path: root/meta-oe/recipes-devtools/gcc/gcc-4.5/linaro/gcc-4.5-linaro-r99312.patch

2010-07-15  Sandra Loosemore  <sandra@codesourcery.com>

	Backport from mainline:

	2010-06-09  Sandra Loosemore  <sandra@codesourcery.com>

	gcc/	
	* tree-ssa-loop-ivopts.c (adjust_setup_cost): New function.
	(get_computation_cost_at): Use it.
	(determine_use_iv_cost_condition): Likewise.
	(determine_iv_cost): Likewise.

	2010-07-05  Sandra Loosemore  <sandra@codesourcery.com>

	PR middle-end/42505

	gcc/
	* tree-ssa-loop-ivopts.c (determine_set_costs): Delete obsolete
	comments about cost model.
	(try_add_cand_for):  Add second strategy for choosing initial set
	based on original IVs, controlled by ORIGINALP argument.
	(get_initial_solution): Add ORIGINALP argument.
	(find_optimal_iv_set_1): New function, split from find_optimal_iv_set.
	(find_optimal_iv_set): Try two different strategies for choosing
	the IV set, and return the one with lower cost.

	gcc/testsuite/
	* gcc.target/arm/pr42505.c: New test case.

	2010-07-10  Sandra Loosemore  <sandra@codesourcery.com>

	PR middle-end/42505

	gcc/
	* tree-inline.c (estimate_num_insns): Refactor builtin complexity
	lookup code into....
	* builtins.c (is_simple_builtin, is_inexpensive_builtin): ...these
	new functions.
	* tree.h (is_simple_builtin, is_inexpensive_builtin): Declare.
	* cfgloopanal.c (target_clobbered_regs): Define.
	(init_set_costs): Initialize target_clobbered_regs.
	(estimate_reg_pressure_cost): Add call_p argument.  When true,
	adjust the number of available registers to exclude the
	call-clobbered registers.
	* cfgloop.h (target_clobbered_regs): Declare.
	(estimate_reg_pressure_cost): Adjust declaration.
	* tree-ssa-loop-ivopts.c (struct ivopts_data): Add body_includes_call.
	(ivopts_global_cost_for_size): Pass it to estimate_reg_pressure_cost.
	(determine_set_costs): Dump target_clobbered_regs.
	(loop_body_includes_call): New function.
	(tree_ssa_iv_optimize_loop): Use it to initialize new field.
	* loop-invariant.c (gain_for_invariant): Adjust arguments to pass
	call_p flag through.
	(best_gain_for_invariant): Likewise.
	(find_invariants_to_move): Likewise.
	(move_single_loop_invariants): Likewise, using already-computed
	has_call field.

