* Makefile.in (value-prof.o): New dependencies on $(DIAGNOSTIC_H)

	$(TREE_H) and $(COVERAGE_H).
	* coverage.c (compute_checksum): Use DECL_NAME not DECL_ASSEMBLER_NAME.
	* opts.c (common_handle_option): Enable tree-based value transforms.
	* toplev.c (process_options): Ditto.
	* value-prof.h (struct histogram_value_t): Redefine. "Adjust" below
	refers to references to this type.
	* tree-flow.h: (struct stmt_ann_d): Add histograms field.
	* rtl-profile.c (rtl_gen_interval_profiler): Adjust. Remove checks
	for may_be_more, may_be_less.
	(rtl_gen_pow2_profiler): Adjust.
	(rtl_gen_one_value_profiler_no_edge_manip): Adjust.
	(rtl_gen_one_value_profiler): Adjust.
	(rtl_gen_const_delta_profiler): Adjust.
	* tree-profile.c (tree_gen_interval_profiler): Implement.
	(tree_gen_pow2_profiler): Ditto.
	(tree_gen_one_value_profiler): Ditto.
	(tree_profiling): New.
	(pass_tree_profile): Reference it.
	* value-prof.c: Include tree-flow.h, tree-flow-inline.h, diagnostic.h,
	tree.h, gcov-io.h.
	(insn_divmod_values_to_profile): Rename to
	rtl_divmod_values_to_profile. Adjust.
	(insn_values_to_profile): Rename to rtl_values_to_profile. Adjust.
	(insn_prefetch_values_to_profile): Adjust.
	(rtl_value_profile_transformations): Adjust.
	(gen_divmod_fixed_value): Rename to rtl_divmod_fixed_value.
	(gen_mod_pow2): Rename to rtl_mod_pow2.
	(gen_mod_subtract): Rename to rtl_mod_subtract.
	(divmod_fixed_value_transform): Rename to
	rtl_divmod_fixed_value_transform.
	(mod_pow2_value_transform): Rename to rtl_mod_pow2_value_transform.
	(mod_subtract_transform): Rename to rtl_mod_subtract_transform.
	(rtl_find_values_to_profile): Adjust.
	(tree_value_profile_transformations): Implement.
	(tree_divmod_values_to_profile): New.
	(tree_values_to_profile): New.
	(tree_divmod_fixed_value): New.
	(tree_mod_pow2): New.
	(tree_mod_subtract): New.
	(tree_divmod_fixed_value_transform): New.
	(tree_mod_pow2_value_transform): New.
	(tree_mod_subtract_transform): New.
	(tree_find_values_to_profile): Implement.
	* profile.c (instrument_values):  Free histograms.
	(compute_value_histograms): Adjust. Implement tree version.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@97156 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 473 insertions, 50 deletions

diff --git a/gcc/tree-profile.c b/gcc/tree-profile.c
index 145c7213158..4f6b792c369 100644
--- a/gcc/tree-profile.c
+++ b/gcc/tree-profile.c
@@ -24,30 +24,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 02111-1307, USA.  */
 
 /* Generate basic block profile instrumentation and auxiliary files.
-   Profile generation is optimized, so that not all arcs in the basic
-   block graph need instrumenting. First, the BB graph is closed with
-   one entry (function start), and one exit (function exit).  Any
-   ABNORMAL_EDGE cannot be instrumented (because there is no control
-   path to place the code). We close the graph by inserting fake
-   EDGE_FAKE edges to the EXIT_BLOCK, from the sources of abnormal
-   edges that do not go to the exit_block. We ignore such abnormal
-   edges.  Naturally these fake edges are never directly traversed,
-   and so *cannot* be directly instrumented.  Some other graph
-   massaging is done. To optimize the instrumentation we generate the
-   BB minimal span tree, only edges that are not on the span tree
-   (plus the entry point) need instrumenting. From that information
-   all other edge counts can be deduced.  By construction all fake
-   edges must be on the spanning tree. We also attempt to place
-   EDGE_CRITICAL edges on the spanning tree.
