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authorRaoni Fassina Firmino <raoni@linux.ibm.com>2022-02-25 10:57:31 -0300
committerRaoni Fassina Firmino <raoni@linux.ibm.com>2022-02-25 10:57:31 -0300
commit0d6fdf9f0590f090651716b729ca5db2f1b9d620 (patch)
treeebe6dbc1ac10368fa8a781cccf52a92c7246d008
parent6bbd88c2511fa62d4b682b24bfda8dcb0af39e50 (diff)
parenta79bc55e5be07d797d77b63fc0018eb515ae7049 (diff)
downloadglibc-ibm/2.30/master.zip
glibc-ibm/2.30/master.tar.gz
glibc-ibm/2.30/master.tar.bz2
Merge branch release/2.30/master into ibm/2.30/masteribm/2.30/master
-rw-r--r--NEWS3
-rw-r--r--string/test-memchr.c39
-rw-r--r--string/test-strncat.c61
-rw-r--r--string/test-strncmp.c13
-rw-r--r--string/test-strnlen.c33
-rw-r--r--sysdeps/x86/Makefile7
-rw-r--r--sysdeps/x86/cpu-features.c40
-rw-r--r--sysdeps/x86/cpu-features.h3
-rw-r--r--sysdeps/x86/tst-get-cpu-features.c1
-rw-r--r--sysdeps/x86/tst-strncmp-rtm.c43
-rw-r--r--sysdeps/x86/tst-wcsncmp-rtm.c21
-rw-r--r--sysdeps/x86_64/Makefile7
-rw-r--r--sysdeps/x86_64/multiarch/ifunc-impl-list.c4
-rw-r--r--sysdeps/x86_64/multiarch/strcmp-avx2.S2
-rw-r--r--sysdeps/x86_64/multiarch/strlen-evex.S581
-rw-r--r--sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S1
-rw-r--r--sysdeps/x86_64/multiarch/strncmp-avx2.S1
-rw-r--r--sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S2
-rw-r--r--sysdeps/x86_64/multiarch/wcsncmp-avx2.S2
-rw-r--r--sysdeps/x86_64/tst-rsi-strlen.c81
-rw-r--r--sysdeps/x86_64/tst-rsi-wcslen.c20
21 files changed, 681 insertions, 284 deletions
diff --git a/NEWS b/NEWS
index f7501ac..64fa988 100644
--- a/NEWS
+++ b/NEWS
@@ -74,7 +74,10 @@ The following bugs are resolved with this release:
[27130] "rep movsb" performance issue
[27177] GLIBC_TUNABLES=glibc.cpu.x86_ibt=on:glibc.cpu.x86_shstk=on doesn't work
[27457] vzeroupper use in AVX2 multiarch string functions cause HTM aborts
+ [27974] Overflow bug in some implementation of wcsnlen, wmemchr, and wcsncat
[28755] overflow bug in wcsncmp_avx2 and wcsncmp_evex
+ [28896] strncmp-avx2-rtm and wcsncmp-avx2-rtm fallback on non-rtm
+ variants when avoiding overflow
Version 2.30
diff --git a/string/test-memchr.c b/string/test-memchr.c
index 58bb54e..32582fd 100644
--- a/string/test-memchr.c
+++ b/string/test-memchr.c
@@ -65,8 +65,8 @@ do_one_test (impl_t *impl, const CHAR *s, int c, size_t n, CHAR *exp_res)
CHAR *res = CALL (impl, s, c, n);
if (res != exp_res)
{
- error (0, 0, "Wrong result in function %s %p %p", impl->name,
- res, exp_res);
+ error (0, 0, "Wrong result in function %s (%p, %d, %zu) -> %p != %p",
+ impl->name, s, c, n, res, exp_res);
ret = 1;
return;
}
@@ -91,7 +91,7 @@ do_test (size_t align, size_t pos, size_t len, size_t n, int seek_char)
}
buf[align + len] = 0;
- if (pos < len)
+ if (pos < MIN(n, len))
{
buf[align + pos] = seek_char;
buf[align + len] = -seek_char;
@@ -108,6 +108,38 @@ do_test (size_t align, size_t pos, size_t len, size_t n, int seek_char)
}
static void
+do_overflow_tests (void)
+{
+ size_t i, j, len;
+ const size_t one = 1;
+ uintptr_t buf_addr = (uintptr_t) buf1;
+
+ for (i = 0; i < 750; ++i)
+ {
+ do_test (0, i, 751, SIZE_MAX - i, BIG_CHAR);
+ do_test (0, i, 751, i - buf_addr, BIG_CHAR);
+ do_test (0, i, 751, -buf_addr - i, BIG_CHAR);
+ do_test (0, i, 751, SIZE_MAX - buf_addr - i, BIG_CHAR);
+ do_test (0, i, 751, SIZE_MAX - buf_addr + i, BIG_CHAR);
+
+ len = 0;
+ for (j = 8 * sizeof(size_t) - 1; j ; --j)
+ {
+ len |= one << j;
+ do_test (0, i, 751, len - i, BIG_CHAR);
+ do_test (0, i, 751, len + i, BIG_CHAR);
+ do_test (0, i, 751, len - buf_addr - i, BIG_CHAR);
+ do_test (0, i, 751, len - buf_addr + i, BIG_CHAR);
+
+ do_test (0, i, 751, ~len - i, BIG_CHAR);
+ do_test (0, i, 751, ~len + i, BIG_CHAR);
+ do_test (0, i, 751, ~len - buf_addr - i, BIG_CHAR);
+ do_test (0, i, 751, ~len - buf_addr + i, BIG_CHAR);
+ }
+ }
+}
+
+static void
do_random_tests (void)
{
size_t i, j, n, align, pos, len;
@@ -221,6 +253,7 @@ test_main (void)
do_test (page_size / 2 - i, i, i, 1, 0x9B);
do_random_tests ();
+ do_overflow_tests ();
return ret;
}
diff --git a/string/test-strncat.c b/string/test-strncat.c
index 4b71f4a..b9c8c57 100644
--- a/string/test-strncat.c
+++ b/string/test-strncat.c
@@ -135,6 +135,66 @@ do_test (size_t align1, size_t align2, size_t len1, size_t len2,
}
static void
+do_overflow_tests (void)
+{
+ size_t i, j, len;
+ const size_t one = 1;
+ CHAR *s1, *s2;
+ uintptr_t s1_addr;
+ s1 = (CHAR *) buf1;
+ s2 = (CHAR *) buf2;
+ s1_addr = (uintptr_t)s1;
+ for (j = 0; j < 200; ++j)
+ s2[j] = 32 + 23 * j % (BIG_CHAR - 32);
+ s2[200] = 0;
+ for (i = 0; i < 750; ++i) {
+ for (j = 0; j < i; ++j)
