Arm32 dynamic function dispatch

Previous change was reverted in 9690b121e342676453c58f5940964350762085a0.
This change added .arch directive to kryo/ to avoid invalid instruction error.

Test: Run bionic unit test.
Test: Use gdb to make sure the right function is selected.
Test: Build previously failed target: make PRODUCT-sdk_phone_arm64-sdk
Change-Id: I14de41851121fc1a0b38c98fda5eb844b6a9695c

40 files changed, 737 insertions, 239 deletions

diff --git a/libc/Android.bp b/libc/Android.bp
index 62093747b..c08df9d9b 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -551,13 +551,9 @@ cc_library_static {
         arm: {
             exclude_srcs: [
                 "upstream-openbsd/lib/libc/string/strcpy.c",
+                "upstream-openbsd/lib/libc/string/stpcpy.c",
+                "upstream-openbsd/lib/libc/string/strcat.c",
             ],
-            neon: {
-                exclude_srcs: [
-                    "upstream-openbsd/lib/libc/string/stpcpy.c",
-                    "upstream-openbsd/lib/libc/string/strcat.c",
-                ],
-            },
         },
         arm64: {
             exclude_srcs: [
@@ -849,6 +845,8 @@ cc_library_static {
                 "arch-arm/generic/bionic/memcmp.S",
                 "arch-arm/generic/bionic/memmove.S",
                 "arch-arm/generic/bionic/memset.S",
+                "arch-arm/generic/bionic/stpcpy.c",
+                "arch-arm/generic/bionic/strcat.c",
                 "arch-arm/generic/bionic/strcmp.S",
                 "arch-arm/generic/bionic/strcpy.S",
                 "arch-arm/generic/bionic/strlen.c",
@@ -862,162 +860,44 @@ cc_library_static {
                 "arch-arm/bionic/setjmp.S",
                 "arch-arm/bionic/syscall.S",
                 "arch-arm/bionic/vfork.S",
-            ],
-            cortex_a7: {
-                srcs: [
-                    "arch-arm/cortex-a7/bionic/memcpy.S",
-                    "arch-arm/cortex-a7/bionic/memset.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                ],
-            },
-            cortex_a9: {
-                srcs: [
-                    "arch-arm/cortex-a9/bionic/memcpy.S",
-                    "arch-arm/cortex-a9/bionic/memset.S",
-
-                    "arch-arm/cortex-a9/bionic/stpcpy.S",
-                    "arch-arm/cortex-a9/bionic/strcat.S",
-                    "arch-arm/cortex-a9/bionic/strcmp.S",
-                    "arch-arm/cortex-a9/bionic/strcpy.S",
-                    "arch-arm/cortex-a9/bionic/strlen.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                    "arch-arm/cortex-a15/bionic/memset.S",
-
-                    "arch-arm/cortex-a15/bionic/stpcpy.S",
-                    "arch-arm/cortex-a15/bionic/strcat.S",
-                    "arch-arm/cortex-a15/bionic/strcmp.S",
-                    "arch-arm/cortex-a15/bionic/strcpy.S",
-                    "arch-arm/cortex-a15/bionic/strlen.S",
-                ],
-            },
-            krait: {
-                srcs: [
-                    "arch-arm/krait/bionic/memcpy.S",
-                    "arch-arm/krait/bionic/memset.S",
-
-                    "arch-arm/krait/bionic/strcmp.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-
-                    "arch-arm/cortex-a15/bionic/strcmp.S",
-                ],
-            },
-            cortex_a53: {
-                srcs: [
-                    "arch-arm/cortex-a53/bionic/memcpy.S",
-                    "arch-arm/cortex-a7/bionic/memset.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                ],
-            },
-            cortex_a55: {
-                srcs: [
-                    "arch-arm/cortex-a7/bionic/memset.S",
-                    "arch-arm/denver/bionic/memcpy.S",
-
-                    "arch-arm/krait/bionic/strcmp.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                    "arch-arm/cortex-a15/bionic/strcmp.S",
-                ],
-            },
-            cortex_a73: {
-                srcs: [
-                    "arch-arm/cortex-a7/bionic/memset.S",
-                    "arch-arm/denver/bionic/memcpy.S",
-
-                    "arch-arm/krait/bionic/strcmp.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                    "arch-arm/cortex-a15/bionic/strcmp.S",
-                ],
-            },
-            cortex_a75: {
-                srcs: [
-                    "arch-arm/cortex-a7/bionic/memset.S",
-                    "arch-arm/denver/bionic/memcpy.S",
-
-                    "arch-arm/krait/bionic/strcmp.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                    "arch-arm/cortex-a15/bionic/strcmp.S",
-                ],
-            },
-            cortex_a76: {
-                srcs: [
-                    "arch-arm/cortex-a7/bionic/memset.S",
-                    "arch-arm/denver/bionic/memcpy.S",
 