-
-   The auxiliary file generated is <dumpbase>.bbg. The format is
-   described in full in gcov-io.h.  */
-
-/* ??? Register allocation should use basic block execution counts to
-   give preference to the most commonly executed blocks.  */
-
-/* ??? Should calculate branch probabilities before instrumenting code, since
-   then we can use arc counts to help decide which arcs to instrument.  */
+   Tree-based version.  See profile.c for overview.  */
 
 #include "config.h"
 #include "system.h"
@@ -102,15 +79,163 @@ tree_gen_edge_profiler (int edgeno, edge e)
    tag of the section for counters, BASE is offset of the counter position.  */
 
 static void
-tree_gen_interval_profiler (histogram_value value ATTRIBUTE_UNUSED, 
-			    unsigned tag ATTRIBUTE_UNUSED, 
-			    unsigned base ATTRIBUTE_UNUSED)
+tree_gen_interval_profiler (histogram_value value, unsigned tag, unsigned base)
 {
-  /* FIXME implement this.  */
-#ifdef ENABLE_CHECKING
-  internal_error ("unimplemented functionality");
-#endif
-  gcc_unreachable ();
+  tree op, op1, op2, op1copy, op2copy;
+  tree tmp1, tmp2, tmp3, val, index;
+  tree label_decl2, label_decl3, label_decl4, label_decl5, label_decl6;
+  edge e12, e23, e34, e45, e56;
+  tree label2, label3, label4, label5, label6;
+  tree stmt1, stmt2, stmt3, stmt4;
+  /* Initializations are to prevent bogus uninitialized warnings. */
+  tree bb1end = NULL_TREE, bb2end = NULL_TREE, bb3end = NULL_TREE;
+  tree bb4end = NULL_TREE, bb5end = NULL_TREE;
+  tree ref = tree_coverage_counter_ref (tag, base), ref2;
+  basic_block bb2, bb3, bb4, bb5, bb6;
+  tree stmt = value->hvalue.tree.stmt;
+  block_stmt_iterator bsi = bsi_for_stmt (stmt);
+  basic_block bb = bb_for_stmt (stmt);
+  tree optype;
+
+  op = stmt;
+  if (TREE_CODE (stmt) == RETURN_EXPR
+      && TREE_OPERAND (stmt, 0)
+      && TREE_CODE (TREE_OPERAND (stmt, 0)) == MODIFY_EXPR)
+    op = TREE_OPERAND (stmt, 0);
+  /* op == MODIFY_EXPR */
+  op = TREE_OPERAND (op, 1);
+  /* op == TRUNC_DIV or TRUNC_MOD */
+  op1 = TREE_OPERAND (op, 0);
+  op2 = TREE_OPERAND (op, 1);
+  optype = TREE_TYPE (op);
+
+  /* Blocks:
+     Original = 1 
+     For 2nd compare = 2
+     Normal case, neither more nor less = 3
+     More = 4
+     Less = 5
+     End = 6  */
+  label_decl2 = create_artificial_label ();
+  label_decl3 = create_artificial_label ();
+  label_decl4 = create_artificial_label ();
+  label_decl5 = create_artificial_label ();
+  label_decl6 = create_artificial_label ();
+
+  /* Do not evaluate op1 or op2 more than once.  Probably
+     volatile loads are the only things that could cause
+     a problem, but this is harmless in any case.  */
+  op1copy = create_tmp_var (optype, "PROF");
+  op2copy = create_tmp_var (optype, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, optype, op1copy, op1);
+  stmt2 = build2 (MODIFY_EXPR, optype, op2copy, op2);
+  TREE_OPERAND (op, 0) = op1copy;
+  TREE_OPERAND (op, 1) = op2copy;
+
+  val = create_tmp_var (optype, "PROF");
+  stmt3 = build2 (MODIFY_EXPR, optype, val,
+		  build2 (TRUNC_DIV_EXPR, optype, op1copy, op2copy));
+  stmt4 = build2 (MODIFY_EXPR, optype, val,
+		  build2 (MINUS_EXPR, optype, val,
+				build_int_cst (optype, value->hdata.intvl.int_start)));
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt4, BSI_SAME_STMT);
+
