Messages in this thread Patch in this message | | | From | Denis Efremov <> | Subject | [PATCH] lib/memweight.c: optimize by inlining bitmap_weight() | Date | Wed, 21 Aug 2019 10:42:00 +0300 |
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This patch inlines bitmap_weight() call. Thus, removing the BUG_ON, and 'longs to bits -> bits to longs' conversion by directly calling hweight_long().
./scripts/bloat-o-meter lib/memweight.o.old lib/memweight.o.new add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-10 (-10) Function old new delta memweight 162 152 -10
Co-developed-by: Erdem Tumurov <erdemus@gmail.com> Co-developed-by: Vladimir Shelekhov <vshel@iis.nsk.su> Signed-off-by: Erdem Tumurov <erdemus@gmail.com> Signed-off-by: Vladimir Shelekhov <vshel@iis.nsk.su> Signed-off-by: Denis Efremov <efremov@ispras.ru> --- lib/memweight.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/lib/memweight.c b/lib/memweight.c index 94dd72ccaa7f..f050b2b4c5e2 100644 --- a/lib/memweight.c +++ b/lib/memweight.c @@ -20,11 +20,13 @@ size_t memweight(const void *ptr, size_t bytes) longs = bytes / sizeof(long); if (longs) { - BUG_ON(longs >= INT_MAX / BITS_PER_LONG); - ret += bitmap_weight((unsigned long *)bitmap, - longs * BITS_PER_LONG); + const unsigned long *bitmap_long = + (const unsigned long *)bitmap; + bytes -= longs * sizeof(long); - bitmap += longs * sizeof(long); + for (; longs > 0; longs--, bitmap_long++) + ret += hweight_long(*bitmap_long); + bitmap = (const unsigned char *)bitmap_long; } /* * The reason that this last loop is distinct from the preceding -- 2.21.0
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