r600c: fix setting negative values to bitfields

when setting negative integers to bitfields we could overwrite
other parts of it. So mask the value to be written correctly.
This is used quite often in the driver - hope it doesnt affect
performace or uncover behaviour relied before...

fixes strange effects when setting negative lodbias on evergreen

diff --git a/src/mesa/drivers/dri/r600/r700_chip.h b/src/mesa/drivers/dri/r600/r700_chip.h
index ebf1840a79501e1d10975d821fc8eba47f3f354f..0ca237b1fe00073a5524693288c743e902e7c6e7 100644 (file)
--- a/src/mesa/drivers/dri/r600/r700_chip.h
+++ b/src/mesa/drivers/dri/r600/r700_chip.h
@@ -38,7 +38,7 @@
 
 #include "r700_chipoffset.h"
 
-#define SETfield(x, val, shift, mask)  ( (x) = ((x) & ~(mask)) | ((val) << (shift)) ) /* u32All */
+#define SETfield(x, val, shift, mask)  ( (x) = ((x) & ~(mask)) | (((val) << (shift)) & (mask)) )/* u32All */
 #define CLEARfield(x, mask)            ( (x) &= ~(mask) )
 #define SETbit(x, bit)                 ( (x) |= (bit) )
 #define CLEARbit(x, bit)               ( (x) &= ~(bit) )