Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 88 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/i386/stpcpy.S b/REORG.TODO/sysdeps/i386/stpcpy.S
new file mode 100644
index 0000000000..d9981b677b
--- /dev/null
+++ b/REORG.TODO/sysdeps/i386/stpcpy.S
@@ -0,0 +1,88 @@
+/* Copy SRC to DEST returning the address of the terminating '\0' in DEST.
+   For Intel 80x86, x>=3.
+   Copyright (C) 1994-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper (drepper@gnu.ai.mit.edu).
+
+   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/>.  */
+
+/* This function is defined neither in ANSI nor POSIX standards but is
+   also not invented here.  */
+
+#include <sysdep.h>
+#include "asm-syntax.h"
+
+#define PARMS	4		/* no space for saved regs */
+#define RTN	PARMS
+#define DEST	RTN
+#define SRC	DEST+4
+
+	.text
+ENTRY (__stpcpy)
+
+	movl DEST(%esp), %eax
+	movl SRC(%esp), %ecx
+	subl %eax, %ecx		/* magic: reduce number of loop variants
+				   to one using addressing mode */
+
+	/* Here we would like to write
+
+	subl $4, %eax
+	ALIGN (4)
+
+	but the assembler is too smart and optimizes for the shortest
+	form where the number only needs one byte.  But if we could
+	have the long form we would not need the alignment.  */
+
+	.byte 0x81, 0xe8	/* This is `subl $0x00000004, %eax' */
+	.long 0x00000004
+
+	/* Four times unfolded loop with only one loop counter.  This
+	   is achieved by the use of index+base addressing mode.  As the
+	   loop counter we use the destination address because this is
+	   also the result.  */
+L(1):	addl $4, %eax		/* increment loop counter */
+
+	movb (%eax,%ecx), %dl	/* load current char */
+	movb %dl, (%eax)	/* and store it */
+	testb %dl, %dl		/* was it NUL? */
+	jz L(2)			/* yes, then exit */
+
+	movb 1(%eax,%ecx), %dl	/* load current char */
+	movb %dl, 1(%eax)	/* and store it */
+	testb %dl, %dl		/* was it NUL? */
+	jz L(3)			/* yes, then exit */
+
+	movb 2(%eax,%ecx), %dl	/* load current char */
+	movb %dl, 2(%eax)	/* and store it */
+	testb %dl, %dl		/* was it NUL? */
+	jz L(4)			/* yes, then exit */
+
+	movb 3(%eax,%ecx), %dl	/* load current char */
+	movb %dl, 3(%eax)	/* and store it */
+	testb %dl, %dl		/* was it NUL? */
+	jnz L(1)		/* no, then continue loop */
+
+	incl %eax		/* correct loop counter */
+L(4):	incl %eax
+L(3):	incl %eax
+L(2):
+
+	ret
+END (__stpcpy)
+
+weak_alias (__stpcpy, stpcpy)
+libc_hidden_def (__stpcpy)
+libc_hidden_builtin_def (stpcpy)