE1 > MLO_OUT_HEIGHT
					top_df_off = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? top_df_off : 0;
					mask = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? 1 : 0;
#endif
					// move in the last output scans

					if (spn == MLO_N_SPANS_PER_SCAN - 1)
					{
						spanRightSiding5x5(k, top_df_off, (MLO_FILTER_SIZE1 - 1), mask, top_dat, top_df);
					}
					else
					{
						int pvt_off = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + (MLO_FILTER_SIZE1 - 1) *MLO_IN_TILE0;
						for (int i = 0; i < MLO_IN_TILE0; ++i)
						{
							top_dat[pvt_off + i] = top_df[top_df_off + i] * mask;
						}
					}

				}

				// processing
				Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, 0, pvt_accum, lcl_bot, top_dat);

				// move up output to reduce overfetch
				moveOutputUp(top_dat);

			}
		}

// handling 3x3 out of range
#if MLO_IN_N_VERT_LOOPS == 1 && MLO_OUT_N_PIXS_OFF > 0  && (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0) <= 16
		{
			for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
			{
				int top_df_off = gbl_out_scan_off + k*MLO_OUT_STACKS * MLO_OUT_CHANNEL_STRIDE;
				_FLOAT mask = 1;

#if MLO_FILTER_SIZE1 > MLO_OUT_HEIGHT
				top_df_off = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? top_df_off : 0;
				mask = ((sc + MLO_FILTER_PAD1) < MLO_OUT_HEIGHT) ? 1 : 0;
#endif
				// move in the last output scans

				if (spn == MLO_N_SPANS_PER_SCAN - 1 )
				{
					spanRightSiding5x5(k, top_df_off, (MLO_FILTER_SIZE1 - 1), mask, top_dat, top_df);
				}
				else
				{

					int pvt_off = k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + (MLO_FILTER_SIZE1 - 1) *MLO_IN_TILE0;
					for (int i = 0; i < MLO_IN_TILE0; ++i)
					{
						top_dat[pvt_off + i] = top_df[top_df_off + i] * mask;
					}
				}

			}

			// processing
			Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, 0, pvt_accum, lcl_bot, top_dat);

			// move up output to reduce overfetch
			moveOutputUp(top_dat);

		}

		++sc; gbl_out_scan_off += MLO_OUT_STRIDE; sc_lcl_off += MLO_IN_LCL_WIDTH;
#endif

		// epilog
		// handling padding
		// pad0/1

		for (; sc < MLO_OUT_HEIGHT; ++sc, sc_lcl_off += MLO_IN_LCL_WIDTH)
		{
			// processing
			Processing(sc, sc_lcl_off, MLO_FILTER_SIZE1 - 1, (MLO_FILTER_PAD1 + 1 - (MLO_OUT_HEIGHT - sc)), pvt_accum, lcl_bot, top_dat);
			// move up output to reduce overfetch
			moveOutputUp(top_dat);

		} // for (; sc < MLO_OUT_HEIGHT - MLO_FILTER_PAD1 + 2; ++sc, gbl_out_scan_off += MLO_OUT_CHANNEL_STRIDE, gbl_in_scan_off += MLO_IN_CHANNEL_STRIDE)

	} // 	for (int b = 0;

	// final summation over all output maps and each filter row
	// this coudl be done with log but it negligeble anyway
	for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
	{
		for (int l = 0; l < MLO_FILTER_SIZE1; ++l)
		{

			barrier(CLK_LOCAL_MEM_FENCE);
			for (int n = 0; n < MLO_FILTER_SIZE0; ++n)
			{
				int pvt_off = k*MLO_FILTER_SIZE0 * MLO_FILTER_SIZE1 + l*MLO_FILTER_SIZE0 + n;
				lcl[lcl_id * MLO_FILTER_SIZE0 + n] =
					pvt_accum[pvt_off];

			}

			barrier(CLK_LOCAL_MEM_FENCE);

			if (spn == 0)
			{
				for (int s = 0; s < MLO_N_SPANS_PER_SCAN - 1; ++s)
				{

					for (int n = 0; n < MLO_FILTER_SIZE0; ++n)
					{
						int pvt_off = k*MLO_FILTER_SIZE0 * MLO_FILTER_SIZE1 + l*MLO_FILTER_SIZE0 + n;
						pvt_accum[pvt_off]
							+= lcl[(lcl_id + s + 1) * MLO_FILTER_SIZE0 + n];
#if 0
						if (/*fabs(pvt_accum[pvt_off] - 0.020364f) < 0.0001f*/ pvt_off == 12 && get_global_id(1) == 0 && get_global_id(2) == 0 && get_local_id(0) == 0 && k == 0/* && l == 2 && n == 2*/)
						{
							printf("G:s: %d %d %d  %f %f\n",
								get_local_id(0),
								(lcl_id + s + 1) * MLO_FILTER_SIZE0 + n,
								pvt_off,
								pvt_accum[pvt_off],
								lcl[(lcl_id + s + 1) * MLO_FILTER_SIZE0 + n]
							);
						}
#endif

					}

				}
			}

//			barrier(CLK_LOCAL_MEM_FENCE);
		}
	}

// output
// inputs are outputs
// TODO : for more than 1 input
	int c = 0;

	int wei_df_off = ((ib * MLO_N_OUTPUTS + o_idx + o) * (int)MLO_WEI_BATCH_STRIDE)
		// this input channel
		+ mul24((c_idx + c), (int)MLO_WEI_CHANNEL_STRIDE);
	for (int k = 0; k < MLO_N_LCL_OUT_MAPS; ++k)
	{
		if (spn == 0 && o_idx + o + k*MLO_OUT_STACKS < MLO_N_OUTPUTS && o < MLO_OUT_STACKS)
		{

			for (int i = 0; i < (MLO_FILTER_SIZE1 * MLO_FILTER_SIZE0); ++i)
			{
				weights_df[wei_df_off + k*MLO_OUT_STACKS*MLO_WEI_BATCH_STRIDE + i] = pvt_accum[k*MLO_FILTER_SIZE0 * MLO_FILTER_SIZE1 + i];
#if 0
				if (wei_df_off + k*MLO_OUT_STACKS*MLO_WEI_BATCH_STRIDE + i == 12)
				{
					printf("G:o: %d %d  %f\n",
						get_local_id(0),
						k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + i,
						pvt_accum[k*MLO_IN_TILE0 * MLO_FILTER_SIZE1 + i]
					);
				}
#endif
			}

		}
	}

}

// final reduction kernel
// add filters over batches
__attribute__((reqd_work_group_size(MLO_UT_GRP_SZ0, 1, 1)))
__kernel void MLOpenCvBwdWrW_rdc(
	const __global _FLOAT * weight_df_tmp,
	__global _FLOAT * weights_df
)
{
	int gbl_id = get_global_id(0);
	int wei_idx0 = gbl_id * MLO_UT_READ_UNIT;

	int wei_blk_idx = iDiv(wei_idx0, MLO_WEI_CHANNEL_STRIDE);
	int wei_idx = iMod(wei_idx0, wei_blk_idx, MLO_WEI_CHANNEL_STRIDE);

	_FLOAT pvt_accum_wei[MLO_UT_READ_UNIT];
	for (int i = 0; i < MLO_UT_READ_UNIT; ++i)
	{
		pvt_accum_wei[i] = 0;
	}

	int batch_loop = (MLO_BATCH_SZ + (MLO_N_BATCH_LOOPS*MLO_N_LCL_BATCHS) - 1) / (MLO_N_BATCH_LOOPS*MLO_N_LCL_BATCHS);
	for (int i = 0; i < batch_loop; ++i)
	{
		*(MLO_UT_READ_TYPE*)pvt_accum_wei
			+= *(__global MLO_UT_READ_TYPE*)&weight_df_tmp[(wei_blk_idx * MLO_WEI_CHANNEL_STRIDE + i* MLO_N_OUTPUTS*MLO_WEI_BATCH_STRIDE)  + wei_idx];
	}

	*(__global MLO_UT_READ_TYPE*)&weights_df[wei_idx0] = *(MLO_UT_READ_TYPE*)pvt_accum_wei;

}


another fix

another fix

/*
 * Copyright (c) 2016 AMD Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and/or associated documentation files (the
 * "Materials"), to deal in the Materials without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Materials, and to
 * permit persons to whom the Materials are furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Materials.
 *
 * THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
 */

#define _FLOAT					float
#define _FLOAT2					float2
#define _FLOAT4					float4
#define _FLOAT8					float8

#ifndef FLT_MAX
#define FLT_MAX         3.402823466e+38F        /* max value */
#endif