 2010-07-15  Jie Zhang  <jie@codesourcery.com>
 
 	Issue #8497, #8893

=== modified file 'gcc/builtins.c'
--- old/gcc/builtins.c	2010-04-13 12:47:11 +0000
+++ new/gcc/builtins.c	2010-08-02 13:51:23 +0000
@@ -13624,3 +13624,123 @@
       break;
     }
 }
+
+/* Return true if DECL is a builtin that expands to a constant or similarly
+   simple code.  */
+bool
+is_simple_builtin (tree decl)
+{
+  if (decl && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
+    switch (DECL_FUNCTION_CODE (decl))
+      {
+	/* Builtins that expand to constants.  */
+      case BUILT_IN_CONSTANT_P:
+      case BUILT_IN_EXPECT:
+      case BUILT_IN_OBJECT_SIZE:
+      case BUILT_IN_UNREACHABLE:
+	/* Simple register moves or loads from stack.  */
+      case BUILT_IN_RETURN_ADDRESS:
+      case BUILT_IN_EXTRACT_RETURN_ADDR:
+      case BUILT_IN_FROB_RETURN_ADDR:
+      case BUILT_IN_RETURN:
+      case BUILT_IN_AGGREGATE_INCOMING_ADDRESS:
+      case BUILT_IN_FRAME_ADDRESS:
+      case BUILT_IN_VA_END:
+      case BUILT_IN_STACK_SAVE:
+      case BUILT_IN_STACK_RESTORE:
+	/* Exception state returns or moves registers around.  */
+      case BUILT_IN_EH_FILTER:
+      case BUILT_IN_EH_POINTER:
+      case BUILT_IN_EH_COPY_VALUES:
+	return true;
+
+      default:
+	return false;
+      }
+
+  return false;
+}
+
+/* Return true if DECL is a builtin that is not expensive, i.e., they are
+   most probably expanded inline into reasonably simple code.  This is a
+   superset of is_simple_builtin.  */
+bool
+is_inexpensive_builtin (tree decl)
+{
+  if (!decl)
+    return false;
+  else if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_MD)
+    return true;
+  else if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
+    switch (DECL_FUNCTION_CODE (decl))
+      {
+      case BUILT_IN_ABS:
+      case BUILT_IN_ALLOCA:
+      case BUILT_IN_BSWAP32:
+      case BUILT_IN_BSWAP64:
+      case BUILT_IN_CLZ:
+      case BUILT_IN_CLZIMAX:
+      case BUILT_IN_CLZL:
+      case BUILT_IN_CLZLL:
+      case BUILT_IN_CTZ:
+      case BUILT_IN_CTZIMAX:
+      case BUILT_IN_CTZL:
+      case BUILT_IN_CTZLL:
+      case BUILT_IN_FFS:
+      case BUILT_IN_FFSIMAX:
+      case BUILT_IN_FFSL:
+      case BUILT_IN_FFSLL:
+      case BUILT_IN_IMAXABS:
+      case BUILT_IN_FINITE:
+      case BUILT_IN_FINITEF:
+      case BUILT_IN_FINITEL:
+      case BUILT_IN_FINITED32:
+      case BUILT_IN_FINITED64:
+      case BUILT_IN_FINITED128:
+      case BUILT_IN_FPCLASSIFY:
+      case BUILT_IN_ISFINITE:
+      case BUILT_IN_ISINF_SIGN:
+      case BUILT_IN_ISINF:
+      case BUILT_IN_ISINFF:
+      case BUILT_IN_ISINFL:
+      case BUILT_IN_ISINFD32:
+      case BUILT_IN_ISINFD64:
+      case BUILT_IN_ISINFD128:
+      case BUILT_IN_ISNAN:
+      case BUILT_IN_ISNANF:
+      case BUILT_IN_ISNANL:
+      case BUILT_IN_ISNAND32:
+      case BUILT_IN_ISNAND64:
+      case BUILT_IN_ISNAND128:
+      case BUILT_IN_ISNORMAL:
+      case BUILT_IN_ISGREATER:
+      case BUILT_IN_ISGREATEREQUAL:
+      case BUILT_IN_ISLESS:
+      case BUILT_IN_ISLESSEQUAL:
+      case BUILT_IN_ISLESSGREATER:
+      case BUILT_IN_ISUNORDERED:
+      case BUILT_IN_VA_ARG_PACK:
+      case BUILT_IN_VA_ARG_PACK_LEN:
+      case BUILT_IN_VA_COPY:
+      case BUILT_IN_TRAP:
+      case BUILT_IN_SAVEREGS:
+      case BUILT_IN_POPCOUNTL:
+      case BUILT_IN_POPCOUNTLL:
+      case BUILT_IN_POPCOUNTIMAX:
+      case BUILT_IN_POPCOUNT:
+      case BUILT_IN_PARITYL:
+      case BUILT_IN_PARITYLL:
+      case BUILT_IN_PARITYIMAX:
+      case BUILT_IN_PARITY:
+      case BUILT_IN_LABS:
+      case BUILT_IN_LLABS:
+      case BUILT_IN_PREFETCH:
+	return true;
+
+      default:
+	return is_simple_builtin (decl);
+      }
+
+  return false;
+}
+

