1 files changed, 117 insertions, 0 deletions
diff --git a/libc/arch-arm/bionic/memset.S b/libc/arch-arm/bionic/memset.S
new file mode 100644
index 0000000..d52d622
--- /dev/null
+++ b/libc/arch-arm/bionic/memset.S
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+	.text
+
+    .global memset
+    .type memset, %function
+
+    .global bzero
+    .type bzero, %function
+
+    .align
+	
+		/*
+		 * Optimized memset() for ARM.
+         *
+         * memset() returns its first argument.
+		 */
+	
+bzero:
+        mov     r2, r1
+        mov     r1, #0
+
+memset:	
+		/* compute the offset to align the destination
+		 * offset = (4-(src&3))&3 = -src & 3
+		 */
+        .fnstart
+        .save       {r0, r4-r7, lr}
+		stmfd		sp!, {r0, r4-r7, lr}
+		rsb			r3, r0, #0
+		ands		r3, r3, #3
+        cmp         r3, r2
+        movhi       r3, r2
+
+        /* splat r1 */
+        mov         r1, r1, lsl #24
+        orr         r1, r1, r1, lsr #8
+        orr         r1, r1, r1, lsr #16
+
+		movs		r12, r3, lsl #31
+		strcsb		r1, [r0], #1    /* can't use strh (alignment unknown) */
+		strcsb		r1, [r0], #1
+		strmib		r1, [r0], #1
+		subs		r2, r2, r3
+        ldmlsfd     sp!, {r0, r4-r7, lr}   /* return */
+        bxls        lr
+
+		/* align the destination to a cache-line */
+        mov         r12, r1
+        mov         lr, r1
+        mov         r4, r1
+        mov         r5, r1
+        mov         r6, r1
+        mov         r7, r1
+        
+		rsb         r3, r0, #0
+		ands		r3, r3, #0x1C
+		beq         aligned32
+		cmp         r3, r2
+		andhi		r3, r2, #0x1C
+		sub         r2, r2, r3
+
+		/* conditionnaly writes 0 to 7 words (length in r3) */
+		movs		r3, r3, lsl #28
+		stmcsia		r0!, {r1, lr}
+		stmcsia		r0!, {r1, lr}
+		stmmiia		r0!, {r1, lr}
+		movs		r3, r3, lsl #2
+        strcs       r1, [r0], #4
+
+aligned32:
+        subs        r2, r2, #32
+        mov         r3, r1
+        bmi         2f
+1:      subs        r2, r2, #32
+        stmia		r0!, {r1,r3,r4,r5,r6,r7,r12,lr}
+        bhs         1b
+2:      add         r2, r2, #32
+
+		/* conditionnaly stores 0 to 31 bytes */
+		movs		r2, r2, lsl #28
+		stmcsia		r0!, {r1,r3,r12,lr}
+		stmmiia		r0!, {r1, lr}
+		movs		r2, r2, lsl #2
+        strcs       r1, [r0], #4
+		strmih		r1, [r0], #2
+		movs		r2, r2, lsl #2
+		strcsb		r1, [r0]
+        ldmfd		sp!, {r0, r4-r7, lr}
+        bx          lr
+        .fnend
+