+  index = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+
+  /* Check for too big.  */
+  stmt1 = build3 (COND_EXPR, void_type_node,
+	    build2 (GE_EXPR, boolean_type_node, val,
+			build_int_cst (optype, value->hdata.intvl.steps)),
+	    build1 (GOTO_EXPR, void_type_node, label_decl4),
+	    build1 (GOTO_EXPR, void_type_node, label_decl2));
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bb1end = stmt1;
+
+  /* Check for too small.  */
+  label2 = build1 (LABEL_EXPR, void_type_node, label_decl2);
+  bsi_insert_before (&bsi, label2, BSI_SAME_STMT);
+  stmt1 = build3 (COND_EXPR, void_type_node,
+	    build2 (LT_EXPR, boolean_type_node, val, integer_zero_node),
+	    build1 (GOTO_EXPR, void_type_node, label_decl5),
+	    build1 (GOTO_EXPR, void_type_node, label_decl3));
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bb2end = stmt1;
+
+  /* Normal case, within range. */
+  label3 = build1 (LABEL_EXPR, void_type_node, label_decl3);
+  bsi_insert_before (&bsi, label3, BSI_SAME_STMT);
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, index, 
+		    build1 (NOP_EXPR, GCOV_TYPE_NODE, val));
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bb3end = stmt1;
+
+  /* Too big */
+  label4 = build1 (LABEL_EXPR, void_type_node, label_decl4);
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, index, 
+		    build_int_cst (GCOV_TYPE_NODE, value->hdata.intvl.steps));
+  bsi_insert_before (&bsi, label4, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bb4end = stmt1;
+
+  /* Too small */
+  label5 = build1 (LABEL_EXPR, void_type_node, label_decl5);
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, index, 
+		    build_int_cst (GCOV_TYPE_NODE, value->hdata.intvl.steps + 1));
+  bsi_insert_before (&bsi, label5, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bb5end = stmt1;
+
+  /* Increment appropriate counter. */
+  label6 = build1 (LABEL_EXPR, void_type_node, label_decl6);
+  bsi_insert_before (&bsi, label6, BSI_SAME_STMT);
+
+  tmp1 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  tmp2 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  tmp3 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp1, 
+		    build2 (PLUS_EXPR, GCOV_TYPE_NODE, index, 
+			    TREE_OPERAND (ref, 1)));
+  TREE_OPERAND (ref, 1) = tmp1;
+  /* Make a copy to avoid sharing complaints. */
+  ref2 = build4 (ARRAY_REF, TREE_TYPE (ref), TREE_OPERAND (ref, 0), 
+		TREE_OPERAND (ref, 1), TREE_OPERAND (ref, 2), 
+		TREE_OPERAND (ref, 3));
+
+  stmt2 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp2, ref);
+  stmt3 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp3, 
+		    build2 (PLUS_EXPR, GCOV_TYPE_NODE, tmp2, integer_one_node));
+  stmt4 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, ref2, tmp3);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt4, BSI_SAME_STMT);
+
+  /* Now fix up the CFG. */
+  /* 1->2,4; 2->3,5; 3->6; 4->6; 5->6 */
+  e12 = split_block (bb, bb1end);
+  bb2 = e12->dest;
+  e23 = split_block (bb2, bb2end);
+  bb3 = e23->dest;
+  e34 = split_block (bb3, bb3end);
+  bb4 = e34->dest;
+  e45 = split_block (bb4, bb4end);
+  bb5 = e45->dest;
+  e56 = split_block (bb5, bb5end);
+  bb6 = e56->dest;
+
+  e12->flags &= ~EDGE_FALLTHRU;
+  e12->flags |= EDGE_FALSE_VALUE;
+  make_edge (bb, bb4, EDGE_TRUE_VALUE);
+  e23->flags &= ~EDGE_FALLTHRU;
