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, 249 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/mips/strcmp.S b/REORG.TODO/sysdeps/mips/strcmp.S
new file mode 100644
index 0000000000..61e52b8c73
--- /dev/null
+++ b/REORG.TODO/sysdeps/mips/strcmp.S
@@ -0,0 +1,249 @@
+/* Copyright (C) 2014-2017 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/>.  */
+
+#ifdef ANDROID_CHANGES
+# include "machine/asm.h"
+# include "machine/regdef.h"
+#elif _LIBC
+# include <sysdep.h>
+# include <regdef.h>
+# include <sys/asm.h>
+#elif defined _COMPILING_NEWLIB
+# include "machine/asm.h"
+# include "machine/regdef.h"
+#else
+# include <regdef.h>
+# include <sys/asm.h>
+#endif
+
+/* Technically strcmp should not read past the end of the strings being
+   compared.  We will read a full word that may contain excess bits beyond
+   the NULL string terminator but unless ENABLE_READAHEAD is set, we will not
+   read the next word after the end of string.  Setting ENABLE_READAHEAD will
+   improve performance but is technically illegal based on the definition of
+   strcmp.  */
+#ifdef ENABLE_READAHEAD
+# define DELAY_READ
+#else
+# define DELAY_READ nop
+#endif
+
+/* Testing on a little endian machine showed using CLZ was a
+   performance loss, so we are not turning it on by default.  */
+#if defined(ENABLE_CLZ) && (__mips_isa_rev > 1)
+# define USE_CLZ
+#endif
+
+/* Some asm.h files do not have the L macro definition.  */
+#ifndef L
+# if _MIPS_SIM == _ABIO32
+#  define L(label) $L ## label
+# else
+#  define L(label) .L ## label
+# endif
+#endif
+
+/* Some asm.h files do not have the PTR_ADDIU macro definition.  */
+#ifndef PTR_ADDIU
+# ifdef USE_DOUBLE
+#  define PTR_ADDIU       daddiu
+# else
+#  define PTR_ADDIU       addiu
+# endif
+#endif
+
+/* Allow the routine to be named something else if desired.  */
+#ifndef STRCMP_NAME
+# define STRCMP_NAME strcmp
+#endif
+
+#ifdef ANDROID_CHANGES
+LEAF(STRCMP_NAME, 0)
+#else
+LEAF(STRCMP_NAME)
+#endif
+	.set	nomips16
+	.set	noreorder
+
+	or	t0, a0, a1
+	andi	t0,0x3
+	bne	t0, zero, L(byteloop)
+
+/* Both strings are 4 byte aligned at this point.  */
+
+	lui	t8, 0x0101
+	ori	t8, t8, 0x0101
+	lui	t9, 0x7f7f
+	ori	t9, 0x7f7f
+
+#define STRCMP32(OFFSET) \
+	lw	v0, OFFSET(a0); \
+	lw	v1, OFFSET(a1); \
+	subu	t0, v0, t8; \
+	bne	v0, v1, L(worddiff); \
+	nor	t1, v0, t9; \
+	and	t0, t0, t1; \
+	bne	t0, zero, L(returnzero)
+
+L(wordloop):
+	STRCMP32(0)
+	DELAY_READ
+	STRCMP32(4)
+	DELAY_READ
+	STRCMP32(8)
+	DELAY_READ
+	STRCMP32(12)
+	DELAY_READ
+	STRCMP32(16)
+	DELAY_READ
+	STRCMP32(20)
+	DELAY_READ
