lib: Add swap() macro

swap() will swap its two arguments while keeping the required
tmp variable hidden. Makes for neater code.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

diff --git a/lib/igt_aux.h b/lib/igt_aux.h
index 6c83c53..63e1b06 100644 (file)
--- a/lib/igt_aux.h
+++ b/lib/igt_aux.h
@@ -90,4 +90,10 @@ void intel_require_memory(uint32_t count, uint32_t size, unsigned mode);
 #define min(a, b) ((a) < (b) ? (a) : (b))
 #define max(a, b) ((a) > (b) ? (a) : (b))
 
+#define swap(a, b) do {                \
+       typeof(a) _tmp = (a);   \
+       (a) = (b);              \
+       (b) = _tmp;             \
+} while (0)
+
 #endif /* IGT_AUX_H */