tesseract::IntSimdMatrix Class Reference

#include <intsimdmatrix.h>

Inheritance diagram for tesseract::IntSimdMatrix:

Public Member Functions
	IntSimdMatrix ()
void	Init (const GENERIC_2D_ARRAY< int8_t > &w)
int	RoundInputs (int size) const
int	RoundOutputs (int size) const
void	MatrixDotVector (const GENERIC_2D_ARRAY< int8_t > &w, const GenericVector< double > &scales, const int8_t *u, double *v) const

Static Public Member Functions
static IntSimdMatrix *	GetFastestMultiplier ()

Protected Types
typedef void(*	PartialFunc) (const int8_t *w, const double *scales, const int8_t *u, int num_in, int num_out, double *v)

Static Protected Member Functions
static int	Roundup (int input, int factor)

Protected Attributes
int	num_outputs_per_register_
int	max_output_registers_
int	num_inputs_per_register_
int	num_inputs_per_group_
int	num_input_groups_
std::vector< int8_t >	shaped_w_
std::vector< PartialFunc >	partial_funcs_

Detailed Description

Definition at line 60 of file intsimdmatrix.h.

Member Typedef Documentation

PartialFunc

typedef void(* tesseract::IntSimdMatrix::PartialFunc) (const int8_t *w, const double *scales, const int8_t *u, int num_in, int num_out, double *v)

protected

Definition at line 108 of file intsimdmatrix.h.

Constructor & Destructor Documentation

IntSimdMatrix()

tesseract::IntSimdMatrix::IntSimdMatrix ( )

inline

Definition at line 64 of file intsimdmatrix.h.

      : num_outputs_per_register_(1),
        max_output_registers_(1),
        num_inputs_per_register_(1),
        num_inputs_per_group_(1),
        num_input_groups_(1) {}

Member Function Documentation

GetFastestMultiplier()

IntSimdMatrix * tesseract::IntSimdMatrix::GetFastestMultiplier ( )

static

Definition at line 29 of file intsimdmatrix.cpp.

                                                   {
  IntSimdMatrix* multiplier = nullptr;
  if (SIMDDetect::IsAVX2Available()) {
    multiplier = new IntSimdMatrixAVX2();
  } else if (SIMDDetect::IsSSEAvailable()) {
    multiplier = new IntSimdMatrixSSE();
  } else {
    // Default c++ implementation.
    multiplier = new IntSimdMatrix();
  }
  return multiplier;
}

Init()

void tesseract::IntSimdMatrix::Init

(

const GENERIC_2D_ARRAY< int8_t > &

w

)

Definition at line 44 of file intsimdmatrix.cpp.

                                                          {
  if (partial_funcs_.empty()) return;
  int num_out = w.dim1();
  int num_in = w.dim2() - 1;
  // The rounded-up sizes of the reshaped weight matrix, excluding biases.
  int rounded_num_in = Roundup(num_in, num_inputs_per_group_);
  int rounded_num_out = RoundOutputs(num_out);
  // Add the bias and compute the required size.
  shaped_w_.resize((rounded_num_in + 1) * rounded_num_out, 0);
  int shaped_index = 0;
  int output = 0;
  // Each number of registers needs a different format! Iterates over the
  // different numbers of registers (each a power of 2).
  for (int num_registers = max_output_registers_; num_registers >= 1;
       num_registers /= 2) {
    // The number of outputs that we will generate with this many registers.
    int num_outputs_per_register_set =
        num_registers * num_outputs_per_register_;
    // Use the max number of registers until we have to go fewer.
    while (output + num_outputs_per_register_set <= rounded_num_out) {
      // Accumulating outputs in registers saves iterating over the inputs, so
      // we only have to do it once per output register set.
      for (int input = 0; input < num_in; input += num_inputs_per_group_) {
        // Iterate over the number of outputs in a register set.
        for (int j = 0; j < num_outputs_per_register_set; ++j) {
          // Inner-most loop corresponds to the number of inputs in an input
          // group.
          for (int i = 0; i < num_inputs_per_group_; ++i) {
            int8_t weight = 0;
            if (output + j < num_out && input + i < num_in)
              weight = w(output + j, input + i);
            shaped_w_[shaped_index++] = weight;
          }
        }
      }
      // Append the bias weights for the register set.
      for (int j = 0; j < num_outputs_per_register_set; ++j) {
        int8_t weight = 0;
        if (output + j < num_out) weight = w(output + j, num_in);
        shaped_w_[shaped_index++] = weight;
      }
      output += num_outputs_per_register_set;
    }
  }
}