#define MLO_N_OUT_HORIZ_READS (MLO_ALIGNED_OUT_SCAN_LN)
#define MLO_OUT_HORIZ_PIX_SZ (MLO_N_OUT_HORIZ_READS * MLO_READ_UNIT)

// number of filter taps in the processing wk_item
#define MLO_WEI_WKITEM 4
// n of of filter blks
#define MLO_WEI_BLK_SZ0 ((MLO_FILTER_SIZE0 + MLO_WEI_WKITEM -1)/MLO_WEI_WKITEM)
#define MLO_WEI_BLK_SZ (MLO_FILTER_SIZE1*MLO_WEI_BLK_SZ0)
// n of filter tiles in the group grid
#define MLO_N_WEI_BLK (MLO_GRP_SZ/ MLO_WEI_BLK_SZ)
// n of steps per scan line to be made in the inner loop
#define MLO_OUT_WEI_SCAN_BLK ((MLO_OUT_WIDTH + MLO_N_WEI_BLK - 1) / MLO_N_WEI_BLK)

// max loop over virtual blocks for small images
#define MLO_MAX_WEI_BLK_LOOP_TMP ((MLO_OUT_WIDTH + MLO_OUT_WEI_SCAN_BLK - 1)/MLO_OUT_WEI_SCAN_BLK)
#if MLO_MAX_WEI_BLK_LOOP_TMP < MLO_N_WEI_BLK
#define MLO_MAX_WEI_BLK_LOOP MLO_MAX_WEI_BLK_LOOP_TMP
#else
#define MLO_MAX_WEI_BLK_LOOP MLO_N_WEI_BLK
#endif

#define MLO_WEI_BLKS_SZ (MLO_MAX_WEI_BLK_LOOP * MLO_WEI_BLK_SZ *MLO_WEI_WKITEM)
#define MLO_WEI_BLKS_LCL_SZ (MLO_WEI_BLKS_SZ * MLO_N_LCL_OUT_MAPS)

#define MLO_OUT_BLK_GRP_PIX_SZ (MLO_OUT_HORIZ_PIX_SZ * MLO_N_ALIGNED_OUT_SCAN_BLK)
#define MLO_OUT_BLK_GRP_WK_SZ (MLO_OUT_BLK_GRP_PIX_SZ / MLO_READ_UNIT)

// extended scan to deal with overshot in the inner loop
#define MLO_OUT_WEI_EXT_SCAN_BLK ((MLO_OUT_HORIZ_PIX_SZ + MLO_N_WEI_BLK - 1) / MLO_N_WEI_BLK)
#define MLO_OUT_HORIZ_PIX_EXT_SZ ((((MLO_OUT_WEI_EXT_SCAN_BLK * MLO_N_WEI_BLK) + MLO_READ_UNIT - 1) / MLO_READ_UNIT) * MLO_READ_UNIT)
#define MLO_OUT_BLK_GRP_EXT_PIX_SZ (MLO_OUT_HORIZ_PIX_EXT_SZ * MLO_N_ALIGNED_OUT_SCAN_BLK)
#define MLO_OUT_LCL_SZ (MLO_OUT_BLK_GRP_EXT_PIX_SZ)
// LDS OUT SIZE
#define MLO_TOTAL_OUT_LCL_SZ (MLO_N_LCL_OUT_MAPS*MLO_OUT_LCL_SZ)

// input size depends on output scan length and
// number of output scans
// this number is constrained by amount or LDS and size of register file.
// TO DO:: CHECK PADDING!!!
#define MLO_IN_LCL_HEIGHT ((MLO_N_ALIGNED_OUT_SCAN_BLK-1)*MLO_FILTER_STRIDE1 + MLO_FILTER_SIZE1)
#define MLO_N_IN_HORIZ_READS ((((MLO_OUT_HORIZ_PIX_SZ-1)*MLO_FILTER_STRIDE0 + MLO_FILTER_SIZE0) + MLO_READ_UNIT - 1) / MLO_READ_UNIT)
#define MLO_IN_LCL_WIDTH (MLO_N_IN_HORIZ_READS * MLO_READ_UNIT)
#define MLO_IN_BLK_GRP_PIX_SZ (MLO_IN_LCL_WIDTH * MLO_IN_LCL_HEIGHT)
#define MLO_IN_BLK_GRP_WK_SZ (MLO_IN_BLK_GRP_PIX_SZ/MLO_READ_UNIT)
#define MLO_IN_LCL_SZ (MLO_IN_BLK_GRP_PIX_SZ)
// LDS IN SIZE
#define MLO_TOTAL_IN_LCL_SZ (MLO_N_LCL_IN_MAPS*MLO_IN_LCL_SZ)
#define MLO_IN_VERT_READS (MLO_GRP_SZ/MLO_N_IN_HORIZ_READS)

#if (MLO_TOTAL_OUT_LCL_SZ + MLO_TOTAL_IN_LCL_SZ) > (MLO_WEI_BLKS_LCL_SZ)
#define MLO_LCL_SZ (MLO_TOTAL_OUT_LCL_SZ + MLO_TOTAL_IN_LCL_SZ)
#else
#define MLO_LCL_SZ (MLO_WEI_BLKS_LCL_SZ)
#endif

#define MLO_HW_WAVE_ID_SETTING 0

#if MLO_HW_WAVE_ID_SETTING
extern __attribute__((const)) uint __hsail_get_dynwave_id(void);
inline int getWaveId()
{
	int wave_id = 0;

	wave_id = __hsail_get_dynwave_id();
	wave_id = wave_id & MLO_N_PHYS_WAVES_MASK;
	return(wave_id);
}
#else
inline int getWaveId()
{
	int wave_id = 0;

	wave_id = (get_local_id(0) >> MLO_LG2_PHYS_WAVE_SZ);

	return(wave_id);
}
#endif

inline int iDiv(int v, int d)
{
	int r = (int)((float)v / d + 0.00001f);
	return(r);
}

inline int iMod(int v, int u, int d)
{
	int r = v - mul24((int)u,(int)d);
	return(r);
}

inline void ReduceKernel(__local _FLOAT * lcl_blob, _FLOAT *weights_accum, int lcl_id, int scan_lcl, int sum_stride, int unit_len, bool debug)
{
	for (int j = (sum_stride >> 1); j > 0; j >>= 1)
	{
		barrier(CLK_LOCAL_MEM_FENCE);
		if (scan_lcl < j)
		{
			for (int i = 0; i < unit_len; ++i)
			{

				weights_accum[i] += lcl_blob[(lcl_id + j) * unit_len + i];

				lcl_blob[lcl_id * unit_len + i] = weights_accum[i];
			}

		}
	}
}

/*********************************************************************************************************
// wrw algorithm
// data layout.
// registers:
// per wk_item:
// MLO_READ_UNIT x MLO_N_LCL_OUT_MAPS of dy
// group:
// MLO_N_OUT_BLK_GRP blocks of MLO_N_OUT_BLK_GRP_PIX_SZ of dy
//
// LDS:
// data buffer
// MLO_N_LCL_IN_MAPS blocks of MLO_IN_LCL_SZ of x

// dw local buffer keeps 1 set of dweghts calculated at each iteration
	MLO_TEMP_WEI_BUFFER_SZ

//
// inputs:
// read into LDS
// MLO_N_IN_BLK_GRP groups
// output
// fetch
// MLO_N_OUT_BLK_GRP groups

// alg
// for each batch
//		until end of output map (MLO_N_OUT_BLK)
//			load input map block in LDS
//			load output maps in LDS
//          for k in filter size1
//				for l in filter size 0
//					at for each out/in pixel pair op,ip in wk_item
//                  calculate the contribution to a dweights by formula ip.x (input pixel.x) = (op.x * stride.x - pad .x + l) % (filter size 0), ip.y = (op.y * stride.y - pad.y + k) % filter size1,
//					wei[k,l] = in[ip.y, ip.x]*op[op.y, op.x]
//                  lcl_wei[MLO_OUT_BLK_GRP_PIX_SZ * out.grp + [op.y, op.x]] = we[k,l]
//                  accumulate the weights in the wk_item with wei_accum +=  lcl_wei[accum_id], accum_id = MLO_OUT_BLK_GRP*MLO_N_LCL_OUT_MAPS*map_id + k*(filter size 0) + l
//	write out accululate weights

// group layout
// 0 - input channel index
// 1 - output channel index
// 2 - 1

// loop over batches
**********************************************************************************************************/