=== modified file 'gcc/cfgloop.h'
--- old/gcc/cfgloop.h	2009-11-25 10:55:54 +0000
+++ new/gcc/cfgloop.h	2010-08-02 13:51:23 +0000
@@ -622,13 +622,14 @@
 /* The properties of the target.  */
 
 extern unsigned target_avail_regs;
+extern unsigned target_clobbered_regs;
 extern unsigned target_res_regs;
 extern unsigned target_reg_cost [2];
 extern unsigned target_spill_cost [2];
 
 /* Register pressure estimation for induction variable optimizations & loop
    invariant motion.  */
-extern unsigned estimate_reg_pressure_cost (unsigned, unsigned, bool);
+extern unsigned estimate_reg_pressure_cost (unsigned, unsigned, bool, bool);
 extern void init_set_costs (void);
 
 /* Loop optimizer initialization.  */

=== modified file 'gcc/cfgloopanal.c'
--- old/gcc/cfgloopanal.c	2009-09-30 08:57:56 +0000
+++ new/gcc/cfgloopanal.c	2010-08-02 13:51:23 +0000
@@ -320,6 +320,8 @@
 /* The properties of the target.  */
 
 unsigned target_avail_regs;	/* Number of available registers.  */
+unsigned target_clobbered_regs; /* Number of available registers that are
+				   call-clobbered.  */
 unsigned target_res_regs;	/* Number of registers reserved for temporary
 				   expressions.  */
 unsigned target_reg_cost[2];	/* The cost for register when there still
@@ -342,10 +344,15 @@
   unsigned i;
 
   target_avail_regs = 0;
+  target_clobbered_regs = 0;
   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
     if (TEST_HARD_REG_BIT (reg_class_contents[GENERAL_REGS], i)
 	&& !fixed_regs[i])
-      target_avail_regs++;
+      {
+	target_avail_regs++;
+	if (call_used_regs[i])
+	  target_clobbered_regs++;
+      }
 
   target_res_regs = 3;
 
@@ -379,20 +386,29 @@
 
 /* Estimates cost of increased register pressure caused by making N_NEW new
    registers live around the loop.  N_OLD is the number of registers live
-   around the loop.  */
+   around the loop.  If CALL_P is true, also take into account that
+   call-used registers may be clobbered in the loop body, reducing the
+   number of available registers before we spill.  */
 
 unsigned
-estimate_reg_pressure_cost (unsigned n_new, unsigned n_old, bool speed)
+estimate_reg_pressure_cost (unsigned n_new, unsigned n_old, bool speed,
+			    bool call_p)
 {
   unsigned cost;
   unsigned regs_needed = n_new + n_old;
+  unsigned available_regs = target_avail_regs;
+
+  /* If there is a call in the loop body, the call-clobbered registers
+     are not available for loop invariants.  */
+  if (call_p)
+    available_regs = available_regs - target_clobbered_regs;
 
   /* If we have enough registers, we should use them and not restrict
      the transformations unnecessarily.  */
-  if (regs_needed + target_res_regs <= target_avail_regs)
+  if (regs_needed + target_res_regs <= available_regs)
     return 0;
 
-  if (regs_needed <= target_avail_regs)
+  if (regs_needed <= available_regs)
     /* If we are close to running out of registers, try to preserve
        them.  */
     cost = target_reg_cost [speed] * n_new;

=== modified file 'gcc/loop-invariant.c'
--- old/gcc/loop-invariant.c	2010-04-02 18:54:46 +0000
+++ new/gcc/loop-invariant.c	2010-08-02 13:51:23 +0000
@@ -1173,11 +1173,13 @@
 /* Calculates gain for eliminating invariant INV.  REGS_USED is the number
    of registers used in the loop, NEW_REGS is the number of new variables
    already added due to the invariant motion.  The number of registers needed
-   for it is stored in *REGS_NEEDED.  */
+   for it is stored in *REGS_NEEDED.  SPEED and CALL_P are flags passed
+   through to estimate_reg_pressure_cost. */
 
 static int
 gain_for_invariant (struct invariant *inv, unsigned *regs_needed,
-		    unsigned *new_regs, unsigned regs_used, bool speed)
+		    unsigned *new_regs, unsigned regs_used,
+		    bool speed, bool call_p)
 {
   int comp_cost, size_cost;
 
