aarch64 cabac optimizations

common/aarch64/asm-offsets.c

@@ -26,11 +26,19 @@
 #include "common/common.h"
 #include "asm-offsets.h"
 
+#define STATIC_ASSERT(name, x) int assert_##name[2 * !!(x) - 1]
+
 #define X264_CHECK_OFFSET(s, m, o) struct check_##s##_##m \
 { \
-    int m_##m[2 * (offsetof(s, m) == o) - 1]; \
+    STATIC_ASSERT(offset_##m, offsetof(s, m) == o); \
+}
+
+#define X264_CHECK_REL_OFFSET(s, a, type, b) struct check_##s##_##a##_##b \
+{ \
+    STATIC_ASSERT(rel_offset_##a##_##b, offsetof(s, a) + sizeof(type) == offsetof(s, b)); \
 }
 
+
 X264_CHECK_OFFSET(x264_cabac_t, i_low,               CABAC_I_LOW);
 X264_CHECK_OFFSET(x264_cabac_t, i_range,             CABAC_I_RANGE);
 X264_CHECK_OFFSET(x264_cabac_t, i_queue,             CABAC_I_QUEUE);
@@ -40,3 +48,9 @@ X264_CHECK_OFFSET(x264_cabac_t, p,                   CABAC_P);
 X264_CHECK_OFFSET(x264_cabac_t, p_end,               CABAC_P_END);
 X264_CHECK_OFFSET(x264_cabac_t, f8_bits_encoded,     CABAC_F8_BITS_ENCODED);
 X264_CHECK_OFFSET(x264_cabac_t, state,               CABAC_STATE);
+
+// the aarch64 asm makes following additional assumptions about the x264_cabac_t
+// memory layout
+
+X264_CHECK_REL_OFFSET(x264_cabac_t, i_low,    int, i_range);
+X264_CHECK_REL_OFFSET(x264_cabac_t, i_queue,  int, i_bytes_outstanding);