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authorLuke T. Shumaker <lukeshu@lukeshu.com>2025-02-26 16:18:27 -0700
committerLuke T. Shumaker <lukeshu@lukeshu.com>2025-02-26 16:18:27 -0700
commit560706708d7ff4a57880f855573fd525ebd309fe (patch)
tree0ee5cd6955d18cd5ce2ad83cbe90d190daa338f0 /libmisc
parent4a4998bc256f079f7a1a6393d3944c7458c29574 (diff)
parent8a231f17a865fbae5b4548f0aba80554b3c39d72 (diff)
Merge branch 'lukeshu/misc'
Diffstat (limited to 'libmisc')
-rw-r--r--libmisc/include/libmisc/macro.h8
-rw-r--r--libmisc/include/libmisc/private.h7
-rw-r--r--libmisc/tests/test_macro.c25
3 files changed, 33 insertions, 7 deletions
diff --git a/libmisc/include/libmisc/macro.h b/libmisc/include/libmisc/macro.h
index fe61410..b3e235c 100644
--- a/libmisc/include/libmisc/macro.h
+++ b/libmisc/include/libmisc/macro.h
@@ -17,9 +17,11 @@
/* numeric */
#define LM_ARRAY_LEN(ary) (sizeof(ary)/sizeof((ary)[0]))
-#define LM_CEILDIV(n, d) ( ((n)+(d)-1) / (d) )
-#define LM_ROUND_UP(n, d) ( LM_CEILDIV(n, d) * (d) ) /** Return `n` rounded up to the nearest multiple of `d` */
-#define LM_NEXT_POWER_OF_2(x) ( (x) ? 1ULL<<((sizeof(unsigned long long)*8)-__builtin_clzll(x)) : 1)
+#define LM_CEILDIV(n, d) ( ((n)+(d)-1) / (d) ) /** Return ceil(n/d) */
+#define LM_ROUND_UP(n, d) ( LM_CEILDIV(n, d) * (d) ) /** Return `n` rounded up to the nearest multiple of `d` */
+#define LM_ROUND_DOWN(n, d) ( ((n)/(d)) * (d) ) /** Return `n` rounded down to the nearest multiple of `d` */
+#define LM_NEXT_POWER_OF_2(x) ( (x) ? 1ULL<<((sizeof(unsigned long long)*8)-__builtin_clzll(x)) : 1) /** Return the lowest power of 2 that is > x */
+#define LM_FLOORLOG2(x) ((sizeof(unsigned long long)*8)-__builtin_clzll(x)-1) /** Return floor(log_2(x) */
/* strings */
diff --git a/libmisc/include/libmisc/private.h b/libmisc/include/libmisc/private.h
index 1db7915..c5382a7 100644
--- a/libmisc/include/libmisc/private.h
+++ b/libmisc/include/libmisc/private.h
@@ -1,6 +1,6 @@
/* libmisc/private.h - Utilities to hide struct fields
*
- * Copyright (C) 2024 Luke T. Shumaker <lukeshu@lukeshu.com>
+ * Copyright (C) 2024-2025 Luke T. Shumaker <lukeshu@lukeshu.com>
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
@@ -10,7 +10,8 @@
#include <libmisc/macro.h>
#define YES LM_SENTINEL()
-#define BEGIN_PRIVATE(name) LM_IF(LM_IS_SENTINEL(IMPLEMENTATION_FOR_##name))()(struct {)
-#define END_PRIVATE(name) LM_IF(LM_IS_SENTINEL(IMPLEMENTATION_FOR_##name))()(} LM_CAT2_(_HIDDEN_, __COUNTER__);)
+#define IS_IMPLEMENTATION_FOR(name) LM_IS_SENTINEL(IMPLEMENTATION_FOR_##name)
+#define BEGIN_PRIVATE(name) LM_IF(IS_IMPLEMENTATION_FOR(name))()(struct {)
+#define END_PRIVATE(name) LM_IF(IS_IMPLEMENTATION_FOR(name))()(} LM_CAT2_(_HIDDEN_, __COUNTER__);)
#endif /* _LIBMISC_PRIVATE_H_ */
diff --git a/libmisc/tests/test_macro.c b/libmisc/tests/test_macro.c
index 7cbf9d3..69655d1 100644
--- a/libmisc/tests/test_macro.c
+++ b/libmisc/tests/test_macro.c
@@ -1,6 +1,6 @@
/* libmisc/tests/test_macro.c - Tests for <libmisc/macro.h>
*
- * Copyright (C) 2024 Luke T. Shumaker <lukeshu@lukeshu.com>
+ * Copyright (C) 2024-2025 Luke T. Shumaker <lukeshu@lukeshu.com>
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
@@ -9,6 +9,7 @@
#include "test.h"
int main() {
+ printf("== LM_NEXT_POWER_OF_2 =====================================\n");
/* valid down to 0. */
test_assert(LM_NEXT_POWER_OF_2(0) == 1);
test_assert(LM_NEXT_POWER_OF_2(1) == 2);
@@ -28,5 +29,27 @@ int main() {
/* Valid up to 0x8000000000000000-1 = (1<<63)-1 */
test_assert(LM_NEXT_POWER_OF_2(0x8000000000000000) == 0); /* :( */
+ printf("== LM_FLOORLOG2 ===========================================\n");
+ /* valid down to 1. */
+ test_assert(LM_FLOORLOG2(1) == 0);
+ test_assert(LM_FLOORLOG2(2) == 1);
+ test_assert(LM_FLOORLOG2(3) == 1);
+ test_assert(LM_FLOORLOG2(4) == 2);
+ test_assert(LM_FLOORLOG2(5) == 2);
+ test_assert(LM_FLOORLOG2(6) == 2);
+ test_assert(LM_FLOORLOG2(7) == 2);
+ test_assert(LM_FLOORLOG2(8) == 3);
+ /* ... */
+ test_assert(LM_FLOORLOG2(16) == 4);
+ /* ... */
+ test_assert(LM_FLOORLOG2(0x80000000) == 31);
+ /* ... */
+ test_assert(LM_FLOORLOG2(0xFFFFFFFF) == 31);
+ test_assert(LM_FLOORLOG2(0x100000000) == 32);
+ /* ... */
+ test_assert(LM_FLOORLOG2(0x8000000000000000) == 63);
+ /* ... */
+ test_assert(LM_FLOORLOG2(0xFFFFFFFFFFFFFFFF) == 63);
+
return 0;
}