__attribute__((reqd_work_group_size(MLO_GRP_SZ0, MLO_GRP_SZ1, MLO_GRP_SZ2)))
__kernel void MLOpenCvBwdWrW(
	const __global _FLOAT * top_df,
	const __global _FLOAT * bot,
	__global _FLOAT * weights_df,
#if MLO_CONV_BIAS
	__global _FLOAT * bias_df,
#endif
	_FLOAT padding_val
)
{
// input/output tiles

	__local _FLOAT lcl[(MLO_LCL_SZ)];
	__local _FLOAT * lcl_bot = lcl;
	__local _FLOAT * lcl_top = lcl + MLO_TOTAL_IN_LCL_SZ;

	// guarnteeing an uniformity over a wave
	int wave_id = getWaveId();

	int c_idx_base = get_group_id(1); // input map index base

// register memory
	int o_idx_base = get_group_id(2); // output map index base

	int c_idx = c_idx_base * MLO_N_LCL_IN_MAPS; // input map index

	int o_idx = o_idx_base * (MLO_N_OUT_BLK_GRP * MLO_N_LCL_OUT_MAPS); // output map index

	int lcl_id = get_local_id(0);

// output global read
//	int o_blk_idx = iDiv(lcl_id, MLO_OUT_LCL_SZ);
//	int o_pix_X4 = iMod(lcl_id, o_blk_idx, MLO_OUT_LCL_SZ);
	int o_scan = iDiv(lcl_id, MLO_N_OUT_HORIZ_READS);
	int o_pix4 = iMod(lcl_id, o_scan, MLO_N_OUT_HORIZ_READS);

// input global read
	int i_blk_idx = 0; //iDiv(lcl_id, MLO_IN_LCL_SZ);
	//int c_pix_X4 = iMod(lcl_id, i_blk_idx, MLO_IN_LCL_SZ);
	int c_scan0 = iDiv(lcl_id, MLO_N_IN_HORIZ_READS);
	int c_pix4 = iMod(lcl_id,c_scan0, MLO_N_IN_HORIZ_READS);

	int w_blk_idx = iDiv(lcl_id, MLO_WEI_BLK_SZ);
	int w_idx = iMod(lcl_id, w_blk_idx, MLO_WEI_BLK_SZ);
	int w_y = iDiv(w_idx, MLO_WEI_BLK_SZ0);
	int w_x0 = iMod(w_idx, w_y, MLO_WEI_BLK_SZ0);

// FILTR SPECIFIC !!!!!
	int last_tap_to_remove = (w_x0 + (MLO_WEI_WKITEM - 1)* MLO_WEI_BLK_SZ0 >= MLO_FILTER_SIZE0)? 0 : (-1);

// mask to shut down the overshot filter tap
	__constant int filter_mask0 = ~(1 << MLO_FILTER_SIZE0);
	int working_mask = 0;
// filled with 1 evry stride bit
	for(int i = 0; i < MLO_WEI_WKITEM; ++i)
	{
		working_mask |= (1 << (i*MLO_FILTER_STRIDE0));
	}
// add strting point
	working_mask <<= w_x0;
// clamp to the filter size
	working_mask &= filter_mask0;
// move back to the relative start

	__private _FLOAT pvt_accum[(MLO_N_OUT_BLK_GRP * MLO_N_LCL_OUT_MAPS * MLO_WEI_WKITEM)];

	int gbl_in_off = c_idx * MLO_IN_CHANNEL_STRIDE;
	int gbl_out_off = o_idx * MLO_OUT_CHANNEL_STRIDE;

	for (int i = 0; i < (MLO_N_OUT_BLK_GRP * MLO_N_LCL_OUT_MAPS * MLO_WEI_WKITEM); ++i)
	{
		pvt_accum[i] = 0;
	}

// zero out LDS
	for (int i = 0; i < ( MLO_LCL_SZ ); i += MLO_GRP_SZ)
	{
		lcl[i] = 0;
	}

	barrier(CLK_LOCAL_MEM_FENCE);
// zero out pvt accum
	// over all batches

#if 0
	if (c_idx == 0 && o_idx == 0 && lcl_id == 0)
	{
		printf("K:i: %d %d %d %d %d\n",
			MLO_OUT_WIDTH,
			MLO_OUT_HORIZ_PIX_SZ,
			MLO_OUT_WEI_EXT_SCAN_BLK,
			MLO_N_WEI_BLK,
			MLO_OUT_HORIZ_PIX_EXT_SZ
		);
	}
#endif

#if 1
	for (int b = 0;
		b < MLO_N_BATCH_LOOPS;
		++b,
		gbl_in_off += MLO_N_LCL_BATCHS * MLO_IN_BATCH_STRIDE,
		gbl_out_off += MLO_N_LCL_BATCHS * MLO_OUT_BATCH_STRIDE
		)
	{
		int in_y = 0;
		int out_y = 0;
// prefetch MLO_FILTER_STRIDE1 - MLO_FILTER_PAD1
// LDS UPDATE !!!!
// input scan
		__private _FLOAT in_rd_data[MLO_READ_UNIT];

		int gbl_in_scan_off = 0;
		int gbl_out_scan_off = 0;

		for(int c_scan = c_scan0;  in_y + c_scan < MLO_IN_HEIGHT && c_scan < MLO_FILTER_SIZE1 - MLO_FILTER_PAD1 - 1; c_scan += MLO_IN_VERT_READS)
		{
// TODO :: multiply on right mask if needed
			*(MLO_READ_TYPE*)in_rd_data = *(MLO_READ_TYPE*)&bot[gbl_in_scan_off + c_scan * MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT];
// TO DO:: CHECK HEIGHT
// TO DO:: CHECK PADDING
//			*(MLO_READ_TYPE*)&lcl_bot[(c_scan + MLO_FILTER_PAD1)*MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT] = *(MLO_READ_TYPE*)in_rd_data;
			for (int i = 0; i < MLO_READ_UNIT; ++i)
			{
				lcl_bot[(c_scan + MLO_FILTER_PAD1)*MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT + i] = in_rd_data[i];
			}

#if 0
			if (c_idx == 0 && o_idx == 0 && c_scan == 2 /*&& (c_pix4 == 0 || c_pix4 == 1)*/)
			{
				printf("K:i: %d %d %f %f\n",
					lcl_id,
					gbl_in_scan_off + c_scan * MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT,
					in_rd_data[0],
					in_rd_data[2]
				);
			}
#endif

		}

		in_y +=  MLO_FILTER_SIZE1 - MLO_FILTER_PAD1 - 1;

// TO DO: HANDLE PADDING
// over all out blocks
		for (int ob = 0; ob < MLO_N_OUT_BLK; ++ob, in_y += (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1), out_y += MLO_N_ALIGNED_OUT_SCAN_BLK)
		{

			barrier(CLK_LOCAL_MEM_FENCE);

// fetch input: (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1)
               // TODO:: HANDLE multiple INPUTS
			   // overshot i shadled by out put
			gbl_in_scan_off = gbl_in_off + mul24(in_y, MLO_IN_STRIDE);

			for (int c_scan = c_scan0;i_blk_idx < MLO_N_LCL_IN_MAPS && in_y + c_scan < MLO_IN_HEIGHT && c_scan <  (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1); c_scan += MLO_IN_VERT_READS)
			{

					*(MLO_READ_TYPE*)in_rd_data = *(MLO_READ_TYPE*)&bot[gbl_in_scan_off + c_scan * MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT];
//					*(MLO_READ_TYPE*)&lcl_bot[(c_scan + MLO_FILTER_SIZE1 - 1)*MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT] = *(MLO_READ_TYPE*)in_rd_data;
					for (int i = 0; i < MLO_READ_UNIT; ++i)
					{
						lcl_bot[(c_scan + MLO_FILTER_SIZE1 - 1)*MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT + i] = in_rd_data[i];
					}

#if 0
					if (c_idx == 0 && o_idx == 0 && in_y + c_scan == 0 && (c_pix4 == 0 || c_pix4 == 1))
					{
						printf("K:i: %d %d %f %f\n",
							lcl_id,
							gbl_in_scan_off + c_scan * MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT,
							in_rd_data[0],
							in_rd_data[2]
						);
					}
#endif

			}

			// ouput scan
			__private _FLOAT out_rd_data[MLO_N_LCL_OUT_MAPS * MLO_READ_UNIT];

			gbl_out_scan_off = gbl_out_off + mul24(out_y, MLO_OUT_STRIDE);

// over all outputs groups

			int gbl_out_scan_off1 = gbl_out_scan_off;
			for(int og = 0; og < MLO_N_OUT_BLK_GRP; ++og, gbl_out_scan_off1 += MLO_N_LCL_OUT_MAPS*MLO_OUT_CHANNEL_STRIDE )
			{
				barrier(CLK_LOCAL_MEM_FENCE);

