From 8a0efa53e44919bcf5ccb1d3353618a82afdf8bc Mon Sep 17 00:00:00 2001
From: Christopher Faylor <me@cgf.cx>
Date: Thu, 17 Feb 2000 19:39:52 +0000
Subject: import newlib-2000-02-17 snapshot

---
 newlib/libc/stdlib/bsearch.c | 100 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 newlib/libc/stdlib/bsearch.c

(limited to 'newlib/libc/stdlib/bsearch.c')

diff --git a/newlib/libc/stdlib/bsearch.c b/newlib/libc/stdlib/bsearch.c
new file mode 100644
index 000000000..b9539aa3b
--- /dev/null
+++ b/newlib/libc/stdlib/bsearch.c
@@ -0,0 +1,100 @@
+/*
+ * bsearch.c
+ * Original Author:	G. Haley
+ * Rewritten by:	G. Noer
+ *
+ * Searches an array of nmemb members, the initial member of which is pointed
+ * to by base, for a member that matches the object pointed to by key. The
+ * contents of the array shall be in ascending order according to a comparison
+ * function pointed to by compar. The function shall return an integer less
+ * than, equal to or greater than zero if the first argument is considered to be
+ * respectively less than, equal to or greater than the second. Returns a
+ * pointer to the matching member of the array, or a null pointer if no match
+ * is found.
+ */
+
+/*
+FUNCTION
+<<bsearch>>---binary search
+
+INDEX
+	bsearch
+
+ANSI_SYNOPSIS
+	#include <stdlib.h>
+	void *bsearch(const void *<[key]>, const void *<[base]>,
+		size_t <[nmemb]>, size_t <[size]>,
+		int (*<[compar]>)(const void *, const void *));
+
+TRAD_SYNOPSIS
+	#include <stdlib.h>
+	char *bsearch(<[key]>, <[base]>, <[nmemb]>, <[size]>, <[compar]>)
+	char *<[key]>;
+	char *<[base]>;
+	size_t <[nmemb]>, <[size]>;
+	int (*<[compar]>)();
+
+DESCRIPTION
+<<bsearch>> searches an array beginning at <[base]> for any element
+that matches <[key]>, using binary search.  <[nmemb]> is the element
+count of the array; <[size]> is the size of each element.
+
+The array must be sorted in ascending order with respect to the
+comparison function <[compar]> (which you supply as the last argument of
+<<bsearch>>).
+
+You must define the comparison function <<(*<[compar]>)>> to have two
+arguments; its result must be negative if the first argument is
+less than the second, zero if the two arguments match, and
+positive if the first argument is greater than the second (where
+``less than'' and ``greater than'' refer to whatever arbitrary
+ordering is appropriate).
+
+RETURNS
+Returns a pointer to an element of <[array]> that matches <[key]>.  If
+more than one matching element is available, the result may point to
+any of them.
+
+PORTABILITY
+<<bsearch>> is ANSI.
+
+No supporting OS subroutines are required.
+*/
+
+#include <stdlib.h>
+
+_PTR
+_DEFUN (bsearch, (key, base, nmemb, size, compar),
+	_CONST _PTR key _AND
+	_CONST _PTR base _AND
+	size_t nmemb _AND
+	size_t size _AND
+	int _EXFUN ((*compar), (const _PTR, const _PTR)))
+{
+  _PTR current;
+  size_t lower = 0;
+  size_t upper = nmemb;
+  size_t index;
+  int result;
+
+  if (nmemb == 0 || size == 0)
+    return NULL;
+
+  while (lower < upper)
+    {
+      index = (lower + upper) / 2;
+      current = (_PTR) (((char *) base) + (index * size));
+
+      result = compar (key, current);
+
+      if (result < 0)
+        upper = index;
+      else if (result > 0)
+        lower = index + 1;
+      else
+	return current;
+    }
+
+  return NULL;
+}
+
-- 
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