PATCH: Add 64-bit preadv.c and pwritev.c

["H.J. Lu" <hongjiu dot lu at intel dot com>]

Hi,

The curent preadv/pwritev on x86-64 has

   a:	49 89 ca             	mov    %rcx,%r10
   d:	85 c0                	test   %eax,%eax
   f:	75 1d                	jne    2e <preadv+0x2e>
  11:	45 31 c0             	xor    %r8d,%r8d
  14:	48 63 d2             	movslq %edx,%rdx
  17:	48 63 ff             	movslq %edi,%rdi
  1a:	b8 27 01 00 00       	mov    $0x127,%eax
  1f:	0f 05                	syscall 

There is uselss:

  11:	45 31 c0             	xor    %r8d,%r8d

It is generated by

#define LO_HI_LONG(val) \
  (off_t) val, \
  (off_t) ((((uint64_t) (val)) >> (sizeof (long) * 4)) >> (sizeof (long) * 4))

It isn't needed for 64-bit archs.  Here is a patch to add 64-bit
preadv.c and pwritev.c.  Now we have

 1ce:	49 89 ca             	mov    %rcx,%r10
 1d1:	48 63 d2             	movslq %edx,%rdx
 1d4:	48 63 ff             	movslq %edi,%rdi
 1d7:	b8 27 01 00 00       	mov    $0x127,%eax
 1dc:	0f 05                	syscall 

They will also be used by x32.  Tested on Linux/x86-64.  OK
to install?

Thanks.

H.J.
	* sysdeps/unix/sysv/linux/wordsize-64/preadv.c: New file.
	* sysdeps/unix/sysv/linux/wordsize-64/pwritev.c: Likewise.

diff --git a/sysdeps/unix/sysv/linux/wordsize-64/preadv.c b/sysdeps/unix/sysv/linux/wordsize-64/preadv.c
new file mode 100644
index 0000000..600af13
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/wordsize-64/preadv.c
@@ -0,0 +1,73 @@
+/* 64-bit preadv.  
+   Copyright (C) 2012 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stddef.h>
+#include <sys/param.h>
+/* Hide the preadv64 declaration.  */
+#define preadv64 __redirect_preadv64
+#include <sys/uio.h>
+
+#include <sysdep-cancel.h>
+#include <sys/syscall.h>
+#include <kernel-features.h>
+
+#ifndef __ASSUME_PREADV
+static ssize_t __atomic_preadv_replacement (int, const struct iovec *,
+					    int, off_t) internal_function;
+#endif
+
+ssize_t
+preadv (int fd, const struct iovec *vector, int count, off_t offset)
+{
+#ifdef __NR_preadv
+  ssize_t result;
+
+  if (SINGLE_THREAD_P)
+    result = INLINE_SYSCALL (preadv, 4, fd, vector, count, offset);
+  else
+    {
+      int oldtype = LIBC_CANCEL_ASYNC ();
+
+      result = INLINE_SYSCALL (preadv, 4, fd, vector, count, offset);
+
+      LIBC_CANCEL_RESET (oldtype);
+    }
+# ifdef __ASSUME_PREADV
+  return result;
+# endif
+#endif
+
+#ifndef __ASSUME_PREADV
+# ifdef __NR_preadv
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+# endif
+
+  return __atomic_preadv_replacement (fd, vector, count, offset);
+#endif
+}
+#undef preadv64
+strong_alias (preadv, preadv64)
+
+#ifndef __ASSUME_PREADV
+# define PREADV static internal_function __atomic_preadv_replacement
+# define PREAD __pread
+# define OFF_T off_t
+# include <sysdeps/posix/preadv.c>
+#endif
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/pwritev.c b/sysdeps/unix/sysv/linux/wordsize-64/pwritev.c
new file mode 100644
index 0000000..f2dee8f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/wordsize-64/pwritev.c
@@ -0,0 +1,73 @@
+/* 64-bi pwritev.
+   Copyright (C) 2012 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stddef.h>
+#include <sys/param.h>
+/* Hide the pwritev64 declaration.  */
+#define pwritev64 __redirect_pwritev64
+#include <sys/uio.h>
+
+#include <sysdep-cancel.h>
+#include <sys/syscall.h>
+#include <kernel-features.h>
+
+#ifndef __ASSUME_PWRITEV
+static ssize_t __atomic_pwritev_replacement (int, const struct iovec *,
+					     int, off_t) internal_function;
+#endif
+
+ssize_t
+pwritev (int fd, const struct iovec *vector, int count, off_t offset)
+{
+#ifdef __NR_pwritev
+  ssize_t result;
+
+  if (SINGLE_THREAD_P)
+    result = INLINE_SYSCALL (pwritev, 4, fd, vector, count, offset);
+  else
+    {
+      int oldtype = LIBC_CANCEL_ASYNC ();
+
+      result = INLINE_SYSCALL (pwritev, 4, fd, vector, count, offset);
+
+      LIBC_CANCEL_RESET (oldtype);
+    }
+# ifdef __ASSUME_PWRITEV
+  return result;
+# endif
+#endif
+
+#ifndef __ASSUME_PWRITEV
+# ifdef __NR_pwritev
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+# endif
+
+  return __atomic_pwritev_replacement (fd, vector, count, offset);
+#endif
+}
+#undef pwritev64
+strong_alias (pwritev, pwritev64)
+
+#ifndef __ASSUME_PWRITEV
+# define PWRITE __pwrite
+# define PWRITEV static internal_function __atomic_pwritev_replacement
+# define OFF_T off_t
+# include <sysdeps/posix/pwritev.c>
+#endif