6 files changed, 65 insertions, 7 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5432bd5..cfa747b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-09-15  Jakub Jelinek  <jakub@redhat.com>
+
+	* builtins.c (expand_builtin_memmove): Optimize memmove (x, y, 1)
+	into memcpy (x, y, 1) if memcpy can be expanded inline.
+
 2004-09-15  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
 
 	PR tree-optimization/17468
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 34dceb9..bf5ec08 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -2940,6 +2940,16 @@ expand_builtin_memmove (tree arglist, rtx target, enum machine_mode mode)
 			      target, mode, EXPAND_NORMAL);
 	}
 
+      /* If length is 1 and we can expand memcpy call inline,
+	 it is ok to use memcpy as well.  */
+      if (integer_onep (len))
+        {
+	  rtx ret = expand_builtin_mempcpy (arglist, target, mode,
+					    /*endp=*/0);
+	  if (ret)
+	    return ret;
+        }
+
       /* Otherwise, call the normal function.  */
       return 0;
    }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3f28435..8cda9ff 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2004-09-15  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.c-torture/execute/builtins/memmove.c (main_test): Formatting.
+	* gcc.c-torture/execute/builtins/memmove-2.c: New test.
+	* gcc.c-torture/execute/builtins/memmove-2-lib.c: New.
+
 2004-09-14  Mark Mitchell  <mark@codesourcery.com>
 
 	PR c++/17324
diff --git a/gcc/testsuite/gcc.c-torture/execute/builtins/memmove-2-lib.c b/gcc/testsuite/gcc.c-torture/execute/builtins/memmove-2-lib.c
new file mode 100644
index 0000000..5be3df5
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/builtins/memmove-2-lib.c
@@ -0,0 +1 @@
+#include "lib/memmove.c"
diff --git a/gcc/testsuite/gcc.c-torture/execute/builtins/memmove-2.c b/gcc/testsuite/gcc.c-torture/execute/builtins/memmove-2.c
new file mode 100644
index 0000000..3afe343
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/builtins/memmove-2.c
@@ -0,0 +1,36 @@
+/* Copyright (C) 2004  Free Software Foundation.
+
+   Check builtin memmove and bcopy optimization when length is 1.
+
+   Written by Jakub Jelinek, 9/14/2004.  */
+
+extern void abort (void);
+typedef __SIZE_TYPE__ size_t;
+extern void *memmove (void *, const void *, size_t);
+extern void bcopy (const void *, void *, size_t);
+extern int memcmp (const void *, const void *, size_t);
+
+char p[32] = "abcdefg";
+char *q = p + 4;
+
+void
+main_test (void)
+{
+  /* memmove with length 1 can be optimized into memcpy if it can be
+     expanded inline.  */
+  if (memmove (p + 2, p + 3, 1) != p + 2 || memcmp (p, "abddefg", 8))
+    abort ();
+  if (memmove (p + 1, p + 1, 1) != p + 1 || memcmp (p, "abddefg", 8))
+    abort ();
+  if (memmove (q, p + 4, 1) != p + 4 || memcmp (p, "abddefg", 8))
+    abort ();
+  bcopy (p + 5, p + 6, 1);
+  if (memcmp (p, "abddeff", 8))
+    abort ();
+  bcopy (p + 1, p + 1, 1);
+  if (memcmp (p, "abddeff", 8))
+    abort ();
+  bcopy (q, p + 4, 1);
+  if (memcmp (p, "abddeff", 8))
+    abort ();
+}
diff --git a/gcc/testsuite/gcc.c-torture/execute/builtins/memmove.c b/gcc/testsuite/gcc.c-torture/execute/builtins/memmove.c
index 4a18fc6..f52332c 100644
--- a/gcc/testsuite/gcc.c-torture/execute/builtins/memmove.c
+++ b/gcc/testsuite/gcc.c-torture/execute/builtins/memmove.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2003  Free Software Foundation.
+/* Copyright (C) 2003, 2004  Free Software Foundation.
 
    Ensure builtin memmove and bcopy perform correctly.
 
@@ -62,13 +62,13 @@ main_test (void)
   struct bar b1[sizeof bar/sizeof*bar];
   int bz[sizeof baz/sizeof*baz];
 
-  if (memmove (f1, foo, sizeof (foo)) != f1 || memcmp (f1, foo, sizeof(foo)))
-    abort();
-  if (memmove (b1, bar, sizeof (bar)) != b1 || memcmp (b1, bar, sizeof(bar)))
-    abort();
+  if (memmove (f1, foo, sizeof (foo)) != f1 || memcmp (f1, foo, sizeof (foo)))
+    abort ();
+  if (memmove (b1, bar, sizeof (bar)) != b1 || memcmp (b1, bar, sizeof (bar)))
+    abort ();
   bcopy (baz, bz, sizeof (baz));
-  if (memcmp (bz, baz, sizeof(baz)))
-    abort();
+  if (memcmp (bz, baz, sizeof (baz)))
+    abort ();
 
   if (memmove (p, "abcde", 6) != p || memcmp (p, "abcde", 6))
     abort ();