@@ -1188,9 +1190,9 @@
   if (! flag_ira_loop_pressure)
     {
       size_cost = (estimate_reg_pressure_cost (new_regs[0] + regs_needed[0],
-					       regs_used, speed)
+					       regs_used, speed, call_p)
 		   - estimate_reg_pressure_cost (new_regs[0],
-						 regs_used, speed));
+						 regs_used, speed, call_p));
     }
   else
     {
@@ -1245,7 +1247,8 @@
 
 static int
 best_gain_for_invariant (struct invariant **best, unsigned *regs_needed,
-			 unsigned *new_regs, unsigned regs_used, bool speed)
+			 unsigned *new_regs, unsigned regs_used,
+			 bool speed, bool call_p)
 {
   struct invariant *inv;
   int i, gain = 0, again;
@@ -1261,7 +1264,7 @@
 	continue;
 
       again = gain_for_invariant (inv, aregs_needed, new_regs, regs_used,
-      				  speed);
+      				  speed, call_p);
       if (again > gain)
 	{
 	  gain = again;
@@ -1314,7 +1317,7 @@
 /* Determines which invariants to move.  */
 
 static void
-find_invariants_to_move (bool speed)
+find_invariants_to_move (bool speed, bool call_p)
 {
   int gain;
   unsigned i, regs_used, regs_needed[N_REG_CLASSES], new_regs[N_REG_CLASSES];
@@ -1353,7 +1356,8 @@
 	new_regs[ira_reg_class_cover[i]] = 0;
     }
   while ((gain = best_gain_for_invariant (&inv, regs_needed,
-					  new_regs, regs_used, speed)) > 0)
+					  new_regs, regs_used,
+					  speed, call_p)) > 0)
     {
       set_move_mark (inv->invno, gain);
       if (! flag_ira_loop_pressure)
@@ -1554,7 +1558,8 @@
   init_inv_motion_data ();
 
   find_invariants (loop);
-  find_invariants_to_move (optimize_loop_for_speed_p (loop));
+  find_invariants_to_move (optimize_loop_for_speed_p (loop),
+			   LOOP_DATA (loop)->has_call);
   move_invariants (loop);
 
   free_inv_motion_data ();

=== added file 'gcc/testsuite/gcc.target/arm/pr42505.c'
--- old/gcc/testsuite/gcc.target/arm/pr42505.c	1970-01-01 00:00:00 +0000
+++ new/gcc/testsuite/gcc.target/arm/pr42505.c	2010-08-02 13:51:23 +0000
@@ -0,0 +1,23 @@
+/* { dg-options "-mthumb -Os -march=armv5te" }  */
+/* { dg-require-effective-target arm_thumb1_ok } */
+/* { dg-final { scan-assembler-not "str\[\\t \]*r.,\[\\t \]*.sp," } } */
+
+struct A {
+ int f1;
+ int f2;
+};
+
+int func(int c);
+
+/* This function should not need to spill anything to the stack.  */
+int test(struct A* src, struct A* dst, int count)
+{
+  while (count--) {
+    if (!func(src->f2)) {
+        return 0;
+      }
+      *dst++ = *src++;
+  }
+
+  return 1;
+}

=== modified file 'gcc/tree-inline.c'
--- old/gcc/tree-inline.c	2010-03-18 20:07:13 +0000
+++ new/gcc/tree-inline.c	2010-08-02 13:51:23 +0000
@@ -3246,34 +3246,13 @@
 	if (POINTER_TYPE_P (funtype))
 	  funtype = TREE_TYPE (funtype);
 