// fetch output

				for(int o = 0; o < MLO_N_LCL_OUT_MAPS
						&&  ( o_idx + o < MLO_N_OUTPUTS && out_y + o_scan < MLO_OUT_HEIGHT && o_scan < MLO_N_ALIGNED_OUT_SCAN_BLK)
						; ++o)
				{
						*(MLO_READ_TYPE*)&out_rd_data[o*MLO_READ_UNIT]
							= *(MLO_READ_TYPE*)&top_df[gbl_out_scan_off1 + o*MLO_OUT_CHANNEL_STRIDE + o_scan * MLO_OUT_STRIDE + o_pix4*MLO_READ_UNIT];
#if MLO_OUT_SCAN_NOT_DIVBY4
						if (o_pix4 == (MLO_N_OUT_HORIZ_READS-1))
						{
							for(int i = MLO_READ_UNIT-1; i >= MLO_READ_UNIT - MLO_OUT_N_PIXS_OFF; --i)
							{
	 							out_rd_data[o*MLO_READ_UNIT + i] = 0;
							}
						}
#endif
// write with MLO_OUT_HORIZ_PIX_EXT_SZ stride
//						*(MLO_READ_TYPE*)&lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT] = *(MLO_READ_TYPE*)&out_rd_data[o*MLO_READ_UNIT];
						for (int i = 0; i < MLO_READ_UNIT; ++i)
						{
							lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT + i] = out_rd_data[o*MLO_READ_UNIT + i];
						}

#if 0
						if (c_idx == 0 && o_idx == 0 && og == 0 && o == 0/* && out_y + o_scan == 0*/)
						{
							printf("K:o: %d %d %d %f %f %f\n",
								lcl_id,
								gbl_out_scan_off + o*MLO_OUT_CHANNEL_STRIDE + o_scan * MLO_OUT_STRIDE + o_pix4*MLO_READ_UNIT,
								o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT,
								lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT + 0],
								lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT + 1],
								lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT + 2]
								);
						}
#endif

				}

				barrier(CLK_LOCAL_MEM_FENCE);

// process
// algorithm

#if 1
//				if (w_blk_idx < MLO_MAX_WEI_BLK_LOOP)
				{
					for (int j = 0; j < MLO_N_ALIGNED_OUT_SCAN_BLK; ++j)
					{

						_FLOAT i_vals[MLO_WEI_WKITEM];
						for (int w = 0; w < MLO_WEI_WKITEM - 1; ++w)
						{
							int w_x = w_x0 + w*MLO_WEI_BLK_SZ0;
							int i_off = (j*MLO_FILTER_STRIDE1 + w_y) * MLO_IN_LCL_WIDTH + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + 0) * MLO_FILTER_STRIDE0 + w_x;
							_FLOAT i_val = lcl_bot[i_off];

							i_vals[w] = i_val;

						}

						// if we overshoot the scanline
						// out data will be 0 by initial setting
						for (int i = 0; i < MLO_OUT_WEI_SCAN_BLK; ++i)
						{

							//						for(int w = 0; w < MLO_WEI_WKITEM; ++w)

							{
								int w_x = w_x0 + (MLO_WEI_WKITEM - 1)* MLO_WEI_BLK_SZ0;
								int i_off = (j*MLO_FILTER_STRIDE1 + w_y) * MLO_IN_LCL_WIDTH + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + i) * MLO_FILTER_STRIDE0 + w_x;
								_FLOAT i_val = lcl_bot[i_off];

								i_vals[(MLO_WEI_WKITEM - 1)] = i_val;

							}

							for (int o = 0; o < MLO_N_LCL_OUT_MAPS; ++o)
							{
								// read with MLO_OUT_HORIX_PIX_EXT_SZ stride
								_FLOAT o_val
									= lcl_top[o*MLO_OUT_LCL_SZ + j * MLO_OUT_HORIZ_PIX_EXT_SZ + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + i)];

								int w = 0;
								_FLOAT i_val;
								for (/*int w = 0*/; w < MLO_WEI_WKITEM; ++w)
								{

									i_val = i_vals[w];
									pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w] += i_val * o_val;

#if 0
									int w_x = w_x0 + w*MLO_WEI_BLK_SZ0;
									if (c_idx == 0 && o_idx == 0 && og == 0 && o == 0 && w_y == 1 && w_x == 1 && w_blk_idx < MLO_MAX_WEI_BLK_LOOP /* && lcl_id < MLO_OUT_WEI_SCAN_BLK * MLO_MAX_WEI_BLK_LOOP * MLO_WEI_BLK_SZ0 * MLO_WEI_WKITEM*/)
									{
										printf("K:s: %d %d %d %d %d %d %f %f %f\n",
											lcl_id,
											j,
											i,
											w,
											last_tap_to_remove,
											o*MLO_OUT_LCL_SZ + j * MLO_OUT_HORIZ_PIX_EXT_SZ + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + i),
											pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w],
											i_val,
											o_val
										);
									}
#endif
								}

								// set input data to zero if MLO_FILTER_SIZE0 is not multiple of MLO_WEI_WKITEM and it's over MLO_FILTER_SIZE0

//								_FLOAT i_val = i_vals[w];
								// not needed becuse it's handled when "virtual" tables are trasnformed into real ones
//								int ii_val = as_uint(i_val) & last_tap_to_remove;
//								i_val = as_float(ii_val);

//								pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w] += i_val * o_val;

#if 0
								int w_x = w_x0 + w*MLO_WEI_BLK_SZ0;
								if (c_idx == 0 && o_idx == 0 && og == 0 && o == 0 && w_y == 1 && w_x == 1 && w_blk_idx < MLO_MAX_WEI_BLK_LOOP /* && lcl_id < MLO_OUT_WEI_SCAN_BLK * MLO_MAX_WEI_BLK_LOOP * MLO_WEI_BLK_SZ0 * MLO_WEI_WKITEM*/)
								{
									printf("K:s: %d %d %d %d %d %d %f %f %f\n",
										lcl_id,
										j,
										i,
										w,
										last_tap_to_remove,
										o*MLO_OUT_LCL_SZ + j * MLO_OUT_HORIZ_PIX_EXT_SZ + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + i),
										pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w],
										i_val,
										o_val
									);
								}
#endif

							}

							for (int w = 0; w < MLO_WEI_WKITEM - 1; ++w)
							{
								i_vals[w] = i_vals[w + 1];

							}

						}
					}
				}
#else
						for(int o = 0; o < MLO_N_LCL_OUT_MAPS; ++o)
						{
							for(int w = 0; w < MLO_WEI_WKITEM; ++w)
							{
								pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w] = lcl_top[(og * MLO_N_LCL_OUT_MAPS + o)] * lcl_bot[w];
							}
						}
#endif

			} // for(; og < (MLO_N_OUT_BLK_GRP; ++og )

			barrier(CLK_LOCAL_MEM_FENCE);

// move data up
			for(int c_scan = c_scan0; c_scan < MLO_FILTER_SIZE1 -1; c_scan += MLO_IN_VERT_READS)
			{
					*(MLO_READ_TYPE*)in_rd_data = *(MLO_READ_TYPE*)&lcl_bot[(c_scan +  (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1))*(MLO_IN_LCL_WIDTH) + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT];
					*(MLO_READ_TYPE*)&lcl_bot[c_scan*(MLO_IN_LCL_WIDTH) + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT] = *(MLO_READ_TYPE*)in_rd_data;

			}

		} // for (int ob = 0; ob < MLO_N_OUT_BLK; ++ob, in_y += (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1), out_y += MLO_N_ALIGNED_OUT_SCAN_BLK)
	} // for (int b = 0;

#endif

	int oo = iDiv(lcl_id, (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0));
	int wei_i = iMod(lcl_id, oo, (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0));
	int wei_i_y = iDiv(wei_i, (MLO_FILTER_SIZE0));
	int wei_i_x = iMod(wei_i,wei_i_y, (MLO_FILTER_SIZE0));
	// send it out
	int wei_df_off = mul24(o_idx, (int)MLO_WEI_BATCH_STRIDE)
		// this input channel
		+ mul24(c_idx, (int)MLO_WEI_CHANNEL_STRIDE);

	int wei_lcl_off = 0;
	_FLOAT final_sum = 0;

