Question

我使用SSE来实现矩阵乘法，运行代码时得到Stack Overflow Exception。 stack overflow exception位于chktsk.asm

; Find next lower page and probe
cs20:
        sub     eax, _PAGESIZE_         ; decrease by PAGESIZE
        test    dword ptr [eax],eax     ; probe page.
        jmp     short cs10

_chkstk endp

        end

很难发现哪里出错了，我的代码是：

main.cpp

#include "sse_matrix.h"

int main(int argc, char* argv[])
{
    float left[size] = {0};
    float right[size] = {0};
    float result[size] = {0};
    // initialize value
    for (int i = 0; i < dim; i ++)
    {
        for (int j = 0; j < dim; j ++)
        {
            left[i*dim + j] = j;
            right[i*dim + j] = j;
        }

    }
    //calculate the result
    SSE_Matrix_Multiply(left, right, result);
    /*for (int i = 0; i < dim; i ++)
    {
        for (int j = 0; j < dim; j ++)
        {
            cout << result[i * dim + j] << " ";
        }
        cout << endl;
    }*/
    system("pause");

    return 0;

}

包含文件：

#ifndef __SSE_MATRIX_H
#define __SSE_MATRIX_H

#include <iostream>
using std::cin;
using std::cout;
using std::endl;

#define dim 512
#define size dim * dim

struct Matrix_Info 
{
    float *A;
    int ax, ay;
    float *B;
    int bx, by;
    float *C;
    int cx, cy;
    int m;
    int n;
};

void Transpose_Matrix_SSE(float * matrix)
{
    __m128 row1 = _mm_loadu_ps(&matrix[0*4]);
    __m128 row2 = _mm_loadu_ps(&matrix[1*4]);
    __m128 row3 = _mm_loadu_ps(&matrix[2*4]);
    __m128 row4 = _mm_loadu_ps(&matrix[3*4]);
    _MM_TRANSPOSE4_PS(row1, row2, row3, row4);
    _mm_storeu_ps(&matrix[0*4], row1);
    _mm_storeu_ps(&matrix[1*4], row2);
    _mm_storeu_ps(&matrix[2*4], row3);
    _mm_storeu_ps(&matrix[3*4], row4);

}

float * Shuffle_Matrix_Multiply(float * left, float * right)
{
    __m128 _t1, _t2, _sum;
    _sum = _mm_setzero_ps(); // set all value of _sum to zero
    float _result[size] = {0};
    float _res[4] = {0};
    for (int i = 0; i < 4; i ++)
    {
        for (int j = 0; j < 4; j ++)
        {
            _t1 = _mm_loadu_ps(left + i * 4);
            _t2 = _mm_loadu_ps(right + j * 4);
            _sum = _mm_mul_ps(_t1, _t2);
            _mm_storeu_ps(_res, _sum);
            _result[i * 4 + j] = _res[0] + _res[1] + _res[2] + _res[3];
        }
    }
    return _result;
}

float * SSE_4_Matrix(struct Matrix_Info * my_info)
{
    int m = my_info->m;
    int n = my_info->n;
    int ax = my_info->ax;
    int ay = my_info->ay;
    int bx = my_info->bx;
    int by = my_info->by;
    //1. split Matrix A and Matrix B
    float * _a = new float[16];
    float * _b = new float[16];
    for (int i = 0; i < m; i ++)
    {
        for (int j = 0; j < m; j ++)
        {
            _a[i*m + j] = *(my_info->A + (i + ax) * n + j + ay);
            _b[i*m + j] = *(my_info->B + (i + bx) * n + j + by);
        }
    }
    //2. transpose Matrix B
    Transpose_Matrix_SSE(_b);
    //3. calculate result and return a float pointer
    return Shuffle_Matrix_Multiply(_a, _b);
}

int Matrix_Multiply(struct Matrix_Info * my_info)
{
    int m = my_info->m;
    int n = my_info->n;
    int cx = my_info->cx;
    int cy = my_info->cy;
    for (int i = 0; i < m; i ++)
    {
        for (int j = 0; j < m; j ++)
        {
            *(my_info->C + (i + cx) * n + j + cy) += SSE_4_Matrix(my_info)[i*m + j];
        }
    }
    return 0;
}

void SSE_Matrix_Multiply(float *left, float *right, float *result)
{
    struct Matrix_Info my_info;
    my_info.A = left;
    my_info.B = right;
    my_info.C = result;
    my_info.n = dim;
    my_info.m = 4;

    // Matrix A row:i, column:j
    for (int i = 0; i < dim; i += 4)
    {
        for (int j = 0; j < dim; j += 4)
        {
            // Matrix B row:j column:k
            for (int k = 0; k < dim; k += 4)
            {
                my_info.ax = i;
                my_info.ay = j;
                my_info.bx = j;
                my_info.by = k;
                my_info.cx = i;
                my_info.cy = k;
                Matrix_Multiply(&my_info);
            }
        }
    }
}

#endif

当包含文件中的dim（矩阵维度）为4, 8, 16, 32, 64, 128 and 256时，Stack Overflow Exception将不会发生。但是，当dim为512或更大时，Stack Overflow Exception将会出现。

我的操作系统为Windows 10，IDE为Visual Studio 2012。

真正让我感到困惑的是，当我在main.cpp #include "sse_matrix.h"处找到一个断点时，当它运行时，它会发生Stack Overflow Exception。我认为我的代码中没有语法错误或逻辑错误。但我不知道如何解决它。

Answer 1

#define之后size dim * dim #define dim 512为size，因此float _result[size]为262,144。然后你将sizeof(float)放在堆栈上。大多数堆栈都小于262,144 * std::vector<float> _result(size, 0);。

正如@πάνταῥεῖ所说，你可能想要更像的东西：

sizeof(float)

这样你的262,144 * std::vector块内存被放在堆上并为你管理（这比自己分配和取消分配内存要好得多 - 甚至比智能指针更好，因为{{1将适应大小的变化）。

正如@ Basile Starynkevitch指出的那样，你不想要：

#define size dim * dim

因为dim * dim文本只会替换为size，并且很容易导致语法错误或更糟。

更好的是：

#define size (dim * dim)

更好的是：

constexpr size_t dim = 512;
constexpr size_t size = dim * dim;

为什么我在这里获得堆栈溢出？

1 个答案: