auto import from //depot/cupcake/@135843
diff --git a/libc/arch-x86/bionic/atomics_x86.S b/libc/arch-x86/bionic/atomics_x86.S
new file mode 100644
index 0000000..2370f23
--- /dev/null
+++ b/libc/arch-x86/bionic/atomics_x86.S
@@ -0,0 +1,140 @@
+#include <sys/linux-syscalls.h>
+
+#define FUTEX_WAIT 0
+#define FUTEX_WAKE 1
+
+
+/*
+ * int __futex_wait(volatile void *ftx, int val, const struct timespec *timeout)
+ */
+.text
+.globl __futex_wait
+.type __futex_wait, @function
+.align 4
+__futex_wait:
+ pushl %ebx
+ pushl %esi
+ mov 12(%esp), %ebx /* ftx */
+ movl $FUTEX_WAIT, %ecx
+ mov 16(%esp), %edx /* val */
+ mov 20(%esp), %esi /* timeout */
+ movl $__NR_futex, %eax
+ int $0x80
+ popl %esi
+ popl %ebx
+ ret
+
+
+/* int __futex_wake(volatile void *ftx, int count) */
+
+.text
+.globl __futex_wake
+.type __futex_wake, @function
+.align 4
+__futex_wake:
+ pushl %ebx
+ mov 8(%esp), %ebx /* ftx */
+ movl $FUTEX_WAKE, %ecx
+ mov 12(%esp), %edx /* count */
+ movl $__NR_futex, %eax
+ int $0x80
+ popl %ebx
+ ret
+
+
+/* int __atomic_cmpxchg(int old, int new, volatile int* addr) */
+
+.text
+.globl __atomic_cmpxchg
+.type __atomic_cmpxchg, @function
+.align 4
+__atomic_cmpxchg:
+ mov 4(%esp), %eax /* old */
+ mov 8(%esp), %ecx /* new */
+ mov 12(%esp), %edx /* addr */
+ lock cmpxchg %ecx, (%edx)
+ jnz 1f
+ xor %eax, %eax
+ jmp 2f
+1:
+ movl $1, %eax
+2:
+ ret /* 0 == success, 1 == failure */
+
+
+/* int __atomic_swap(int new, volatile int* addr) */
+
+.text
+.globl __atomic_swap
+.type __atomic_swap, @function
+.align 4
+__atomic_swap:
+ mov 4(%esp), %ecx /* new */
+ mov 8(%esp), %edx /* addr */
+ lock xchg %ecx, (%edx)
+ mov %ecx, %eax
+ ret
+
+
+/*
+ * int __atomic_dec(volatile int* addr)
+ *
+ * My x86 asm is really rusty.. this is probably suboptimal
+ */
+
+.text
+.globl __atomic_dec
+.type __atomic_dec, @function
+.align 4
+__atomic_dec:
+ pushl %ebx
+ pushl %esi
+ movl 12(%esp), %ebx /* addr */
+
+1:
+ movl (%ebx), %esi /* old = *addr */
+ movl %esi, %edx
+ subl $1, %edx /* new = old - 1 */
+
+ pushl %ebx
+ pushl %edx
+ pushl %esi
+ call __atomic_cmpxchg
+ addl $12, %esp
+ test %eax, %eax
+ jnz 1b
+
+ movl %esi, %eax /* return old */
+ popl %esi
+ popl %ebx
+ ret
+
+
+.text
+/* int __atomic_inc(volatile int* addr) */
+.globl __atomic_inc
+.type __atomic_inc, @function
+.align 4
+__atomic_inc:
+ pushl %ebx
+ pushl %esi
+ movl 12(%esp), %ebx /* addr */
+
+1:
+ movl (%ebx), %esi /* old = *addr */
+ movl %esi, %edx
+ addl $1, %edx /* new = old + 1 */
+
+ pushl %ebx
+ pushl %edx
+ pushl %esi
+ call __atomic_cmpxchg
+ addl $12, %esp
+ test %eax, %eax
+ jnz 1b
+
+ movl %esi, %eax /* return old */
+ popl %esi
+ popl %ebx
+ ret
+