Module: Mesa Branch: main Commit: 6e2bb716b0c7cbe6454cc0f472ff684d8770a51f URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=6e2bb716b0c7cbe6454cc0f472ff684d8770a51f
Author: Chia-I Wu <[email protected]> Date: Mon Oct 16 10:02:50 2023 -0700 util: improve BITFIELD_MASK and BITFIELD64_MASK on clang gcc is able to optimize away either the modulo or the logical and. This makes no difference to gcc. clang is only able to optimize away the logical and. This allows clang to generate faster code for BITFIELD_MASK. As for BITFIELD64_MASK, this also makes no difference to clang except it fixes a compile error for BITFIELD64_MASK(64): error: shift count >= width of type [-Werror,-Wshift-count-overflow] Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/9989 Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25757> --- src/util/macros.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/util/macros.h b/src/util/macros.h index 42f3acaf84c..cfcda53ac0f 100644 --- a/src/util/macros.h +++ b/src/util/macros.h @@ -388,7 +388,7 @@ do { \ #define BITFIELD_BIT(b) (1u << (b)) /** Set all bits up to excluding bit b */ #define BITFIELD_MASK(b) \ - ((b) == 32 ? (~0u) : BITFIELD_BIT((b) % 32) - 1) + ((b) == 32 ? (~0u) : BITFIELD_BIT((b) & 31) - 1) /** Set count bits starting from bit b */ #define BITFIELD_RANGE(b, count) \ (BITFIELD_MASK((b) + (count)) & ~BITFIELD_MASK(b)) @@ -397,7 +397,7 @@ do { \ #define BITFIELD64_BIT(b) (1ull << (b)) /** Set all bits up to excluding bit b */ #define BITFIELD64_MASK(b) \ - ((b) == 64 ? (~0ull) : BITFIELD64_BIT(b) - 1) + ((b) == 64 ? (~0ull) : BITFIELD64_BIT((b) & 63) - 1) /** Set count bits starting from bit b */ #define BITFIELD64_RANGE(b, count) \ (BITFIELD64_MASK((b) + (count)) & ~BITFIELD64_MASK(b))
