gcc/

	Backport from trunk r247750.
	2017-05-08  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	* target.def (compute_frame_layout): New optional target hook.
	* doc/tm.texi.in (TARGET_COMPUTE_FRAME_LAYOUT): Add hook.
	* doc/tm.texi (TARGET_COMPUTE_FRAME_LAYOUT): Add documentation.
	* lra-eliminations.c (update_reg_eliminate): Call compute_frame_layout
	target hook.
	* reload1.c (verify_initial_elim_offsets): Likewise.
	* config/arm/arm.c (TARGET_COMPUTE_FRAME_LAYOUT): Define.
	(use_simple_return_p): Call arm_compute_frame_layout if needed.
	(arm_get_frame_offsets): Split up into this ...
	(arm_compute_frame_layout): ... and this function.

Change-Id: Id438fc023af71b802eddf333f138767a706303fa

1 files changed, 25 insertions, 9 deletions

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 83914913433..acf821a594d 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -85,6 +85,7 @@ static bool arm_const_not_ok_for_debug_p (rtx);
 static int arm_needs_doubleword_align (machine_mode, const_tree);
 static int arm_compute_static_chain_stack_bytes (void);
 static arm_stack_offsets *arm_get_frame_offsets (void);
+static void arm_compute_frame_layout (void);
 static void arm_add_gc_roots (void);
 static int arm_gen_constant (enum rtx_code, machine_mode, rtx,
 			     unsigned HOST_WIDE_INT, rtx, rtx, int, int);
@@ -680,6 +681,9 @@ static const struct attribute_spec arm_attribute_table[] =
 #undef TARGET_SCALAR_MODE_SUPPORTED_P
 #define TARGET_SCALAR_MODE_SUPPORTED_P arm_scalar_mode_supported_p
 
+#undef TARGET_COMPUTE_FRAME_LAYOUT
+#define TARGET_COMPUTE_FRAME_LAYOUT arm_compute_frame_layout
+
 #undef TARGET_FRAME_POINTER_REQUIRED
 #define TARGET_FRAME_POINTER_REQUIRED arm_frame_pointer_required
 
@@ -4031,6 +4035,10 @@ use_simple_return_p (void)
 {
   arm_stack_offsets *offsets;
 
+  /* Note this function can be called before or after reload.  */
+  if (!reload_completed)
+    arm_compute_frame_layout ();
+
   offsets = arm_get_frame_offsets ();
   return offsets->outgoing_args != 0;
 }
@@ -19105,7 +19113,7 @@ arm_compute_static_chain_stack_bytes (void)
 
 /* Compute a bit mask of which registers need to be
    saved on the stack for the current function.
-   This is used by arm_get_frame_offsets, which may add extra registers.  */
+   This is used by arm_compute_frame_layout, which may add extra registers.  */
 
 static unsigned long
 arm_compute_save_reg_mask (void)
@@ -20739,12 +20747,25 @@ any_sibcall_could_use_r3 (void)
   alignment.  */
 
 
+/* Return cached stack offsets.  */
+
+static arm_stack_offsets *
+arm_get_frame_offsets (void)
+{
+  struct arm_stack_offsets *offsets;
+
+  offsets = &cfun->machine->stack_offsets;
+
+  return offsets;
+}
+
+
 /* Calculate stack offsets.  These are used to calculate register elimination
    offsets and in prologue/epilogue code.  Also calculates which registers
    should be saved.  */
 
-static arm_stack_offsets *
-arm_get_frame_offsets (void)
+static void
+arm_compute_frame_layout (void)
 {
   struct arm_stack_offsets *offsets;
   unsigned long func_type;
@@ -20755,9 +20776,6 @@ arm_get_frame_offsets (void)
 
   offsets = &cfun->machine->stack_offsets;
 
-  if (reload_completed)
-    return offsets;
-
   /* Initially this is the size of the local variables.  It will translated
      into an offset once we have determined the size of preceding data.  */
   frame_size = ROUND_UP_WORD (get_frame_size ());
@@ -20822,7 +20840,7 @@ arm_get_frame_offsets (void)
     {
       offsets->outgoing_args = offsets->soft_frame;
       offsets->locals_base = offsets->soft_frame;
-      return offsets;
+      return;
     }
 
   /* Ensure SFP has the correct alignment.  */
@@ -20898,8 +20916,6 @@ arm_get_frame_offsets (void)
 	offsets->outgoing_args += 4;
       gcc_assert (!(offsets->outgoing_args & 7));
     }
-
-  return offsets;
 }