-	if (decl && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_MD)
+	if (is_simple_builtin (decl))
+	  return 0;
+	else if (is_inexpensive_builtin (decl))
 	  cost = weights->target_builtin_call_cost;
 	else
 	  cost = weights->call_cost;
 
-	if (decl && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
-	  switch (DECL_FUNCTION_CODE (decl))
-	    {
-	    case BUILT_IN_CONSTANT_P:
-	      return 0;
-	    case BUILT_IN_EXPECT:
-	      return 0;
-
-	    /* Prefetch instruction is not expensive.  */
-	    case BUILT_IN_PREFETCH:
-	      cost = weights->target_builtin_call_cost;
-	      break;
-
-	    /* Exception state returns or moves registers around.  */
-	    case BUILT_IN_EH_FILTER:
-	    case BUILT_IN_EH_POINTER:
-	    case BUILT_IN_EH_COPY_VALUES:
-	      return 0;
-
-	    default:
-	      break;
-	    }
-
 	if (decl)
 	  funtype = TREE_TYPE (decl);
 

=== modified file 'gcc/tree-ssa-loop-ivopts.c'
--- old/gcc/tree-ssa-loop-ivopts.c	2010-04-01 15:18:07 +0000
+++ new/gcc/tree-ssa-loop-ivopts.c	2010-08-02 13:51:23 +0000
@@ -257,6 +257,9 @@
 
   /* Are we optimizing for speed?  */
   bool speed;
+
+  /* Whether the loop body includes any function calls.  */
+  bool body_includes_call;
 };
 
 /* An assignment of iv candidates to uses.  */
@@ -2926,6 +2929,20 @@
   return get_computation_at (loop, use, cand, use->stmt);
 }
 
+/* Adjust the cost COST for being in loop setup rather than loop body.
+   If we're optimizing for space, the loop setup overhead is constant;
+   if we're optimizing for speed, amortize it over the per-iteration cost.  */
+static unsigned
+adjust_setup_cost (struct ivopts_data *data, unsigned cost)
+{
+  if (cost == INFTY)
+    return cost;
+  else if (optimize_loop_for_speed_p (data->current_loop))
+    return cost / AVG_LOOP_NITER (data->current_loop);
+  else
+    return cost;
+}
+
 /* Returns cost of addition in MODE.  */
 
 static unsigned
@@ -3838,8 +3855,8 @@
   /* Symbol + offset should be compile-time computable so consider that they
       are added once to the variable, if present.  */
   if (var_present && (symbol_present || offset))
-    cost.cost += add_cost (TYPE_MODE (ctype), speed)
-		 / AVG_LOOP_NITER (data->current_loop);
+    cost.cost += adjust_setup_cost (data,
+				    add_cost (TYPE_MODE (ctype), speed));
 
   /* Having offset does not affect runtime cost in case it is added to
      symbol, but it increases complexity.  */
@@ -4104,7 +4121,7 @@
       elim_cost = force_var_cost (data, bound, &depends_on_elim);
       /* The bound is a loop invariant, so it will be only computed
 	 once.  */
-      elim_cost.cost /= AVG_LOOP_NITER (data->current_loop);
+      elim_cost.cost = adjust_setup_cost (data, elim_cost.cost);
     }
   else
     elim_cost = infinite_cost;
@@ -4351,7 +4368,7 @@
   cost_base = force_var_cost (data, base, NULL);
   cost_step = add_cost (TYPE_MODE (TREE_TYPE (base)), data->speed);
 
-  cost = cost_step + cost_base.cost / AVG_LOOP_NITER (current_loop);
+  cost = cost_step + adjust_setup_cost (data, cost_base.cost);
 
   /* Prefer the original ivs unless we may gain something by replacing it.
      The reason is to make debugging simpler; so this is not relevant for
@@ -4404,7 +4421,8 @@
 {
   /* We add size to the cost, so that we prefer eliminating ivs
      if possible.  */
-  return size + estimate_reg_pressure_cost (size, data->regs_used, data->speed);
+  return size + estimate_reg_pressure_cost (size, data->regs_used, data->speed,
+					    data->body_includes_call);
 }
 
