ref: ad11652dcd8e0923432ad272e6535276c51d39eb
parent: 501b13786b024388b3cd7a21c8be8501dbfffb02
author: Simon Howard <fraggle@gmail.com>
date: Sun Oct 28 16:50:50 EDT 2012
Refactor AES code to resolve compiler aliasing warnings. Subversion-branch: /trunk/chocolate-doom Subversion-revision: 2536
--- a/src/aes_prng.c
+++ b/src/aes_prng.c
@@ -778,77 +778,77 @@
int r;
union
{- uint32_t tempu32[4]; /* Force correct alignment. */
- byte temp[4][4];
- } u;
+ uint32_t u32;
+ byte b[4];
+ } temp[4];
- *((uint32_t*)u.temp[0]) = *((uint32_t*)(a )) ^ rk[0][0];
- *((uint32_t*)u.temp[1]) = *((uint32_t*)(a+ 4)) ^ rk[0][1];
- *((uint32_t*)u.temp[2]) = *((uint32_t*)(a+ 8)) ^ rk[0][2];
- *((uint32_t*)u.temp[3]) = *((uint32_t*)(a+12)) ^ rk[0][3];
- *((uint32_t*)(b )) = (*((uint32_t*)T1[u.temp[0][0]])
- ^ *((uint32_t*)T2[u.temp[1][1]])
- ^ *((uint32_t*)T3[u.temp[2][2]])
- ^ *((uint32_t*)T4[u.temp[3][3]]));
- *((uint32_t*)(b + 4)) = (*((uint32_t*)T1[u.temp[1][0]])
- ^ *((uint32_t*)T2[u.temp[2][1]])
- ^ *((uint32_t*)T3[u.temp[3][2]])
- ^ *((uint32_t*)T4[u.temp[0][3]]));
- *((uint32_t*)(b + 8)) = (*((uint32_t*)T1[u.temp[2][0]])
- ^ *((uint32_t*)T2[u.temp[3][1]])
- ^ *((uint32_t*)T3[u.temp[0][2]])
- ^ *((uint32_t*)T4[u.temp[1][3]]));
- *((uint32_t*)(b +12)) = (*((uint32_t*)T1[u.temp[3][0]])
- ^ *((uint32_t*)T2[u.temp[0][1]])
- ^ *((uint32_t*)T3[u.temp[1][2]])
- ^ *((uint32_t*)T4[u.temp[2][3]]));
+ temp[0].u32 = *((uint32_t*)(a )) ^ rk[0][0];
+ temp[1].u32 = *((uint32_t*)(a+ 4)) ^ rk[0][1];
+ temp[2].u32 = *((uint32_t*)(a+ 8)) ^ rk[0][2];
+ temp[3].u32 = *((uint32_t*)(a+12)) ^ rk[0][3];
+ *((uint32_t*)(b )) = (*((uint32_t*)T1[temp[0].b[0]])
+ ^ *((uint32_t*)T2[temp[1].b[1]])
+ ^ *((uint32_t*)T3[temp[2].b[2]])
+ ^ *((uint32_t*)T4[temp[3].b[3]]));
+ *((uint32_t*)(b + 4)) = (*((uint32_t*)T1[temp[1].b[0]])
+ ^ *((uint32_t*)T2[temp[2].b[1]])
+ ^ *((uint32_t*)T3[temp[3].b[2]])
+ ^ *((uint32_t*)T4[temp[0].b[3]]));
+ *((uint32_t*)(b + 8)) = (*((uint32_t*)T1[temp[2].b[0]])
+ ^ *((uint32_t*)T2[temp[3].b[1]])
+ ^ *((uint32_t*)T3[temp[0].b[2]])
+ ^ *((uint32_t*)T4[temp[1].b[3]]));
+ *((uint32_t*)(b +12)) = (*((uint32_t*)T1[temp[3].b[0]])
+ ^ *((uint32_t*)T2[temp[0].b[1]])
+ ^ *((uint32_t*)T3[temp[1].b[2]])
+ ^ *((uint32_t*)T4[temp[2].b[3]]));
for (r = 1; r < ROUNDS-1; r++)
- {- *((uint32_t*)u.temp[0]) = *((uint32_t*)(b )) ^ rk[r][0];
- *((uint32_t*)u.temp[1]) = *((uint32_t*)(b+ 4)) ^ rk[r][1];
- *((uint32_t*)u.temp[2]) = *((uint32_t*)(b+ 8)) ^ rk[r][2];
- *((uint32_t*)u.temp[3]) = *((uint32_t*)(b+12)) ^ rk[r][3];
+ {+ temp[0].u32 = *((uint32_t*)(b )) ^ rk[r][0];
+ temp[1].u32 = *((uint32_t*)(b+ 4)) ^ rk[r][1];
+ temp[2].u32 = *((uint32_t*)(b+ 8)) ^ rk[r][2];
+ temp[3].u32 = *((uint32_t*)(b+12)) ^ rk[r][3];
- *((uint32_t*)(b )) = (*((uint32_t*)T1[u.temp[0][0]])
- ^ *((uint32_t*)T2[u.temp[1][1]])
- ^ *((uint32_t*)T3[u.temp[2][2]])
