* [PATCH 1/2] include: sbi_bitmap: add bitmap_empty() function @ 2026-03-11 12:51 Yu-Chien Peter Lin 2026-03-11 12:51 ` [PATCH 2/2] lib: sbi_bitmap_test: add tests for bitmap_empty() Yu-Chien Peter Lin 2026-04-08 12:37 ` [PATCH 1/2] include: sbi_bitmap: add bitmap_empty() function Anup Patel 0 siblings, 2 replies; 4+ messages in thread From: Yu-Chien Peter Lin @ 2026-03-11 12:51 UTC (permalink / raw) To: opensbi; +Cc: Yu-Chien Peter Lin Add bitmap_empty() to check if bitmap has no bits set. Unlike bitmap_weight() which calls sbi_popcount() on every word, bitmap_empty() uses simple non-zero comparisons with early exit. Signed-off-by: Yu-Chien Peter Lin <peter.lin@sifive.com> --- include/sbi/sbi_bitmap.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/include/sbi/sbi_bitmap.h b/include/sbi/sbi_bitmap.h index 596bcc7d..80d3fe3b 100644 --- a/include/sbi/sbi_bitmap.h +++ b/include/sbi/sbi_bitmap.h @@ -143,4 +143,20 @@ static inline int bitmap_weight(const unsigned long *src, int nbits) return res; } +static inline bool bitmap_empty(const unsigned long *src, int nbits) +{ + if (nbits == 0) + return true; + + if (small_const_nbits(nbits)) + return !(*src & BITMAP_LAST_WORD_MASK(nbits)); + else { + size_t i, len = BITS_TO_LONGS(nbits); + for (i = 0; i < len - 1; i++) + if (src[i]) + return false; + return !(src[len - 1] & BITMAP_LAST_WORD_MASK(nbits)); + } +} + #endif -- 2.53.0 -- opensbi mailing list opensbi@lists.infradead.org http://lists.infradead.org/mailman/listinfo/opensbi ^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] lib: sbi_bitmap_test: add tests for bitmap_empty() 2026-03-11 12:51 [PATCH 1/2] include: sbi_bitmap: add bitmap_empty() function Yu-Chien Peter Lin @ 2026-03-11 12:51 ` Yu-Chien Peter Lin 2026-04-08 12:37 ` Anup Patel 2026-04-08 12:37 ` [PATCH 1/2] include: sbi_bitmap: add bitmap_empty() function Anup Patel 1 sibling, 1 reply; 4+ messages in thread From: Yu-Chien Peter Lin @ 2026-03-11 12:51 UTC (permalink / raw) To: opensbi; +Cc: Yu-Chien Peter Lin Add tests for bitmap_empty(), covers empty/non-empty bitmaps and edge case nbits=0. Signed-off-by: Yu-Chien Peter Lin <peter.lin@sifive.com> --- lib/sbi/tests/sbi_bitmap_test.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/lib/sbi/tests/sbi_bitmap_test.c b/lib/sbi/tests/sbi_bitmap_test.c index d2c35996..b6586fe1 100644 --- a/lib/sbi/tests/sbi_bitmap_test.c +++ b/lib/sbi/tests/sbi_bitmap_test.c @@ -92,10 +92,39 @@ static void bitmap_xor_test(struct sbiunit_test_case *test) SBIUNIT_EXPECT_MEMEQ(test, res, data_zero, DATA_SIZE); } +static void bitmap_empty_test(struct sbiunit_test_case *test) +{ + unsigned long res[DATA_SIZE]; + + /* All zeros = empty */ + SBIUNIT_EXPECT_EQ(test, bitmap_empty(data_zero, DATA_BIT_SIZE), true); + + /* Non-zero data = not empty */ + SBIUNIT_EXPECT_EQ(test, bitmap_empty(data_a, DATA_BIT_SIZE), false); + SBIUNIT_EXPECT_EQ(test, bitmap_empty(data_b, DATA_BIT_SIZE), false); + + /* bitmap_zero