[AArch64] Backport of PR target/70044 fix to GCC 5

2016-04-14  Nick Clifton  <nickc@redhat.com>
            Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	PR target/70044
	* config/aarch64/aarch64.c
	(aarch64_override_options_after_change): When forcing
	flag_omit_frame_pointer to be true, use a special value that can
	be detected if this function is called again, thus preventing
	flag_omit_leaf_frame_pointer from being forced to be false.

	* gcc.target/aarch64/pr70044.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-5-branch@234974 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 49 insertions, 1 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 275be460544..f6cb067a3d8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2016-04-14  Nick Clifton  <nickc@redhat.com>
+            Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR target/70044
+	* config/aarch64/aarch64.c
+	(aarch64_override_options_after_change): When forcing
+	flag_omit_frame_pointer to be true, use a special value that can
+	be detected if this function is called again, thus preventing
+	flag_omit_leaf_frame_pointer from being forced to be false.
+
 2016-04-12  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR target/70630
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 5c7291e535d..4113609d470 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -6917,10 +6917,26 @@ aarch64_override_options (void)
 static void
 aarch64_override_options_after_change (void)
 {
+  /* The logic here is that if we are disabling all frame pointer generation
+     then we do not need to disable leaf frame pointer generation as a
+     separate operation.  But if we are *only* disabling leaf frame pointer
+     generation then we set flag_omit_frame_pointer to true, but in
+     aarch64_frame_pointer_required we return false only for leaf functions.
+
+     PR 70044: We have to be careful about being called multiple times for the
+     same function.  Once we have decided to set flag_omit_frame_pointer just
+     so that we can omit leaf frame pointers, we must then not interpret a
+     second call as meaning that all frame pointer generation should be
+     omitted.  We do this by setting flag_omit_frame_pointer to a special,
+     non-zero value.  */
+
+  if (flag_omit_frame_pointer == 2)
+    flag_omit_frame_pointer = 0;
+
   if (flag_omit_frame_pointer)
     flag_omit_leaf_frame_pointer = false;
   else if (flag_omit_leaf_frame_pointer)
-    flag_omit_frame_pointer = true;
+    flag_omit_frame_pointer = 2;
 
   /* If not optimizing for size, set the default
      alignment to what the target wants */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 74ca8a6b91c..12bda055379 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2016-04-14  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	Backport from mainline
+	2016-03-31  Nick Clifton  <nickc@redhat.com>
+
+	PR target/70044
+	* gcc.target/aarch64/pr70044.c: New test.
+
 2016-04-13  Alan Modra  <amodra@gmail.com>
 
 	Backport from mainline
diff --git a/gcc/testsuite/gcc.target/aarch64/pr70044.c b/gcc/testsuite/gcc.target/aarch64/pr70044.c
new file mode 100644
index 00000000000..1a84941dd7e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr70044.c
@@ -0,0 +1,14 @@
+/* { dg-do link } */
+/* { dg-require-effective-target lto } */
+/* { dg-options "-flto -O --save-temps -fno-omit-frame-pointer" } */
+
+extern int atoi (const char *);
+
+int
+main (int argc, char **argv)
+{
+  return atoi (argv[0]) + 1;
+}
+
+/* Check that the frame pointer really is created.  */
+/* { dg-final { scan-lto-assembler "add	x29, sp," } } */