From 9c5cca784e631a371601f06bac1224b29277e8f3 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Mon, 17 Jun 2024 16:50:23 +0300
Subject: [PATCH] LibC: Implement bsearch()

---
 libc/stdlib.cpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/libc/stdlib.cpp b/libc/stdlib.cpp
index bdfe27a2..e67b5a5e 100644
--- a/libc/stdlib.cpp
+++ b/libc/stdlib.cpp
@@ -495,6 +495,32 @@ int putenv(char* string)
 	return 0;
 }
 
+void* bsearch(const void* key, const void* base, size_t nel, size_t width, int (*compar)(const void*, const void*))
+{
+	if (nel == 0)
+		return nullptr;
+
+	const uint8_t* base_u8 = reinterpret_cast<const uint8_t*>(base);
+
+	size_t l = 0;
+	size_t r = nel - 1;
+	while (l <= r)
+	{
+		const size_t mid = (l + r) / 2;
+
+		int res = compar(key, base_u8 + mid * width);
+		if (res == 0)
+			return const_cast<uint8_t*>(base_u8 + mid * width);
+
+		if (res < 0)
+			r = mid - 1;
+		else
+			l = mid + 1;
+	}
+
+	return nullptr;
+}
+
 static void qsort_swap(void* lhs, void* rhs, size_t width)
 {
 	uint8_t buffer[64];