+ s1[j] = 32 + 23 * j % (BIG_CHAR - 32);
+ s1[i] = '\0';
+
+ FOR_EACH_IMPL (impl, 0)
+ {
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, SIZE_MAX - i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, i - s1_addr);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, -s1_addr - i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, SIZE_MAX - s1_addr - i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, SIZE_MAX - s1_addr + i);
+ }
+
+ len = 0;
+ for (j = 8 * sizeof(size_t) - 1; j ; --j)
+ {
+ len |= one << j;
+ FOR_EACH_IMPL (impl, 0)
+ {
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, len - i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, len + i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, len - s1_addr - i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, len - s1_addr + i);
+
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, ~len - i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, ~len + i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, ~len - s1_addr - i);
+ s2[200] = '\0';
+ do_one_test (impl, s2, s1, ~len - s1_addr + i);
+ }
+ }
+ }
+}
+
+static void
do_random_tests (void)
{
size_t i, j, n, align1, align2, len1, len2, N;
@@ -316,6 +376,7 @@ test_main (void)
}
do_random_tests ();
+ do_overflow_tests ();
return ret;
}
diff --git a/string/test-strncmp.c b/string/test-strncmp.c
index 042e85e..af071bd 100644
--- a/string/test-strncmp.c
+++ b/string/test-strncmp.c
@@ -403,6 +403,18 @@ check2 (void)
free (s2);
}
+static void
+check3 (void)
+{
+ const CHAR *s1 = L ("abc");
+ CHAR *s2 = STRDUP (s1);
+
+ FOR_EACH_IMPL (impl, 0)
+ check_result (impl, s1, s2, SIZE_MAX, 0);
+
+ free (s2);
+}
+
int
test_main (void)
{
@@ -412,6 +424,7 @@ test_main (void)
check1 ();
check2 ();
+ check3 ();
printf ("%23s", "");
FOR_EACH_IMPL (impl, 0)
diff --git a/string/test-strnlen.c b/string/test-strnlen.c
index f7d0896..027b9ad 100644
--- a/string/test-strnlen.c
+++ b/string/test-strnlen.c
@@ -90,6 +90,38 @@ do_test (size_t align, size_t len, size_t maxlen, int max_char)
}
static void
+do_overflow_tests (void)
+{
+ size_t i, j, len;
+ const size_t one = 1;
+ uintptr_t buf_addr = (uintptr_t) buf1;
+
+ for (i = 0; i < 750; ++i)
+ {
+ do_test (0, i, SIZE_MAX - i, BIG_CHAR);
+ do_test (0, i, i - buf_addr, BIG_CHAR);
+ do_test (0, i, -buf_addr - i, BIG_CHAR);
+ do_test (0, i, SIZE_MAX - buf_addr - i, BIG_CHAR);
+ do_test (0, i, SIZE_MAX - buf_addr + i, BIG_CHAR);
+
+ len = 0;
+ for (j = 8 * sizeof(size_t) - 1; j ; --j)
+ {
+ len |= one << j;
+ do_test (0, i, len - i, BIG_CHAR);
+ do_test (0, i, len + i, BIG_CHAR);
+ do_test (0, i, len - buf_addr - i, BIG_CHAR);
+ do_test (0, i, len - buf_addr + i, BIG_CHAR);
+
+ do_test (0, i, ~len - i, BIG_CHAR);
+ do_test (0, i, ~len + i, BIG_CHAR);
+ do_test (0, i, ~len - buf_addr - i, BIG_CHAR);
+ do_test (0, i, ~len - buf_addr + i, BIG_CHAR);
+ }
+ }
+}
+
+static void
do_random_tests (void)
{
size_t i, j, n, align, len;
@@ -274,6 +306,7 @@ test_main (void)
do_random_tests ();
do_page_tests ();
do_page_2_tests ();
+ do_overflow_tests ();
return ret;
}
diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index a93139b..b7aec5d 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -33,7 +33,9 @@ tests += \
tst-strcpy-rtm \
tst-strlen-rtm \
tst-strncmp-rtm \
- tst-strrchr-rtm
+ tst-strrchr-rtm \
+ tst-wcsncmp-rtm \
+# tests
CFLAGS-tst-memchr-rtm.c += -mrtm
CFLAGS-tst-memcmp-rtm.c += -mrtm
@@ -43,8 +45,9 @@ CFLAGS-tst-memset-rtm.c += -mrtm
CFLAGS-tst-strchr-rtm.c += -mrtm
CFLAGS-tst-strcpy-rtm.c += -mrtm
CFLAGS-tst-strlen-rtm.c += -mrtm
-CFLAGS-tst-strncmp-rtm.c += -mrtm
+CFLAGS-tst-strncmp-rtm.c += -mrtm -Wno-error
CFLAGS-tst-strrchr-rtm.c += -mrtm
+CFLAGS-tst-wcsncmp-rtm.c += -mrtm -Wno-error
endif
ifeq ($(enable-cet),yes)
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index a4d1eac..91215f8 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -333,6 +333,9 @@ init_cpu_features (struct cpu_features *cpu_features)
get_extended_indices (cpu_features);
+ if (CPU_FEATURES_CPU_P (cpu_features, RTM_ALWAYS_ABORT))
+ cpu_features->cpuid[index_cpu_RTM].reg_RTM &= ~bit_cpu_RTM;
+
if (family == 0x06)
{
model += extended_model;
@@ -394,11 +397,42 @@ init_cpu_features (struct cpu_features *cpu_features)
break;
}
- /* Disable TSX on some Haswell processors to avoid TSX on kernels that
- weren't updated with the latest microcode package (which disables
- broken feature by default). */
+ /* Disable TSX on some processors to avoid TSX on kernels that
+ weren't updated with the latest microcode package (which
+ disables broken feature by default). */
switch (model)
{
+ case 0x55:
+ if (stepping <= 5)
+ goto disable_tsx;
+ break;
+ case 0x8e:
+ /* NB: Although the errata documents that for model == 0x8e,
+ only 0xb stepping or lower are impacted, the intention of
+ the errata was to disable TSX on all client processors on
+ all steppings. Include 0xc stepping which is an Intel
+ Core i7-8665U, a client mobile processor. */
+ case 0x9e:
+ if (stepping > 0xc)
+ break;
+ /* Fall through. */
+ case 0x4e:
+ case 0x5e:
+ {
+ /* Disable Intel TSX and enable RTM_ALWAYS_ABORT for
+ processors listed in:
+
+https://www.intel.com/content/www/us/en/support/articles/000059422/processors.html
+ */
+disable_tsx:
+ cpu_features->cpuid[index_cpu_HLE].reg_HLE
+ &= ~bit_cpu_HLE;
+ cpu_features->cpuid[index_cpu_RTM].reg_RTM
+ &= ~bit_cpu_RTM;
+ cpu_features->cpuid[index_cpu_RTM_ALWAYS_ABORT].reg_RTM_ALWAYS_ABORT
+ |= bit_cpu_RTM_ALWAYS_ABORT;
+ }
+ break;
case 0x3f:
/* Xeon E7 v3 with stepping >= 4 has working TSX. */
if (stepping >= 4)
diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index ca2924b..3599dd8 100644
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -499,6 +499,7 @@ extern const struct cpu_features *__get_cpu_features (void)
#define bit_cpu_AVX512_4VNNIW (1u << 2)
#define bit_cpu_AVX512_4FMAPS (1u << 3)
#define bit_cpu_FSRM (1u << 4)
+#define bit_cpu_RTM_ALWAYS_ABORT (1u << 11)
#define bit_cpu_PCONFIG (1u << 18)
#define bit_cpu_IBT (1u << 20)
#define bit_cpu_IBRS_IBPB (1u << 26)
@@ -667,6 +668,7 @@ extern const struct cpu_features *__get_cpu_features (void)
#define index_cpu_AVX512_4VNNIW COMMON_CPUID_INDEX_7
#define index_cpu_AVX512_4FMAPS COMMON_CPUID_INDEX_7
#define index_cpu_FSRM COMMON_CPUID_INDEX_7
+#define index_cpu_RTM_ALWAYS_ABORT COMMON_CPUID_INDEX_7
#define index_cpu_PCONFIG COMMON_CPUID_INDEX_7
#define index_cpu_IBT COMMON_CPUID_INDEX_7
#define index_cpu_IBRS_IBPB COMMON_CPUID_INDEX_7
@@ -835,6 +837,7 @@ extern const struct cpu_features *__get_cpu_features (void)
#define reg_AVX512_4VNNIW edx
#define reg_AVX512_4FMAPS edx
#define reg_FSRM edx
+#define reg_RTM_ALWAYS_ABORT edx
#define reg_PCONFIG edx
#define reg_IBT edx
#define reg_IBRS_IBPB edx
diff --git a/sysdeps/x86/tst-get-cpu-features.c b/sysdeps/x86/tst-get-cpu-features.c
index bf2b9b2..08aa421 100644
--- a/sysdeps/x86/tst-get-cpu-features.c
+++ b/sysdeps/x86/tst-get-cpu-features.c
@@ -176,6 +176,7 @@ do_test (void)
CHECK_CPU_FEATURE (AVX512_4VNNIW);
CHECK_CPU_FEATURE (AVX512_4FMAPS);
CHECK_CPU_FEATURE (FSRM);
+ CHECK_CPU_FEATURE (RTM_ALWAYS_ABORT);
CHECK_CPU_FEATURE (PCONFIG);
CHECK_CPU_FEATURE (IBT);
CHECK_CPU_FEATURE (IBRS_IBPB);
diff --git a/sysdeps/x86/tst-strncmp-rtm.c b/sysdeps/x86/tst-strncmp-rtm.c
index 236ad95..aef9866 100644
--- a/sysdeps/x86/tst-strncmp-rtm.c
+++ b/sysdeps/x86/tst-strncmp-rtm.c
@@ -16,20 +16,35 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+#include <stdint.h>
#include <tst-string-rtm.h>
+#ifdef WIDE
+# define CHAR wchar_t
+# define MEMSET wmemset
+# define STRNCMP wcsncmp
+# define TEST_NAME "wcsncmp"
+#else /* !WIDE */
+# define CHAR char
+# define MEMSET memset
+# define STRNCMP strncmp
+# define TEST_NAME "strncmp"
+#endif /* !WIDE */
+
+
+
#define LOOP 3000
#define STRING_SIZE 1024
-char string1[STRING_SIZE];
-char string2[STRING_SIZE];
+CHAR string1[STRING_SIZE];
+CHAR string2[STRING_SIZE];
__attribute__ ((noinline, noclone))
static int
prepare (void)
{
- memset (string1, 'a', STRING_SIZE - 1);
- memset (string2, 'a', STRING_SIZE - 1);
- if (strncmp (string1, string2, STRING_SIZE) == 0)
+ MEMSET (string1, 'a', STRING_SIZE - 1);
+ MEMSET (string2, 'a', STRING_SIZE - 1);
+ if (STRNCMP (string1, string2, STRING_SIZE) == 0)
return EXIT_SUCCESS;
else
return EXIT_FAILURE;
@@ -39,7 +54,17 @@ __attribute__ ((noinline, noclone))
static int
function (void)
{
- if (strncmp (string1, string2, STRING_SIZE) == 0)
+ if (STRNCMP (string1, string2, STRING_SIZE) == 0)
+ return 0;
+ else
+ return 1;
+}
+
+__attribute__ ((noinline, noclone))
+static int
+function_overflow (void)
+{
+ if (STRNCMP (string1, string2, SIZE_MAX) == 0)
return 0;
else
return 1;
@@ -48,5 +73,9 @@ function (void)
static int
do_test (void)
{
- return do_test_1 ("strncmp", LOOP, prepare, function);
+ int status = do_test_1 (TEST_NAME, LOOP, prepare, function);
+ if (status != EXIT_SUCCESS)
+ return status;
+ status = do_test_1 (TEST_NAME, LOOP, prepare, function_overflow);
+ return status;
}
diff --git a/sysdeps/x86/tst-wcsncmp-rtm.c b/sysdeps/x86/tst-wcsncmp-rtm.c
new file mode 100644
index 0000000..bad3b86
--- /dev/null
+++ b/sysdeps/x86/tst-wcsncmp-rtm.c
@@ -0,0 +1,21 @@
+/* Test case for wcsncmp inside a transactionally executing RTM region.
