builtins.c (expand_builtin_strncmp, [...]): New functions.

	* builtins.c (expand_builtin_strncmp, expand_builtin_strncpy): New
	functions.
	(expand_builtin): Handle BUILT_IN_STRNCPY and BUILT_IN_STRNCMP.

	* builtins.def (BUILT_IN_STRNCPY, BUILT_IN_STRNCMP): New entries.

	* c-common.c (c_common_nodes_and_builtins): Declare builtin
	strncpy and strncmp.

	* extend.texi (strncmp, strncpy): Document new builtins.

testsuite:
	* gcc.c-torture/execute/string-opt-7.c: New test.
	* gcc.c-torture/execute/string-opt-8.c: Likewise.

From-SVN: r37777

2 files changed, 131 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.c-torture/execute/string-opt-7.c b/gcc/testsuite/gcc.c-torture/execute/string-opt-7.c
new file mode 100644
index 0000000..105b3dc
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/string-opt-7.c
@@ -0,0 +1,71 @@
+/* Copyright (C) 2000  Free Software Foundation.
+
+   Ensure all expected transformations of builtin strncpy occur and
+   perform correctly.
+
+   Written by Kaveh R. Ghazi, 11/25/2000.  */
+
+extern void abort (void);
+typedef __SIZE_TYPE__ size_t;
+extern char *strncpy (char *, const char *, size_t);
+extern int strcmp (const char *, const char *);
+extern int strncmp (const char *, const char *, size_t);
+extern void *memset (void *, int, size_t);
+
+int main ()
+{
+  const char *const src = "hello world";
+  const char *src2;
+  char dst[64], *dst2;
+  
+  memset (dst, 0, sizeof (dst));
+  if (strncpy (dst, src, 4) != dst || strncmp (dst, src, 4))
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (strncpy (dst+16, src, 4) != dst+16 || strncmp (dst+16, src, 4))
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (strncpy (dst+32, src+5, 4) != dst+32 || strncmp (dst+32, src+5, 4))
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  dst2 = dst;
+  if (strncpy (++dst2, src+5, 4) != dst+1 || strncmp (dst2, src+5, 4)
+      || dst2 != dst+1)
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (strncpy (dst, src, 0) != dst || strcmp (dst, ""))
+    abort();
+  
+  memset (dst, 0, sizeof (dst));
+  dst2 = dst; src2 = src;
+  if (strncpy (++dst2, ++src2, 0) != dst+1 || strcmp (dst2, "")
+      || dst2 != dst+1 || src2 != src+1)
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  dst2 = dst; src2 = src;
+  if (strncpy (++dst2+5, ++src2+5, 0) != dst+6 || strcmp (dst2+5, "")
+      || dst2 != dst+1 || src2 != src+1)
+    abort();
+
+  memset (dst, 0, sizeof (dst));
+  if (strncpy (dst, src, 12) != dst || strcmp (dst, src))
+    abort();
+
+  return 0;
+}
+
+#ifdef __OPTIMIZE__
+/* When optimizing, all the above cases should be transformed into
+   something else.  So any remaining calls to the original function
+   should abort.  */
+static char *
+strncpy(char *s1, const char *s2, size_t n)
+{
+  abort();
+}
+#endif
diff --git a/gcc/testsuite/gcc.c-torture/execute/string-opt-8.c b/gcc/testsuite/gcc.c-torture/execute/string-opt-8.c
new file mode 100644
index 0000000..ca386f0
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/string-opt-8.c
@@ -0,0 +1,60 @@
+/* Copyright (C) 2000  Free Software Foundation.
+
+   Ensure all expected transformations of builtin strncmp occur and
+   perform correctly.
+
+   Written by Kaveh R. Ghazi, 11/26/2000.  */
+
+extern void abort (void);
+typedef __SIZE_TYPE__ size_t;
+extern int strncmp (const char *, const char *, size_t);
+
+int main ()
+{
+  const char *const s1 = "hello world";
+  const char *s2, *s3;
+  
+  if (strncmp (s1, "hello world", 12) != 0)
+    abort();
+  if (strncmp ("hello world", s1, 12) != 0)
+    abort();
+  if (strncmp ("hello", "hello", 6) != 0)
+    abort();
+  if (strncmp ("hello", "hello", 2) != 0)
+    abort();
+  if (strncmp ("hello", "hello", 100) != 0)
+    abort();
+  if (strncmp (s1+10, "d", 100) != 0)
+    abort();
+  if (strncmp (10+s1, "d", 100) != 0)
+    abort();
+  if (strncmp ("d", s1+10, 1) != 0)
+    abort();
+  if (strncmp ("d", 10+s1, 1) != 0)
+    abort();
+  if (strncmp ("hello", "aaaaa", 100) <= 0)
+    abort();
+  if (strncmp ("aaaaa", "hello", 100) >= 0)
+    abort();
+  if (strncmp ("hello", "aaaaa", 1) <= 0)
+    abort();
+  if (strncmp ("aaaaa", "hello", 1) >= 0)
+    abort();
+
+  s2 = s1; s3 = s1+4;
+  if (strncmp (++s2, ++s3, 0) != 0 || s2 != s1+1 || s3 != s1+5)
+    abort();
+  
+  return 0;
+}
+
+#ifdef __OPTIMIZE__
+/* When optimizing, all the above cases should be transformed into
+   something else.  So any remaining calls to the original function
+   should abort.  */
+static char *
+strncmp(const char *s1, const char *s2, size_t n)
+{
+  abort();
+}
+#endif