-                    "arch-arm/krait/bionic/strcmp.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                    "arch-arm/cortex-a15/bionic/strcmp.S",
-                ],
-            },
-            denver: {
-                srcs: [
-                    "arch-arm/denver/bionic/memcpy.S",
-                    "arch-arm/denver/bionic/memset.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                ],
-            },
-            kryo: {
-                srcs: [
-                    "arch-arm/kryo/bionic/memcpy.S",
-                    "arch-arm/cortex-a7/bionic/memset.S",
-
-                    "arch-arm/krait/bionic/strcmp.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/cortex-a15/bionic/memset.S",
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                    "arch-arm/cortex-a15/bionic/strcmp.S",
-                ],
-            },
-            // Cores not listed above (like cortex-a8, cortex-a15) or
-            // "generic" core will use the following implementation.
-            neon: {
-                srcs: [
-                    "arch-arm/cortex-a15/bionic/memcpy.S",
-                    "arch-arm/cortex-a15/bionic/memset.S",
-
-                    "arch-arm/cortex-a15/bionic/stpcpy.S",
-                    "arch-arm/cortex-a15/bionic/strcat.S",
-                    "arch-arm/cortex-a15/bionic/strcmp.S",
-                    "arch-arm/cortex-a15/bionic/strcpy.S",
-                    "arch-arm/cortex-a15/bionic/strlen.S",
-
-                    "arch-arm/denver/bionic/memmove.S",
-                ],
-                exclude_srcs: [
-                    "arch-arm/generic/bionic/memcpy.S",
-                    "arch-arm/generic/bionic/memmove.S",
-                    "arch-arm/generic/bionic/memset.S",
-                    "arch-arm/generic/bionic/strcmp.S",
-                    "arch-arm/generic/bionic/strcpy.S",
-                    "arch-arm/generic/bionic/strlen.c",
-                ],
-            },
+                "arch-arm/cortex-a15/bionic/memcpy.S",
+                "arch-arm/cortex-a15/bionic/memmove.S",
+                "arch-arm/cortex-a15/bionic/memset.S",
+                "arch-arm/cortex-a15/bionic/stpcpy.S",
+                "arch-arm/cortex-a15/bionic/strcat.S",
+                "arch-arm/cortex-a15/bionic/strcmp.S",
+                "arch-arm/cortex-a15/bionic/strcpy.S",
+                "arch-arm/cortex-a15/bionic/strlen.S",
+
+                "arch-arm/cortex-a7/bionic/memcpy.S",
+                "arch-arm/cortex-a7/bionic/memmove.S",
+                "arch-arm/cortex-a7/bionic/memset.S",
+
+                "arch-arm/cortex-a9/bionic/memcpy.S",
+                "arch-arm/cortex-a9/bionic/memmove.S",
+                "arch-arm/cortex-a9/bionic/memset.S",
+                "arch-arm/cortex-a9/bionic/stpcpy.S",
+                "arch-arm/cortex-a9/bionic/strcat.S",
+                "arch-arm/cortex-a9/bionic/strcmp.S",
+                "arch-arm/cortex-a9/bionic/strcpy.S",
+                "arch-arm/cortex-a9/bionic/strlen.S",
+
+                "arch-arm/krait/bionic/memcpy.S",
+                "arch-arm/krait/bionic/memmove.S",
+                "arch-arm/krait/bionic/memset.S",
+                "arch-arm/krait/bionic/strcmp.S",
+
+                "arch-arm/cortex-a53/bionic/memcpy.S",
+                "arch-arm/cortex-a53/bionic/memmove.S",
+
+                "arch-arm/denver/bionic/memcpy.S",
+                "arch-arm/denver/bionic/memmove.S",
+                "arch-arm/denver/bionic/memset.S",
+
+                "arch-arm/kryo/bionic/memcpy.S",
+                "arch-arm/kryo/bionic/memmove.S",
+            ],
         },
         arm64: {
             srcs: [
@@ -1636,6 +1516,9 @@ cc_library_static {
         x86: {
             srcs: ["arch-x86/static_function_dispatch.S"],
         },
+        arm: {
+            srcs: ["arch-arm/static_function_dispatch.S"],
+        },
     },
 
     whole_static_libs: [
@@ -1658,6 +1541,9 @@ cc_library_static {
         x86: {
             srcs: ["arch-x86/dynamic_function_dispatch.cpp"],
         },
+        arm: {
+            srcs: ["arch-arm/dynamic_function_dispatch.cpp"],
+        },
     },
 
     whole_static_libs: [
diff --git a/libc/arch-arm/cortex-a15/bionic/memcpy.S b/libc/arch-arm/cortex-a15/bionic/memcpy.S
index 0bab6ee7d..a9dfaff0f 100644
--- a/libc/arch-arm/cortex-a15/bionic/memcpy.S
+++ b/libc/arch-arm/cortex-a15/bionic/memcpy.S
@@ -64,7 +64,7 @@
         .arch armv7-a
 
 // Prototype: void *memcpy (void *dst, const void *src, size_t count).
-ENTRY(__memcpy)
+ENTRY(__memcpy_a15)
         pld     [r1, #64]
         push    {r0, lr}
         .cfi_def_cfa_offset 8
@@ -72,4 +72,4 @@ ENTRY(__memcpy)
         .cfi_rel_offset lr, 4
 
 #include "memcpy_base.S"
-END(__memcpy)
+END(__memcpy_a15)
diff --git a/libc/arch-arm/cortex-a15/bionic/memmove.S b/libc/arch-arm/cortex-a15/bionic/memmove.S
new file mode 100644
index 000000000..2b12de006
--- /dev/null
+++ b/libc/arch-arm/cortex-a15/bionic/memmove.S
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define MEMMOVE memmove_a15
+#define MEMCPY __memcpy_a15
+
+#include <arch-arm/denver/bionic/memmove.S>
diff --git a/libc/arch-arm/cortex-a15/bionic/memset.S b/libc/arch-arm/cortex-a15/bionic/memset.S
index 4b4388e2e..ead881e49 100644
--- a/libc/arch-arm/cortex-a15/bionic/memset.S
+++ b/libc/arch-arm/cortex-a15/bionic/memset.S
@@ -41,7 +41,7 @@
         // arch. The code generated is exactly the same.
         .arch armv7-a
 
-ENTRY(__memset_chk)
+ENTRY(__memset_chk_a15)
         cmp         r2, r3
         bls         memset
 
@@ -51,9 +51,9 @@ ENTRY(__memset_chk)
         .cfi_rel_offset lr, 0
 
         bl          __memset_chk_fail
-END(__memset_chk)
+END(__memset_chk_a15)
 
-ENTRY(memset)
+ENTRY(memset_a15)
         stmfd       sp!, {r0}
         .cfi_def_cfa_offset 4
         .cfi_rel_offset r0, 0
@@ -171,4 +171,4 @@ ENTRY(memset)
         strbcs      r1, [r0], #1
         ldmfd       sp!, {r0}
         bx          lr
-END(memset)
+END(memset_a15)
diff --git a/libc/arch-arm/cortex-a15/bionic/strcat.S b/libc/arch-arm/cortex-a15/bionic/strcat.S
index 157cc9f1d..260926a0a 100644
--- a/libc/arch-arm/cortex-a15/bionic/strcat.S
+++ b/libc/arch-arm/cortex-a15/bionic/strcat.S
@@ -80,7 +80,7 @@
     \cmd    \reg, \label
     .endm // m_copy_byte
 
-ENTRY(strcat)
+ENTRY(strcat_a15)
     // Quick check to see if src is empty.
     ldrb    r2, [r1]
     pld     [r1, #0]
@@ -572,4 +572,4 @@ ENTRY(strcat)
 .L_strcat_sub2:
     sub     r0, r0, #2
     b       .L_strcat_r0_scan_done
-END(strcat)
+END(strcat_a15)
diff --git a/libc/arch-arm/cortex-a15/bionic/strcmp.S b/libc/arch-arm/cortex-a15/bionic/strcmp.S
index d8993d55f..58dbf170e 100644
--- a/libc/arch-arm/cortex-a15/bionic/strcmp.S
+++ b/libc/arch-arm/cortex-a15/bionic/strcmp.S
@@ -61,7 +61,7 @@
         // arch. The code generated is exactly the same.
         .arch armv7-a
 