+ Copyright (C) 2022 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/>. */
+
+#define WIDE 1
+#include <wchar.h>
+#include "tst-strncmp-rtm.c"
diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index d51cf03..b1951ad 100644
--- a/sysdeps/x86_64/Makefile
+++ b/sysdeps/x86_64/Makefile
@@ -20,6 +20,8 @@ endif
ifeq ($(subdir),string)
sysdep_routines += cacheinfo strcasecmp_l-nonascii strncase_l-nonascii
gen-as-const-headers += locale-defines.sym
+tests += \
+ tst-rsi-strlen
endif
ifeq ($(subdir),elf)
@@ -150,6 +152,11 @@ ifeq ($(subdir),csu)
gen-as-const-headers += tlsdesc.sym rtld-offsets.sym
endif
+ifeq ($(subdir),wcsmbs)
+tests += \
+ tst-rsi-wcslen
+endif
+
$(objpfx)x86_64/tst-x86_64mod-1.os: $(objpfx)tst-x86_64mod-1.os
$(make-target-directory)
rm -f $@
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index e57fb42..28971a6 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -657,9 +657,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
&& HAS_ARCH_FEATURE (AVX512BW_Usable)
&& HAS_CPU_FEATURE (BMI2)),
__wcslen_evex)
- IFUNC_IMPL_ADD (array, i, wcsnlen,
+ IFUNC_IMPL_ADD (array, i, wcslen,
CPU_FEATURE_USABLE (SSE4_1),
- __wcsnlen_sse4_1)
+ __wcslen_sse4_1)
IFUNC_IMPL_ADD (array, i, wcslen, 1, __wcslen_sse2))
/* Support sysdeps/x86_64/multiarch/wcsnlen.c. */
diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S
index f199c91..5c41ba6 100644
--- a/sysdeps/x86_64/multiarch/strcmp-avx2.S
+++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S
@@ -95,7 +95,7 @@ ENTRY (STRCMP)
length to bound a valid memory region. In these cases just use
'wcscmp'. */
shrq $56, %rcx
- jnz __wcscmp_avx2
+ jnz OVERFLOW_STRCMP
# endif
/* Convert units: from wide to byte char. */
shl $2, %RDX_LP
diff --git a/sysdeps/x86_64/multiarch/strlen-evex.S b/sysdeps/x86_64/multiarch/strlen-evex.S
index 0583819..4bf6874 100644
--- a/sysdeps/x86_64/multiarch/strlen-evex.S
+++ b/sysdeps/x86_64/multiarch/strlen-evex.S
@@ -29,11 +29,13 @@
# ifdef USE_AS_WCSLEN
# define VPCMP vpcmpd
# define VPMINU vpminud
-# define SHIFT_REG r9d
+# define SHIFT_REG ecx
+# define CHAR_SIZE 4
# else
# define VPCMP vpcmpb
# define VPMINU vpminub
-# define SHIFT_REG ecx
+# define SHIFT_REG edx
+# define CHAR_SIZE 1
# endif
# define XMMZERO xmm16
@@ -46,132 +48,165 @@
# define YMM6 ymm22
# define VEC_SIZE 32
+# define PAGE_SIZE 4096
+# define CHAR_PER_VEC (VEC_SIZE / CHAR_SIZE)
.section .text.evex,"ax",@progbits
ENTRY (STRLEN)
# ifdef USE_AS_STRNLEN
- /* Check for zero length. */
+ /* Check zero length. */
test %RSI_LP, %RSI_LP
jz L(zero)
-# ifdef USE_AS_WCSLEN
- shl $2, %RSI_LP
-# elif defined __ILP32__
+# ifdef __ILP32__
/* Clear the upper 32 bits. */
movl %esi, %esi
# endif
mov %RSI_LP, %R8_LP
# endif
- movl %edi, %ecx
- movq %rdi, %rdx
+ movl %edi, %eax
vpxorq %XMMZERO, %XMMZERO, %XMMZERO
-
+ /* Clear high bits from edi. Only keeping bits relevant to page
+ cross check. */
+ andl $(PAGE_SIZE - 1), %eax
/* Check if we may cross page boundary with one vector load. */
- andl $(2 * VEC_SIZE - 1), %ecx
- cmpl $VEC_SIZE, %ecx
- ja L(cros_page_boundary)
+ cmpl $(PAGE_SIZE - VEC_SIZE), %eax
+ ja L(cross_page_boundary)
/* Check the first VEC_SIZE bytes. Each bit in K0 represents a
null byte. */
VPCMP $0, (%rdi), %YMMZERO, %k0
kmovd %k0, %eax
- testl %eax, %eax
-
# ifdef USE_AS_STRNLEN
- jnz L(first_vec_x0_check)
- /* Adjust length and check the end of data. */
- subq $VEC_SIZE, %rsi
- jbe L(max)
-# else
- jnz L(first_vec_x0)
+ /* If length < CHAR_PER_VEC handle special. */
+ cmpq $CHAR_PER_VEC, %rsi
+ jbe L(first_vec_x0)
# endif
-
- /* Align data for aligned loads in the loop. */
- addq $VEC_SIZE, %rdi
- andl $(VEC_SIZE - 1), %ecx
- andq $-VEC_SIZE, %rdi
-
+ testl %eax, %eax
+ jz L(aligned_more)
+ tzcntl %eax, %eax
+ ret
# ifdef USE_AS_STRNLEN
- /* Adjust length. */
- addq %rcx, %rsi
+L(zero):
+ xorl %eax, %eax
+ ret
- subq $(VEC_SIZE * 4), %rsi
- jbe L(last_4x_vec_or_less)
+ .p2align 4
+L(first_vec_x0):
+ /* Set bit for max len so that tzcnt will return min of max len
+ and position of first match. */
+ btsq %rsi, %rax
+ tzcntl %eax, %eax
+ ret
# endif
- jmp L(more_4x_vec)
.p2align 4
-L(cros_page_boundary):
- andl $(VEC_SIZE - 1), %ecx
- andq $-VEC_SIZE, %rdi
-
-# ifdef USE_AS_WCSLEN
- /* NB: Divide shift count by 4 since each bit in K0 represent 4
- bytes. */
- movl %ecx, %SHIFT_REG
- sarl $2, %SHIFT_REG
+L(first_vec_x1):
+ tzcntl %eax, %eax
+ /* Safe to use 32 bit instructions as these are only called for
+ size = [1, 159]. */
+# ifdef USE_AS_STRNLEN
+ /* Use ecx which was computed earlier to compute correct value.
