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Diffstat (limited to 'app/nginx/src/os/unix/ngx_gcc_atomic_amd64.h')
-rw-r--r--app/nginx/src/os/unix/ngx_gcc_atomic_amd64.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/app/nginx/src/os/unix/ngx_gcc_atomic_amd64.h b/app/nginx/src/os/unix/ngx_gcc_atomic_amd64.h
new file mode 100644
index 0000000..159a297
--- /dev/null
+++ b/app/nginx/src/os/unix/ngx_gcc_atomic_amd64.h
@@ -0,0 +1,82 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#if (NGX_SMP)
+#define NGX_SMP_LOCK "lock;"
+#else
+#define NGX_SMP_LOCK
+#endif
+
+
+/*
+ * "cmpxchgq r, [m]":
+ *
+ * if (rax == [m]) {
+ * zf = 1;
+ * [m] = r;
+ * } else {
+ * zf = 0;
+ * rax = [m];
+ * }
+ *
+ *
+ * The "r" is any register, %rax (%r0) - %r16.
+ * The "=a" and "a" are the %rax register.
+ * Although we can return result in any register, we use "a" because it is
+ * used in cmpxchgq anyway. The result is actually in %al but not in $rax,
+ * however as the code is inlined gcc can test %al as well as %rax.
+ *
+ * The "cc" means that flags were changed.
+ */
+
+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)
+{
+ u_char res;
+
+ __asm__ volatile (
+
+ NGX_SMP_LOCK
+ " cmpxchgq %3, %1; "
+ " sete %0; "
+
+ : "=a" (res) : "m" (*lock), "a" (old), "r" (set) : "cc", "memory");
+
+ return res;
+}
+
+
+/*
+ * "xaddq r, [m]":
+ *
+ * temp = [m];
+ * [m] += r;
+ * r = temp;
+ *
+ *
+ * The "+r" is any register, %rax (%r0) - %r16.
+ * The "cc" means that flags were changed.
+ */
+
+static ngx_inline ngx_atomic_int_t
+ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add)
+{
+ __asm__ volatile (
+
+ NGX_SMP_LOCK
+ " xaddq %0, %1; "
+
+ : "+r" (add) : "m" (*value) : "cc", "memory");
+
+ return add;
+}
+
+
+#define ngx_memory_barrier() __asm__ volatile ("" ::: "memory")
+
+#define ngx_cpu_pause() __asm__ ("pause")