diff --git a/libc/arch-arm/bionic/memcmp16.S b/libc/arch-arm/bionic/memcmp16.S
new file mode 100644
index 0000000..38d8b62
--- /dev/null
+++ b/libc/arch-arm/bionic/memcmp16.S
@@ -0,0 +1,236 @@
+/*
+ * 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.
+ */
+
+#include <machine/cpu-features.h>
+
+    .text
+
+    .global __memcmp16
+    .type __memcmp16, %function
+    .align 4
+
+/*
+ * Optimized memcmp16() for ARM9.
+ * This would not be optimal on XScale or ARM11, where more prefetching
+ * and use of PLD will be needed.
+ * The 2 major optimzations here are
+ * (1) The main loop compares 16 bytes at a time
+ * (2) The loads are scheduled in a way they won't stall
+ */
+
+__memcmp16:
+        PLD         (r0, #0)
+        PLD         (r1, #0)
+
+        /* take of the case where length is nul or the buffers are the same */
+        cmp         r0, r1
+        cmpne       r2, #0
+        moveq       r0, #0
+        bxeq        lr
+
+        /* since r0 hold the result, move the first source
+         * pointer somewhere else
+         */
+
+        mov         r3, r0
+
+         /* make sure we have at least 12 words, this simplify things below
+          * and avoid some overhead for small blocks
+          */
+
+        cmp         r2, #12
+        bpl         0f
+
+        /* small blocks (less then 12 words) */
+        PLD         (r0, #32)
+        PLD         (r1, #32)
+
+1:      ldrh        r0, [r3], #2
+        ldrh        ip, [r1], #2
+        subs        r0, r0, ip
+        bxne        lr        
+        subs        r2, r2, #1
+        bne         1b
+        bx          lr
+
+
+        /* save registers */
+0:      stmfd       sp!, {r4, lr}
+        
+        /* align first pointer to word boundary */
+        tst         r3, #2
+        beq         0f
+        
+        ldrh        r0, [r3], #2
+        ldrh        ip, [r1], #2
+        sub         r2, r2, #1
+        subs        r0, r0, ip
+        /* restore registers and return */
+        ldmnefd     sp!, {r4, lr}
+        bxne        lr
+
+
+
+0:      /* here the first pointer is aligned, and we have at least 3 words
+         * to process.
+         */
+
+        /* see if the pointers are congruent */
+        eor         r0, r3, r1
+        ands        r0, r0, #2
+        bne         5f
+
+        /* congruent case, 16 half-words per iteration
+         * We need to make sure there are at least 16+2 words left
+         * because we effectively read ahead one long word, and we could
+         * read past the buffer (and segfault) if we're not careful.
+         */
+
+        ldr         ip, [r1]
+        subs        r2, r2, #(16 + 2)
+        bmi         1f
+        
+0:
+        PLD         (r3, #64)
+        PLD         (r1, #64)
+        ldr         r0, [r3], #4
+        ldr         lr, [r1, #4]!
+        eors        r0, r0, ip
+        ldreq       r0, [r3], #4
+        ldreq       ip, [r1, #4]!
+        eoreqs      r0, r0, lr
+        ldreq       r0, [r3], #4
+        ldreq       lr, [r1, #4]!
+        eoreqs      r0, r0, ip
+        ldreq       r0, [r3], #4
+        ldreq       ip, [r1, #4]!
+        eoreqs      r0, r0, lr
+        ldreq       r0, [r3], #4
+        ldreq       lr, [r1, #4]!
+        eoreqs      r0, r0, ip
+        ldreq       r0, [r3], #4
+        ldreq       ip, [r1, #4]!
+        eoreqs      r0, r0, lr
+        ldreq       r0, [r3], #4
+        ldreq       lr, [r1, #4]!
+        eoreqs      r0, r0, ip
+        ldreq       r0, [r3], #4
+        ldreq       ip, [r1, #4]!
+        eoreqs      r0, r0, lr
+        bne         2f        
+        subs        r2, r2, #16
+        bhs         0b
+
+        /* do we have at least 2 words left? */
+1:      adds        r2, r2, #(16 - 2 + 2)
+        bmi         4f
+        
+        /* finish off 2 words at a time */
+3:      ldr         r0, [r3], #4
+        ldr         ip, [r1], #4
+        eors        r0, r0, ip
+        bne         2f
+        subs        r2, r2, #2
+        bhs         3b
+
+        /* are we done? */
+4:      adds        r2, r2, #2
+        bne         8f
+        /* restore registers and return */
+        mov         r0, #0
+        ldmfd       sp!, {r4, lr}
+        bx          lr
+
+2:      /* the last 2 words are different, restart them */
+        ldrh        r0, [r3, #-4]
+        ldrh        ip, [r1, #-4]
+        subs        r0, r0, ip
+        ldreqh      r0, [r3, #-2]
+        ldreqh      ip, [r1, #-2]
+        subeqs      r0, r0, ip
+        /* restore registers and return */
+        ldmfd       sp!, {r4, lr}
+        bx          lr
+
+        /* process the last few words */
+8:      ldrh        r0, [r3], #2
+        ldrh        ip, [r1], #2
+        subs        r0, r0, ip
+        bne         9f
+        subs        r2, r2, #1
+        bne         8b
+
+9:      /* restore registers and return */
+        ldmfd       sp!, {r4, lr}
+        bx          lr
+
+
+5:      /*************** non-congruent case ***************/
+
+        /* align the unaligned pointer */
+        bic         r1, r1, #3
+        ldr         lr, [r1], #4
+        sub         r2, r2, #8
+
+6:
+        PLD         (r3, #64)
+        PLD         (r1, #64)
+        mov         ip, lr, lsr #16
+        ldr         lr, [r1], #4
+        ldr         r0, [r3], #4
+        orr         ip, ip, lr, lsl #16
+        eors        r0, r0, ip
+        moveq       ip, lr, lsr #16
+        ldreq       lr, [r1], #4
+        ldreq       r0, [r3], #4
+        orreq       ip, ip, lr, lsl #16
+        eoreqs      r0, r0, ip
+        moveq       ip, lr, lsr #16
+        ldreq       lr, [r1], #4
+        ldreq       r0, [r3], #4
+        orreq       ip, ip, lr, lsl #16
+        eoreqs      r0, r0, ip
+        moveq       ip, lr, lsr #16
+        ldreq       lr, [r1], #4
+        ldreq       r0, [r3], #4
+        orreq       ip, ip, lr, lsl #16
+        eoreqs      r0, r0, ip
+        bne         7f
+        subs        r2, r2, #8
+        bhs         6b
+        sub         r1, r1, #2
+        /* are we done? */
+        adds        r2, r2, #8
+        moveq       r0, #0
+        beq         9b
+        /* finish off the remaining bytes */
+        b           8b
+
+7:      /* fix up the 2 pointers and fallthrough... */
+        sub         r1, r1, #2
+        b           2b