+ */
+ leal -(CHAR_PER_VEC * 4 + 1)(%rcx, %rax), %eax
+# else
+ subl %edx, %edi
+# ifdef USE_AS_WCSLEN
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarl $2, %edi
+# endif
+ leal CHAR_PER_VEC(%rdi, %rax), %eax
# endif
- VPCMP $0, (%rdi), %YMMZERO, %k0
- kmovd %k0, %eax
+ ret
- /* Remove the leading bytes. */
- sarxl %SHIFT_REG, %eax, %eax
- testl %eax, %eax
- jz L(aligned_more)
+ .p2align 4
+L(first_vec_x2):
tzcntl %eax, %eax
-# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
+ /* Safe to use 32 bit instructions as these are only called for
+ size = [1, 159]. */
# ifdef USE_AS_STRNLEN
- /* Check the end of data. */
- cmpq %rax, %rsi
- jbe L(max)
-# endif
- addq %rdi, %rax
- addq %rcx, %rax
- subq %rdx, %rax
-# ifdef USE_AS_WCSLEN
- shrq $2, %rax
+ /* Use ecx which was computed earlier to compute correct value.
+ */
+ leal -(CHAR_PER_VEC * 3 + 1)(%rcx, %rax), %eax
+# else
+ subl %edx, %edi
+# ifdef USE_AS_WCSLEN
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarl $2, %edi
+# endif
+ leal (CHAR_PER_VEC * 2)(%rdi, %rax), %eax
# endif
ret
.p2align 4
-L(aligned_more):
+L(first_vec_x3):
+ tzcntl %eax, %eax
+ /* Safe to use 32 bit instructions as these are only called for
+ size = [1, 159]. */
# ifdef USE_AS_STRNLEN
- /* "rcx" is less than VEC_SIZE. Calculate "rdx + rcx - VEC_SIZE"
- with "rdx - (VEC_SIZE - rcx)" instead of "(rdx + rcx) - VEC_SIZE"
- to void possible addition overflow. */
- negq %rcx
- addq $VEC_SIZE, %rcx
-
- /* Check the end of data. */
- subq %rcx, %rsi
- jbe L(max)
+ /* Use ecx which was computed earlier to compute correct value.
+ */
+ leal -(CHAR_PER_VEC * 2 + 1)(%rcx, %rax), %eax
+# else
+ subl %edx, %edi
+# ifdef USE_AS_WCSLEN
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarl $2, %edi
+# endif
+ leal (CHAR_PER_VEC * 3)(%rdi, %rax), %eax
# endif
+ ret
- addq $VEC_SIZE, %rdi
-
+ .p2align 4
+L(first_vec_x4):
+ tzcntl %eax, %eax
+ /* Safe to use 32 bit instructions as these are only called for
+ size = [1, 159]. */
# ifdef USE_AS_STRNLEN
- subq $(VEC_SIZE * 4), %rsi
- jbe L(last_4x_vec_or_less)
+ /* Use ecx which was computed earlier to compute correct value.
+ */
+ leal -(CHAR_PER_VEC + 1)(%rcx, %rax), %eax
+# else
+ subl %edx, %edi
+# ifdef USE_AS_WCSLEN
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarl $2, %edi
+# endif
+ leal (CHAR_PER_VEC * 4)(%rdi, %rax), %eax
# endif
+ ret
-L(more_4x_vec):
+ .p2align 5
+L(aligned_more):
+ movq %rdi, %rdx
+ /* Align data to VEC_SIZE. */
+ andq $-(VEC_SIZE), %rdi
+L(cross_page_continue):
/* Check the first 4 * VEC_SIZE. Only one VEC_SIZE at a time
since data is only aligned to VEC_SIZE. */
- VPCMP $0, (%rdi), %YMMZERO, %k0
- kmovd %k0, %eax
- testl %eax, %eax
- jnz L(first_vec_x0)
-
+# ifdef USE_AS_STRNLEN
+ /* + CHAR_SIZE because it simplies the logic in
+ last_4x_vec_or_less. */
+ leaq (VEC_SIZE * 5 + CHAR_SIZE)(%rdi), %rcx
+ subq %rdx, %rcx
+# ifdef USE_AS_WCSLEN
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarl $2, %ecx
+# endif
+# endif
+ /* Load first VEC regardless. */
VPCMP $0, VEC_SIZE(%rdi), %YMMZERO, %k0
+# ifdef USE_AS_STRNLEN
+ /* Adjust length. If near end handle specially. */
+ subq %rcx, %rsi
+ jb L(last_4x_vec_or_less)
+# endif
kmovd %k0, %eax
testl %eax, %eax
jnz L(first_vec_x1)
VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMZERO, %k0
kmovd %k0, %eax
- testl %eax, %eax
+ test %eax, %eax
jnz L(first_vec_x2)
VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMZERO, %k0
@@ -179,258 +214,276 @@ L(more_4x_vec):
testl %eax, %eax
jnz L(first_vec_x3)
- addq $(VEC_SIZE * 4), %rdi
-
-# ifdef USE_AS_STRNLEN
- subq $(VEC_SIZE * 4), %rsi
- jbe L(last_4x_vec_or_less)
-# endif
-
- /* Align data to 4 * VEC_SIZE. */
- movq %rdi, %rcx
- andl $(4 * VEC_SIZE - 1), %ecx
- andq $-(4 * VEC_SIZE), %rdi
+ VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMZERO, %k0
+ kmovd %k0, %eax
+ testl %eax, %eax
+ jnz L(first_vec_x4)
+ addq $VEC_SIZE, %rdi
# ifdef USE_AS_STRNLEN
- /* Adjust length. */
+ /* Check if at last VEC_SIZE * 4 length. */
+ cmpq $(CHAR_PER_VEC * 4 - 1), %rsi
+ jbe L(last_4x_vec_or_less_load)
+ movl %edi, %ecx
+ andl $(VEC_SIZE * 4 - 1), %ecx