-ENTRY(strcmp)
+ENTRY(strcmp_a15)
       /* Use LDRD whenever possible.  */
 
 /* The main thing to look out for when comparing large blocks is that
@@ -376,4 +376,4 @@ ENTRY(strcmp)
         it      ls
         sbcls   r0, r0, r0
         bx      lr
-END(strcmp)
+END(strcmp_a15)
diff --git a/libc/arch-arm/cortex-a15/bionic/string_copy.S b/libc/arch-arm/cortex-a15/bionic/string_copy.S
index 92d1c9804..affbc3b20 100644
--- a/libc/arch-arm/cortex-a15/bionic/string_copy.S
+++ b/libc/arch-arm/cortex-a15/bionic/string_copy.S
@@ -100,9 +100,9 @@
     .endm // m_copy_byte
 
 #if defined(STPCPY)
-ENTRY(stpcpy)
+ENTRY(stpcpy_a15)
 #else
-ENTRY(strcpy)
+ENTRY(strcpy_a15)
 #endif
     // For short copies, hard-code checking the first 8 bytes since this
     // new code doesn't win until after about 8 bytes.
@@ -514,7 +514,7 @@ ENTRY(strcpy)
     strb    r4, [r0]
     m_pop
 #if defined(STPCPY)
-END(stpcpy)
+END(stpcpy_a15)
 #else
-END(strcpy)
+END(strcpy_a15)
 #endif
diff --git a/libc/arch-arm/cortex-a15/bionic/strlen.S b/libc/arch-arm/cortex-a15/bionic/strlen.S
index 4fd62842c..9c5ed2911 100644
--- a/libc/arch-arm/cortex-a15/bionic/strlen.S
+++ b/libc/arch-arm/cortex-a15/bionic/strlen.S
@@ -60,7 +60,7 @@
     .thumb
     .thumb_func
 
-ENTRY(strlen)
+ENTRY(strlen_a15)
     pld     [r0, #0]
     mov     r1, r0
 
@@ -162,4 +162,4 @@ ENTRY(strlen)
 .L_sub2_and_return:
     sub     r0, r0, #2
     bx      lr
-END(strlen)
+END(strlen_a15)
diff --git a/libc/arch-arm/cortex-a53/bionic/memcpy.S b/libc/arch-arm/cortex-a53/bionic/memcpy.S
index 0bab6ee7d..ea748bd00 100644
--- a/libc/arch-arm/cortex-a53/bionic/memcpy.S
+++ b/libc/arch-arm/cortex-a53/bionic/memcpy.S
@@ -64,7 +64,7 @@
         .arch armv7-a
 
 // Prototype: void *memcpy (void *dst, const void *src, size_t count).
-ENTRY(__memcpy)
+ENTRY(__memcpy_a53)
         pld     [r1, #64]
         push    {r0, lr}
         .cfi_def_cfa_offset 8
@@ -72,4 +72,4 @@ ENTRY(__memcpy)
         .cfi_rel_offset lr, 4
 
 #include "memcpy_base.S"
-END(__memcpy)
+END(__memcpy_a53)
diff --git a/libc/arch-arm/cortex-a53/bionic/memmove.S b/libc/arch-arm/cortex-a53/bionic/memmove.S
new file mode 100644
index 000000000..741acb394
--- /dev/null
+++ b/libc/arch-arm/cortex-a53/bionic/memmove.S
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define MEMMOVE memmove_a53
+#define MEMCPY __memcpy_a53
+
+#include <arch-arm/denver/bionic/memmove.S>
diff --git a/libc/arch-arm/cortex-a7/bionic/memcpy.S b/libc/arch-arm/cortex-a7/bionic/memcpy.S
index 0bab6ee7d..2f32d2e7e 100644
--- a/libc/arch-arm/cortex-a7/bionic/memcpy.S
+++ b/libc/arch-arm/cortex-a7/bionic/memcpy.S
@@ -64,7 +64,7 @@
         .arch armv7-a
 
 // Prototype: void *memcpy (void *dst, const void *src, size_t count).
-ENTRY(__memcpy)
+ENTRY(__memcpy_a7)
         pld     [r1, #64]
         push    {r0, lr}
         .cfi_def_cfa_offset 8
@@ -72,4 +72,4 @@ ENTRY(__memcpy)
         .cfi_rel_offset lr, 4
 
 #include "memcpy_base.S"
-END(__memcpy)
+END(__memcpy_a7)
diff --git a/libc/arch-arm/cortex-a7/bionic/memmove.S b/libc/arch-arm/cortex-a7/bionic/memmove.S
new file mode 100644
index 000000000..17ead5a15
--- /dev/null
+++ b/libc/arch-arm/cortex-a7/bionic/memmove.S
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define MEMMOVE memmove_a7
+#define MEMCPY __memcpy_a7
+
+#include <arch-arm/denver/bionic/memmove.S>
diff --git a/libc/arch-arm/cortex-a7/bionic/memset.S b/libc/arch-arm/cortex-a7/bionic/memset.S
index 72ee61363..d7d3b34e0 100644
--- a/libc/arch-arm/cortex-a7/bionic/memset.S
+++ b/libc/arch-arm/cortex-a7/bionic/memset.S
@@ -41,7 +41,7 @@
         // arch. The code generated is exactly the same.
         .arch armv7-a
 
-ENTRY(__memset_chk)
+ENTRY(__memset_chk_a7)
         cmp         r2, r3
         bls         memset
 
@@ -51,9 +51,9 @@ ENTRY(__memset_chk)
         .cfi_rel_offset lr, 0
 
         bl          __memset_chk_fail
-END(__memset_chk)
+END(__memset_chk_a7)
 
-ENTRY(memset)
+ENTRY(memset_a7)
         mov         r3, r0
         // At this point only d0, d1 are going to be used below.
         vdup.8      q0, r1
@@ -160,4 +160,4 @@ ENTRY(memset)
         strbcs      r1, [r3], #1
         strbcs      r1, [r3], #1
         bx          lr
-END(memset)
+END(memset_a7)
diff --git a/libc/arch-arm/cortex-a9/bionic/memcpy.S b/libc/arch-arm/cortex-a9/bionic/memcpy.S
index a71c9d21c..e78a7daa9 100644
--- a/libc/arch-arm/cortex-a9/bionic/memcpy.S
+++ b/libc/arch-arm/cortex-a9/bionic/memcpy.S
@@ -39,15 +39,15 @@
         .thumb
         .thumb_func
 
