Add Aarch64 optimized bzero based on memset

Change-Id: I62cf25bfe23b9d811e00af7307bbd19d89937792
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>

libc/arch-arm64/arm64.mk

@@ -34,7 +34,6 @@ libc_common_src_files_arm64 += \
 ### CPU specific source files
 libc_bionic_src_files_arm64 := \
     arch-arm64/bionic/__bionic_clone.S \
-    arch-arm64/bionic/bzero_arm64.c \
     arch-arm64/bionic/_exit_with_stack_teardown.S \
     arch-arm64/bionic/futex_arm64.S \
     arch-arm64/bionic/__get_sp.S \

libc/arch-arm64/bionic/bzero_arm64.c

@@ -1,33 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *  * Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include <string.h>
-
-void bzero(void* s, size_t n) {
-  memset(s, '\0', n);
-}

libc/arch-arm64/generic/bionic/bzero.S

@@ -0,0 +1,30 @@
+/* Copyright (c) 2014, Linaro Limited
+   All rights reserved.
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are met:
+       * Redistributions of source code must retain the above copyright
+         notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above copyright
+         notice, this list of conditions and the following disclaimer in the
+         documentation and/or other materials provided with the distribution.
+       * Neither the name of the Linaro nor the
+         names of its contributors may be used to endorse or promote products
+         derived from this software without specific prior written permission.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#define BZERO
+#include "memset.S"
+#undef BZERO

libc/arch-arm64/generic/bionic/memset.S

@@ -38,15 +38,19 @@
    data blocks more efficiently.  In some circumstances this might be
    unsafe, for example in an asymmetric multiprocessor environment with
    different DC clear lengths (neither the upper nor lower lengths are
-   safe to use).  The feature can be disabled by defining DONT_USE_DC.
+   safe to use).
 
    If code may be run in a virtualized environment, then define
    MAYBE_VIRT.  This will cause the code to cache the system register
    values rather than re-reading them each call.  */
 
 #define dstin		x0
-#define val		w1
+#ifdef BZERO
+#define count		x1
+#else
 #define count		x2
+#endif
+#define val		w1
 #define tmp1		x3
 #define tmp1w		w3
 #define tmp2		x4
@@ -60,13 +64,18 @@
 #define dst		x8
 #define tmp3w		w9
 
+#ifdef BZERO
+ENTRY(bzero)
+#else
 ENTRY(memset)
+#endif
 
 	mov	dst, dstin		/* Preserve return value.  */
-	ands	A_lw, val, #255
+#ifdef BZERO
-#ifndef DONT_USE_DC
+	b	.Lzero_mem
-	b.eq	.Lzero_mem
 #endif
+	ands	A_lw, val, #255
+	b.eq	.Lzero_mem
 	orr	A_lw, A_lw, A_lw, lsl #8
 	orr	A_lw, A_lw, A_lw, lsl #16
 	orr	A_l, A_l, A_l, lsl #32
@@ -143,7 +152,6 @@ ENTRY(memset)
 	b.ne	.Ltail63
 	ret
 
-#ifndef DONT_USE_DC
 	/* For zeroing memory, check to see if we can use the ZVA feature to
 	 * zero entire 'cache' lines.  */
 .Lzero_mem:
@@ -225,7 +233,11 @@ ENTRY(memset)
 	ands	count, count, zva_bits_x
 	b.ne	.Ltail_maybe_long
 	ret
+#ifdef BZERO
+END(bzero)
+#else
 END(memset)
+#endif
 
 #ifdef MAYBE_VIRT
 	.bss
@@ -233,4 +245,3 @@ END(memset)
 .Lcache_clear:
 	.space 4
 #endif
-#endif /* DONT_USE_DC */

libc/arch-arm64/generic/generic.mk

@@ -1,5 +1,6 @@
 libc_bionic_src_files_arm64 += \
     arch-arm64/generic/bionic/bcopy.S \
+    arch-arm64/generic/bionic/bzero.S \
     arch-arm64/generic/bionic/memcmp.S \
     arch-arm64/generic/bionic/memcpy.S \
     arch-arm64/generic/bionic/memmove.S \