// save in lcl and orgnize in a proper order
// outputs
//	filter size1
//	  filter size0
// TO DO DEPENDING ON THE GROUP SIZE
	for(int og = 0; og < MLO_N_OUT_BLK_GRP; ++og)
	{
		for(int o = 0;  w_blk_idx < MLO_MAX_WEI_BLK_LOOP/* && lcl_id < MLO_OUT_WEI_SCAN_BLK * MLO_MAX_WEI_BLK_LOOP * MLO_WEI_BLK_SZ0 * MLO_WEI_WKITEM*/ && o < MLO_N_LCL_OUT_MAPS; ++o)
		{
			int w = 0;
			for(; w < MLO_WEI_WKITEM; ++w)
			{
// save "virtual" filter table
				int w_x = w_x0 + w*MLO_WEI_BLK_SZ0;
				wei_lcl_off = ((o * MLO_MAX_WEI_BLK_LOOP + w_blk_idx) * MLO_FILTER_SIZE1  + w_y) * (MLO_WEI_BLK_SZ0 *MLO_WEI_WKITEM) + w_x;
				lcl_bot[wei_lcl_off] = pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w];
#if 0
				// wei_lcl_off == 1020 || wei_lcl_off == 1080 || wei_lcl_off == 1140)
				if (c_idx == 0 && o_idx == 0 && og == 0 && o == 0 && w_y == 1 && w_x == 1/* && lcl_id < MLO_OUT_WEI_SCAN_BLK * MLO_MAX_WEI_BLK_LOOP * MLO_WEI_BLK_SZ0 * MLO_WEI_WKITEM*/)
				{
					printf("K:u: %d %d %d %f %f\n",
						lcl_id,
						w_blk_idx,
						wei_lcl_off,
						lcl_bot[wei_lcl_off],
						pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w]
					);
				}
#endif

			}

		}

		barrier(CLK_LOCAL_MEM_FENCE);
#if 1
// read into real filter table

		if (lcl_id < ( MLO_N_LCL_OUT_MAPS *MLO_FILTER_SIZE1*MLO_FILTER_SIZE0))
		{
			final_sum = 0;
			for(int i = 0; i < MLO_MAX_WEI_BLK_LOOP; ++i)
			{
				final_sum += lcl_bot[((oo * MLO_MAX_WEI_BLK_LOOP + i) * MLO_FILTER_SIZE1 + wei_i_y) * (MLO_WEI_BLK_SZ0 *MLO_WEI_WKITEM) + wei_i_x];
#if 0
				if (c_idx == 0 && o_idx == 0  && og == 0 && oo  == 0 && wei_i_y == 1 && wei_i_x == 1)
				{
					printf("K:fs: %d %d %d  %f %f\n",
						lcl_id,
						i,
						((oo * MLO_MAX_WEI_BLK_LOOP + i) * MLO_FILTER_SIZE1 + wei_i_y) * (MLO_WEI_BLK_SZ0 *MLO_WEI_WKITEM) + wei_i_x,
						final_sum,
						lcl_bot[((oo * MLO_MAX_WEI_BLK_LOOP + i) * MLO_FILTER_SIZE1 + wei_i_y) * (MLO_WEI_BLK_SZ0 *MLO_WEI_WKITEM) + wei_i_x]
					);
				}
#endif
			}

#if 1

			weights_df[wei_df_off + (og *  MLO_N_LCL_OUT_MAPS + oo) * MLO_WEI_BATCH_STRIDE + wei_i] = final_sum; //lcl_bot[lcl_id]; //

#if 0
			if (og == 1 && oo == 0 && wei_i == 0)
			{

				printf("K:o: %d %d %f\n",
					wei_df_off,
					wei_df_off + (og *  MLO_N_LCL_OUT_MAPS + oo) * MLO_WEI_BATCH_STRIDE + wei_i,
					weights_df[wei_df_off + (og *  MLO_N_LCL_OUT_MAPS + oo) * MLO_WEI_BATCH_STRIDE + wei_i]
					);
			}
#endif
#else
			_FLOAT t_accum = 0;

			for (int og = 0; og < MLO_N_OUT_BLK_GRP; ++og)
			{
				for (int o = 0; o < MLO_N_LCL_OUT_MAPS; ++o)
				{
					for (int w = 0; w < MLO_WEI_WKITEM; ++w)
					{
						t_accum += pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w];
					}
				}
			}

			weights_df[lcl_id] = t_accum;
#endif

		}
#endif
		barrier(CLK_LOCAL_MEM_FENCE);

	} // for(int og = 0; og < MLO_N_OUT_BLK_GRP; ++og)

}

/*
 * Copyright (c) 2016 AMD Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and/or associated documentation files (the
 * "Materials"), to deal in the Materials without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Materials, and to
 * permit persons to whom the Materials are furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Materials.
 *
 * THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
 */

#define _FLOAT					float
#define _FLOAT2					float2
#define _FLOAT4					float4
#define _FLOAT8					float8

#ifndef FLT_MAX
#define FLT_MAX         3.402823466e+38F        /* max value */
#endif

#define MLO_N_OUT_HORIZ_READS (MLO_ALIGNED_OUT_SCAN_LN)
#define MLO_OUT_HORIZ_PIX_SZ (MLO_N_OUT_HORIZ_READS * MLO_READ_UNIT)

// number of filter taps in the processing wk_item
#define MLO_WEI_WKITEM 4
// n of of filter blks
#define MLO_WEI_BLK_SZ0 ((MLO_FILTER_SIZE0 + MLO_WEI_WKITEM -1)/MLO_WEI_WKITEM)
#define MLO_WEI_BLK_SZ (MLO_FILTER_SIZE1*MLO_WEI_BLK_SZ0)
// n of filter tiles in the group grid
#define MLO_N_WEI_BLK (MLO_GRP_SZ/ MLO_WEI_BLK_SZ)
// n of steps per scan line to be made in the inner loop
#define MLO_OUT_WEI_SCAN_BLK ((MLO_OUT_WIDTH + MLO_N_WEI_BLK - 1) / MLO_N_WEI_BLK)

// max loop over virtual blocks for small images
#define MLO_MAX_WEI_BLK_LOOP_TMP ((MLO_OUT_WIDTH + MLO_OUT_WEI_SCAN_BLK - 1)/MLO_OUT_WEI_SCAN_BLK)
#if MLO_MAX_WEI_BLK_LOOP_TMP < MLO_N_WEI_BLK
#define MLO_MAX_WEI_BLK_LOOP MLO_MAX_WEI_BLK_LOOP_TMP
#else
#define MLO_MAX_WEI_BLK_LOOP MLO_N_WEI_BLK
#endif

#define MLO_WEI_BLKS_SZ (MLO_MAX_WEI_BLK_LOOP * MLO_WEI_BLK_SZ *MLO_WEI_WKITEM)
#define MLO_WEI_BLKS_LCL_SZ (MLO_WEI_BLKS_SZ * MLO_N_LCL_OUT_MAPS)

#define MLO_OUT_BLK_GRP_PIX_SZ (MLO_OUT_HORIZ_PIX_SZ * MLO_N_ALIGNED_OUT_SCAN_BLK)
#define MLO_OUT_BLK_GRP_WK_SZ (MLO_OUT_BLK_GRP_PIX_SZ / MLO_READ_UNIT)

// extended scan to deal with overshot in the inner loop
#define MLO_OUT_WEI_EXT_SCAN_BLK ((MLO_OUT_HORIZ_PIX_SZ + MLO_N_WEI_BLK - 1) / MLO_N_WEI_BLK)
#define MLO_OUT_HORIZ_PIX_EXT_SZ (MLO_OUT_WEI_EXT_SCAN_BLK * MLO_N_WEI_BLK)
#define MLO_OUT_BLK_GRP_EXT_PIX_SZ (MLO_OUT_HORIZ_PIX_EXT_SZ * MLO_N_ALIGNED_OUT_SCAN_BLK)
#define MLO_OUT_LCL_SZ (MLO_OUT_BLK_GRP_EXT_PIX_SZ)
// LDS OUT SIZE
#define MLO_TOTAL_OUT_LCL_SZ (MLO_N_LCL_OUT_MAPS*MLO_OUT_LCL_SZ)