-ENTRY(__memcpy)
+ENTRY(__memcpy_a9)
         pld     [r1, #0]
         stmfd   sp!, {r0, lr}
         .cfi_def_cfa_offset 8
         .cfi_rel_offset r0, 0
         .cfi_rel_offset lr, 4
         pld     [r1, #64]
-END(__memcpy)
+END(__memcpy_a9)
 
-#define MEMCPY_BASE         __memcpy_base
-#define MEMCPY_BASE_ALIGNED __memcpy_base_aligned
+#define MEMCPY_BASE         __memcpy_base_a9
+#define MEMCPY_BASE_ALIGNED __memcpy_base_aligned_a9
 #include "memcpy_base.S"
diff --git a/libc/arch-arm/cortex-a9/bionic/memcpy_base.S b/libc/arch-arm/cortex-a9/bionic/memcpy_base.S
index 966b9b3c0..39da7ffcf 100644
--- a/libc/arch-arm/cortex-a9/bionic/memcpy_base.S
+++ b/libc/arch-arm/cortex-a9/bionic/memcpy_base.S
@@ -32,6 +32,12 @@
  * cache line.
  */
 
+        .syntax unified
+
+        // To avoid warning about deprecated instructions, add an explicit
+        // arch. The code generated is exactly the same.
+        .arch armv7-a
+
 ENTRY_PRIVATE(MEMCPY_BASE)
         .cfi_def_cfa_offset 8
         .cfi_rel_offset r0, 0
diff --git a/libc/arch-arm/cortex-a9/bionic/memmove.S b/libc/arch-arm/cortex-a9/bionic/memmove.S
new file mode 100644
index 000000000..a45763372
--- /dev/null
+++ b/libc/arch-arm/cortex-a9/bionic/memmove.S
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define MEMMOVE memmove_a9
+#define MEMCPY __memcpy_a9
+
+#include <arch-arm/denver/bionic/memmove.S>
diff --git a/libc/arch-arm/cortex-a9/bionic/memset.S b/libc/arch-arm/cortex-a9/bionic/memset.S
index d00231bdc..cf66e86c9 100644
--- a/libc/arch-arm/cortex-a9/bionic/memset.S
+++ b/libc/arch-arm/cortex-a9/bionic/memset.S
@@ -36,7 +36,7 @@
     .fpu    neon
     .syntax unified
 
-ENTRY(__memset_chk)
+ENTRY(__memset_chk_a9)
         cmp         r2, r3
         bls         memset
 
@@ -46,10 +46,10 @@ ENTRY(__memset_chk)
         .cfi_rel_offset lr, 0
 
         bl          __memset_chk_fail
-END(__memset_chk)
+END(__memset_chk_a9)
 
 /* memset() returns its first argument.  */
-ENTRY(memset)
+ENTRY(memset_a9)
         // The neon memset only wins for less than 132.
         cmp         r2, #132
         bhi         .L_memset_large_copy
@@ -158,4 +158,4 @@ ENTRY(memset)
         movs        r2, r2, lsl #2
         strbcs      r1, [r0]
         ldmfd       sp!, {r0, r4-r7, pc}
-END(memset)
+END(memset_a9)
diff --git a/libc/arch-arm/cortex-a9/bionic/strcat.S b/libc/arch-arm/cortex-a9/bionic/strcat.S
index 9077a7449..430748f25 100644
--- a/libc/arch-arm/cortex-a9/bionic/strcat.S
+++ b/libc/arch-arm/cortex-a9/bionic/strcat.S
@@ -57,6 +57,10 @@
 
     .syntax unified
 
+    // To avoid warning about deprecated instructions, add an explicit
+    // arch. The code generated is exactly the same.
+    .arch armv7-a
+
     .thumb
     .thumb_func
 
@@ -80,7 +84,7 @@
     \cmd    \reg, \label
     .endm // m_copy_byte
 
-ENTRY(strcat)
+ENTRY(strcat_a9)
     // Quick check to see if src is empty.
     ldrb        r2, [r1]
     pld         [r1, #0]
@@ -552,4 +556,4 @@ ENTRY(strcat)
 .Lstrcat_r0_update:
     sub     r0, r0, #1
     b .Lstrcat_r0_scan_done
-END(strcat)
+END(strcat_a9)
diff --git a/libc/arch-arm/cortex-a9/bionic/strcmp.S b/libc/arch-arm/cortex-a9/bionic/strcmp.S
index ba191d60b..ba7ea13a3 100644
--- a/libc/arch-arm/cortex-a9/bionic/strcmp.S
+++ b/libc/arch-arm/cortex-a9/bionic/strcmp.S
@@ -52,12 +52,16 @@
 
 .syntax         unified
 
+// To avoid warning about deprecated instructions, add an explicit
+// arch. The code generated is exactly the same.
+.arch armv7-a
+
 #if defined (__thumb__)
         .thumb
         .thumb_func
 #endif
 
-ENTRY(strcmp)
+ENTRY(strcmp_a9)
       /* Use LDRD whenever possible.  */
 
 /* The main thing to look out for when comparing large blocks is that
@@ -544,4 +548,4 @@ ENTRY(strcmp)
     adds    sp, sp, #16
 
 	bx	lr
-END(strcmp)
+END(strcmp_a9)
diff --git a/libc/arch-arm/cortex-a9/bionic/string_copy.S b/libc/arch-arm/cortex-a9/bionic/string_copy.S
index 642db0f19..3605b7a57 100644
--- a/libc/arch-arm/cortex-a9/bionic/string_copy.S
+++ b/libc/arch-arm/cortex-a9/bionic/string_copy.S
@@ -64,6 +64,10 @@
     .thumb
     .thumb_func
 
+    // To avoid warning about deprecated instructions, add an explicit
+    // arch. The code generated is exactly the same.
+    .arch armv7-a
+
 #if defined(STPCPY)
     .macro m_push
     push    {r4, r5, lr}
@@ -100,9 +104,9 @@
     .endm // m_copy_byte
 
