The patch titled Subject: lib: bitmap: change bitmap_shift_right to take unsigned parameters has been added to the -mm tree. Its filename is lib-bitmap-change-bitmap_shift_right-to-take-unsigned-parameters.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/lib-bitmap-change-bitmap_shift_right-to-take-unsigned-parameters.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/lib-bitmap-change-bitmap_shift_right-to-take-unsigned-parameters.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: change bitmap_shift_right to take unsigned parameters I've previously changed the nbits parameter of most bitmap_* functions to unsigned; now it is bitmap_shift_{left,right}'s turn. This alone saves some .text, but while at it I found that there were a few other things one could do. The end result of these seven patches is $ scripts/bloat-o-meter /tmp/bitmap.o.{old,new} add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-328 (-328) function old new delta __bitmap_shift_right 384 226 -158 __bitmap_shift_left 306 136 -170 and less importantly also a smaller stack footprint $ stack-o-meter.pl master bitmap file function old new delta lib/bitmap.o __bitmap_shift_right 24 8 -16 lib/bitmap.o __bitmap_shift_left 24 0 -24 For each pair of 0 <= shift <= nbits <= 256 I've tested the end result with a few randomly filled src buffers (including garbage beyond nbits), in each case verifying that the shift {left,right}-most bits of dst are zero and the remaining nbits-shift bits correspond to src, so I'm fairly confident I didn't screw up. That hasn't stopped me from being wrong before, though. This patch (of 7): gcc can generate slightly better code for stuff like "nbits % BITS_PER_LONG" when it knows nbits is not negative. Since negative size bitmaps or shift amounts don't make sense, change these parameters of bitmap_shift_right to unsigned. The expressions involving "lim - 1" are still ok, since if lim is 0 the loop is never executed. Also use "shift" and "nbits" consistently for the parameter names. Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/bitmap.h | 12 ++++++------ lib/bitmap.c | 10 +++++----- 2 files changed, 11 insertions(+), 11 deletions(-) diff -puN include/linux/bitmap.h~lib-bitmap-change-bitmap_shift_right-to-take-unsigned-parameters include/linux/bitmap.h --- a/include/linux/bitmap.h~lib-bitmap-change-bitmap_shift_right-to-take-unsigned-parameters +++ a/include/linux/bitmap.h @@ -96,8 +96,8 @@ extern int __bitmap_equal(const unsigned const unsigned long *bitmap2, unsigned int nbits); extern void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int nbits); -extern void __bitmap_shift_right(unsigned long *dst, - const unsigned long *src, int shift, int bits); +extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, + unsigned int shift, unsigned int nbits); extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, int shift, int bits); extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, @@ -313,13 +313,13 @@ static inline int bitmap_weight(const un return __bitmap_weight(src, nbits); } -static inline void bitmap_shift_right(unsigned long *dst, - const unsigned long *src, int n, int nbits) +static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, + unsigned int shift, int nbits) { if (small_const_nbits(nbits)) - *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> n; + *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; else - __bitmap_shift_right(dst, src, n, nbits); + __bitmap_shift_right(dst, src, shift, nbits); } static inline void bitmap_shift_left(unsigned long *dst, diff -puN lib/bitmap.c~lib-bitmap-change-bitmap_shift_right-to-take-unsigned-parameters lib/bitmap.c --- a/lib/bitmap.c~lib-bitmap-change-bitmap_shift_right-to-take-unsigned-parameters +++ a/lib/bitmap.c @@ -104,17 +104,17 @@ EXPORT_SYMBOL(__bitmap_complement); * @dst : destination bitmap * @src : source bitmap * @shift : shift by this many bits - * @bits : bitmap size, in bits + * @nbits : bitmap size, in bits * * Shifting right (dividing) means moving bits in the MS -> LS bit * direction. Zeros are fed into the vacated MS positions and the * LS bits shifted off the bottom are lost. */ -void __bitmap_shift_right(unsigned long *dst, - const unsigned long *src, int shift, int bits) +void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, + unsigned shift, unsigned nbits) { - int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; - int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; + unsigned k, lim = BITS_TO_LONGS(nbits), left = nbits % BITS_PER_LONG; + unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; unsigned long mask = (1UL << left) - 1; for (k = 0; off + k < lim; ++k) { unsigned long upper, lower; _ 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