squiid/mlibc
1
0
Fork 0
Code Issues Pull requests Actions Packages Projects Releases Wiki Activity

libc: Implement bsearch()

Browse source
This commit is contained in:
Alexander van der Grinten 2017-12-22 18:09:35 +01:00
parent e9e1d3ddeb
commit 819e03e6ad
1 changed files with 19 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

21
libc/generic/ansi/src/stdlib-stubs.cpp
View file

@ -197,8 +197,25 @@ char *mktemp(char *) {
void *bsearch(const void *key, const void *base, size_t count, size_t size,
int (*compare)(const void *, const void *)) {
__ensure(!"Not implemented");
__builtin_unreachable();
// Invariant: Element is in the interval [i, j).
size_t i = 0;
size_t j = count;
while(i < j) {
size_t k = (j - i) / 2;
auto element = reinterpret_cast<const char *>(base) + (i + k) * size;
auto res = compare(key, element);
if(res < 0) {
j = i + k;
}else if(res > 0) {
i = i + k + 1;
}else{
return const_cast<char *>(element);
}
}
__ensure(i == j);
return nullptr;
}
void qsort(void *base, size_t count, size_t size,
int (*compare)(const void *, const void *)) {