+# ifdef USE_AS_WCSLEN
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarl $2, %ecx
+# endif
+ /* Readjust length. */
addq %rcx, %rsi
# endif
+ /* Align data to VEC_SIZE * 4. */
+ andq $-(VEC_SIZE * 4), %rdi
+ /* Compare 4 * VEC at a time forward. */
.p2align 4
L(loop_4x_vec):
- /* Compare 4 * VEC at a time forward. */
- VMOVA (%rdi), %YMM1
- VMOVA VEC_SIZE(%rdi), %YMM2
- VMOVA (VEC_SIZE * 2)(%rdi), %YMM3
- VMOVA (VEC_SIZE * 3)(%rdi), %YMM4
-
- VPMINU %YMM1, %YMM2, %YMM5
- VPMINU %YMM3, %YMM4, %YMM6
+ /* Load first VEC regardless. */
+ VMOVA (VEC_SIZE * 4)(%rdi), %YMM1
+# ifdef USE_AS_STRNLEN
+ /* Break if at end of length. */
+ subq $(CHAR_PER_VEC * 4), %rsi
+ jb L(last_4x_vec_or_less_cmpeq)
+# endif
+ /* Save some code size by microfusing VPMINU with the load. Since
+ the matches in ymm2/ymm4 can only be returned if there where no
+ matches in ymm1/ymm3 respectively there is no issue with overlap.
+ */
+ VPMINU (VEC_SIZE * 5)(%rdi), %YMM1, %YMM2
+ VMOVA (VEC_SIZE * 6)(%rdi), %YMM3
+ VPMINU (VEC_SIZE * 7)(%rdi), %YMM3, %YMM4
+
+ VPCMP $0, %YMM2, %YMMZERO, %k0
+ VPCMP $0, %YMM4, %YMMZERO, %k1
+ subq $-(VEC_SIZE * 4), %rdi
+ kortestd %k0, %k1
+ jz L(loop_4x_vec)
+
+ /* Check if end was in first half. */
+ kmovd %k0, %eax
+ subq %rdx, %rdi
+# ifdef USE_AS_WCSLEN
+ shrq $2, %rdi
+# endif
+ testl %eax, %eax
+ jz L(second_vec_return)
- VPMINU %YMM5, %YMM6, %YMM5
- VPCMP $0, %YMM5, %YMMZERO, %k0
- ktestd %k0, %k0
- jnz L(4x_vec_end)
+ VPCMP $0, %YMM1, %YMMZERO, %k2
+ kmovd %k2, %edx
+ /* Combine VEC1 matches (edx) with VEC2 matches (eax). */
+# ifdef USE_AS_WCSLEN
+ sall $CHAR_PER_VEC, %eax
+ orl %edx, %eax
+ tzcntl %eax, %eax
+# else
+ salq $CHAR_PER_VEC, %rax
+ orq %rdx, %rax
+ tzcntq %rax, %rax
+# endif
+ addq %rdi, %rax
+ ret
- addq $(VEC_SIZE * 4), %rdi
-# ifndef USE_AS_STRNLEN
- jmp L(loop_4x_vec)
-# else
- subq $(VEC_SIZE * 4), %rsi
- ja L(loop_4x_vec)
+# ifdef USE_AS_STRNLEN
+L(last_4x_vec_or_less_load):
+ /* Depending on entry adjust rdi / prepare first VEC in YMM1. */
+ VMOVA (VEC_SIZE * 4)(%rdi), %YMM1
+L(last_4x_vec_or_less_cmpeq):
+ VPCMP $0, %YMM1, %YMMZERO, %k0
+ addq $(VEC_SIZE * 3), %rdi
L(last_4x_vec_or_less):
- /* Less than 4 * VEC and aligned to VEC_SIZE. */
- addl $(VEC_SIZE * 2), %esi
- jle L(last_2x_vec)
-
- VPCMP $0, (%rdi), %YMMZERO, %k0
kmovd %k0, %eax
+ /* If remaining length > VEC_SIZE * 2. This works if esi is off by
+ VEC_SIZE * 4. */
+ testl $(CHAR_PER_VEC * 2), %esi
+ jnz L(last_4x_vec)
+
+ /* length may have been negative or positive by an offset of
+ CHAR_PER_VEC * 4 depending on where this was called from. This
+ fixes that. */
+ andl $(CHAR_PER_VEC * 4 - 1), %esi
testl %eax, %eax
- jnz L(first_vec_x0)
+ jnz L(last_vec_x1_check)
- VPCMP $0, VEC_SIZE(%rdi), %YMMZERO, %k0
- kmovd %k0, %eax
- testl %eax, %eax
- jnz L(first_vec_x1)
+ /* Check the end of data. */
+ subl $CHAR_PER_VEC, %esi
+ jb L(max)
VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMZERO, %k0
kmovd %k0, %eax
- testl %eax, %eax
- jnz L(first_vec_x2_check)
- subl $VEC_SIZE, %esi
- jle L(max)
+ tzcntl %eax, %eax
+ /* Check the end of data. */
+ cmpl %eax, %esi
+ jb L(max)
- VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMZERO, %k0
- kmovd %k0, %eax
- testl %eax, %eax
- jnz L(first_vec_x3_check)
+ subq %rdx, %rdi
+# ifdef USE_AS_WCSLEN
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarq $2, %rdi
+# endif
+ leaq (CHAR_PER_VEC * 2)(%rdi, %rax), %rax
+ ret
+L(max):
movq %r8, %rax
+ ret
+# endif
+
+ /* Placed here in strnlen so that the jcc L(last_4x_vec_or_less)
+ in the 4x VEC loop can use 2 byte encoding. */
+ .p2align 4
+L(second_vec_return):
+ VPCMP $0, %YMM3, %YMMZERO, %k0
+ /* Combine YMM3 matches (k0) with YMM4 matches (k1). */
+# ifdef USE_AS_WCSLEN
+ kunpckbw %k0, %k1, %k0
+ kmovd %k0, %eax
+ tzcntl %eax, %eax
+# else
+ kunpckdq %k0, %k1, %k0
+ kmovq %k0, %rax
+ tzcntq %rax, %rax
+# endif
+ leaq (CHAR_PER_VEC * 2)(%rdi, %rax), %rax
+ ret
+
+
+# ifdef USE_AS_STRNLEN
+L(last_vec_x1_check):
+ tzcntl %eax, %eax
+ /* Check the end of data. */
+ cmpl %eax, %esi
+ jb L(max)
+ subq %rdx, %rdi
# ifdef USE_AS_WCSLEN
- shrq $2, %rax
