diff options
Diffstat (limited to 'utils/memxor.c')
| -rw-r--r-- | utils/memxor.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/utils/memxor.c b/utils/memxor.c new file mode 100644 index 00000000..4fd41f41 --- /dev/null +++ b/utils/memxor.c @@ -0,0 +1,34 @@ +/* + * XOR two pieces of memory, copying the result into a third, which + * may precisely alias one of the input pair (but no guarantees if it + * partially overlaps). + */ + +#include "defs.h" +#include "misc.h" + +void memxor(uint8_t *out, const uint8_t *in1, const uint8_t *in2, size_t size) +{ + switch (size & 15) { + case 0: + while (size >= 16) { + size -= 16; + *out++ = *in1++ ^ *in2++; + case 15: *out++ = *in1++ ^ *in2++; + case 14: *out++ = *in1++ ^ *in2++; + case 13: *out++ = *in1++ ^ *in2++; + case 12: *out++ = *in1++ ^ *in2++; + case 11: *out++ = *in1++ ^ *in2++; + case 10: *out++ = *in1++ ^ *in2++; + case 9: *out++ = *in1++ ^ *in2++; + case 8: *out++ = *in1++ ^ *in2++; + case 7: *out++ = *in1++ ^ *in2++; + case 6: *out++ = *in1++ ^ *in2++; + case 5: *out++ = *in1++ ^ *in2++; + case 4: *out++ = *in1++ ^ *in2++; + case 3: *out++ = *in1++ ^ *in2++; + case 2: *out++ = *in1++ ^ *in2++; + case 1: *out++ = *in1++ ^ *in2++; + } + } +} |