creates empty bitmap */ + bitmap_zero(res, DATA_BIT_SIZE); + SBIUNIT_EXPECT_EQ(test, bitmap_empty(res, DATA_BIT_SIZE), true); + + /* bitmap_fill creates non-empty bitmap */ + bitmap_fill(res, DATA_BIT_SIZE); + SBIUNIT_EXPECT_EQ(test, bitmap_empty(res, DATA_BIT_SIZE), false); + + /* Single bit set = not empty */ + bitmap_zero(res, DATA_BIT_SIZE); + bitmap_set(res, 0, 1); + SBIUNIT_EXPECT_EQ(test, bitmap_empty(res, DATA_BIT_SIZE), false); + + /* Zero nbits = empty */ + SBIUNIT_EXPECT_EQ(test, bitmap_empty(data_a, 0), true); +} + static struct sbiunit_test_case bitmap_test_cases[] = { SBIUNIT_TEST_CASE(bitmap_and_test), SBIUNIT_TEST_CASE(bitmap_or_test), SBIUNIT_TEST_CASE(bitmap_xor_test), + SBIUNIT_TEST_CASE(bitmap_empty_test), SBIUNIT_END_CASE, }; -- 2.53.0 -- opensbi mailing list opensbi@lists.infradead.org http://lists.infradead.org/mailman/listinfo/opensbi ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] lib: sbi_bitmap_test: add tests for bitmap_empty() 2026-03-11 12:51 ` [PATCH 2/2] lib: sbi_bitmap_test: add tests for bitmap_empty() Yu-Chien Peter Lin @ 2026-04-08 12:37 ` Anup Patel 0 siblings, 0 replies; 4+ messages in thread From: Anup Patel @ 2026-04-08 12:37 UTC (permalink / raw) To: Yu-Chien Peter Lin; +Cc: opensbi On Wed, Mar 11, 2026 at 6:21 PM Yu-Chien Peter Lin <peter.lin@sifive.com> wrote: > > Add tests for bitmap_empty(), covers empty/non-empty bitmaps and > edge case nbits=0. > > Signed-off-by: Yu-Chien Peter Lin <peter.lin@sifive.com> LGTM. Reviewed-by: Anup Patel <anup@brainfault.org> Applied this patch to the riscv/opensbi repo. Thanks, Anup > --- > lib/sbi/tests/sbi_bitmap_test.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/lib/sbi/tests/sbi_bitmap_test.c b/lib/sbi/tests/sbi_bitmap_test.c > index d2c35996..b6586fe1 100644 > --- a/lib/sbi/tests/sbi_bitmap_test.c > +++ b/lib/sbi/tests/sbi_bitmap_test.c > @@ -92,10 +92,39 @@ static void bitmap_xor_test(struct sbiunit_test_case *test) > SBIUNIT_EXPECT_MEMEQ(test, res, data_zero, DATA_SIZE); > } > > +static void bitmap_empty_test(struct sbiunit_test_case *test) > +{ > + unsigned long res[DATA_SIZE]; > + > + /* All zeros = empty */ > + SBIUNIT_EXPECT_EQ(test, bitmap_empty(data_zero, DATA_BIT_SIZE), true); > + > + /* Non-zero data = not empty */ > + SBIUNIT_EXPECT_EQ(test, bitmap_empty(data_a, DATA_BIT_SIZE), false); > + SBIUNIT_EXPECT_EQ(test, bitmap_empty(data_b, DATA_BIT_SIZE), false); > + > + /* bitmap_zero creates empty bitmap */ > + bitmap_zero(res, DATA_BIT_SIZE); > + SBIUNIT_EXPECT_EQ(test, bitmap_empty(res, DATA_BIT_SIZE), true); > + > + /* bitmap_fill creates non-empty bitmap */ > + bitmap_fill(res, DATA_BIT_SIZE); > + SBIUNIT_EXPECT_EQ(test, bitmap_empty(res, DATA_BIT_SIZE), false); > + > + /* Single bit set = not empty */ > + bitmap_zero(res, DATA_BIT_SIZE); > + bitmap_set(res, 0, 