 #if defined(STPCPY)
-ENTRY(stpcpy)
+ENTRY(stpcpy_a9)
 #else
-ENTRY(strcpy)
+ENTRY(strcpy_a9)
 #endif
     // Unroll the first 8 bytes that will be copied.
     m_push
@@ -536,7 +540,7 @@ ENTRY(strcpy)
 #endif
     m_ret   inst=pop
 #if defined(STPCPY)
-END(stpcpy)
+END(stpcpy_a9)
 #else
-END(strcpy)
+END(strcpy_a9)
 #endif
diff --git a/libc/arch-arm/cortex-a9/bionic/strlen.S b/libc/arch-arm/cortex-a9/bionic/strlen.S
index b92b04352..ffebc9dea 100644
--- a/libc/arch-arm/cortex-a9/bionic/strlen.S
+++ b/libc/arch-arm/cortex-a9/bionic/strlen.S
@@ -57,10 +57,14 @@
 
     .syntax unified
 
+    // To avoid warning about deprecated instructions, add an explicit
+    // arch. The code generated is exactly the same.
+    .arch armv7-a
+
     .thumb
     .thumb_func
 
-ENTRY(strlen)
+ENTRY(strlen_a9)
     pld     [r0, #0]
     mov     r1, r0
 
@@ -164,4 +168,4 @@ done:
     sub     r0, r1, r0
     sub     r0, r0, #1
     bx      lr
-END(strlen)
+END(strlen_a9)
diff --git a/libc/arch-arm/denver/bionic/memcpy.S b/libc/arch-arm/denver/bionic/memcpy.S
index f0825421e..5edee1e31 100644
--- a/libc/arch-arm/denver/bionic/memcpy.S
+++ b/libc/arch-arm/denver/bionic/memcpy.S
@@ -65,14 +65,14 @@
         // arch. The code generated is exactly the same.
         .arch armv7-a
 
-ENTRY(__memcpy)
+ENTRY(__memcpy_denver)
         pld     [r1, #64]
         push    {r0, lr}
         .cfi_def_cfa_offset 8
         .cfi_rel_offset r0, 0
         .cfi_rel_offset lr, 4
-END(__memcpy)
+END(__memcpy_denver)
 
-#define MEMCPY_BASE         __memcpy_base
-#define MEMCPY_BASE_ALIGNED __memcpy_base_aligned
+#define MEMCPY_BASE         __memcpy_base_denver
+#define MEMCPY_BASE_ALIGNED __memcpy_base_aligned_denver
 #include "memcpy_base.S"
diff --git a/libc/arch-arm/denver/bionic/memmove.S b/libc/arch-arm/denver/bionic/memmove.S
index 74d2b31bc..13c90efc1 100644
--- a/libc/arch-arm/denver/bionic/memmove.S
+++ b/libc/arch-arm/denver/bionic/memmove.S
@@ -29,6 +29,14 @@
 
 #include <private/bionic_asm.h>
 
+#ifndef MEMMOVE
+# define MEMMOVE memmove_denver
+#endif
+
+#ifndef MEMCPY
+# define MEMCPY __memcpy_denver
+#endif
+
         .text
         .syntax unified
         .fpu    neon
@@ -40,7 +48,7 @@
 #define PREFETCH_DISTANCE_MID   (CACHE_LINE_SIZE*4)
 #define PREFETCH_DISTANCE_FAR   (CACHE_LINE_SIZE*16)
 
-ENTRY(memmove)
+ENTRY(MEMMOVE)
         cmp         r2, #0
         cmpne       r0, r1
         bxeq        lr
@@ -50,7 +58,7 @@ ENTRY(memmove)
         bhi         .L_reversed_memcpy
 
 .L_jump_to_memcpy:
-        b           __memcpy
+        b           MEMCPY
 
 .L_reversed_memcpy:
         push        {r0, lr}
@@ -277,6 +285,4 @@ ENTRY(memmove)
 
         pop         {r0, pc}
 
-END(memmove)
-
-ALIAS_SYMBOL(memcpy, memmove)
+END(MEMMOVE)
diff --git a/libc/arch-arm/denver/bionic/memset.S b/libc/arch-arm/denver/bionic/memset.S
index 88ffe5c4f..198ecf3ec 100644
--- a/libc/arch-arm/denver/bionic/memset.S
+++ b/libc/arch-arm/denver/bionic/memset.S
@@ -39,7 +39,7 @@
         .fpu        neon
         .syntax     unified
 
-ENTRY(__memset_chk)
+ENTRY(__memset_chk_denver)
         cmp         r2, r3
         bls         memset
 
@@ -49,9 +49,9 @@ ENTRY(__memset_chk)
         .cfi_rel_offset lr, 0
 
         bl          __memset_chk_fail
-END(__memset_chk)
+END(__memset_chk_denver)
 
-ENTRY(memset)
+ENTRY(memset_denver)
         pldw        [r0]
         mov         r3, r0
 