// input size depends on output scan length and
// number of output scans
// this number is constrained by amount or LDS and size of register file.
// TO DO:: CHECK PADDING!!!
#define MLO_IN_LCL_HEIGHT ((MLO_N_ALIGNED_OUT_SCAN_BLK-1)*MLO_FILTER_STRIDE1 + MLO_FILTER_SIZE1)
#define MLO_N_IN_HORIZ_READS ((((MLO_OUT_HORIZ_PIX_SZ-1)*MLO_FILTER_STRIDE0 + MLO_FILTER_SIZE0) + MLO_READ_UNIT - 1) / MLO_READ_UNIT)
#define MLO_IN_LCL_WIDTH (MLO_N_IN_HORIZ_READS * MLO_READ_UNIT)
#define MLO_IN_BLK_GRP_PIX_SZ (MLO_IN_LCL_WIDTH * MLO_IN_LCL_HEIGHT)
#define MLO_IN_BLK_GRP_WK_SZ (MLO_IN_BLK_GRP_PIX_SZ/MLO_READ_UNIT)
#define MLO_IN_LCL_SZ (MLO_IN_BLK_GRP_PIX_SZ)
// LDS IN SIZE
#define MLO_TOTAL_IN_LCL_SZ (MLO_N_LCL_IN_MAPS*MLO_IN_LCL_SZ)
#define MLO_IN_VERT_READS (MLO_GRP_SZ/MLO_N_IN_HORIZ_READS)

#if (MLO_TOTAL_OUT_LCL_SZ + MLO_TOTAL_IN_LCL_SZ) > (MLO_WEI_BLKS_LCL_SZ)
#define MLO_LCL_SZ (MLO_TOTAL_OUT_LCL_SZ + MLO_TOTAL_IN_LCL_SZ)
#else
#define MLO_LCL_SZ (MLO_WEI_BLKS_LCL_SZ)
#endif

#define MLO_HW_WAVE_ID_SETTING 0

#if MLO_HW_WAVE_ID_SETTING
extern __attribute__((const)) uint __hsail_get_dynwave_id(void);
inline int getWaveId()
{
	int wave_id = 0;

	wave_id = __hsail_get_dynwave_id();
	wave_id = wave_id & MLO_N_PHYS_WAVES_MASK;
	return(wave_id);
}
#else
inline int getWaveId()
{
	int wave_id = 0;

	wave_id = (get_local_id(0) >> MLO_LG2_PHYS_WAVE_SZ);

	return(wave_id);
}
#endif

inline int iDiv(int v, int d)
{
	int r = (int)((float)v / d + 0.00001f);
	return(r);
}

inline int iMod(int v, int u, int d)
{
	int r = v - mul24((int)u,(int)d);
	return(r);
}

inline void ReduceKernel(__local _FLOAT * lcl_blob, _FLOAT *weights_accum, int lcl_id, int scan_lcl, int sum_stride, int unit_len, bool debug)
{
	for (int j = (sum_stride >> 1); j > 0; j >>= 1)
	{
		barrier(CLK_LOCAL_MEM_FENCE);
		if (scan_lcl < j)
		{
			for (int i = 0; i < unit_len; ++i)
			{

				weights_accum[i] += lcl_blob[(lcl_id + j) * unit_len + i];

				lcl_blob[lcl_id * unit_len + i] = weights_accum[i];
			}

		}
	}
}

/*********************************************************************************************************
// wrw algorithm
// data layout.
// registers:
// per wk_item:
// MLO_READ_UNIT x MLO_N_LCL_OUT_MAPS of dy
// group:
// MLO_N_OUT_BLK_GRP blocks of MLO_N_OUT_BLK_GRP_PIX_SZ of dy
//
// LDS:
// data buffer
// MLO_N_LCL_IN_MAPS blocks of MLO_IN_LCL_SZ of x

// dw local buffer keeps 1 set of dweghts calculated at each iteration
	MLO_TEMP_WEI_BUFFER_SZ

//
// inputs:
// read into LDS
// MLO_N_IN_BLK_GRP groups
// output
// fetch
// MLO_N_OUT_BLK_GRP groups

// alg
// for each batch
//		until end of output map (MLO_N_OUT_BLK)
//			load input map block in LDS
//			load output maps in LDS
//          for k in filter size1
//				for l in filter size 0
//					at for each out/in pixel pair op,ip in wk_item
//                  calculate the contribution to a dweights by formula ip.x (input pixel.x) = (op.x * stride.x - pad .x + l) % (filter size 0), ip.y = (op.y * stride.y - pad.y + k) % filter size1,
//					wei[k,l] = in[ip.y, ip.x]*op[op.y, op.x]
//                  lcl_wei[MLO_OUT_BLK_GRP_PIX_SZ * out.grp + [op.y, op.x]] = we[k,l]
//                  accumulate the weights in the wk_item with wei_accum +=  lcl_wei[accum_id], accum_id = MLO_OUT_BLK_GRP*MLO_N_LCL_OUT_MAPS*map_id + k*(filter size 0) + l
//	write out accululate weights

// group layout
// 0 - input channel index
// 1 - output channel index
// 2 - 1

// loop over batches
**********************************************************************************************************/

__attribute__((reqd_work_group_size(MLO_GRP_SZ0, MLO_GRP_SZ1, MLO_GRP_SZ2)))
__kernel void MLOpenCvBwdWrW(
	const __global _FLOAT * top_df,
	const __global _FLOAT * bot,
	__global _FLOAT * weights_df,
#if MLO_CONV_BIAS
	__global _FLOAT * bias_df,
#endif
	_FLOAT padding_val
)
{
// input/output tiles

	__local _FLOAT lcl[(MLO_LCL_SZ)];
	__local _FLOAT * lcl_bot = lcl;
	__local _FLOAT * lcl_top = lcl + MLO_TOTAL_IN_LCL_SZ;

	// guarnteeing an uniformity over a wave
	int wave_id = getWaveId();

	int c_idx_base = get_group_id(1); // input map index base

// register memory
	int o_idx_base = get_group_id(2); // output map index base

	int c_idx = c_idx_base * MLO_N_LCL_IN_MAPS; // input map index

	int o_idx = o_idx_base * (MLO_N_OUT_BLK_GRP * MLO_N_LCL_OUT_MAPS); // output map index

	int lcl_id = get_local_id(0);

// output global read
//	int o_blk_idx = iDiv(lcl_id, MLO_OUT_LCL_SZ);
//	int o_pix_X4 = iMod(lcl_id, o_blk_idx, MLO_OUT_LCL_SZ);
	int o_scan = iDiv(lcl_id, MLO_N_OUT_HORIZ_READS);
	int o_pix4 = iMod(lcl_id, o_scan, MLO_N_OUT_HORIZ_READS);

// input global read
	int i_blk_idx = 0; //iDiv(lcl_id, MLO_IN_LCL_SZ);
	//int c_pix_X4 = iMod(lcl_id, i_blk_idx, MLO_IN_LCL_SZ);
	int c_scan0 = iDiv(lcl_id, MLO_N_IN_HORIZ_READS);
	int c_pix4 = iMod(lcl_id,c_scan0, MLO_N_IN_HORIZ_READS);

	int w_blk_idx = iDiv(lcl_id, MLO_WEI_BLK_SZ);
	int w_idx = iMod(lcl_id, w_blk_idx, MLO_WEI_BLK_SZ);
	int w_y = iDiv(w_idx, MLO_WEI_BLK_SZ0);
	int w_x0 = iMod(w_idx, w_y, MLO_WEI_BLK_SZ0);

// FILTR SPECIFIC !!!!!
	int last_tap_to_remove = (w_x0 > 0)? 0 : 1;

// mask to shut down the overshot filter tap
	__constant int filter_mask0 = ~(1 << MLO_FILTER_SIZE0);
	int working_mask = 0;
// filled with 1 evry stride bit
	for(int i = 0; i < MLO_WEI_WKITEM; ++i)
	{
		working_mask |= (1 << (i*MLO_FILTER_STRIDE0));
	}
// add strting point
	working_mask <<= w_x0;
// clamp to the filter size
	working_mask &= filter_mask0;
// move back to the relative start

	__private _FLOAT pvt_accum[(MLO_N_OUT_BLK_GRP * MLO_N_LCL_OUT_MAPS * MLO_WEI_WKITEM)];

	int gbl_in_off = c_idx * MLO_IN_CHANNEL_STRIDE;
	int gbl_out_off = o_idx * MLO_OUT_CHANNEL_STRIDE;

	for (int i = 0; i < (MLO_N_OUT_BLK_GRP * MLO_N_LCL_OUT_MAPS * MLO_WEI_WKITEM); ++i)
	{
		pvt_accum[i] = 0;
	}

// zero out LDS
	for (int i = 0; i < ( MLO_LCL_SZ ); i += MLO_GRP_SZ)
	{
		lcl[i] = 0;
	}

	barrier(CLK_LOCAL_MEM_FENCE);
// zero out pvt accum
	// over all batches

#if 0
	if (c_idx == 0 && o_idx == 0 && lcl_id == 0)
	{
		printf("K:i: %d %d %d %d %d\n",
			MLO_MAX_WEI_BLK_LOOP,
			MLO_WEI_BLK_SZ,
			MLO_N_LCL_OUT_MAPS,
			MLO_WEI_BLKS_LCL_SZ,
			(MLO_LCL_SZ)
		);
	}
#endif

