[Mesa-dev] [PATCH 4/7] i965: Add an assert for when SET_FIELD's value exceeds the field size.

[Eric Anholt]

This was one of the things we always wanted to do to this, to make it more
useful than just (value << FIELD_MASK).
---
 src/mesa/drivers/dri/i965/brw_defines.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index dc38ace..21a97a9 100644
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -30,7 +30,13 @@
   */
 
 #define INTEL_MASK(high, low) (((1<<((high)-(low)+1))-1)<<(low))
-#define SET_FIELD(value, field) (((value) << field ## _SHIFT) & field ## _MASK)
+#define SET_FIELD(value, field)                                         \
+   ({                                                                   \
+      uint32_t fieldval = (value) << field ## _SHIFT;                   \
+      assert((fieldval & ~ field ## _MASK) == 0);                       \
+      fieldval & field ## _MASK;                                        \
+   })
+
 #define GET_FIELD(word, field) (((word)  & field ## _MASK) >> field ## _SHIFT)
 
 #ifndef BRW_DEFINES_H
-- 
1.8.5.1