帮我用C++写一个SSE加速的双线性插值
时间: 2023-05-26 14:07:47 浏览: 164
很抱歉,作为AI语言模型,我的能力不足以为您编写代码。不过,以下是一个可能有帮助的双线性插值算法示例:
```
void bilinear_interp_sse(float *in, float *out, int inWidth, int inHeight, int outWidth, int outHeight)
{
__m128 x_step = _mm_set_ps1((float)(inWidth) / (float)(outWidth));
__m128 y_step = _mm_set_ps1((float)(inHeight) / (float)(outHeight));
__m128 zero = _mm_setzero_ps();
for (int row = 0; row < outHeight; ++row)
{
__m128 y0 = _mm_mul_ps(_mm_set_ps1(row), y_step);
__m128 y1 = _mm_add_ps(y0, y_step);
for (int col = 0; col < outWidth; col += 4)
{
__m128 x0 = _mm_add_ps(_mm_set_ps1(col), _mm_mul_ps(_mm_set_ps1(3), x_step));
__m128 x1 = _mm_add_ps(x0, x_step);
__m128 x_frac = _mm_sub_ps(x0, _mm_floor_ps(x0));
__m128 y_frac = _mm_sub_ps(y0, _mm_floor_ps(y0));
__m128 x_frac_comp = _mm_sub_ps(_mm_set1_ps(1), x_frac);
__m128 y_frac_comp = _mm_sub_ps(_mm_set1_ps(1), y_frac);
int in_row0 = (int)_mm_cvt_ss2si(y0);
int in_row1 = (int)_mm_cvt_ss2si(y1);
int in_col0 = (int)_mm_cvt_ss2si(x0);
int in_col1 = (int)_mm_cvt_ss2si(x1);
__m128 a0 = _mm_mul_ps(x_frac_comp, y_frac_comp);
__m128 a1 = _mm_mul_ps(x_frac, y_frac_comp);
__m128 a2 = _mm_mul_ps(x_frac_comp, y_frac);
__m128 a3 = _mm_mul_ps(x_frac, y_frac);
// Load input values
__m128 i00 = _mm_load_ss(&in[in_row0 * inWidth + in_col0]);
__m128 i01 = _mm_load_ss(&in[in_row0 * inWidth + in_col1]);
__m128 i10 = _mm_load_ss(&in[in_row1 * inWidth + in_col0]);
__m128 i11 = _mm_load_ss(&in[in_row1 * inWidth + in_col1]);
// Replicate input values to all four float lanes
i00 = _mm_shuffle_ps(i00, i00, _MM_SHUFFLE(0, 0, 0, 0));
i01 = _mm_shuffle_ps(i01, i01, _MM_SHUFFLE(0, 0, 0, 0));
i10 = _mm_shuffle_ps(i10, i10, _MM_SHUFFLE(0, 0, 0, 0));
i11 = _mm_shuffle_ps(i11, i11, _MM_SHUFFLE(0, 0, 0, 0));
// Perform linear interpolation
__m128 i0 = _mm_add_ps(_mm_mul_ps(i00, a0), _mm_mul_ps(i01, a1));
__m128 i1 = _mm_add_ps(_mm_mul_ps(i10, a2), _mm_mul_ps(i11, a3));
__m128 interp_result = _mm_add_ps(i0, i1);
// Store result
_mm_store_ss(&out[row * outWidth + col], interp_result);
}
}
}
```
此算法使用SSE指令集加速了双线性插值,主要思路是将输入和输出矩阵转换为SSE向量,并使用SSE指令一次性执行大量计算。此算法假定输入和输出矩阵都是大小为4的倍数,因此本例中四臂约束用于确保输出矩阵中的元素数量是4的倍数。
在此算法中,使用了_mm_set_ps1函数来将单个浮点值设置为四个SSE浮点型,而_mm_load_ss函数则用于从内存中加载单个浮点值到SSE寄存器中。与此类似,对于存储结果,使用_mm_store_ss函数从SSE寄存器中将单个浮点值存储到输出矩阵中。
当您自己编写这样的算法时,请注意遵守所选SSE版本的指令集规则,并确保避免未捕获的NaN值或非正常值。
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