#if 1
	for (int b = 0;
		b < MLO_N_BATCH_LOOPS;
		++b,
		gbl_in_off += MLO_N_LCL_BATCHS * MLO_IN_BATCH_STRIDE,
		gbl_out_off += MLO_N_LCL_BATCHS * MLO_OUT_BATCH_STRIDE
		)
	{
		int in_y = 0;
		int out_y = 0;
// prefetch MLO_FILTER_STRIDE1 - MLO_FILTER_PAD1
// LDS UPDATE !!!!
// input scan
		__private _FLOAT in_rd_data[MLO_READ_UNIT];

		int gbl_in_scan_off = 0;
		int gbl_out_scan_off = 0;

		for(int c_scan = c_scan0;  in_y + c_scan < MLO_IN_HEIGHT && c_scan < MLO_FILTER_SIZE1 - MLO_FILTER_PAD1 - 1; c_scan += MLO_IN_VERT_READS)
		{
// TODO :: multiply on right mask if needed
			*(MLO_READ_TYPE*)in_rd_data = *(MLO_READ_TYPE*)&bot[gbl_in_scan_off + c_scan * MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT];
// TO DO:: CHECK HEIGHT
// TO DO:: CHECK PADDING
//			*(MLO_READ_TYPE*)&lcl_bot[(c_scan + MLO_FILTER_PAD1)*MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT] = *(MLO_READ_TYPE*)in_rd_data;
			for (int i = 0; i < MLO_READ_UNIT; ++i)
			{
				lcl_bot[(c_scan + MLO_FILTER_PAD1)*MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT + i] = in_rd_data[i];
			}

#if 0
			if (c_idx == 0 && o_idx == 0 && c_scan == 2 /*&& (c_pix4 == 0 || c_pix4 == 1)*/)
			{
				printf("K:i: %d %d %f %f\n",
					lcl_id,
					gbl_in_scan_off + c_scan * MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT,
					in_rd_data[0],
					in_rd_data[2]
				);
			}
#endif

		}

		in_y +=  MLO_FILTER_SIZE1 - MLO_FILTER_PAD1 - 1;

// TO DO: HANDLE PADDING
// over all out blocks
		for (int ob = 0; ob < MLO_N_OUT_BLK; ++ob, in_y += (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1), out_y += MLO_N_ALIGNED_OUT_SCAN_BLK)
		{

			barrier(CLK_LOCAL_MEM_FENCE);

// fetch input: (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1)
               // TODO:: HANDLE multiple INPUTS
			   // overshot i shadled by out put
			gbl_in_scan_off = gbl_in_off + mul24(in_y, MLO_IN_STRIDE);

			for (int c_scan = c_scan0;i_blk_idx < MLO_N_LCL_IN_MAPS && in_y + c_scan < MLO_IN_HEIGHT && c_scan <  (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1); c_scan += MLO_IN_VERT_READS)
			{

					*(MLO_READ_TYPE*)in_rd_data = *(MLO_READ_TYPE*)&bot[gbl_in_scan_off + c_scan * MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT];
//					*(MLO_READ_TYPE*)&lcl_bot[(c_scan + MLO_FILTER_SIZE1 - 1)*MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT] = *(MLO_READ_TYPE*)in_rd_data;
					for (int i = 0; i < MLO_READ_UNIT; ++i)
					{
						lcl_bot[(c_scan + MLO_FILTER_SIZE1 - 1)*MLO_IN_LCL_WIDTH + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT + i] = in_rd_data[i];
					}

#if 0
					if (c_idx == 0 && o_idx == 0 && in_y + c_scan == 2 && (c_pix4 == 0 || c_pix4 == 1))
					{
						printf("K:i: %d %d %f %f\n",
							lcl_id,
							gbl_in_scan_off + c_scan * MLO_IN_STRIDE + c_pix4*MLO_READ_UNIT,
							in_rd_data[0],
							in_rd_data[2]
						);
					}
#endif

			}

			// ouput scan
			__private _FLOAT out_rd_data[MLO_N_LCL_OUT_MAPS * MLO_READ_UNIT];

			gbl_out_scan_off = gbl_out_off + mul24(out_y, MLO_OUT_STRIDE);

// over all outputs groups

			int gbl_out_scan_off1 = gbl_out_scan_off;
			for(int og = 0; og < MLO_N_OUT_BLK_GRP; ++og, gbl_out_scan_off1 += MLO_N_LCL_OUT_MAPS*MLO_OUT_CHANNEL_STRIDE )
			{

// fetch output

				for(int o = 0; o < MLO_N_LCL_OUT_MAPS
						&&  ( o_idx + o < MLO_N_OUTPUTS && out_y + o_scan < MLO_OUT_HEIGHT && o_scan < MLO_N_ALIGNED_OUT_SCAN_BLK)
						; ++o)
				{
						*(MLO_READ_TYPE*)&out_rd_data[o*MLO_READ_UNIT]
							= *(MLO_READ_TYPE*)&top_df[gbl_out_scan_off1 + o*MLO_OUT_CHANNEL_STRIDE + o_scan * MLO_OUT_STRIDE + o_pix4*MLO_READ_UNIT];
#if MLO_OUT_SCAN_NOT_DIVBY4
						if (o_pix4 == (MLO_N_OUT_HORIZ_READS-1))
						{
							for(int i = MLO_READ_UNIT-1; i >= MLO_READ_UNIT - MLO_OUT_N_PIXS_OFF; --i)
							{
	 							out_rd_data[o*MLO_READ_UNIT + i] = 0;
							}
						}
#endif
// write with MLO_OUT_HORIZ_PIX_EXT_SZ stride
//						*(MLO_READ_TYPE*)&lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT] = *(MLO_READ_TYPE*)&out_rd_data[o*MLO_READ_UNIT];
						for (int i = 0; i < MLO_READ_UNIT; ++i)
						{
							lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT + i] = out_rd_data[o*MLO_READ_UNIT + i];
						}

#if 0
						if (c_idx == 0 && o_idx == 0 && og == 0 && o == 1 && out_y + o_scan == 1)
						{
							printf("K:o: %d %d %d %f %f %f\n",
								lcl_id,
								gbl_out_scan_off + o*MLO_IN_CHANNEL_STRIDE + o_scan * MLO_IN_STRIDE + o_pix4*MLO_READ_UNIT,
								o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT,
								lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT + 0],
								lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT + 1],
								lcl_top[o * MLO_OUT_LCL_SZ + o_scan * MLO_OUT_HORIZ_PIX_EXT_SZ + o_pix4*MLO_READ_UNIT + 2]
								);
						}
#endif

				}

// process
// algorithm

#if 1
				for(int j = 0; j < MLO_N_ALIGNED_OUT_SCAN_BLK; ++j)
				{

					_FLOAT i_vals[MLO_WEI_WKITEM];
					for(int w = 0; w < MLO_WEI_WKITEM - 1; ++w)
					{
							int w_x = w_x0 + w*MLO_WEI_BLK_SZ0;
							int i_off = (j*MLO_FILTER_STRIDE1 + w_y) * MLO_IN_LCL_WIDTH + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + 0) * MLO_FILTER_STRIDE0 + w_x;
							_FLOAT i_val = lcl_bot[i_off];

							i_vals[w] = i_val;

					}

// if we overshoot the scanline
// out data will be 0 by initial setting

					for(int i = 0; i < MLO_OUT_WEI_SCAN_BLK; ++i)
					{

//						for(int w = 0; w < MLO_WEI_WKITEM; ++w)

						{
							int w_x = w_x0 + (MLO_WEI_WKITEM-1)* MLO_WEI_BLK_SZ0;
							int i_off = (j*MLO_FILTER_STRIDE1 + w_y) * MLO_IN_LCL_WIDTH + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + i) * MLO_FILTER_STRIDE0 + w_x;
							_FLOAT i_val = lcl_bot[i_off];

							i_vals[(MLO_WEI_WKITEM-1)] = i_val;

						}

						for(int o = 0; o < MLO_N_LCL_OUT_MAPS; ++o)
						{
// read with MLO_OUT_HORIX_PIX_EXT_SZ stride
							_FLOAT o_val
								= lcl_top[o*MLO_OUT_LCL_SZ + j * MLO_OUT_HORIZ_PIX_EXT_SZ + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + i)];

							int w = 0;
							for(/*int w = 0*/; w < MLO_WEI_WKITEM - 1; ++w )
							{

								_FLOAT i_val = i_vals[w];
								pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w] += i_val * o_val;