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarq $2, %rdi
# endif
+ leaq (CHAR_PER_VEC)(%rdi, %rax), %rax
ret
.p2align 4
-L(last_2x_vec):
- addl $(VEC_SIZE * 2), %esi
+L(last_4x_vec):
+ /* Test first 2x VEC normally. */
+ testl %eax, %eax
+ jnz L(last_vec_x1)
- VPCMP $0, (%rdi), %YMMZERO, %k0
+ VPCMP $0, (VEC_SIZE * 2)(%rdi), %YMMZERO, %k0
kmovd %k0, %eax
testl %eax, %eax
- jnz L(first_vec_x0_check)
- subl $VEC_SIZE, %esi
- jle L(max)
+ jnz L(last_vec_x2)
- VPCMP $0, VEC_SIZE(%rdi), %YMMZERO, %k0
+ /* Normalize length. */
+ andl $(CHAR_PER_VEC * 4 - 1), %esi
+ VPCMP $0, (VEC_SIZE * 3)(%rdi), %YMMZERO, %k0
kmovd %k0, %eax
testl %eax, %eax
- jnz L(first_vec_x1_check)
- movq %r8, %rax
-# ifdef USE_AS_WCSLEN
- shrq $2, %rax
-# endif
- ret
+ jnz L(last_vec_x3)
- .p2align 4
-L(first_vec_x0_check):
+ /* Check the end of data. */
+ subl $(CHAR_PER_VEC * 3), %esi
+ jb L(max)
+
+ VPCMP $0, (VEC_SIZE * 4)(%rdi), %YMMZERO, %k0
+ kmovd %k0, %eax
tzcntl %eax, %eax
-# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
/* Check the end of data. */
- cmpq %rax, %rsi
- jbe L(max)
- addq %rdi, %rax
- subq %rdx, %rax
+ cmpl %eax, %esi
+ jb L(max_end)
+
+ subq %rdx, %rdi
# ifdef USE_AS_WCSLEN
- shrq $2, %rax
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarq $2, %rdi
# endif
+ leaq (CHAR_PER_VEC * 4)(%rdi, %rax), %rax
ret
.p2align 4
-L(first_vec_x1_check):
+L(last_vec_x1):
tzcntl %eax, %eax
+ subq %rdx, %rdi
# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
- /* Check the end of data. */
- cmpq %rax, %rsi
- jbe L(max)
- addq $VEC_SIZE, %rax
- addq %rdi, %rax
- subq %rdx, %rax
-# ifdef USE_AS_WCSLEN
- shrq $2, %rax
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarq $2, %rdi
# endif
+ leaq (CHAR_PER_VEC)(%rdi, %rax), %rax
ret
.p2align 4
-L(first_vec_x2_check):
+L(last_vec_x2):
tzcntl %eax, %eax
+ subq %rdx, %rdi
# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
- /* Check the end of data. */
- cmpq %rax, %rsi
- jbe L(max)
- addq $(VEC_SIZE * 2), %rax
- addq %rdi, %rax
- subq %rdx, %rax
-# ifdef USE_AS_WCSLEN
- shrq $2, %rax
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarq $2, %rdi
# endif
+ leaq (CHAR_PER_VEC * 2)(%rdi, %rax), %rax
ret
.p2align 4
-L(first_vec_x3_check):
+L(last_vec_x3):
tzcntl %eax, %eax
-# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
+ subl $(CHAR_PER_VEC * 2), %esi
/* Check the end of data. */
- cmpq %rax, %rsi
- jbe L(max)
- addq $(VEC_SIZE * 3), %rax
- addq %rdi, %rax
- subq %rdx, %rax
+ cmpl %eax, %esi
+ jb L(max_end)
+ subq %rdx, %rdi
# ifdef USE_AS_WCSLEN
- shrq $2, %rax
+ /* NB: Divide bytes by 4 to get the wchar_t count. */
+ sarq $2, %rdi
# endif
+ leaq (CHAR_PER_VEC * 3)(%rdi, %rax), %rax
ret
-
- .p2align 4
-L(max):
+L(max_end):
movq %r8, %rax
-# ifdef USE_AS_WCSLEN
- shrq $2, %rax
-# endif
- ret
-
- .p2align 4
-L(zero):
- xorl %eax, %eax
ret
# endif
+ /* Cold case for crossing page with first load. */
.p2align 4
-L(first_vec_x0):
- tzcntl %eax, %eax
-# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
- addq %rdi, %rax
- subq %rdx, %rax
+L(cross_page_boundary):
+ movq %rdi, %rdx
+ /* Align data to VEC_SIZE. */
+ andq $-VEC_SIZE, %rdi
+ VPCMP $0, (%rdi), %YMMZERO, %k0
+ kmovd %k0, %eax
+ /* Remove the leading bytes. */
# ifdef USE_AS_WCSLEN
- shrq $2, %rax
+ /* NB: Divide shift count by 4 since each bit in K0 represent 4
+ bytes. */
+ movl %edx, %ecx
+ shrl $2, %ecx
+ andl $(CHAR_PER_VEC - 1), %ecx
# endif
- ret
-
- .p2align 4
-L(first_vec_x1):
+ /* SHIFT_REG is ecx for USE_AS_WCSLEN and edx otherwise. */
+ sarxl %SHIFT_REG, %eax, %eax
+ testl %eax, %eax
+# ifndef USE_AS_STRNLEN
+ jz L(cross_page_continue)
tzcntl %eax, %eax
-# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
- addq $VEC_SIZE, %rax
- addq %rdi, %rax
- subq %rdx, %rax
-# ifdef USE_AS_WCSLEN
- shrq $2, %rax
-# endif
ret
-
- .p2align 4
-L(first_vec_x2):
- tzcntl %eax, %eax
-# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
- addq $(VEC_SIZE * 2), %rax
- addq %rdi, %rax
- subq %rdx, %rax
-# ifdef USE_AS_WCSLEN
- shrq $2, %rax
-# endif
+# else
+ jnz L(cross_page_less_vec)
+# ifndef USE_AS_WCSLEN
+ movl %edx, %ecx
+ andl $(CHAR_PER_VEC - 1), %ecx