@@ -183,4 +183,4 @@ ENTRY(memset)
         strbcs      r1, [r3]
 2:
         bx          lr
-END(memset)
+END(memset_denver)
diff --git a/libc/arch-arm/dynamic_function_dispatch.cpp b/libc/arch-arm/dynamic_function_dispatch.cpp
new file mode 100644
index 000000000..17f00876b
--- /dev/null
+++ b/libc/arch-arm/dynamic_function_dispatch.cpp
@@ -0,0 +1,267 @@
+/*
+ * Copyright (C) 2018 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 <fcntl.h>
+#include <sys/syscall.h>
+
+extern "C" {
+
+enum CpuVariant {
+    kUnknown = 0,
+    kGeneric,
+    kCortexA7,
+    kCortexA9,
+    kCortexA53,
+    kCortexA55,
+    kDenver,
+    kKrait,
+    kKryo,
+};
+
+static constexpr int MAX_CPU_NAME_LEN = 12;
+struct CpuVariantNames {
+    char name[MAX_CPU_NAME_LEN];
+    CpuVariant variant;
+};
+
+static constexpr CpuVariantNames cpu_variant_names[] = {
+    {"cortex-a76", kCortexA55},
+    {"cortex-a75", kCortexA55},
+    {"kryo", kKryo},
+    {"cortex-a73", kCortexA55},
+    {"cortex-a55", kCortexA55},
+    {"cortex-a53", kCortexA53},
+    {"krait", kKrait},
+    {"cortex-a9", kCortexA9},
+    {"cortex-a7", kCortexA7},
+    {"denver", kDenver},
+    // kUnknown indicates the end of this array.
+    {"", kUnknown},
+};
+
+static long ifunc_open(const char* pathname) {
+    register long r0 __asm__("r0") = AT_FDCWD;
+    register long r1 __asm__("r1") = reinterpret_cast<long>(pathname);
+    register long r2 __asm__("r2") = O_RDONLY;
+    register long r3 __asm__("r3") = 0;
+    register long r7 __asm__("r7") = __NR_openat;
+    __asm__ volatile("swi #0" : "=r"(r0) : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r7));
+    return r0;
+}
+
+static ssize_t ifunc_read(int fd, void* buf, size_t count) {
+    register long r0 __asm__("r0") = fd;
+    register long r1 __asm__("r1") = reinterpret_cast<long>(buf);
+    register long r2 __asm__("r2") = count;
+    register long r7 __asm__("r7") = __NR_read;
+    __asm__ volatile("swi #0" : "=r"(r0) : "r"(r0), "r"(r1), "r"(r2), "r"(r7) : "memory");
+    return r0;
+}
+
+static int ifunc_close(int fd) {
+    register long r0 __asm__("r0") = fd;
+    register long r7 __asm__("r7") = __NR_close;
+    __asm__ volatile("swi #0" : "=r"(r0) : "r"(r0), "r"(r7));
+    return r0;
+}
+
+#define DEFINE_IFUNC(name) \
+    name##_func name __attribute__((ifunc(#name "_resolver"))); \
+    __attribute__((visibility("hidden"))) \
+    name##_func* name##_resolver()
+
+#define DECLARE_FUNC(type, name) \
+    __attribute__((visibility("hidden"))) \
+    type name
+
+#define RETURN_FUNC(type, name) { \
+        DECLARE_FUNC(type, name); \
+        return name; \
+    }
+
+static CpuVariant init_cpu_variant() {
+    int fd = ifunc_open("/dev/cpu_variant:arm");
+    if (fd < 0) return kGeneric;
+
+    char name[MAX_CPU_NAME_LEN];
+
+    int bytes_read, total_read = 0;
+    while (total_read < MAX_CPU_NAME_LEN - 1 &&
+           (bytes_read = ifunc_read(fd, name + total_read,
+                                    MAX_CPU_NAME_LEN - 1 - total_read)) > 0) {
+        total_read += bytes_read;
+    }
+    ifunc_close(fd);
+
+    if (bytes_read != 0) {
+        // The file is too big. We haven't reach the end. Or maybe there is an
+        // error when reading.
+        return kGeneric;
+    }
+    name[total_read] = 0;
+
+    typedef int strcmp_func(const char* __lhs, const char* __rhs);
+    DECLARE_FUNC(strcmp_func, strcmp_a15);
+
+    const CpuVariantNames* cpu_variant = cpu_variant_names;
+    while (cpu_variant->variant != kUnknown) {
+        if (strcmp_a15(cpu_variant->name, name) == 0) {
+            return cpu_variant->variant;
+        }
+        cpu_variant++;
+    }
+    return kGeneric;
+}
+
+static CpuVariant get_cpu_variant() {
+    static CpuVariant cpu_variant = kUnknown;
+    if (cpu_variant == kUnknown) {
+        cpu_variant = init_cpu_variant();
+    }
+    return cpu_variant;
+}
+
+typedef void* memmove_func(void* __dst, const void* __src, size_t __n);
+DEFINE_IFUNC(memmove) {
+    switch(get_cpu_variant()) {
+        case kCortexA7:
+            RETURN_FUNC(memmove_func, memmove_a7);
+        case kCortexA9:
+            RETURN_FUNC(memmove_func, memmove_a9);
+        case kKrait:
+            RETURN_FUNC(memmove_func, memmove_krait);
+        case kCortexA53:
+            RETURN_FUNC(memmove_func, memmove_a53);
+        case kCortexA55:
+        case kDenver:
+            RETURN_FUNC(memmove_func, memmove_denver);
+        case kKryo:
+            RETURN_FUNC(memmove_func, memmove_kryo);
+        default:
+            RETURN_FUNC(memmove_func, memmove_a15);
+    }
+}
+
+typedef void* memcpy_func(void*, const void*, size_t);
+DEFINE_IFUNC(memcpy) {
+    return memmove_resolver();
+}
+
+typedef void* __memset_chk_func(void* s, int c, size_t n, size_t n2);
+DEFINE_IFUNC(__memset_chk) {
+    switch(get_cpu_variant()) {
+        case kCortexA7:
+        case kCortexA53:
+        case kCortexA55:
+        case kKryo:
+            RETURN_FUNC(__memset_chk_func, __memset_chk_a7);
+        case kCortexA9:
+            RETURN_FUNC(__memset_chk_func, __memset_chk_a9);
+        case kKrait:
+            RETURN_FUNC(__memset_chk_func, __memset_chk_krait);
+        case kDenver:
+            RETURN_FUNC(__memset_chk_func, __memset_chk_denver);
+        default:
+            RETURN_FUNC(__memset_chk_func, __memset_chk_a15);
+    }
+}
+
+typedef void* memset_func(void* __dst, int __ch, size_t __n);
+DEFINE_IFUNC(memset) {
+    switch(get_cpu_variant()) {
+        case kCortexA7:
+        case kCortexA53:
+        case kCortexA55:
+        case kKryo:
+             RETURN_FUNC(memset_func, memset_a7);
+        case kCortexA9:
+             RETURN_FUNC(memset_func, memset_a9);
+        case kKrait:
+             RETURN_FUNC(memset_func, memset_krait);
+        case kDenver:
+             RETURN_FUNC(memset_func, memset_denver);
+        default:
+             RETURN_FUNC(memset_func, memset_a15);
+    }
+}
+
+typedef char* strcpy_func(char* __dst, const char* __src);
+DEFINE_IFUNC(strcpy) {
+    switch(get_cpu_variant()) {
+        case kCortexA9:
+            RETURN_FUNC(strcpy_func, strcpy_a9);
+        default:
+            RETURN_FUNC(strcpy_func, strcpy_a15);
+    }
+}
+
+typedef char* stpcpy_func(char* __dst, const char* __src);
+DEFINE_IFUNC(stpcpy) {
+    switch(get_cpu_variant()) {
+        case kCortexA9:
+            RETURN_FUNC(stpcpy_func, stpcpy_a9);
+        default:
+            RETURN_FUNC(stpcpy_func, stpcpy_a15);
+    }
+}
+
+typedef char* strcat_func(char* __dst, const char* __src);
+DEFINE_IFUNC(strcat) {
+    switch(get_cpu_variant()) {
+        case kCortexA9:
+            RETURN_FUNC(strcat_func, strcat_a9);
+        default:
+            RETURN_FUNC(strcat_func, strcat_a15);
+    }
+}
+
+typedef int strcmp_func(const char* __lhs, const char* __rhs);
+DEFINE_IFUNC(strcmp) {
+    switch(get_cpu_variant()) {
+        case kCortexA9:
+            RETURN_FUNC(strcmp_func, strcmp_a9);
+        case kCortexA55:
+        case kKrait:
+        case kKryo:
+            RETURN_FUNC(strcmp_func, strcmp_krait);
+        default:
+            RETURN_FUNC(strcmp_func, strcmp_a15);
+    }
+}
+
+typedef size_t strlen_func(const char* __s);
+DEFINE_IFUNC(strlen) {
+    switch(get_cpu_variant()) {
+        case kCortexA9:
+            RETURN_FUNC(strlen_func, strlen_a9);
+        default:
+            RETURN_FUNC(strlen_func, strlen_a15);
+    }
+}
+
+}  // extern "C"
diff --git a/libc/arch-arm/generic/bionic/memmove.S b/libc/arch-arm/generic/bionic/memmove.S
index c52e17ed5..0cf82d14f 100644
--- a/libc/arch-arm/generic/bionic/memmove.S
+++ b/libc/arch-arm/generic/bionic/memmove.S
@@ -464,10 +464,8 @@ ENTRY_PRIVATE(bsd_safe_memcpy)
 	b	.Lmemcpy_bl4
 END(bsd_safe_memcpy)
 