 /* For each size of the induction variable set determine the penalty.  */
@@ -4419,30 +4437,11 @@
   struct loop *loop = data->current_loop;
   bitmap_iterator bi;
 
-  /* We use the following model (definitely improvable, especially the
-     cost function -- TODO):
-
-     We estimate the number of registers available (using MD data), name it A.
-
-     We estimate the number of registers used by the loop, name it U.  This
-     number is obtained as the number of loop phi nodes (not counting virtual
-     registers and bivs) + the number of variables from outside of the loop.
-
-     We set a reserve R (free regs that are used for temporary computations,
-     etc.).  For now the reserve is a constant 3.
-
-     Let I be the number of induction variables.
-
-     -- if U + I + R <= A, the cost is I * SMALL_COST (just not to encourage
-	make a lot of ivs without a reason).
-     -- if A - R < U + I <= A, the cost is I * PRES_COST
-     -- if U + I > A, the cost is I * PRES_COST and
-        number of uses * SPILL_COST * (U + I - A) / (U + I) is added.  */
-
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
       fprintf (dump_file, "Global costs:\n");
       fprintf (dump_file, "  target_avail_regs %d\n", target_avail_regs);
+      fprintf (dump_file, "  target_clobbered_regs %d\n", target_clobbered_regs);
       fprintf (dump_file, "  target_reg_cost %d\n", target_reg_cost[data->speed]);
       fprintf (dump_file, "  target_spill_cost %d\n", target_spill_cost[data->speed]);
     }
@@ -5062,11 +5061,13 @@
 }
 
 /* Tries to extend the sets IVS in the best possible way in order
-   to express the USE.  */
+   to express the USE.  If ORIGINALP is true, prefer candidates from
+   the original set of IVs, otherwise favor important candidates not
+   based on any memory object.  */
 
 static bool
 try_add_cand_for (struct ivopts_data *data, struct iv_ca *ivs,
-		  struct iv_use *use)
+		  struct iv_use *use, bool originalp)
 {
   comp_cost best_cost, act_cost;
   unsigned i;
@@ -5085,7 +5086,8 @@
       iv_ca_set_no_cp (data, ivs, use);
     }
 
-  /* First try important candidates not based on any memory object.  Only if
+  /* If ORIGINALP is true, try to find the original IV for the use.  Otherwise
+     first try important candidates not based on any memory object.  Only if
      this fails, try the specific ones.  Rationale -- in loops with many
      variables the best choice often is to use just one generic biv.  If we
      added here many ivs specific to the uses, the optimization algorithm later
@@ -5097,7 +5099,10 @@
     {
       cand = iv_cand (data, i);
 
-      if (cand->iv->base_object != NULL_TREE)
+      if (originalp && cand->pos !=IP_ORIGINAL)
+	continue;
+
+      if (!originalp && cand->iv->base_object != NULL_TREE)
 	continue;
 
       if (iv_ca_cand_used_p (ivs, cand))
@@ -5133,8 +5138,13 @@
 	    continue;
 
 	  /* Already tried this.  */
-	  if (cand->important && cand->iv->base_object == NULL_TREE)
-	    continue;
+	  if (cand->important)
+	    {
+	      if (originalp && cand->pos == IP_ORIGINAL)
+		continue;
+	      if (!originalp && cand->iv->base_object == NULL_TREE)
+		continue;
+	    }
 
 	  if (iv_ca_cand_used_p (ivs, cand))
 	    continue;
@@ -5168,13 +5178,13 @@
 /* Finds an initial assignment of candidates to uses.  */
 
 static struct iv_ca *
-get_initial_solution (struct ivopts_data *data)
+get_initial_solution (struct ivopts_data *data, bool originalp)
 {
   struct iv_ca *ivs = iv_ca_new (data);
   unsigned i;
 
   for (i = 0; i < n_iv_uses (data); i++)
-    if (!try_add_cand_for (data, ivs, iv_use (data, i)))
+    if (!try_add_cand_for (data, ivs, iv_use (data, i), originalp))
       {
 	iv_ca_free (&ivs);
 	return NULL;
@@ -5246,14 +5256,12 @@
    solution and remove the unused ivs while this improves the cost.  */
 
 static struct iv_ca *
-find_optimal_iv_set (struct ivopts_data *data)
+find_optimal_iv_set_1 (struct ivopts_data *data, bool originalp)
 {
-  unsigned i;
   struct iv_ca *set;
-  struct iv_use *use;
 
