commit 38560563587ad8eafa700c56800ff844f18fbad1

Author: Naohiro Tamura <naohirot@fujitsu.com>

Date:   Thu May 20 07:34:37 2021 +0000

    aarch64: Added Vector Length Set test helper script

    This patch is a test helper script to change Vector Length for child

    process. This script can be used as test-wrapper for 'make check'.

    Usage examples:

    ~/build$ make check subdirs=string \

    test-wrapper='~/glibc/sysdeps/unix/sysv/linux/aarch64/vltest.py 16'

    ~/build$ ~/glibc/sysdeps/unix/sysv/linux/aarch64/vltest.py 16 \

    make test t=string/test-memcpy

    ~/build$ ~/glibc/sysdeps/unix/sysv/linux/aarch64/vltest.py 32 \

    ./debugglibc.sh string/test-memmove

    ~/build$ ~/glibc/sysdeps/unix/sysv/linux/aarch64/vltest.py 64 \

    ./testrun.sh string/test-memset

diff --git a/INSTALL b/INSTALL

index 065565093bd76d5b..b3a4370f592c5047 100644

--- a/INSTALL

+++ b/INSTALL

@@ -387,6 +387,10 @@ the same syntax as 'test-wrapper-env', the only difference in its

 semantics being starting with an empty set of environment variables

 rather than the ambient set.

+   For AArch64 with SVE, when testing the GNU C Library, 'test-wrapper'

+may be set to "SRCDIR/sysdeps/unix/sysv/linux/aarch64/vltest.py

+VECTOR-LENGTH" to change Vector Length.

+

 Installing the C Library

 ========================

diff --git a/manual/install.texi b/manual/install.texi

index 7e9f2be150e6f98a..c262fd56d0cef67b 100644

--- a/manual/install.texi

+++ b/manual/install.texi

@@ -425,6 +425,9 @@ use has the same syntax as @samp{test-wrapper-env}, the only

 difference in its semantics being starting with an empty set of

 environment variables rather than the ambient set.

+For AArch64 with SVE, when testing @theglibc{}, @samp{test-wrapper}

+may be set to "@var{srcdir}/sysdeps/unix/sysv/linux/aarch64/vltest.py

+@var{vector-length}" to change Vector Length.

 @node Running make install

 @appendixsec Installing the C Library

diff --git a/sysdeps/unix/sysv/linux/aarch64/vltest.py b/sysdeps/unix/sysv/linux/aarch64/vltest.py

new file mode 100755

index 0000000000000000..bed62ad151e06868

--- /dev/null

+++ b/sysdeps/unix/sysv/linux/aarch64/vltest.py

@@ -0,0 +1,82 @@

+#!/usr/bin/python3

+# Set Scalable Vector Length test helper

+# 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/>.

+"""Set Scalable Vector Length test helper.

+

+Set Scalable Vector Length for child process.

+

+examples:

+

+~/build$ make check subdirs=string \

+test-wrapper='~/glibc/sysdeps/unix/sysv/linux/aarch64/vltest.py 16'

+

+~/build$ ~/glibc/sysdeps/unix/sysv/linux/aarch64/vltest.py 16 \

+make test t=string/test-memcpy

+

+~/build$ ~/glibc/sysdeps/unix/sysv/linux/aarch64/vltest.py 32 \

+./debugglibc.sh string/test-memmove

+

+~/build$ ~/glibc/sysdeps/unix/sysv/linux/aarch64/vltest.py 64 \

+./testrun.sh string/test-memset

+"""

+import argparse

+from ctypes import cdll, CDLL

+import os

+import sys

+

+EXIT_SUCCESS = 0

+EXIT_FAILURE = 1

+EXIT_UNSUPPORTED = 77

+

+AT_HWCAP = 16

+HWCAP_SVE = (1 << 22)

+

+PR_SVE_GET_VL = 51

+PR_SVE_SET_VL = 50

+PR_SVE_SET_VL_ONEXEC = (1 << 18)

+PR_SVE_VL_INHERIT = (1 << 17)

+PR_SVE_VL_LEN_MASK = 0xffff

+

+def main(args):

+    libc = CDLL("libc.so.6")

+    if not libc.getauxval(AT_HWCAP) & HWCAP_SVE:

+        print("CPU doesn't support SVE")

+        sys.exit(EXIT_UNSUPPORTED)

+

+    libc.prctl(PR_SVE_SET_VL,

+               args.vl[0] | PR_SVE_SET_VL_ONEXEC | PR_SVE_VL_INHERIT)

+    os.execvp(args.args[0], args.args)

+    print("exec system call failure")

+    sys.exit(EXIT_FAILURE)

+

+if __name__ == '__main__':

+    parser = argparse.ArgumentParser(description=

+            "Set Scalable Vector Length test helper",

+            formatter_class=argparse.ArgumentDefaultsHelpFormatter)

+

+    # positional argument

+    parser.add_argument("vl", nargs=1, type=int,

+                        choices=range(16, 257, 16),

+                        help=('vector length '\

+                              'which is multiples of 16 from 16 to 256'))

+    # remainDer arguments

+    parser.add_argument('args', nargs=argparse.REMAINDER,

+                        help=('args '\

+                              'which is passed to child process'))

+    args = parser.parse_args()

+    main(args)