[commit] SPU i-cache: Correct calculation of number of required stubs (1/2)

["Ulrich Weigand" <uweigand at de dot ibm dot com>]

Hello,

spu_elf_auto_overlay computes the number of stubs required per overlay /
i-cache section by counting the number of distinct outgoing function calls.
This is correct for the overlay case, but incorrect for the i-cache case
-- due to branch rewriting, we need a separate stub for each call site.

This patch uses the call_info->count field to properly account for multiple
calls to the same symbol.  However, as spu_elf_auto_overlay operates on
copies of the call_info structs, and those copies lost their proper counts
while going through copy_callee / insert_callee, the patch fixes this as well.

Tested on spu-elf with no regressions.
Approved off-line by Alan Modra; committed to mainline.

Bye,
Ulrich


ChangeLog:

	* elf32-spu.c (insert_callee): Accumulate incoming callee->count.
	(mark_functions_via_relocs): Initialize callee->count to 1.
	(pasted_function): Likewise.
	(spu_elf_auto_overlay): Honor call counts when determining number
	of stubs required in software i-cache mode.

--- src/bfd/elf32-spu.c.orig	2009-05-26 21:23:13.000000000 +0200
+++ src/bfd/elf32-spu.c	2009-05-26 21:24:41.000000000 +0200
@@ -2588,7 +2589,7 @@ insert_callee (struct function_info *cal
 	    p->fun->start = NULL;
 	    p->fun->is_func = TRUE;
 	  }
-	p->count += 1;
+	p->count += callee->count;
 	/* Reorder list so most recent call is first.  */
 	*pp = p->next;
 	p->next = caller->call_list;
@@ -2596,7 +2597,6 @@ insert_callee (struct function_info *cal
 	return FALSE;
       }
   callee->next = caller->call_list;
-  callee->count += 1;
   caller->call_list = callee;
   return TRUE;
 }
@@ -2786,7 +2786,7 @@ mark_functions_via_relocs (asection *sec
       callee->is_tail = !is_call;
       callee->is_pasted = FALSE;
       callee->priority = priority;
-      callee->count = 0;
+      callee->count = 1;
       if (callee->fun->last_caller != sec)
 	{
 	  callee->fun->last_caller = sec;
@@ -2878,7 +2878,7 @@ pasted_function (asection *sec)
 	      callee->fun = fun;
 	      callee->is_tail = TRUE;
 	      callee->is_pasted = TRUE;
-	      callee->count = 0;
+	      callee->count = 1;
 	      if (!insert_callee (fun_start, callee))
 		free (callee);
 	      return TRUE;
@@ -4434,14 +4439,18 @@ spu_elf_auto_overlay (struct bfd_link_in
 	  for (call = dummy_caller.call_list; call; call = call->next)
 	    {
 	      unsigned int k;
+	      unsigned int stub_delta = 1;
+
+	      if (htab->params->ovly_flavour == ovly_soft_icache)
+		stub_delta = call->count;
+	      num_stubs += stub_delta;
 
-	      ++num_stubs;
 	      /* If the call is within this overlay, we won't need a
 		 stub.  */
 	      for (k = base; k < i + 1; k++)
 		if (call->fun->sec == ovly_sections[2 * k])
 		  {
-		    --num_stubs;
+		    num_stubs -= stub_delta;
 		    break;
 		  }
 	    }
-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com