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fix(bit_tricks): make sure no one calls math.h's log2()

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this fixes the bit_trick test with MSVC
This commit is contained in:
Nuno Lopes 2018-03-05 16:49:04 +00:00 • committed by Leonardo de Moura
parent d569533bf5
commit 9152aaa7d6
3 changed files with 23 additions and 14 deletions
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28
src/tests/util/bit_tricks.cpp
View file

@ -9,20 +9,20 @@ Author: Leonardo de Moura
using namespace lean;
static void tst1() {
lean_assert(log2(255) == 7);
lean_assert(log2(256) == 8);
lean_assert(log2(257) == 8);
lean_assert(log2(321) == 8);
lean_assert(log2(520) == 9);
lean_assert(log2(65535) == 15);
lean_assert(log2(65536) == 16);
lean_assert(log2(65537) == 16);
lean_assert(log2(5203939) == 22);
lean_assert(log2(10309482) == 23);
lean_assert(log2(41039392) == 25);
lean_assert(log2(213469392) == 27);
lean_assert(log2(1293828727) == 30);
lean_assert(log2(1073741824) == 30);
lean_assert(log2(255u) == 7);
lean_assert(log2(256u) == 8);
lean_assert(log2(257u) == 8);
lean_assert(log2(321u) == 8);
lean_assert(log2(520u) == 9);
lean_assert(log2(65535u) == 15);
lean_assert(log2(65536u) == 16);
lean_assert(log2(65537u) == 16);
lean_assert(log2(5203939u) == 22);
lean_assert(log2(10309482u) == 23);
lean_assert(log2(41039392u) == 25);
lean_assert(log2(213469392u) == 27);
lean_assert(log2(1293828727u) == 30);
lean_assert(log2(1073741824u) == 30);
lean_assert(log2(2147483648u) == 31);
lean_assert(log2(4294967295u) == 31);
}

8
src/util/bit_tricks.cpp
View file

@ -4,6 +4,8 @@ Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include "util/debug.h"
namespace lean {
unsigned log2(unsigned v) {
unsigned r = 0;
@ -29,4 +31,10 @@ unsigned log2(unsigned v) {
}
return r;
}
// make sure no one calls the math.h log2 accidentally
double log2(int v) {
(void)v;
lean_unreachable();
}
}

1
src/util/bit_tricks.h
View file

@ -9,4 +9,5 @@ Author: Leonardo de Moura
namespace lean {
inline bool is_power_of_two(unsigned v) { return !(v & (v - 1)) && v; }
unsigned log2(unsigned v);
double log2(int v);
}