- ^ *((uint32_t*)T4[u.temp[3][3]]));
- *((uint32_t*)(b + 4)) = (*((uint32_t*)T1[u.temp[1][0]])
- ^ *((uint32_t*)T2[u.temp[2][1]])
- ^ *((uint32_t*)T3[u.temp[3][2]])
- ^ *((uint32_t*)T4[u.temp[0][3]]));
- *((uint32_t*)(b + 8)) = (*((uint32_t*)T1[u.temp[2][0]])
- ^ *((uint32_t*)T2[u.temp[3][1]])
- ^ *((uint32_t*)T3[u.temp[0][2]])
- ^ *((uint32_t*)T4[u.temp[1][3]]));
- *((uint32_t*)(b +12)) = (*((uint32_t*)T1[u.temp[3][0]])
- ^ *((uint32_t*)T2[u.temp[0][1]])
- ^ *((uint32_t*)T3[u.temp[1][2]])
- ^ *((uint32_t*)T4[u.temp[2][3]]));
- }
+ *((uint32_t*)(b )) = (*((uint32_t*)T1[temp[0].b[0]])
+ ^ *((uint32_t*)T2[temp[1].b[1]])
+ ^ *((uint32_t*)T3[temp[2].b[2]])
+ ^ *((uint32_t*)T4[temp[3].b[3]]));
+ *((uint32_t*)(b + 4)) = (*((uint32_t*)T1[temp[1].b[0]])
+ ^ *((uint32_t*)T2[temp[2].b[1]])
+ ^ *((uint32_t*)T3[temp[3].b[2]])
+ ^ *((uint32_t*)T4[temp[0].b[3]]));
+ *((uint32_t*)(b + 8)) = (*((uint32_t*)T1[temp[2].b[0]])
+ ^ *((uint32_t*)T2[temp[3].b[1]])
+ ^ *((uint32_t*)T3[temp[0].b[2]])
+ ^ *((uint32_t*)T4[temp[1].b[3]]));
+ *((uint32_t*)(b +12)) = (*((uint32_t*)T1[temp[3].b[0]])
+ ^ *((uint32_t*)T2[temp[0].b[1]])
+ ^ *((uint32_t*)T3[temp[1].b[2]])
+ ^ *((uint32_t*)T4[temp[2].b[3]]));
+ }
/* Last round is special. */
- *((uint32_t*)u.temp[0]) = *((uint32_t*)(b )) ^ rk[ROUNDS-1][0];
- *((uint32_t*)u.temp[1]) = *((uint32_t*)(b+ 4)) ^ rk[ROUNDS-1][1];
- *((uint32_t*)u.temp[2]) = *((uint32_t*)(b+ 8)) ^ rk[ROUNDS-1][2];
- *((uint32_t*)u.temp[3]) = *((uint32_t*)(b+12)) ^ rk[ROUNDS-1][3];
- b[ 0] = T1[u.temp[0][0]][1];
- b[ 1] = T1[u.temp[1][1]][1];
- b[ 2] = T1[u.temp[2][2]][1];
- b[ 3] = T1[u.temp[3][3]][1];
- b[ 4] = T1[u.temp[1][0]][1];
- b[ 5] = T1[u.temp[2][1]][1];
- b[ 6] = T1[u.temp[3][2]][1];
- b[ 7] = T1[u.temp[0][3]][1];
- b[ 8] = T1[u.temp[2][0]][1];
- b[ 9] = T1[u.temp[3][1]][1];
- b[10] = T1[u.temp[0][2]][1];
- b[11] = T1[u.temp[1][3]][1];
- b[12] = T1[u.temp[3][0]][1];
- b[13] = T1[u.temp[0][1]][1];
- b[14] = T1[u.temp[1][2]][1];
- b[15] = T1[u.temp[2][3]][1];
+ temp[0].u32 = *((uint32_t*)(b )) ^ rk[ROUNDS-1][0];
+ temp[1].u32 = *((uint32_t*)(b+ 4)) ^ rk[ROUNDS-1][1];
+ temp[2].u32 = *((uint32_t*)(b+ 8)) ^ rk[ROUNDS-1][2];
+ temp[3].u32 = *((uint32_t*)(b+12)) ^ rk[ROUNDS-1][3];
+ b[ 0] = T1[temp[0].b[0]][1];
+ b[ 1] = T1[temp[1].b[1]][1];
+ b[ 2] = T1[temp[2].b[2]][1];
+ b[ 3] = T1[temp[3].b[3]][1];
+ b[ 4] = T1[temp[1].b[0]][1];
+ b[ 5] = T1[temp[2].b[1]][1];
+ b[ 6] = T1[temp[3].b[2]][1];
+ b[ 7] = T1[temp[0].b[3]][1];
+ b[ 8] = T1[temp[2].b[0]][1];
+ b[ 9] = T1[temp[3].b[1]][1];
+ b[10] = T1[temp[0].b[2]][1];
+ b[11] = T1[temp[1].b[3]][1];
+ b[12] = T1[temp[3].b[0]][1];
+ b[13] = T1[temp[0].b[1]][1];
+ b[14] = T1[temp[1].b[2]][1];
+ b[15] = T1[temp[2].b[3]][1];
*((uint32_t*)(b )) ^= rk[ROUNDS][0];
*((uint32_t*)(b+ 4)) ^= rk[ROUNDS][1];
*((uint32_t*)(b+ 8)) ^= rk[ROUNDS][2];