#if 0
								int w_x = w_x0 + w*MLO_WEI_BLK_SZ0;
								if (c_idx == 0 && o_idx == 0 && og ==1 && o == 0 && w_y ==0 && w_x == 0 && lcl_id < MLO_OUT_WEI_SCAN_BLK * MLO_MAX_WEI_BLK_LOOP * MLO_WEI_BLK_SZ0 * MLO_WEI_WKITEM)
								{
									printf("K:s: %d %d %d %d %d %f %f %f\n",
										lcl_id,
										j,
										i,
										w,
										o*MLO_OUT_LCL_SZ + j * MLO_OUT_HORIZ_PIX_EXT_SZ + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + i),
										pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w],
										i_val,
										o_val
									);
								}
#endif
							}

// set input data to zero if MLO_FILTER_SIZE0 is not multiple of MLO_WEI_WKITEM and it's over MLO_FILTER_SIZE0

							_FLOAT i_val = i_vals[w];
// not needed becuse it's handled when "virtual" tables are trasnformed into real ones
	//						int ii_val = as_uint(i_val) & last_tap_to_remove;
	//						i_val = as_float(ii_val);

							pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w] += i_val * o_val;

#if 0
							int w_x = w_x0 + w*MLO_WEI_BLK_SZ0;
							if (c_idx == 0 && o_idx == 0 && og == 1 && o == 0 && w_y == 0 && w_x == 0 && lcl_id < MLO_OUT_WEI_SCAN_BLK * MLO_MAX_WEI_BLK_LOOP * MLO_WEI_BLK_SZ0 * MLO_WEI_WKITEM)
							{
								printf("K:s: %d %d %d %d %d %f %f %f\n",
									lcl_id,
									j,
									i,
									w,
									o*MLO_OUT_LCL_SZ + j * MLO_OUT_HORIZ_PIX_EXT_SZ + (w_blk_idx*MLO_OUT_WEI_SCAN_BLK + i),
									pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w],
									i_val,
									o_val
								);
							}
#endif

						}

						for(int w = 0; w < MLO_WEI_WKITEM - 1; ++w)
						{
							i_vals[w] = i_vals[w + 1];

						}

					}
				}
#else
						for(int o = 0; o < MLO_N_LCL_OUT_MAPS; ++o)
						{
							for(int w = 0; w < MLO_WEI_WKITEM; ++w)
							{
								pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w] = lcl_top[(og * MLO_N_LCL_OUT_MAPS + o)] * lcl_bot[w];
							}
						}
#endif

			} // for(; og < (MLO_N_OUT_BLK_GRP; ++og )

			barrier(CLK_LOCAL_MEM_FENCE);

// move data up
			for(int c_scan = c_scan0; c_scan < MLO_FILTER_SIZE1 -1; c_scan += MLO_IN_VERT_READS)
			{
					*(MLO_READ_TYPE*)in_rd_data = *(MLO_READ_TYPE*)&lcl_bot[(c_scan +  (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1))*(MLO_IN_LCL_WIDTH) + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT];
					*(MLO_READ_TYPE*)&lcl_bot[c_scan*(MLO_IN_LCL_WIDTH) + MLO_FILTER_PAD0 + c_pix4*MLO_READ_UNIT] = *(MLO_READ_TYPE*)in_rd_data;

			}

		} // for (int ob = 0; ob < MLO_N_OUT_BLK; ++ob, in_y += (MLO_IN_LCL_HEIGHT - MLO_FILTER_SIZE1 + 1), out_y += MLO_N_ALIGNED_OUT_SCAN_BLK)
	} // for (int b = 0;

#endif

	int oo = iDiv(lcl_id, (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0));
	int wei_i = iMod(lcl_id, oo, (MLO_FILTER_SIZE1*MLO_FILTER_SIZE0));
	int wei_i_y = iDiv(wei_i, (MLO_FILTER_SIZE0));
	int wei_i_x = iMod(wei_i,wei_i_y, (MLO_FILTER_SIZE0));
	// send it out
	int wei_df_off = mul24(o_idx, (int)MLO_WEI_BATCH_STRIDE)
		// this input channel
		+ mul24(c_idx, (int)MLO_WEI_CHANNEL_STRIDE);

	int wei_lcl_off = 0;
	_FLOAT final_sum = 0;

// save in lcl and orgnize in a proper order
// outputs
//	filter size1
//	  filter size0
// TO DO DEPENDING ON THE GROUP SIZE
	for(int og = 0; og < MLO_N_OUT_BLK_GRP; ++og)
	{
		for(int o = 0;  w_blk_idx < MLO_MAX_WEI_BLK_LOOP && o < MLO_N_LCL_OUT_MAPS; ++o)
		{
			int w = 0;
			for(; w < MLO_WEI_WKITEM; ++w)
			{
// save "virtual" filter table
				int w_x = w_x0 + w*MLO_WEI_BLK_SZ0;
				wei_lcl_off = ((o * MLO_MAX_WEI_BLK_LOOP + w_blk_idx) * MLO_FILTER_SIZE1  + w_y) * (MLO_WEI_BLK_SZ0 *MLO_WEI_WKITEM) + w_x;
				lcl_bot[wei_lcl_off] = pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w];
#if 0
				// wei_lcl_off == 1020 || wei_lcl_off == 1080 || wei_lcl_off == 1140)
				if (c_idx == 0 && o_idx == 0 && og == 1 && o == 0 && w_y == 0 && w_x == 0 && lcl_id <= 45/* && (j == 0 || j == 1) */)
				{
					printf("K:u: %d %d %d %f %f\n",
						lcl_id,
						w_blk_idx,
						wei_lcl_off,
						lcl_bot[wei_lcl_off],
						pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w]
					);
				}
#endif

			}

		}

		barrier(CLK_LOCAL_MEM_FENCE);
#if 1
// read into real filter table

		if (lcl_id < ( MLO_N_LCL_OUT_MAPS *MLO_FILTER_SIZE1*MLO_FILTER_SIZE0))
		{
			final_sum = 0;
			for(int i = 0; i < MLO_MAX_WEI_BLK_LOOP; ++i)
			{
				final_sum += lcl_bot[((oo * MLO_MAX_WEI_BLK_LOOP + i) * MLO_FILTER_SIZE1 + wei_i_y) * (MLO_WEI_BLK_SZ0 *MLO_WEI_WKITEM) + wei_i_x];
#if 0
				if (c_idx == 0 && o_idx == 0  && og == 1 && oo  == 0 && wei_i_y == 0 && wei_i_x == 0)
				{
					printf("K:fs: %d %d %d  %f %f\n",
						lcl_id,
						i,
						((oo * MLO_MAX_WEI_BLK_LOOP + i) * MLO_FILTER_SIZE1 + wei_i_y) * (MLO_WEI_BLK_SZ0 *MLO_WEI_WKITEM) + wei_i_x,
						final_sum,
						lcl_bot[((oo * MLO_MAX_WEI_BLK_LOOP + i) * MLO_FILTER_SIZE1 + wei_i_y) * (MLO_WEI_BLK_SZ0 *MLO_WEI_WKITEM) + wei_i_x]
					);
				}
#endif
			}

#if 1

			weights_df[wei_df_off + (og *  MLO_N_LCL_OUT_MAPS + oo) * MLO_WEI_BATCH_STRIDE + wei_i] = final_sum; //lcl_bot[lcl_id]; //

#if 0
			if (og == 1 && oo == 0 && wei_i == 0)
			{

				printf("K:o: %d %d %f\n",
					wei_df_off,
					wei_df_off + (og *  MLO_N_LCL_OUT_MAPS + oo) * MLO_WEI_BATCH_STRIDE + wei_i,
					weights_df[wei_df_off + (og *  MLO_N_LCL_OUT_MAPS + oo) * MLO_WEI_BATCH_STRIDE + wei_i]
					);
			}
#endif
#else
			_FLOAT t_accum = 0;

			for (int og = 0; og < MLO_N_OUT_BLK_GRP; ++og)
			{
				for (int o = 0; o < MLO_N_LCL_OUT_MAPS; ++o)
				{
					for (int w = 0; w < MLO_WEI_WKITEM; ++w)
					{
						t_accum += pvt_accum[(og * MLO_N_LCL_OUT_MAPS + o) * MLO_WEI_WKITEM + w];
					}
				}
			}

			weights_df[lcl_id] = t_accum;
#endif

		}
#endif
		barrier(CLK_LOCAL_MEM_FENCE);

	} // for(int og = 0; og < MLO_N_OUT_BLK_GRP; ++og)

}