-ENTRY(memmove)
+ENTRY(memmove_generic)
         stmfd   sp!, {r0, lr}
         bl      bsd_safe_memcpy
         ldmfd   sp!, {r0, pc}
-END(memmove)
-
-ALIAS_SYMBOL(memcpy, memmove)
+END(memmove_generic)
diff --git a/libc/arch-arm/generic/bionic/memset.S b/libc/arch-arm/generic/bionic/memset.S
index 1fd0de1db..e70002f02 100644
--- a/libc/arch-arm/generic/bionic/memset.S
+++ b/libc/arch-arm/generic/bionic/memset.S
@@ -36,14 +36,14 @@
 
          .syntax unified
 
-ENTRY(__memset_chk)
+ENTRY(__memset_chk_generic)
         cmp         r2, r3
         bls         memset
 
         bl          __memset_chk_fail
-END(__memset_chk)
+END(__memset_chk_generic)
 
-ENTRY(memset)
+ENTRY(memset_generic)
         /* compute the offset to align the destination
          * offset = (4-(src&3))&3 = -src & 3
          */
@@ -108,4 +108,4 @@ ENTRY(memset)
         movs        r2, r2, lsl #2
         strbcs      r1, [r0]
         ldmfd       sp!, {r0, r4-r7, pc}
-END(memset)
+END(memset_generic)
diff --git a/libc/arch-arm/generic/bionic/stpcpy.c b/libc/arch-arm/generic/bionic/stpcpy.c
new file mode 100644
index 000000000..0aabaa5da
--- /dev/null
+++ b/libc/arch-arm/generic/bionic/stpcpy.c
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define stpcpy stpcpy_generic
+#include <upstream-openbsd/lib/libc/string/stpcpy.c>
diff --git a/libc/arch-arm/generic/bionic/strcat.c b/libc/arch-arm/generic/bionic/strcat.c
new file mode 100644
index 000000000..8e70531d0
--- /dev/null
+++ b/libc/arch-arm/generic/bionic/strcat.c
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define strcat strcat_generic
+#include <upstream-openbsd/lib/libc/string/strcat.c>
diff --git a/libc/arch-arm/generic/bionic/strcmp.S b/libc/arch-arm/generic/bionic/strcmp.S
index 10b670422..03225a006 100644
--- a/libc/arch-arm/generic/bionic/strcmp.S
+++ b/libc/arch-arm/generic/bionic/strcmp.S
@@ -31,6 +31,10 @@
 
 	.text
 
+        // To avoid warning about deprecated instructions, add an explicit
+        // arch. The code generated is exactly the same.
+        .arch armv7-a
+
 #ifdef __ARMEB__
 #define SHFT2LSB lsl
 #define SHFT2LSBEQ lsleq
@@ -50,7 +54,7 @@
 #define magic1(REG) REG
 #define magic2(REG) REG, lsl #7
 
-ENTRY(strcmp)
+ENTRY(strcmp_generic)
 	pld	[r0, #0]
 	pld	[r1, #0]
 	eor	r2, r0, r1
@@ -313,4 +317,4 @@ ENTRY(strcmp)
 	ldr	r4, [sp], #4
 	ldr	r5, [sp], #4
 	bx	lr
-END(strcmp)
+END(strcmp_generic)
diff --git a/libc/arch-arm/generic/bionic/strcpy.S b/libc/arch-arm/generic/bionic/strcpy.S
index c0ab9e5dc..89bd69913 100644
--- a/libc/arch-arm/generic/bionic/strcpy.S
+++ b/libc/arch-arm/generic/bionic/strcpy.S
@@ -33,7 +33,11 @@
 
 .syntax unified
 
-ENTRY(strcpy)
+// To avoid warning about deprecated instructions, add an explicit
+// arch. The code generated is exactly the same.
+.arch armv7-a
+
+ENTRY(strcpy_generic)
 	pld	[r1, #0]
 	eor	r2, r0, r1
 	mov	ip, r0
@@ -131,4 +135,4 @@ ENTRY(strcpy)
 	cmp	r2, #0
 	bne	4b
 	bx	lr
-END(strcpy)
+END(strcpy_generic)
diff --git a/libc/arch-arm/generic/bionic/strlen.c b/libc/arch-arm/generic/bionic/strlen.c
index 44bd72ff5..43d9e514c 100644
--- a/libc/arch-arm/generic/bionic/strlen.c
+++ b/libc/arch-arm/generic/bionic/strlen.c
@@ -29,7 +29,7 @@
 #include <string.h>
 #include <stdint.h>
 