   /* Get the initial solution.  */
-  set = get_initial_solution (data);
+  set = get_initial_solution (data, originalp);
   if (!set)
     {
       if (dump_file && (dump_flags & TDF_DETAILS))
@@ -5276,11 +5284,46 @@
 	}
     }
 
+  return set;
+}
+
+static struct iv_ca *
+find_optimal_iv_set (struct ivopts_data *data)
+{
+  unsigned i;
+  struct iv_ca *set, *origset;
+  struct iv_use *use;
+  comp_cost cost, origcost;
+
+  /* Determine the cost based on a strategy that starts with original IVs,
+     and try again using a strategy that prefers candidates not based
+     on any IVs.  */
+  origset = find_optimal_iv_set_1 (data, true);
+  set = find_optimal_iv_set_1 (data, false);
+
+  if (!origset && !set)
+    return NULL;
+
+  origcost = origset ? iv_ca_cost (origset) : infinite_cost;
+  cost = set ? iv_ca_cost (set) : infinite_cost;
+
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
-      comp_cost cost = iv_ca_cost (set);
-      fprintf (dump_file, "Final cost %d (complexity %d)\n\n", cost.cost, cost.complexity);
-    }
+      fprintf (dump_file, "Original cost %d (complexity %d)\n\n",
+	       origcost.cost, origcost.complexity);
+      fprintf (dump_file, "Final cost %d (complexity %d)\n\n",
+	       cost.cost, cost.complexity);
+    }
+
+  /* Choose the one with the best cost.  */
+  if (compare_costs (origcost, cost) <= 0)
+    {
+      if (set)
+	iv_ca_free (&set);
+      set = origset;
+    }
+  else if (origset)
+    iv_ca_free (&origset);
 
   for (i = 0; i < n_iv_uses (data); i++)
     {
@@ -5768,6 +5811,25 @@
   VEC_free (iv_cand_p, heap, data->iv_candidates);
 }
 
+/* Returns true if the loop body BODY includes any function calls.  */
+
+static bool
+loop_body_includes_call (basic_block *body, unsigned num_nodes)
+{
+  gimple_stmt_iterator gsi;
+  unsigned i;
+
+  for (i = 0; i < num_nodes; i++)
+    for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi))
+      {
+	gimple stmt = gsi_stmt (gsi);
+	if (is_gimple_call (stmt)
+	    && !is_inexpensive_builtin (gimple_call_fndecl (stmt)))
+	  return true;
+      }
+  return false;
+}
+
 /* Optimizes the LOOP.  Returns true if anything changed.  */
 
 static bool
@@ -5799,6 +5861,7 @@
     }
 
   body = get_loop_body (loop);
+  data->body_includes_call = loop_body_includes_call (body, loop->num_nodes);
   renumber_gimple_stmt_uids_in_blocks (body, loop->num_nodes);
   free (body);
 

=== modified file 'gcc/tree.h'
--- old/gcc/tree.h	2010-04-02 18:54:46 +0000
+++ new/gcc/tree.h	2010-08-02 13:51:23 +0000
@@ -4962,6 +4962,8 @@
 extern bool merge_ranges (int *, tree *, tree *, int, tree, tree, int,
 			  tree, tree);
 extern void set_builtin_user_assembler_name (tree decl, const char *asmspec);
+extern bool is_simple_builtin (tree);
+extern bool is_inexpensive_builtin (tree);
 
 /* In convert.c */
 extern tree strip_float_extensions (tree);