MatrixDotVector()

void tesseract::IntSimdMatrix::MatrixDotVector	(	const GENERIC_2D_ARRAY< int8_t > &	w,
		const GenericVector< double > &	scales,
		const int8_t *	u,
		double *	v
	)		const

Definition at line 94 of file intsimdmatrix.cpp.

                                                                      {
  int num_out = w.dim1();
  int num_in = w.dim2() - 1;
  if (partial_funcs_.empty()) {
    // Base implementation.
    for (int i = 0; i < num_out; ++i) {
      const int8_t* wi = w[i];
      int total = 0;
      for (int j = 0; j < num_in; ++j) total += wi[j] * u[j];
      // Add in the bias and correct for integer values.
      v[i] = (static_cast<double>(total) / MAX_INT8 + wi[num_in]) * scales[i];
    }
  } else {
    const int8_t* w_data = shaped_w_.data();
    const double* scales_data = &scales[0];
    // Each call to a partial_func_ produces group_size outputs, except the
    // last one, which can produce less.
    int group_size = num_outputs_per_register_ * max_output_registers_;
    int rounded_num_in = Roundup(num_in, num_inputs_per_group_);
    int rounded_num_out = RoundOutputs(num_out);
    int output = 0;
    for (auto fn : partial_funcs_) {
      // The amount of w_data consumed by each call to fn.
      int w_step = (rounded_num_in + 1) * group_size;
      // Run with this group size, until it would produce too much output, then
      // switch to a smaller size.
      for (; output + group_size <= rounded_num_out; output += group_size) {
        (*fn)(w_data, scales_data, u, rounded_num_in, num_out - output, v);
        w_data += w_step;
        scales_data += group_size;
        v += group_size;
      }
      group_size /= 2;
    }
  }
}

RoundInputs()

int tesseract::IntSimdMatrix::RoundInputs ( int  size ) const

inline

Definition at line 80 of file intsimdmatrix.h.

                                  {
    return Roundup(size, num_inputs_per_register_);
  }

RoundOutputs()

int tesseract::IntSimdMatrix::RoundOutputs ( int  size ) const

inline

Definition at line 84 of file intsimdmatrix.h.

                                   {
    return Roundup(size, num_outputs_per_register_);
  }

Roundup()

static int tesseract::IntSimdMatrix::Roundup ( int  input, int  factor  )

inlinestaticprotected

Definition at line 113 of file intsimdmatrix.h.

                                            {
    return (input + factor - 1) / factor * factor;
  }

Member Data Documentation

max_output_registers_

int tesseract::IntSimdMatrix::max_output_registers_

protected

Definition at line 120 of file intsimdmatrix.h.

num_input_groups_

int tesseract::IntSimdMatrix::num_input_groups_

protected

Definition at line 126 of file intsimdmatrix.h.

num_inputs_per_group_

int tesseract::IntSimdMatrix::num_inputs_per_group_

protected

Definition at line 124 of file intsimdmatrix.h.

num_inputs_per_register_

int tesseract::IntSimdMatrix::num_inputs_per_register_

protected

Definition at line 122 of file intsimdmatrix.h.

num_outputs_per_register_

int tesseract::IntSimdMatrix::num_outputs_per_register_

protected

Definition at line 118 of file intsimdmatrix.h.

partial_funcs_

std::vector<PartialFunc> tesseract::IntSimdMatrix::partial_funcs_

protected

Definition at line 130 of file intsimdmatrix.h.

shaped_w_

std::vector<int8_t> tesseract::IntSimdMatrix::shaped_w_

protected

Definition at line 128 of file intsimdmatrix.h.

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The documentation for this class was generated from the following files:

• /home/stweil/src/github/tesseract-ocr/tesseract/arch/intsimdmatrix.h
• /home/stweil/src/github/tesseract-ocr/tesseract/arch/intsimdmatrix.cpp