Mesa (master): i965: Add an assert for when SET_FIELD' s value exceeds the field size.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 5d2e86924ebe7b520a5964e9c90c5bb7213c67cf
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=5d2e86924ebe7b520a5964e9c90c5bb7213c67cf

Author: Eric Anholt <eric at anholt.net>
Date:   Mon Dec 23 01:39:42 2013 -0800

i965: Add an assert for when SET_FIELD's value exceeds the field size.

This was one of the things we always wanted to do to this, to make it more
useful than just (value << FIELD_MASK).

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>
Reviewed-by: Anuj Phogat <anuj.phogat at gmail.com>

---

 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 0fc24a7..78df0b8 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