+  e23->flags |= EDGE_FALSE_VALUE;
+  make_edge (bb2, bb5, EDGE_TRUE_VALUE);
+  remove_edge (e34);
+  make_edge (bb3, bb6, EDGE_FALLTHRU);
+  remove_edge (e45);
+  make_edge (bb4, bb6, EDGE_FALLTHRU);
 }
 
 /* Output instructions as GIMPLE trees to increment the power of two histogram 
@@ -118,15 +243,162 @@ tree_gen_interval_profiler (histogram_value value ATTRIBUTE_UNUSED,
    of the section for counters, BASE is offset of the counter position.  */
 
 static void
-tree_gen_pow2_profiler (histogram_value value ATTRIBUTE_UNUSED, 
-			unsigned tag ATTRIBUTE_UNUSED,
-			unsigned base ATTRIBUTE_UNUSED)
+tree_gen_pow2_profiler (histogram_value value, unsigned tag, unsigned base)
 {
-  /* FIXME implement this.  */
-#ifdef ENABLE_CHECKING
-  internal_error ("unimplemented functionality");
-#endif
-  gcc_unreachable ();
+  tree op;
+  tree tmp1, tmp2, tmp3;
+  tree index, denom;
+  tree label_decl1 = create_artificial_label ();
+  tree label_decl2 = create_artificial_label ();
+  tree label_decl3 = create_artificial_label ();
+  tree label1, label2, label3;
+  tree stmt1, stmt2, stmt3, stmt4;
+  tree bb1end, bb2end, bb3end;
+  tree ref = tree_coverage_counter_ref (tag, base), ref2;
+  basic_block bb2, bb3, bb4;
+  tree stmt = value->hvalue.tree.stmt;
+  block_stmt_iterator bsi = bsi_for_stmt (stmt);
+  basic_block bb = bb_for_stmt (stmt);
+  tree optype, optypesigned, optypeunsigned;
+
+  op = stmt;
+  if (TREE_CODE (stmt) == RETURN_EXPR
+      && TREE_OPERAND (stmt, 0)
+      && TREE_CODE (TREE_OPERAND (stmt, 0)) == MODIFY_EXPR)
+    op = TREE_OPERAND (stmt, 0);
+  /* op == MODIFY_EXPR */
+  op = TREE_OPERAND (op, 1);
+  /* op == TRUNC_DIV or TRUNC_MOD */
+  op = TREE_OPERAND (op, 1);
+  /* op == denominator */
+  optype = TREE_TYPE (op);
+  if (TYPE_UNSIGNED (optype))
+    {
+      /* Right shift must be unsigned. */
+      optypeunsigned = optype;
+      optypesigned = build_distinct_type_copy (optype);
+      TYPE_UNSIGNED (optypesigned) = false;
+    }
+  else
+    {
+      /* Compare to zero must be signed. */
+      optypesigned = optype;
+      optypeunsigned = build_distinct_type_copy (optype);
+      TYPE_UNSIGNED (optypeunsigned) = true;
+    }
+
+  /* Set up variables and check if denominator is negative when considered
+     as signed.  */
+  index = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  denom = create_tmp_var (optype, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, index, integer_zero_node);
+  stmt2 = build2 (MODIFY_EXPR, optype, denom, op);
+  if (optypesigned == optype)
+    {
+      tmp1 = denom;
+      stmt3 = NULL_TREE;
+    }
+  else
+    {
+      tmp1 = create_tmp_var (optypesigned, "PROF");
+      stmt3 = build2 (MODIFY_EXPR, optypesigned, tmp1,
+			    build1 (NOP_EXPR, optypesigned, denom));
+    }
+  stmt4 = build3 (COND_EXPR, void_type_node,
+		build2 (LE_EXPR, boolean_type_node, tmp1, integer_zero_node),
+		build1 (GOTO_EXPR, void_type_node, label_decl3),
+		build1 (GOTO_EXPR, void_type_node, label_decl1));
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  if (stmt3)
+    bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt4, BSI_SAME_STMT);
+  bb1end = stmt4;
+
+  /* Nonnegative.  Check if denominator is power of 2. */
+  label1 = build1 (LABEL_EXPR, void_type_node, label_decl1);
+  tmp1 = create_tmp_var (optype, "PROF");
