36 lines
923 B
C++
36 lines
923 B
C++
/// @file transpose8x1_noinline.cpp
|
|
/// Defines the 8x1 transposition function
|
|
|
|
#include "fl/stdint.h"
|
|
|
|
#include "transpose8x1_noinline.h"
|
|
|
|
#pragma GCC diagnostic push
|
|
#pragma GCC diagnostic ignored "-Wcast-align"
|
|
|
|
void transpose8x1_noinline(unsigned char *A, unsigned char *B) {
|
|
uint32_t x, y, t;
|
|
|
|
// Load the array and pack it into x and y.
|
|
y = *(unsigned int*)(A);
|
|
x = *(unsigned int*)(A+4);
|
|
|
|
// pre-transform x
|
|
t = (x ^ (x >> 7)) & 0x00AA00AA; x = x ^ t ^ (t << 7);
|
|
t = (x ^ (x >>14)) & 0x0000CCCC; x = x ^ t ^ (t <<14);
|
|
|
|
// pre-transform y
|
|
t = (y ^ (y >> 7)) & 0x00AA00AA; y = y ^ t ^ (t << 7);
|
|
t = (y ^ (y >>14)) & 0x0000CCCC; y = y ^ t ^ (t <<14);
|
|
|
|
// final transform
|
|
t = (x & 0xF0F0F0F0) | ((y >> 4) & 0x0F0F0F0F);
|
|
y = ((x << 4) & 0xF0F0F0F0) | (y & 0x0F0F0F0F);
|
|
x = t;
|
|
|
|
*((uint32_t*)B) = y;
|
|
*((uint32_t*)(B+4)) = x;
|
|
}
|
|
|
|
#pragma GCC diagnostic pop
|