1 files changed, 99 insertions, 0 deletions
diff --git a/private/crt32/misc/bsearch.c b/private/crt32/misc/bsearch.c
new file mode 100644
index 000000000..5769de6b5
--- /dev/null
+++ b/private/crt32/misc/bsearch.c
@@ -0,0 +1,99 @@
+/***
+*bsearch.c - do a binary search
+*
+*	Copyright (c) 1985-1992, Microsoft Corporation. All rights reserved.
+*
+*Purpose:
+*	defines bsearch() - do a binary search an an array
+*
+*Revision History:
+*	07-05-84  RN	initial version
+*	06-19-85  TC	put in ifdefs to handle case of multiplication
+*			in large/huge model.
+*	04-13-87  JCR	added const to declaration
+*	08-04-87  JCR	Added "long" cast to mid= assignment for large/huge
+*			model.
+*	11-10-87  SKS	Removed IBMC20 switch
+*	12-11-87  JCR	Added "_LOAD_DS" to declaration
+*	01-21-88  JCR	Backed out _LOAD_DS...
+*	02-22-88  JCR	Added cast to get rid of cl const warning
+*	10-20-89  JCR	Added _cdecl to prototype, changed 'char' to 'void'
+*	03-14-90  GJF	Replaced _cdecl with _CALLTYPE1, added #include
+*			<cruntime.h>, removed #include <register.h> and fixed
+*			the copyright. Also, cleaned up the formatting a bit.
+*	04-05-90  GJF	Added #include <stdlib.h> and #include <search.h>.
+*			Fixed some resulting compiler warnings (at -W3).
+*			Also, removed #include <sizeptr.h>.
+*	07-25-90  SBM	Removed redundant include (stdio.h), made args match
+*			prototype
+*	10-04-90  GJF	New-style function declarator.
+*
+*******************************************************************************/
+
+#include <cruntime.h>
+#include <stdlib.h>
+#include <search.h>
+
+/***
+*char *bsearch() - do a binary search on an array
+*
+*Purpose:
+*	Does a binary search of a sorted array for a key.
+*
+*Entry:
+*	const char *key    - key to search for
+*	const char *base   - base of sorted array to search
+*	unsigned int num   - number of elements in array
+*	unsigned int width - number of bytes per element
+*	int (*compare)()   - pointer to function that compares two array
+*		elements, returning neg when #1 < #2, pos when #1 > #2, and
+*		0 when they are equal. Function is passed pointers to two
+*		array elements.
+*
+*Exit:
+*	if key is found:
+*		returns pointer to occurrence of key in array
+*	if key is not found:
+*		returns NULL
+*
+*Exceptions:
+*
+*******************************************************************************/
+
+void * _CALLTYPE1 bsearch (
+	REG4 const void *key,
+	const void *base,
+	size_t num,
+	size_t width,
+	int (_CALLTYPE1 *compare)(const void *, const void *)
+	)
+{
+	REG1 char *lo = (char *)base;
+	REG2 char *hi = (char *)base + (num - 1) * width;
+	REG3 char *mid;
+	unsigned int half;
+	int result;
+
+	while (lo <= hi)
+		if (half = num / 2)
+		{
+			mid = lo + (num & 1 ? half : (half - 1)) * width;
+			if (!(result = (*compare)(key,mid)))
+				return(mid);
+			else if (result < 0)
+			{
+				hi = mid - width;
+				num = num & 1 ? half : half-1;
+			}
+			else	{
+				lo = mid + width;
+				num = half;
+			}
+		}
+		else if (num)
+			return((*compare)(key,lo) ? NULL : lo);
+		else
+			break;
+
+	return(NULL);
+}