diff --git a/benchmarks/unistd_benchmark.cpp b/benchmarks/unistd_benchmark.cpp
index e839bf8..12b788a 100644
--- a/benchmarks/unistd_benchmark.cpp
+++ b/benchmarks/unistd_benchmark.cpp
@@ -28,3 +28,14 @@
   StopBenchmarkTiming();
 }
 BENCHMARK(BM_unistd_getpid);
+
+static void BM_unistd_gettid(int iters) {
+  StartBenchmarkTiming();
+
+  for (int i = 0; i < iters; ++i) {
+    gettid();
+  }
+
+  StopBenchmarkTiming();
+}
+BENCHMARK(BM_unistd_gettid);
diff --git a/libc/Android.mk b/libc/Android.mk
index c573e30..4783bd3 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -128,6 +128,7 @@
     bionic/getauxval.cpp \
     bionic/getcwd.cpp \
     bionic/getpgrp.cpp \
+    bionic/gettid.cpp \
     bionic/inotify_init.cpp \
     bionic/lchown.cpp \
     bionic/lfs64_support.cpp \
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 785d191..584c1ae 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -38,7 +38,6 @@
 uid_t   getresuid:getresuid(uid_t* ruid, uid_t* euid, uid_t* suid)     arm64,mips,mips64,x86_64
 gid_t   getresgid:getresgid32(gid_t* rgid, gid_t* egid, gid_t* sgid)   arm,x86
 gid_t   getresgid:getresgid(gid_t* rgid, gid_t* egid, gid_t* sgid)     arm64,mips,mips64,x86_64
-pid_t   gettid()                   all
 ssize_t readahead(int, off64_t, size_t)     all
 int     getgroups:getgroups32(int, gid_t*)    arm,x86
 int     getgroups:getgroups(int, gid_t*)      arm64,mips,mips64,x86_64
diff --git a/libc/arch-arm/syscalls/gettid.S b/libc/arch-arm/syscalls/gettid.S
deleted file mode 100644
index 3928be1..0000000
--- a/libc/arch-arm/syscalls/gettid.S
+++ /dev/null
@@ -1,14 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <private/bionic_asm.h>
-
-ENTRY(gettid)
-    mov     ip, r7
-    ldr     r7, =__NR_gettid
-    swi     #0
-    mov     r7, ip
-    cmn     r0, #(MAX_ERRNO + 1)
-    bxls    lr
-    neg     r0, r0
-    b       __set_errno
-END(gettid)
diff --git a/libc/arch-arm64/syscalls/gettid.S b/libc/arch-arm64/syscalls/gettid.S
deleted file mode 100644
index 44ca913..0000000
--- a/libc/arch-arm64/syscalls/gettid.S
+++ /dev/null
@@ -1,25 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <private/bionic_asm.h>
-
-ENTRY(gettid)
-    stp     x29, x30, [sp, #-16]!
-    .cfi_def_cfa_offset 16
-    .cfi_rel_offset x29, 0
-    .cfi_rel_offset x30, 8
-    mov     x29,  sp
-
-    mov     x8, __NR_gettid
-    svc     #0
-
-    ldp     x29, x30, [sp], #16
-    .cfi_def_cfa_offset 0
-    .cfi_restore x29
-    .cfi_restore x30
-
-    cmn     x0, #(MAX_ERRNO + 1)
-    cneg    x0, x0, hi
-    b.hi    __set_errno
-
-    ret
-END(gettid)
diff --git a/libc/arch-mips/syscalls/gettid.S b/libc/arch-mips/syscalls/gettid.S
deleted file mode 100644
index cfdc57b..0000000
--- a/libc/arch-mips/syscalls/gettid.S
+++ /dev/null
@@ -1,19 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <private/bionic_asm.h>
-
-ENTRY(gettid)
-    .set noreorder
-    .cpload t9
-    li v0, __NR_gettid
-    syscall
-    bnez a3, 1f
-    move a0, v0
-    j ra
-    nop
-1:
-    la t9,__set_errno
-    j t9
-    nop
-    .set reorder
-END(gettid)
diff --git a/libc/arch-mips64/syscalls/gettid.S b/libc/arch-mips64/syscalls/gettid.S
deleted file mode 100644
index 30c30c8..0000000
--- a/libc/arch-mips64/syscalls/gettid.S
+++ /dev/null
@@ -1,25 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <private/bionic_asm.h>
-
-ENTRY(gettid)
-    .set push
-    .set noreorder
-    li v0, __NR_gettid
-    syscall
-    bnez a3, 1f
-    move a0, v0
-    j ra
-    nop
-1:
-    move t0, ra
-    bal     2f
-    nop
-2:
-    .cpsetup ra, t1, 2b
-    LA t9,__set_errno
-    .cpreturn
-    j t9
-    move ra, t0
-    .set pop
-END(gettid)
diff --git a/libc/arch-x86/syscalls/gettid.S b/libc/arch-x86/syscalls/gettid.S
deleted file mode 100644
index 1f264b1..0000000
--- a/libc/arch-x86/syscalls/gettid.S
+++ /dev/null
@@ -1,17 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <private/bionic_asm.h>
-
-ENTRY(gettid)
-    movl    $__NR_gettid, %eax
-    int     $0x80
-    cmpl    $-MAX_ERRNO, %eax
-    jb      1f
-    negl    %eax
-    pushl   %eax
-    call    __set_errno
-    addl    $4, %esp
-    orl     $-1, %eax
-1:
-    ret
-END(gettid)
diff --git a/libc/arch-x86_64/syscalls/gettid.S b/libc/arch-x86_64/syscalls/gettid.S
deleted file mode 100644
index 65ecc16..0000000
--- a/libc/arch-x86_64/syscalls/gettid.S
+++ /dev/null
@@ -1,16 +0,0 @@
-/* Generated by gensyscalls.py. Do not edit. */
-
-#include <private/bionic_asm.h>
-
-ENTRY(gettid)
-    movl    $__NR_gettid, %eax
-    syscall
-    cmpq    $-MAX_ERRNO, %rax
-    jb      1f
-    negl    %eax
-    movl    %eax, %edi
-    call    __set_errno
-    orq     $-1, %rax
-1:
-    ret
-END(gettid)
diff --git a/libc/bionic/gettid.cpp b/libc/bionic/gettid.cpp
new file mode 100644
index 0000000..f42e36a
--- /dev/null
+++ b/libc/bionic/gettid.cpp
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2014 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 <unistd.h>
+
+#include "pthread_internal.h"
+
+pid_t gettid() {
+  return __get_thread()->tid;
+}