The patch titled FRV: Optimise ffs() has been added to the -mm tree. Its filename is frv-optimise-ffs.patch See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: FRV: Optimise ffs() From: David Howells <dhowells@xxxxxxxxxx> Optimise ffs(x) by using fls(x & x - 1) which we optimise to use the SCAN instruction. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxx> --- include/asm-frv/bitops.h | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff -puN include/asm-frv/bitops.h~frv-optimise-ffs include/asm-frv/bitops.h --- a/include/asm-frv/bitops.h~frv-optimise-ffs +++ a/include/asm-frv/bitops.h @@ -157,8 +157,6 @@ static inline int __test_bit(int nr, con __constant_test_bit((nr),(addr)) : \ __test_bit((nr),(addr))) -#include <asm-generic/bitops/ffs.h> -#include <asm-generic/bitops/__ffs.h> #include <asm-generic/bitops/find.h> /** @@ -227,6 +225,37 @@ int fls64(u64 n) } +/** + * ffs - find first bit set + * @x: the word to search + * + * - return 32..1 to indicate bit 31..0 most least significant bit set + * - return 0 to indicate no bits set + */ +static inline __attribute__((const)) +int ffs(int x) +{ + /* Note: (x & -x) gives us a mask that is the least significant + * (rightmost) 1-bit of the value in x. + */ + return fls(x & -x); +} + +/** + * __ffs - find first bit set + * @x: the word to search + * + * - return 31..0 to indicate bit 31..0 most least significant bit set + * - if no bits are set in x, the result is undefined + */ +static inline __attribute__((const)) +int __ffs(unsigned long x) +{ + int bit; + asm("scan %1,gr0,%0" : "=r"(bit) : "r"(x & -x)); + return 31 - bit; +} + #include <asm-generic/bitops/sched.h> #include <asm-generic/bitops/hweight.h> _ Patches currently in -mm which might be from dhowells@xxxxxxxxxx are git-block.patch git-block-hack.patch git-gfs2.patch git-nfs.patch nfs-replace-null-dentries-that-appear-in-readdirs-list-2.patch mm-tracking-shared-dirty-pages-nommu-fix-2.patch binfmt_elf-consistently-use-loff_t.patch frv-use-the-generic-irq-stuff.patch frv-improve-frvs-use-of-generic-irq-handling.patch frv-permit-__do_irq-to-be-dispensed-with.patch frv-fix-fls-to-handle-bit-31-being-set-correctly.patch frv-implement-fls64.patch frv-optimise-ffs.patch nommu-check-that-access_process_vm-has-a-valid-target.patch nommu-set-bdi-capabilities-for-dev-mem-and-dev-kmem.patch nommu-set-bdi-capabilities-for-dev-mem-and-dev-kmem-tidy.patch nommu-use-find_vma-rather-than-reimplementing-a-vma-search.patch check-if-start-address-is-in-vma-region-in-nommu-function-get_user_pages.patch nommu-check-vma-protections.patch nommu-permit-ptrace-to-ignore-non-prot_write-vmas-in-nommu-mode.patch nommu-implement-proc-pid-maps-for-nommu.patch nommu-order-the-per-mm_struct-vma-list.patch nommu-make-mremap-partially-work-for-nommu-kernels.patch nommu-add-docs-about-shared-memory.patch nommu-make-futexes-work-under-nommu-conditions.patch nommu-make-futexes-work-under-nommu-conditions-doc.patch nommu-move-the-fallback-arch_vma_name-to-a-sensible-place.patch nommu-move-the-fallback-arch_vma_name-to-a-sensible-place-fix.patch afs-add-lock-annotations-to-afs_proc_cell_servers_startstop.patch elf_fdpic_core_dump-dont-take-tasklist_lock.patch simplify-update_times-avoid-jiffies-jiffies_64-aliasing-problem-2.patch lib-rwsemc-un-inline-rwsem_down_failed_common.patch implement-a-general-integer-log2-facility-in-the-kernel.patch alter-get_order-so-that-it-can-make-use-of-ilog2-on-a-constant.patch alter-roundup_pow_of_two-so-that-it-can-make-use-of-ilog2-on-a-constant.patch provide-ilog2-fallbacks-for-powerpc.patch kill-wall_jiffies.patch reiserfs-make-sure-all-dentries-refs-are-released-before-calling-kill_block_super-try-2.patch fs-cache-provide-a-filesystem-specific-syncable-page-bit.patch fs-cache-generic-filesystem-caching-facility.patch fs-cache-release-page-private-in-failed-readahead.patch fs-cache-release-page-private-after-failed-readahead-12.patch fs-cache-make-kafs-use-fs-cache.patch fs-cache-make-kafs-use-fs-cache-fix.patch fs-cache-make-kafs-use-fs-cache-12.patch fs-cache-make-kafs-use-fs-cache-12-fix.patch fs-cache-make-kafs-use-fs-cache-vs-streamline-generic_file_-interfaces-and-filemap.patch nfs-use-local-caching.patch nfs-use-local-caching-12.patch nfs-use-local-caching-12-fix.patch fs-cache-cachefiles-ia64-missing-copy_page-export.patch fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem.patch fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-printk-format-warning.patch fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-warning-fixes.patch fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-cachefiles_write_page-shouldnt-indicate-error-twice.patch fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-handle-enospc-on-create-mkdir-better.patch fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-inode-count-maintenance.patch autofs-make-sure-all-dentries-refs-are-released-before-calling-kill_anon_super.patch vfs-destroy-the-dentries-contributed-by-a-superblock-on-unmounting.patch generic-ioremap_page_range-implementation-nommu-fix.patch vfs-make-filldir_t-and-struct-kstat-deal-in-64-bit-inode-numbers.patch vfs-make-filldir_t-and-struct-kstat-deal-in-64-bit-inode-numbers-alpha-fix.patch nfs-represent-64-bit-fileids-as-64-bit-inode-numbers-on-32-bit-systems.patch ecryptfs-get_sb_dev-fix.patch ecryptfs-inode-numbering-fixes.patch introduce-kernel_execve.patch rename-the-provided-execve-functions-to-kernel_execve.patch provide-kernel_execve-on-all-architectures.patch provide-kernel_execve-on-all-architectures-fix.patch remove-the-use-of-_syscallx-macros-in-uml.patch sh64-remove-the-use-of-kernel-syscalls.patch remove-remaining-errno-and-__kernel_syscalls__-references.patch reiser4-get_sb_dev-fix.patch mutex-subsystem-synchro-test-module.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html