+# endif
+ movl $CHAR_PER_VEC, %eax
+ subl %ecx, %eax
+ /* Check the end of data. */
+ cmpq %rax, %rsi
+ ja L(cross_page_continue)
+ movl %esi, %eax
ret
-
- .p2align 4
-L(4x_vec_end):
- VPCMP $0, %YMM1, %YMMZERO, %k0
- kmovd %k0, %eax
- testl %eax, %eax
- jnz L(first_vec_x0)
- VPCMP $0, %YMM2, %YMMZERO, %k1
- kmovd %k1, %eax
- testl %eax, %eax
- jnz L(first_vec_x1)
- VPCMP $0, %YMM3, %YMMZERO, %k2
- kmovd %k2, %eax
- testl %eax, %eax
- jnz L(first_vec_x2)
- VPCMP $0, %YMM4, %YMMZERO, %k3
- kmovd %k3, %eax
-L(first_vec_x3):
+L(cross_page_less_vec):
tzcntl %eax, %eax
-# ifdef USE_AS_WCSLEN
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- sall $2, %eax
-# endif
- addq $(VEC_SIZE * 3), %rax
- addq %rdi, %rax
- subq %rdx, %rax
-# ifdef USE_AS_WCSLEN
- shrq $2, %rax
-# endif
+ /* Select min of length and position of first null. */
+ cmpq %rax, %rsi
+ cmovb %esi, %eax
ret
+# endif
END (STRLEN)
#endif
diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
index 37d1224..68bad36 100644
--- a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
+++ b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
@@ -1,3 +1,4 @@
#define STRCMP __strncmp_avx2_rtm
#define USE_AS_STRNCMP 1
+#define OVERFLOW_STRCMP __strcmp_avx2_rtm
#include "strcmp-avx2-rtm.S"
diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2.S b/sysdeps/x86_64/multiarch/strncmp-avx2.S
index 1678bcc..f138e9f 100644
--- a/sysdeps/x86_64/multiarch/strncmp-avx2.S
+++ b/sysdeps/x86_64/multiarch/strncmp-avx2.S
@@ -1,3 +1,4 @@
#define STRCMP __strncmp_avx2
#define USE_AS_STRNCMP 1
+#define OVERFLOW_STRCMP __strcmp_avx2
#include "strcmp-avx2.S"
diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
index 4e88c70..f467582 100644
--- a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
+++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
@@ -1,5 +1,5 @@
#define STRCMP __wcsncmp_avx2_rtm
#define USE_AS_STRNCMP 1
#define USE_AS_WCSCMP 1
-
+#define OVERFLOW_STRCMP __wcscmp_avx2_rtm
#include "strcmp-avx2-rtm.S"
diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
index 4fa1de4..e9ede52 100644
--- a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
+++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
@@ -1,5 +1,5 @@
#define STRCMP __wcsncmp_avx2
#define USE_AS_STRNCMP 1
#define USE_AS_WCSCMP 1
-
+#define OVERFLOW_STRCMP __wcscmp_avx2
#include "strcmp-avx2.S"
diff --git a/sysdeps/x86_64/tst-rsi-strlen.c b/sysdeps/x86_64/tst-rsi-strlen.c
new file mode 100644
index 0000000..a80c4f8
--- /dev/null
+++ b/sysdeps/x86_64/tst-rsi-strlen.c
@@ -0,0 +1,81 @@
+/* Test strlen with 0 in the RSI register.
+ Copyright (C) 2021 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/>. */
+
+#ifdef WIDE
+# define TEST_NAME "wcslen"
+#else
+# define TEST_NAME "strlen"
+#endif /* WIDE */
+
+#define TEST_MAIN
+#include <string/test-string.h>
+
+#ifdef WIDE
+# include <wchar.h>
+# define STRLEN wcslen
+# define CHAR wchar_t
+#else
+# define STRLEN strlen
+# define CHAR char
+#endif /* WIDE */
+
+IMPL (STRLEN, 1)
+
+typedef size_t (*proto_t) (const CHAR *);
+
+typedef struct
+{
+ void (*fn) (void);
+} parameter_t;
+
+size_t
+__attribute__ ((weak, noinline, noclone))
+do_strlen (parameter_t *a, int zero, const CHAR *str)
+{
+ return CALL (a, str);
+}
+
+static int
+test_main (void)
+{
+ test_init ();
+
+ size_t size = page_size / sizeof (CHAR) - 1;
+ CHAR *buf = (CHAR *) buf2;
+ buf[size] = 0;
+
+ parameter_t a;
+
+ int ret = 0;
+ FOR_EACH_IMPL (impl, 0)
+ {
+ a.fn = impl->fn;
+ /* NB: Pass 0 in RSI. */
+ size_t res = do_strlen (&a, 0, buf);
+ if (res != size)
+ {
+ error (0, 0, "Wrong result in function %s: %zu != %zu",
+ impl->name, res, size);
+ ret = 1;
+ }
+ }
+
+ return ret ? EXIT_FAILURE : EXIT_SUCCESS;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/x86_64/tst-rsi-wcslen.c b/sysdeps/x86_64/tst-rsi-wcslen.c
new file mode 100644
index 0000000..f45a7df
--- /dev/null
+++ b/sysdeps/x86_64/tst-rsi-wcslen.c
@@ -0,0 +1,20 @@
+/* Test wcslen with 0 in the RSI register.
+ Copyright (C) 2021 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/>. */
+
+#define WIDE 1
+#include "tst-rsi-strlen.c"