global.c (compute_regsets): Set frame_pointer_needed here.

2008-06-30  Joey Ye  <joey.ye@intel.com>
	    H.J. Lu  <hongjiu.lu@intel.com>

	* global.c (compute_regsets): Set frame_pointer_needed here.

	* reload1.c (init_elim_table): Don't set frame_pointer_needed
	here.

Co-Authored-By: H.J. Lu <hongjiu.lu@intel.com>

From-SVN: r137275

gcc/ChangeLog

+2008-06-30  Joey Ye  <joey.ye@intel.com>
+	    H.J. Lu  <hongjiu.lu@intel.com>
+
+	* global.c (compute_regsets): Set frame_pointer_needed here.
+
+	* reload1.c (init_elim_table): Don't set frame_pointer_needed
+	here.
+
 2008-06-30  Aaron W. LaFramboise  <aaronavay62@aaronwl.com>
 
 	* doc/install.texi (specific): Expand Windows build notes.

gcc/global.c

@@ -206,7 +206,9 @@ static void build_insn_chain (void);
 
    This will normally be called with ELIM_SET as the file static
    variable eliminable_regset, and NO_GLOBAL_SET as the file static
-   variable NO_GLOBAL_ALLOC_REGS.  */
+   variable NO_GLOBAL_ALLOC_REGS.
+
+   It also initializes global flag frame_pointer_needed.  */
 
 static void
 compute_regsets (HARD_REG_SET *elim_set, 
@@ -222,11 +224,19 @@ compute_regsets (HARD_REG_SET *elim_set,
   static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
   size_t i;
 #endif
+
+  /* FIXME: If EXIT_IGNORE_STACK is set, we will not save and restore
+     sp for alloca.  So we can't eliminate the frame pointer in that
+     case.  At some point, we should improve this by emitting the
+     sp-adjusting insns for this case.  */
   int need_fp
     = (! flag_omit_frame_pointer
        || (cfun->calls_alloca && EXIT_IGNORE_STACK)
+       || crtl->accesses_prior_frames
        || FRAME_POINTER_REQUIRED);
 
+  frame_pointer_needed = need_fp;
+
   max_regno = max_reg_num ();
   compact_blocks ();
 

gcc/reload1.c

@@ -3695,7 +3695,9 @@ elimination_target_reg_p (rtx x)
   return false;
 }
 
-/* Initialize the table of registers to eliminate.  */
+/* Initialize the table of registers to eliminate.
+   Pre-condition: global flag frame_pointer_needed has been set before
+   calling this function.  */
 
 static void
 init_elim_table (void)
@@ -3708,19 +3710,6 @@ init_elim_table (void)
   if (!reg_eliminate)
     reg_eliminate = XCNEWVEC (struct elim_table, NUM_ELIMINABLE_REGS);
 
-  /* Does this function require a frame pointer?  */
-
-  frame_pointer_needed = (! flag_omit_frame_pointer
-			  /* ?? If EXIT_IGNORE_STACK is set, we will not save
-			     and restore sp for alloca.  So we can't eliminate
-			     the frame pointer in that case.  At some point,
-			     we should improve this by emitting the
-			     sp-adjusting insns for this case.  */
-			  || (cfun->calls_alloca
-			      && EXIT_IGNORE_STACK)
-			  || crtl->accesses_prior_frames
-			  || FRAME_POINTER_REQUIRED);
-
   num_eliminable = 0;
 
 #ifdef ELIMINABLE_REGS