Module: Mesa Branch: 7.10 Commit: ff77a69ae33f04b2fbfdc9a228214ef373d54f61 URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=ff77a69ae33f04b2fbfdc9a228214ef373d54f61
Author: Ian Romanick <[email protected]> Date: Fri Apr 8 16:31:22 2011 -0700 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 <[email protected]> Reviewed-by: Keith Whitwell <[email protected]> Reviewed-by: Kenneth Graunke <[email protected]> (cherry picked from commit 7e809f0b8d635c8d5519b3d0fdaf11ac0ddda7eb) --- src/mesa/drivers/dri/intel/intel_context.h | 30 +++++++++++++++++++++++++-- 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 53a11ba..f3e856d 100644 --- a/src/mesa/drivers/dri/intel/intel_context.h +++ b/src/mesa/drivers/dri/intel/intel_context.h @@ -278,9 +278,33 @@ 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 _______________________________________________ mesa-commit mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-commit
