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 065a568..bc761ab 100644 (file)
--- a/INSTALL
+++ b/INSTALL
@@ -380,6 +380,10 @@ 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.
 
 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
 ========================
 
 Installing the C Library
 ========================
 

diff --git a/manual/install.texi b/manual/install.texi
index eb41fbd..f1d858f 100644 (file)
--- a/manual/install.texi
+++ b/manual/install.texi
@@ -418,6 +418,9 @@ 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.
 
 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
 
 @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 (executable)
index 0000000..bed62ad
--- /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)