-size_t strlen(const char *s)
+size_t strlen_generic(const char *s)
 {
     __builtin_prefetch(s);
     __builtin_prefetch(s+32);
diff --git a/libc/arch-arm/krait/bionic/memcpy.S b/libc/arch-arm/krait/bionic/memcpy.S
index 49fd04069..6618b3ad0 100644
--- a/libc/arch-arm/krait/bionic/memcpy.S
+++ b/libc/arch-arm/krait/bionic/memcpy.S
@@ -42,7 +42,7 @@
         .thumb
         .thumb_func
 
-ENTRY(__memcpy)
+ENTRY(__memcpy_krait)
         pld     [r1, #64]
         stmfd   sp!, {r0, lr}
         .cfi_adjust_cfa_offset 8
@@ -50,4 +50,4 @@ ENTRY(__memcpy)
         .cfi_rel_offset lr, 4
 
 #include "memcpy_base.S"
-END(__memcpy)
+END(__memcpy_krait)
diff --git a/libc/arch-arm/krait/bionic/memcpy_base.S b/libc/arch-arm/krait/bionic/memcpy_base.S
index dc8ad2cdf..5b4b70d5c 100644
--- a/libc/arch-arm/krait/bionic/memcpy_base.S
+++ b/libc/arch-arm/krait/bionic/memcpy_base.S
@@ -41,8 +41,13 @@
 #endif
 
 	.text
+	.syntax unified
 	.fpu    neon
 
+	// To avoid warning about deprecated instructions, add an explicit
+	// arch. The code generated is exactly the same.
+	.arch armv7-a
+
 .L_memcpy_base:
 	cmp	r2, #4
 	blt	.L_neon_lt4
diff --git a/libc/arch-arm/krait/bionic/memmove.S b/libc/arch-arm/krait/bionic/memmove.S
new file mode 100644
index 000000000..af85ea62e
--- /dev/null
+++ b/libc/arch-arm/krait/bionic/memmove.S
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define MEMMOVE memmove_krait
+#define MEMCPY __memcpy_krait
+
+#include <arch-arm/denver/bionic/memmove.S>
diff --git a/libc/arch-arm/krait/bionic/memset.S b/libc/arch-arm/krait/bionic/memset.S
index 228942cbe..675ab53bc 100644
--- a/libc/arch-arm/krait/bionic/memset.S
+++ b/libc/arch-arm/krait/bionic/memset.S
@@ -37,7 +37,7 @@
     .fpu    neon
     .syntax unified
 
-ENTRY(__memset_chk)
+ENTRY(__memset_chk_krait)
         cmp         r2, r3
         bls         memset
 
@@ -47,10 +47,10 @@ ENTRY(__memset_chk)
         .cfi_rel_offset lr, 0
 
         bl          __memset_chk_fail
-END(__memset_chk)
+END(__memset_chk_krait)
 
 /* memset() returns its first argument.  */
-ENTRY(memset)
+ENTRY(memset_krait)
         mov         r3, r0
         vdup.8      q0, r1
 
@@ -82,4 +82,4 @@ ENTRY(memset)
         strbcs      r1, [r3], #1
         strbcs      r1, [r3], #1
         bx          lr
-END(memset)
+END(memset_krait)
diff --git a/libc/arch-arm/krait/bionic/strcmp.S b/libc/arch-arm/krait/bionic/strcmp.S
index b871c7622..ec692e524 100644
--- a/libc/arch-arm/krait/bionic/strcmp.S
+++ b/libc/arch-arm/krait/bionic/strcmp.S
@@ -52,12 +52,16 @@
 
 .syntax         unified
 
+// To avoid warning about deprecated instructions, add an explicit
+// arch. The code generated is exactly the same.
+.arch armv7-a
+
 #if defined (__thumb__)
         .thumb
         .thumb_func
 #endif
 
-ENTRY(strcmp)
+ENTRY(strcmp_krait)
       /* Use LDRD whenever possible.  */
 
 /* The main thing to look out for when comparing large blocks is that
@@ -482,4 +486,4 @@ ENTRY(strcmp)
     .cfi_restore r7
 
 	bx	lr
-END(strcmp)
+END(strcmp_krait)
diff --git a/libc/arch-arm/kryo/bionic/memcpy.S b/libc/arch-arm/kryo/bionic/memcpy.S
index 74036ef3a..250f7bc61 100644
--- a/libc/arch-arm/kryo/bionic/memcpy.S
+++ b/libc/arch-arm/kryo/bionic/memcpy.S
@@ -33,8 +33,14 @@
 #define PLDOFFS (16)
 #define PLDSIZE (128) /* L2 cache line size */
 
+        .syntax unified
+
+        // To avoid warning about deprecated instructions, add an explicit
+        // arch. The code generated is exactly the same.
+        .arch armv7-a
+
         .code 32
-ENTRY(__memcpy)
+ENTRY(__memcpy_kryo)
         push            {r0}
         .cfi_def_cfa_offset 4
         .cfi_rel_offset r0, 0
@@ -123,4 +129,4 @@ ENTRY(__memcpy)
         pop             {r0}
         bx              lr
 
-END(__memcpy)
+END(__memcpy_kryo)
diff --git a/libc/arch-arm/kryo/bionic/memmove.S b/libc/arch-arm/kryo/bionic/memmove.S
new file mode 100644
index 000000000..d0fdd8fa9
--- /dev/null
+++ b/libc/arch-arm/kryo/bionic/memmove.S
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define MEMMOVE memmove_kryo
+#define MEMCPY __memcpy_kryo
+
+#include <arch-arm/denver/bionic/memmove.S>
diff --git a/libc/arch-arm/static_function_dispatch.S b/libc/arch-arm/static_function_dispatch.S
new file mode 100644
index 000000000..f3dd741f9
--- /dev/null
+++ b/libc/arch-arm/static_function_dispatch.S
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2018 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 <private/bionic_asm.h>
+
+#define FUNCTION_DELEGATE(name, impl) \
+ENTRY(name); \
+    b impl; \
+END(name)
+
+FUNCTION_DELEGATE(memmove, memmove_generic)
+FUNCTION_DELEGATE(memcpy, memmove_generic)
+FUNCTION_DELEGATE(memset, memset_generic)
+FUNCTION_DELEGATE(__memset_chk, __memset_chk_generic)
+FUNCTION_DELEGATE(strcpy, strcpy_generic)
+FUNCTION_DELEGATE(stpcpy, stpcpy_generic)
+FUNCTION_DELEGATE(strcat, strcat_generic)
+FUNCTION_DELEGATE(strcmp, strcmp_generic)
+FUNCTION_DELEGATE(strlen, strlen_generic)