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authorIan Romanick <ian.d.romanick@intel.com>2011-04-08 16:31:22 -0700
committerIan Romanick <ian.d.romanick@intel.com>2011-04-11 14:43:42 -0700
commit7e809f0b8d635c8d5519b3d0fdaf11ac0ddda7eb (patch)
tree51f95543bbe7134f3a4c6157905d1a82058a2b40
parent03eade164d45cc35422dfc03aeaf579c9c3183f9 (diff)
intel: Fix ROUND_DOWN_TO macro
Previously the macro would (ALIGN(value - alignment - 1, alignment)). At the very least, this was missing parenthesis around "alignment - 1". As a result, if value was already aligned, it would be reduced by alignment. Condisder: x = ROUND_DOWN_TO(256, 128); This becomes: x = ALIGN(256 - 128 - 1, 128); Or: x = ALIGN(127, 128); Which becomes: x = 128; This macro is currently only used in brw_state_batch (brw_state_batch.c). It looks like the original version of this macro would just use too much space in the batch buffer. It's possible, but not at all clear to me from the code, that the original behavior is actually desired. In any case, this patch does not cause any piglit regressions on my Ironlake system. I also think that ALIGN_FLOOR would be a better name for this macro, but ROUND_DOWN_TO matches rounddown in the Linux kernel. Reviewed-by: Eric Anholt <eric@anholt.net> Reviewed-by: Keith Whitwell <keithw@vmware.com> Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
-rw-r--r--src/mesa/drivers/dri/intel/intel_context.h30
1 files changed, 27 insertions, 3 deletions
diff --git a/src/mesa/drivers/dri/intel/intel_context.h b/src/mesa/drivers/dri/intel/intel_context.h
index 772b2fba5a8..c59119373da 100644
--- a/src/mesa/drivers/dri/intel/intel_context.h
+++ b/src/mesa/drivers/dri/intel/intel_context.h
@@ -295,9 +295,33 @@ extern char *__progname;
#define SUBPIXEL_Y 0.125
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
-#define ALIGN(value, alignment) ((value + alignment - 1) & ~(alignment - 1))
-#define ROUND_DOWN_TO(value, alignment) (ALIGN(value - alignment - 1, \
- alignment))
+
+/**
+ * Align a value up to an alignment value
+ *
+ * If \c value is not already aligned to the requested alignment value, it
+ * will be rounded up.
+ *
+ * \param value Value to be rounded
+ * \param alignment Alignment value to be used. This must be a power of two.
+ *
+ * \sa ROUND_DOWN_TO()
+ */
+#define ALIGN(value, alignment) (((value) + alignment - 1) & ~(alignment - 1))
+
+/**
+ * Align a value down to an alignment value
+ *
+ * If \c value is not already aligned to the requested alignment value, it
+ * will be rounded down.
+ *
+ * \param value Value to be rounded
+ * \param alignment Alignment value to be used. This must be a power of two.
+ *
+ * \sa ALIGN()
+ */
+#define ROUND_DOWN_TO(value, alignment) ((value) & ~(alignment - 1))
+
#define IS_POWER_OF_TWO(val) (((val) & (val - 1)) == 0)
static INLINE uint32_t