The patch titled Subject: lib: bitmap: eliminate branch in __bitmap_shift_left has been added to the -mm tree. Its filename is lib-bitmap-eliminate-branch-in-__bitmap_shift_left.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/lib-bitmap-eliminate-branch-in-__bitmap_shift_left.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/lib-bitmap-eliminate-branch-in-__bitmap_shift_left.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Subject: lib: bitmap: eliminate branch in __bitmap_shift_left We can shift the bits from lower and upper into place before assembling dst[k + off]; moving the shift of lower into the branch where we already know that rem is non-zero allows us to remove a conditional. Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/bitmap.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff -puN lib/bitmap.c~lib-bitmap-eliminate-branch-in-__bitmap_shift_left lib/bitmap.c --- a/lib/bitmap.c~lib-bitmap-eliminate-branch-in-__bitmap_shift_left +++ a/lib/bitmap.c @@ -169,15 +169,14 @@ void __bitmap_shift_left(unsigned long * * word below and make them the bottom rem bits of result. */ if (rem && k > 0) - lower = src[k - 1]; + lower = src[k - 1] >> (BITS_PER_LONG - rem); else lower = 0; upper = src[k]; if (left && k == lim - 1) upper &= (1UL << left) - 1; - dst[k + off] = upper << rem; - if (rem) - dst[k + off] |= lower >> (BITS_PER_LONG - rem); + upper <<= rem; + dst[k + off] = lower | upper; if (left && k + off == lim - 1) dst[k + off] &= (1UL << left) - 1; } _ Patches currently in -mm which might be from linux@xxxxxxxxxxxxxxxxxx are lib-string_get_size-remove-redundant-prefixes.patch lib-string_get_size-use-32-bit-arithmetic-when-possible.patch lib-string_get_size-return-void.patch lib-bitmap-more-signed-unsigned-conversions.patch linux-nodemaskh-update-bitmap-wrappers-to-take-unsigned-int.patch linux-cpumaskh-update-bitmap-wrappers-to-take-unsigned-int.patch lib-bitmap-update-bitmap_onto-to-unsigned.patch lib-bitmap-update-bitmap_onto-to-unsigned-checkpatch-fixes.patch lib-bitmap-change-parameters-of-bitmap_fold-to-unsigned.patch lib-bitmap-simplify-bitmap_pos_to_ord.patch lib-bitmap-simplify-bitmap_ord_to_pos.patch lib-bitmap-make-the-bits-parameter-of-bitmap_remap-unsigned.patch lib-remove-strnicmp.patch lib-interval_treec-simplify-includes.patch lib-sortc-use-simpler-includes.patch lib-dynamic_queue_limitsc-simplify-includes.patch lib-halfmd4c-simplify-includes.patch lib-idrc-remove-redundant-include.patch lib-genallocc-remove-redundant-include.patch lib-list_sortc-rearrange-includes.patch lib-md5c-simplify-include.patch lib-llistc-remove-redundant-include.patch lib-kobject_ueventc-remove-redundant-include.patch lib-nlattrc-remove-redundant-include.patch lib-plistc-remove-redundant-include.patch lib-radix-treec-change-to-simpler-include.patch lib-show_memc-remove-redundant-include.patch lib-sortc-move-include-inside-if-0.patch lib-stmp_devicec-replace-moduleh-include.patch lib-strncpy_from_userc-replace-moduleh-include.patch lib-percpu_idac-remove-redundant-includes.patch lib-lcmc-replace-include.patch lib-bitmapc-change-prototype-of-bitmap_copy_le.patch lib-bitmapc-elide-bitmap_copy_le-on-little-endian.patch lib-bitmap-change-bitmap_shift_right-to-take-unsigned-parameters.patch lib-bitmap-eliminate-branch-in-__bitmap_shift_right.patch lib-bitmap-remove-redundant-code-from-__bitmap_shift_right.patch lib-bitmap-yet-another-simplification-in-__bitmap_shift_right.patch lib-bitmap-change-bitmap_shift_left-to-take-unsigned-parameters.patch lib-bitmap-eliminate-branch-in-__bitmap_shift_left.patch lib-bitmap-remove-redundant-code-from-__bitmap_shift_left.patch checkpatch-emit-an-error-when-using-predefined-timestamp-macros.patch linux-next.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