common.opt: Add -foptimize-strlen option.

	* common.opt: Add -foptimize-strlen option.
	* Makefile.in (OBJS): Add tree-ssa-strlen.o.
	(tree-sssa-strlen.o): Add dependencies.
	* opts.c (default_options_table): Enable -foptimize-strlen
	by default at -O2 if not -Os.
	* passes.c (init_optimization_passes): Add pass_strlen
	after pass_object_sizes.
	* timevar.def (TV_TREE_STRLEN): New timevar.
	* params.def (PARAM_MAX_TRACKED_STRLENS): New parameter.
	* tree-pass.h (pass_strlen): Declare.
	* tree-ssa-strlen.c: New file.
	* c-decl.c (merge_decls): If compatible stpcpy prototype
	is seen, set implicit_built_in_decls[BUILT_IN_STPCPY].
cp/
	* decl.c (duplicate_decls): If compatible stpcpy prototype
	is seen, set implicit_built_in_decls[BUILT_IN_STPCPY].
testsuite/
	* gcc.dg/strlenopt-1.c: New test.
	* gcc.dg/strlenopt-1f.c: New test.
	* gcc.dg/strlenopt-2.c: New test.
	* gcc.dg/strlenopt-2f.c: New test.
	* gcc.dg/strlenopt-3.c: New test.
	* gcc.dg/strlenopt-4.c: New test.
	* gcc.dg/strlenopt-4g.c: New test.
	* gcc.dg/strlenopt-4gf.c: New test.
	* gcc.dg/strlenopt-5.c: New test.
	* gcc.dg/strlenopt-6.c: New test.
	* gcc.dg/strlenopt-7.c: New test.
	* gcc.dg/strlenopt-8.c: New test.
	* gcc.dg/strlenopt-9.c: New test.
	* gcc.dg/strlenopt-10.c: New test.
	* gcc.dg/strlenopt-11.c: New test.
	* gcc.dg/strlenopt-12.c: New test.
	* gcc.dg/strlenopt-12g.c: New test.
	* gcc.dg/strlenopt-13.c: New test.
	* gcc.dg/strlenopt-14g.c: New test.
	* gcc.dg/strlenopt-14gf.c: New test.
	* gcc.dg/strlenopt-15.c: New test.
	* gcc.dg/strlenopt-16g.c: New test.
	* gcc.dg/strlenopt-17g.c: New test.
	* gcc.dg/strlenopt-18g.c: New test.
	* gcc.dg/strlenopt.h: New file.

From-SVN: r179277

1 files changed, 47 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/strlenopt-1.c b/gcc/testsuite/gcc.dg/strlenopt-1.c
new file mode 100644
index 0000000..5bc4f0c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/strlenopt-1.c
@@ -0,0 +1,47 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-strlen" } */
+
+#include "strlenopt.h"
+
+__attribute__((noinline, noclone)) char *
+foo (char *p, char *r)
+{
+  char *q = malloc (strlen (p) + strlen (r) + 64);
+  if (q == NULL) return NULL;
+  /* This strcpy can be optimized into memcpy, using the remembered
+     strlen (p).  */
+  strcpy (q, p);
+  /* These two strcat can be optimized into memcpy.  The first one
+     could be even optimized into a *ptr = '/'; store as the '\0'
+     is immediately overwritten.  */
+  strcat (q, "/");
+  strcat (q, "abcde");
+  /* Due to inefficient PTA (PR50262) the above calls invalidate
+     string length of r, so it is optimized just into strcpy instead
+     of memcpy.  */
+  strcat (q, r);
+  return q;
+}
+
+int
+main ()
+{
+  char *volatile p = "string1";
+  char *volatile r = "string2";
+  char *q = foo (p, r);
+  if (q != NULL)
+    {
+      if (strcmp (q, "string1/abcdestring2"))
+	abort ();
+      free (q);
+    }
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "memcpy \\(" 3 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strcpy \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
+/* { dg-final { cleanup-tree-dump "strlen" } } */