+  tmp2 = create_tmp_var (optype, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, optype, tmp1,
+		    build2 (PLUS_EXPR, optype, denom, integer_minus_one_node));
+  stmt2 = build2 (MODIFY_EXPR, optype, tmp2,
+		    build2 (BIT_AND_EXPR, optype, tmp1, denom));
+  stmt3 = build3 (COND_EXPR, void_type_node, 
+		build2 (NE_EXPR, boolean_type_node, tmp2, integer_zero_node),
+		build1 (GOTO_EXPR, void_type_node, label_decl3),
+		build1 (GOTO_EXPR, void_type_node, label_decl2));
+  bsi_insert_before (&bsi, label1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bb2end = stmt3;
+
+  /* Loop.  Increment index, shift denominator, repeat if denominator nonzero. */
+  label2 = build1 (LABEL_EXPR, void_type_node, label_decl2);
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, index, 
+		    build2 (PLUS_EXPR, GCOV_TYPE_NODE, index, integer_one_node));
+  if (optypeunsigned == optype)
+    {
+      tmp1 = denom;
+      stmt2 = NULL_TREE;
+    }
+  else
+    {
+      tmp1 = create_tmp_var (optypeunsigned, "PROF");
+      stmt2 = build2 (MODIFY_EXPR, optypeunsigned, tmp1,
+			build1 (NOP_EXPR, optypeunsigned, denom));
+    }
+  stmt3 = build2 (MODIFY_EXPR, optype, denom,
+		    build2 (RSHIFT_EXPR, optype, tmp1, integer_one_node));
+  stmt4 = build3 (COND_EXPR, void_type_node, 
+		build2 (NE_EXPR, boolean_type_node, denom, integer_zero_node),
+		build1 (GOTO_EXPR, void_type_node, label_decl2),
+		build1 (GOTO_EXPR, void_type_node, label_decl3));
+  bsi_insert_before (&bsi, label2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  if (stmt2)
+    bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt4, BSI_SAME_STMT);
+  bb3end = stmt4;
+
+  /* Increment the appropriate counter.  */
+  label3 = build1 (LABEL_EXPR, void_type_node, label_decl3);
+  tmp1 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  tmp2 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  tmp3 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp1, 
+		    build2 (PLUS_EXPR, GCOV_TYPE_NODE, index, TREE_OPERAND (ref, 1)));
+  TREE_OPERAND (ref, 1) = tmp1;
+  /* Make a copy to avoid sharing complaints. */
+  ref2 = build4 (ARRAY_REF, TREE_TYPE (ref), TREE_OPERAND (ref, 0), 
+		TREE_OPERAND (ref, 1), TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
+  stmt2 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp2, ref);
+  stmt3 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp3, 
+		    build2 (PLUS_EXPR, GCOV_TYPE_NODE, tmp2, integer_one_node));
+  stmt4 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, ref2, tmp3);
+  bsi_insert_before (&bsi, label3, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt4, BSI_SAME_STMT);
+
+  /* Now fix up the CFG. */
+  bb2 = (split_block (bb, bb1end))->dest;
+  bb3 = (split_block (bb2, bb2end))->dest;
+  bb4 = (split_block (bb3, bb3end))->dest;
+
+  EDGE_SUCC (bb, 0)->flags &= ~EDGE_FALLTHRU;
+  EDGE_SUCC (bb, 0)->flags |= EDGE_FALSE_VALUE;
+  make_edge (bb, bb4, EDGE_TRUE_VALUE);
+
+  EDGE_SUCC (bb2, 0)->flags &= ~EDGE_FALLTHRU;
+  EDGE_SUCC (bb2, 0)->flags |= EDGE_FALSE_VALUE;
+  make_edge (bb2, bb4, EDGE_TRUE_VALUE);
+
+  EDGE_SUCC (bb3, 0)->flags &= ~EDGE_FALLTHRU;
+  EDGE_SUCC (bb3, 0)->flags |= EDGE_FALSE_VALUE;
+  make_edge (bb3, bb3, EDGE_TRUE_VALUE);
 }
 
 /* Output instructions as GIMPLE trees for code to find the most common value.
