new file mode 100644
--- /dev/null
+++ b/src/os/unix/ngx_gcc_atomic_ppc.h
@@ -0,0 +1,66 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+/*
+ * The ppc assembler treats ";" as comment, so we have to use "\n".
+ * The minus in "bne-" is a hint for the branch prediction unit that
+ * this branch is unlikely to be taken.
+ * The "1b" means the nearest backward label "1" and the "1f" means
+ * the nearest forward label "1".
+ *  
+ * The "b" means that the base registers can be used only, i.e.
+ * any register except r0.  The r0 register always has a zero value and
+ * could not be used in "addi  r0, r0, 1".
+ * The "=&b" means that no input registers can be used.
+ */
+
+static ngx_inline ngx_atomic_uint_t
+ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old,
+    ngx_atomic_uint_t set)
+{
+    ngx_atomic_uint_t  res, temp;
+
+    __asm__ volatile (
+
+    "    li      %0, 0       \n" /* preset "0" to "res"                      */
+    "    lwarx   %1, 0, %2   \n" /* load from [lock] into "temp"             */
+                                 /*   and store reservation                  */
+    "    cmpw    %1, %3      \n" /* compare "temp" and "old"                 */
+    "    bne-    1f          \n" /* not equal                                */
+    "    stwcx.  %4, 0, %2   \n" /* store "set" into [lock] if reservation   */
+                                 /*   is not cleared                         */
+    "    bne-    1f          \n" /* the reservation was cleared              */
+    "    li      %0, 1       \n" /* set "1" to "res"                         */
+    "1:                      \n"
+
+    : "=&b" (res), "=&b" (temp)
+    : "b" (lock), "b" (old), "b" (set)
+    : "cc", "memory");
+
+    return res;
+}
+
+
+static ngx_inline ngx_atomic_int_t
+ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add)
+{
+    ngx_atomic_uint_t  res, temp;
+
+    __asm__ volatile (
+
+    "1:  lwarx   %0, 0, %2   \n" /* load from [value] into "res"             */
+                                 /*   and store reservation                  */
+    "    add     %1, %0, %3  \n" /* "res" + "add" store in "temp"            */
+    "    stwcx.  %1, 0, %2   \n" /* store "temp" into [value] if reservation */
+                                 /*   is not cleared                         */
+    "    bne-    1b          \n" /* try again if reservation was cleared     */
+
+    : "=&b" (res), "=&b" (temp)
+    : "b" (value), "b" (add)
+    : "cc", "memory");
+
+    return res;
+}