+	STRCMP32(24)
+	DELAY_READ
+	STRCMP32(28)
+	PTR_ADDIU a0, a0, 32
+	b	L(wordloop)
+	PTR_ADDIU a1, a1, 32
+
+L(returnzero):
+	j	ra
+	move	v0, zero
+
+L(worddiff):
+#ifdef USE_CLZ
+	subu	t0, v0, t8
+	nor	t1, v0, t9
+	and	t1, t0, t1
+	xor	t0, v0, v1
+	or	t0, t0, t1
+# if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	wsbh	t0, t0
+	rotr	t0, t0, 16
+# endif
+	clz	t1, t0
+	and	t1, 0xf8
+# if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+	neg	t1
+	addu	t1, 24
+# endif
+	rotrv	v0, v0, t1
+	rotrv	v1, v1, t1
+	and	v0, v0, 0xff
+	and	v1, v1, 0xff
+	j	ra
+	subu	v0, v0, v1
+#else /* USE_CLZ */
+# if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	andi	t0, v0, 0xff
+	beq	t0, zero, L(wexit01)
+	andi	t1, v1, 0xff
+	bne	t0, t1, L(wexit01)
+
+	srl	t8, v0, 8
+	srl	t9, v1, 8
+	andi	t8, t8, 0xff
+	beq	t8, zero, L(wexit89)
+	andi	t9, t9, 0xff
+	bne	t8, t9, L(wexit89)
+
+	srl	t0, v0, 16
+	srl	t1, v1, 16
+	andi	t0, t0, 0xff
+	beq	t0, zero, L(wexit01)
+	andi	t1, t1, 0xff
+	bne	t0, t1, L(wexit01)
+
+	srl	t8, v0, 24
+	srl	t9, v1, 24
+# else /* __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ */
+	srl	t0, v0, 24
+	beq	t0, zero, L(wexit01)
+	srl	t1, v1, 24
+	bne	t0, t1, L(wexit01)
+
+	srl	t8, v0, 16
+	srl	t9, v1, 16
+	andi	t8, t8, 0xff
+	beq	t8, zero, L(wexit89)
+	andi	t9, t9, 0xff
+	bne	t8, t9, L(wexit89)
+
+	srl	t0, v0, 8
+	srl	t1, v1, 8
+	andi	t0, t0, 0xff
+	beq	t0, zero, L(wexit01)
+	andi	t1, t1, 0xff
+	bne	t0, t1, L(wexit01)
+
+	andi	t8, v0, 0xff
+	andi	t9, v1, 0xff
+# endif /* __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ */
+
+L(wexit89):
+	j	ra
+	subu	v0, t8, t9
+L(wexit01):
+	j	ra
+	subu	v0, t0, t1
+#endif /* USE_CLZ */
+
+/* It might seem better to do the 'beq' instruction between the two 'lbu'
+   instructions so that the nop is not needed but testing showed that this
+   code is actually faster (based on glibc strcmp test).  */
+#define BYTECMP01(OFFSET) \
+	lbu	v0, OFFSET(a0); \
+	lbu	v1, OFFSET(a1); \
+	beq	v0, zero, L(bexit01); \
+	nop; \
+	bne	v0, v1, L(bexit01)
+
+#define BYTECMP89(OFFSET) \
+	lbu	t8, OFFSET(a0); \
+	lbu	t9, OFFSET(a1); \
+	beq	t8, zero, L(bexit89); \
+	nop;	\
+	bne	t8, t9, L(bexit89)
+
+L(byteloop):
+	BYTECMP01(0)
+	BYTECMP89(1)
+	BYTECMP01(2)
+	BYTECMP89(3)
+	BYTECMP01(4)
+	BYTECMP89(5)
+	BYTECMP01(6)
+	BYTECMP89(7)
+	PTR_ADDIU a0, a0, 8
+	b	L(byteloop)
+	PTR_ADDIU a1, a1, 8
+
+L(bexit01):
+	j	ra
+	subu	v0, v0, v1
+L(bexit89):
+	j	ra
+	subu	v0, t8, t9
+
+	.set	at
+	.set	reorder
+
+END(STRCMP_NAME)
+#ifndef ANDROID_CHANGES
+# ifdef _LIBC
+libc_hidden_builtin_def (STRCMP_NAME)
+# endif
+#endif