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putty-source/utils/memxor.c
Simon Tatham 3396c97da9 New library-style 'utils' subdirectories.
Now that the new CMake build system is encouraging us to lay out the
code like a set of libraries, it seems like a good idea to make them
look more _like_ libraries, by putting things into separate modules as
far as possible.

This fixes several previous annoyances in which you had to link
against some object in order to get a function you needed, but that
object also contained other functions you didn't need which included
link-time symbol references you didn't want to have to deal with. The
usual offender was subsidiary supporting programs including misc.c for
some innocuous function and then finding they had to deal with the
requirements of buildinfo().

This big reorganisation introduces three new subdirectories called
'utils', one at the top level and one in each platform subdir. In each
case, the directory contains basically the same files that were
previously placed in the 'utils' build-time library, except that the
ones that were extremely miscellaneous (misc.c, utils.c, uxmisc.c,
winmisc.c, winmiscs.c, winutils.c) have been split up into much
smaller pieces.
2021-04-18 08:18:27 +01:00

35 lines
1.1 KiB
C

/*
* 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++;
}
}
}