@@ -134,15 +406,150 @@ tree_gen_pow2_profiler (histogram_value value ATTRIBUTE_UNUSED,
    section for counters, BASE is offset of the counter position.  */
 
 static void
-tree_gen_one_value_profiler (histogram_value value ATTRIBUTE_UNUSED, 
-			    unsigned tag ATTRIBUTE_UNUSED,
-			    unsigned base ATTRIBUTE_UNUSED)
+tree_gen_one_value_profiler (histogram_value value, unsigned tag, unsigned base)
 {
-  /* FIXME implement this.  */
-#ifdef ENABLE_CHECKING
-  internal_error ("unimplemented functionality");
-#endif
-  gcc_unreachable ();
+  tree op;
+  tree tmp1, tmp2, tmp3;
+  tree label_decl1 = create_artificial_label ();
+  tree label_decl2 = create_artificial_label ();
+  tree label_decl3 = create_artificial_label ();
+  tree label_decl4 = create_artificial_label ();
+  tree label_decl5 = create_artificial_label ();
+  tree label1, label2, label3, label4, label5;
+  tree stmt1, stmt2, stmt3, stmt4;
+  tree bb1end, bb2end, bb3end, bb4end, bb5end;
+  tree ref1 = tree_coverage_counter_ref (tag, base);
+  tree ref2 = tree_coverage_counter_ref (tag, base + 1);
+  tree ref3 = tree_coverage_counter_ref (tag, base + 2);
+  basic_block bb2, bb3, bb4, bb5, bb6;
+  tree stmt = value->hvalue.tree.stmt;
+  block_stmt_iterator bsi = bsi_for_stmt (stmt);
+  basic_block bb = bb_for_stmt (stmt);
+  tree optype;
+
+  op = stmt;
+  if (TREE_CODE (stmt) == RETURN_EXPR
+      && TREE_OPERAND (stmt, 0)
+      && TREE_CODE (TREE_OPERAND (stmt, 0)) == MODIFY_EXPR)
+    op = TREE_OPERAND (stmt, 0);
+  /* op == MODIFY_EXPR */
+  op = TREE_OPERAND (op, 1);
+  /* op == TRUNC_DIV or TRUNC_MOD */
+  op = TREE_OPERAND (op, 1);
+  /* op == denominator */
+  optype = TREE_TYPE (op);
+
+  /* Check if the stored value matches. */
+  tmp1 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  tmp2 = create_tmp_var (optype, "PROF");
+  tmp3 = create_tmp_var (optype, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp1, ref1);
+  stmt2 = build2 (MODIFY_EXPR, optype, tmp2, 
+		    build1 (NOP_EXPR, optype, tmp1));
+  stmt3 = build2 (MODIFY_EXPR, optype, tmp3, op);
+  stmt4 = build3 (COND_EXPR, void_type_node, 
+		build2 (EQ_EXPR, boolean_type_node, tmp2, tmp3),
+		build1 (GOTO_EXPR, void_type_node, label_decl4),
+		build1 (GOTO_EXPR, void_type_node, label_decl1));
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt4, BSI_SAME_STMT);
+  bb1end = stmt4;
+
+  /* Does not match; check whether the counter is zero. */
+  label1 = build1 (LABEL_EXPR, void_type_node, label_decl1);
+  tmp1 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp1, ref2);
+  stmt2 = build3 (COND_EXPR, void_type_node, 
+		build2 (EQ_EXPR, boolean_type_node, tmp1, integer_zero_node),
+		build1 (GOTO_EXPR, void_type_node, label_decl3), 
+		build1 (GOTO_EXPR, void_type_node, label_decl2));
+  bsi_insert_before (&bsi, label1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bb2end = stmt2;
+
+  /* Counter is not zero yet, decrement. */
+  label2 = build1 (LABEL_EXPR, void_type_node, label_decl2);
+  tmp1 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  tmp2 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp1, ref2);
+  stmt2 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp2,
