diff options
| -rw-r--r-- | lib/Target/README.txt | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt index 695fcc8fa8..e55513b395 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -260,12 +260,13 @@ quantum_sigma_x in 462.libquantum contains the following loop: Where MAX_UNSIGNED/state is a 64-bit int. On a 32-bit platform it would be just so cool to turn it into something like: + long long Res = ((MAX_UNSIGNED) 1 << target); if (target < 32) { for(i=0; i<reg->size; i++) - reg->node[i].state ^= ((int) (1 << target)); + reg->node[i].state ^= Res & 0xFFFFFFFFULL; } else { for(i=0; i<reg->size; i++) - reg->node[i].state ^= (long long)((int) (1 << (target-32))) << 32; + reg->node[i].state ^= Res & 0xFFFFFFFF00000000ULL } ... which would only do one 32-bit XOR per loop iteration instead of two. |