2009-11-23 Paul Brook <paul@codesourcery.com>

	gcc/
	* config/arm/arm.c (arm_compute_save_reg0_reg12_mask): Add special
	case for noreturn functions.
	(arm_compute_save_reg_mask): Remove special noreturn handling.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@154441 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a00e858..0fffc28 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-11-23  Paul Brook  <paul@codesourcery.com>
+
+       * config/arm/arm.c (arm_compute_save_reg0_reg12_mask): Add special
+       case for noreturn functions.
+       (arm_compute_save_reg_mask): Remove special noreturn handling.
+
 2009-11-23  Richard Guenther  <rguenther@suse.de>
 
        * tree-dfa.c (get_ref_base_and_extent): Adjust maximum access

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 3a94745..289f27a 100644 (file)
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -12831,6 +12831,20 @@ arm_compute_save_reg0_reg12_mask (void)
          && crtl->uses_pic_offset_table)
        save_reg_mask |= 1 << PIC_OFFSET_TABLE_REGNUM;
     }
+  else if (IS_VOLATILE(func_type))
+    {
+      /* For noreturn functions we historically omitted register saves
+        altogether.  However this really messes up debugging.  As a
+        compromise save just the fame pointers.  Combined with the link
+        register saved elsewhere this should be sufficient to get
+        a backtrace.  */
+      if (frame_pointer_needed)
+       save_reg_mask |= 1 << HARD_FRAME_POINTER_REGNUM;
+      if (df_regs_ever_live_p (ARM_HARD_FRAME_POINTER_REGNUM))
+       save_reg_mask |= 1 << ARM_HARD_FRAME_POINTER_REGNUM;
+      if (df_regs_ever_live_p (THUMB_HARD_FRAME_POINTER_REGNUM))
+       save_reg_mask |= 1 << THUMB_HARD_FRAME_POINTER_REGNUM;
+    }
   else
     {
       /* In the normal case we only need to save those registers
@@ -12917,11 +12931,6 @@ arm_compute_save_reg_mask (void)
       | (1 << LR_REGNUM)
       | (1 << PC_REGNUM);
 
-  /* Volatile functions do not return, so there
-     is no need to save any other registers.  */
-  if (IS_VOLATILE (func_type))
-    return save_reg_mask;
-
   save_reg_mask |= arm_compute_save_reg0_reg12_mask ();
 
   /* Decide if we need to save the link register.