diff options
| -rw-r--r-- | string/Makefile | 12 | ||||
| -rw-r--r-- | string/test-memswap.c | 192 | ||||
| -rw-r--r-- | sysdeps/generic/memswap.h | 41 |
3 files changed, 245 insertions, 0 deletions
diff --git a/string/Makefile b/string/Makefile index 040a38d..850bfba 100644 --- a/string/Makefile +++ b/string/Makefile @@ -211,6 +211,18 @@ tests := \ tst-xbzero-opt \ # tests +tests-static-internal := \ + test-memswap \ +# tests-static-internal + +tests-internal := \ + $(tests-static-internal) \ + # tests-internal + +tests-static := \ + $(tests-static-internal) \ + # tests-static + # Both tests require the .mo translation files generated by msgfmt. tests-translation := \ tst-strerror \ diff --git a/string/test-memswap.c b/string/test-memswap.c new file mode 100644 index 0000000..162beb9 --- /dev/null +++ b/string/test-memswap.c @@ -0,0 +1,192 @@ +/* Test and measure memcpy functions. + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <string.h> +#include <support/check.h> +#include <memswap.h> + +#define TEST_MAIN +#define BUF1PAGES 3 +#include "test-string.h" + +static unsigned char *ref1; +static unsigned char *ref2; + +static void +do_one_test (unsigned char *p1, unsigned char *ref1, unsigned char *p2, + unsigned char *ref2, size_t len) +{ + __memswap (p1, p2, len); + + TEST_COMPARE_BLOB (p1, len, ref2, len); + TEST_COMPARE_BLOB (p2, len, ref1, len); +} + +static inline void +do_test (size_t align1, size_t align2, size_t len) +{ + align1 &= page_size; + if (align1 + len >= page_size) + return; + + align2 &= page_size; + if (align2 + len >= page_size) + return; + + unsigned char *p1 = buf1 + align1; + unsigned char *p2 = buf2 + align2; + for (size_t repeats = 0; repeats < 2; ++repeats) + { + size_t i, j; + for (i = 0, j = 1; i < len; i++, j += 23) + { + ref1[i] = p1[i] = j; + ref2[i] = p2[i] = UCHAR_MAX - j; + } + + do_one_test (p1, ref1, p2, ref2, len); + } +} + +static void +do_random_tests (void) +{ + for (size_t n = 0; n < ITERATIONS; n++) + { + size_t len, size, size1, size2, align1, align2; + + if (n == 0) + { + len = getpagesize (); + size = len + 512; + size1 = size; + size2 = size; + align1 = 512; + align2 = 512; + } + else + { + if ((random () & 255) == 0) + size = 65536; + else + size = 768; + if (size > page_size) + size = page_size; + size1 = size; + size2 = size; + size_t i = random (); + if (i & 3) + size -= 256; + if (i & 1) + size1 -= 256; + if (i & 2) + size2 -= 256; + if (i & 4) + { + len = random () % size; + align1 = size1 - len - (random () & 31); + align2 = size2 - len - (random () & 31); + if (align1 > size1) + align1 = 0; + if (align2 > size2) + align2 = 0; + } + else + { + align1 = random () & 63; + align2 = random () & 63; + len = random () % size; + if (align1 + len > size1) + align1 = size1 - len; + if (align2 + len > size2) + align2 = size2 - len; + } + } + unsigned char *p1 = buf1 + page_size - size1; + unsigned char *p2 = buf2 + page_size - size2; + size_t j = align1 + len + 256; + if (j > size1) + j = size1; + for (size_t i = 0; i < j; ++i) + ref1[i] = p1[i] = random () & 255; + + j = align2 + len + 256; + if (j > size2) + j = size2; + + for (size_t i = 0; i < j; ++i) + ref2[i] = p2[i] = random () & 255; + + do_one_test (p1 + align1, ref1 + align1, p2 + align2, ref2 + align2, len); + } +} + +static int +test_main (void) +{ + test_init (); + /* Use the start of buf1 for reference buffers. */ + ref1 = buf1; + ref2 = buf1 + page_size; + buf1 = ref2 + page_size; + + printf ("%23s", ""); + printf ("\t__memswap\n"); + + for (size_t i = 0; i < 18; ++i) + { + do_test (0, 0, 1 << i); + do_test (i, 0, 1 << i); + do_test (0, i, 1 << i); + do_test (i, i, 1 << i); + } + + for (size_t i = 0; i < 32; ++i) + { + do_test (0, 0, i); + do_test (i, 0, i); + do_test (0, i, i); + do_test (i, i, i); + } + + for (size_t i = 3; i < 32; ++i) + { + if ((i & (i - 1)) == 0) + continue; + do_test (0, 0, 16 * i); + do_test (i, 0, 16 * i); + do_test (0, i, 16 * i); + do_test (i, i, 16 * i); + } + + for (size_t i = 19; i <= 25; ++i) + { + do_test (255, 0, 1 << i); + do_test (0, 4000, 1 << i); + do_test (0, 255, i); + do_test (0, 4000, i); + } + + do_test (0, 0, getpagesize ()); + + do_random_tests (); + + return 0; +} + +#include <support/test-driver.c> diff --git a/sysdeps/generic/memswap.h b/sysdeps/generic/memswap.h new file mode 100644 index 0000000..f09dae1 --- /dev/null +++ b/sysdeps/generic/memswap.h @@ -0,0 +1,41 @@ +/* Swap the content of two memory blocks, overlap is NOT handled. + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <string.h> + +static inline void +__memswap (void *__restrict p1, void *__restrict p2, size_t n) +{ + /* Use multiple small memcpys with constant size to enable inlining on most + targets. */ + enum { SWAP_GENERIC_SIZE = 32 }; + unsigned char tmp[SWAP_GENERIC_SIZE]; + while (n > SWAP_GENERIC_SIZE) + { + memcpy (tmp, p1, SWAP_GENERIC_SIZE); + p1 = __mempcpy (p1, p2, SWAP_GENERIC_SIZE); + p2 = __mempcpy (p2, tmp, SWAP_GENERIC_SIZE); + n -= SWAP_GENERIC_SIZE; + } + while (n > 0) + { + unsigned char t = ((unsigned char *)p1)[--n]; + ((unsigned char *)p1)[n] = ((unsigned char *)p2)[n]; + ((unsigned char *)p2)[n] = t; + } +} |