1); > + SBIUNIT_EXPECT_EQ(test, bitmap_empty(res, DATA_BIT_SIZE), false); > + > + /* Zero nbits = empty */ > + SBIUNIT_EXPECT_EQ(test, bitmap_empty(data_a, 0), true); > +} > + > static struct sbiunit_test_case bitmap_test_cases[] = { > SBIUNIT_TEST_CASE(bitmap_and_test), > SBIUNIT_TEST_CASE(bitmap_or_test), > SBIUNIT_TEST_CASE(bitmap_xor_test), > + SBIUNIT_TEST_CASE(bitmap_empty_test), > SBIUNIT_END_CASE, > }; > > -- > 2.53.0 > > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi -- opensbi mailing list opensbi@lists.infradead.org http://lists.infradead.org/mailman/listinfo/opensbi ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] include: sbi_bitmap: add bitmap_empty() function 2026-03-11 12:51 [PATCH 1/2] include: sbi_bitmap: add bitmap_empty() function Yu-Chien Peter Lin 2026-03-11 12:51 ` [PATCH 2/2] lib: sbi_bitmap_test: add tests for bitmap_empty() Yu-Chien Peter Lin @ 2026-04-08 12:37 ` Anup Patel 1 sibling, 0 replies; 4+ messages in thread From: Anup Patel @ 2026-04-08 12:37 UTC (permalink / raw) To: Yu-Chien Peter Lin; +Cc: opensbi On Wed, Mar 11, 2026 at 6:21 PM Yu-Chien Peter Lin <peter.lin@sifive.com> wrote: > > Add bitmap_empty() to check if bitmap has no bits set. > > Unlike bitmap_weight() which calls sbi_popcount() on every word, > bitmap_empty() uses simple non-zero comparisons with early exit. > > Signed-off-by: Yu-Chien Peter Lin <peter.lin@sifive.com> LGTM. Reviewed-by: Anup Patel <anup@brainfault.org> Applied this patch to the riscv/opensbi repo. Thanks, Anup > --- > include/sbi/sbi_bitmap.h | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/include/sbi/sbi_bitmap.h b/include/sbi/sbi_bitmap.h > index 596bcc7d..80d3fe3b 100644 > --- a/include/sbi/sbi_bitmap.h > +++ b/include/sbi/sbi_bitmap.h > @@ -143,4 +143,20 @@ static inline int bitmap_weight(const unsigned long *src, int nbits) > return res; > } > > +static inline bool bitmap_empty(const unsigned long *src, int nbits) > +{ > + if (nbits == 0) > + return true; > + > + if (small_const_nbits(nbits)) > + return !(*src & BITMAP_LAST_WORD_MASK(nbits)); > + else { > + size_t i, len = BITS_TO_LONGS(nbits); > + for (i = 0; i < len - 1; i++) > + if (src[i]) > + return false; > + return !(src[len - 1] & BITMAP_LAST_WORD_MASK(nbits)); > + } > +} > + > #endif > -- > 2.53.0 > > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi -- opensbi mailing list opensbi@lists.infradead.org http://lists.infradead.org/mailman/listinfo/opensbi ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-04-08 12:38 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-03-11 12:51 [PATCH 1/2] include: sbi_bitmap: add bitmap_empty() function Yu-Chien Peter Lin 2026-03-11 12:51 ` [PATCH 2/2] lib: sbi_bitmap_test: add tests for bitmap_empty() Yu-Chien Peter Lin 2026-04-08 12:37 ` Anup Patel 2026-04-08 12:37 ` [PATCH 1/2] include: sbi_bitmap: add bitmap_empty() function Anup Patel
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