+		      build (MINUS_EXPR, GCOV_TYPE_NODE, 
+			     tmp1, integer_one_node));
+  stmt3 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, ref2, tmp2);
+  bsi_insert_before (&bsi, label2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bb3end = stmt3;
+
+  /* Counter was zero, store new value. */
+  label3 = build1 (LABEL_EXPR, void_type_node, label_decl3);
+  tmp1 = create_tmp_var (optype, "PROF");
+  tmp2 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, optype, tmp1, op);
+  stmt2 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp2, 
+			build1 (NOP_EXPR, GCOV_TYPE_NODE, tmp1));
+  stmt3 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, ref1, tmp2);
+  bsi_insert_before (&bsi, label3, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bb4end = stmt3;
+  /* (fall through) */
+
+  /* Increment counter.  */
+  label4 = build1 (LABEL_EXPR, void_type_node, label_decl4);
+  tmp1 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  tmp2 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp1, ref2);
+  stmt2 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp2,
+		      build (PLUS_EXPR, GCOV_TYPE_NODE, 
+			     tmp1, integer_one_node));
+  stmt3 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, ref2, tmp2);
+  bsi_insert_before (&bsi, label4, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+  bb5end = stmt3;
+
+  /* Increment the counter of all executions; this seems redundant given
+     that we have counts for edges in cfg, but it may happen that some
+     optimization will change the counts for the block (either because
+     it is unable to update them correctly, or because it will duplicate
+     the block or its part).  */
+  label5 = build1 (LABEL_EXPR, void_type_node, label_decl5);
+  tmp1 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  tmp2 = create_tmp_var (GCOV_TYPE_NODE, "PROF");
+  stmt1 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp1, ref3);
+  stmt2 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, tmp2,
+		      build (PLUS_EXPR, GCOV_TYPE_NODE, 
+			     tmp1, integer_one_node));
+  stmt3 = build2 (MODIFY_EXPR, GCOV_TYPE_NODE, ref3, tmp2);
+  bsi_insert_before (&bsi, label5, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
+  bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
+
+  /* Now fix up the CFG. */
+  bb2 = (split_block (bb, bb1end))->dest;
+  bb3 = (split_block (bb2, bb2end))->dest;
+  bb4 = (split_block (bb3, bb3end))->dest;
+  bb5 = (split_block (bb4, bb4end))->dest;
+  bb6 = (split_block (bb5, bb5end))->dest;
+
+  EDGE_SUCC (bb, 0)->flags &= ~EDGE_FALLTHRU;
+  EDGE_SUCC (bb, 0)->flags |= EDGE_FALSE_VALUE;
+  make_edge (bb, bb5, EDGE_TRUE_VALUE);
+
+  EDGE_SUCC (bb2, 0)->flags &= ~EDGE_FALLTHRU;
+  EDGE_SUCC (bb2, 0)->flags |= EDGE_FALSE_VALUE;
+  make_edge (bb2, bb4, EDGE_TRUE_VALUE);
+
+  remove_edge (EDGE_SUCC (bb3, 0));
+  make_edge (bb3, bb6, EDGE_FALLTHRU);
 }
 
 /* Output instructions as GIMPLE trees for code to find the most common value 
@@ -166,7 +573,8 @@ tree_gen_const_delta_profiler (histogram_value value ATTRIBUTE_UNUSED,
    If it is, set up hooks for tree-based profiling.
    Gate for pass_tree_profile.  */
 
-static bool do_tree_profiling (void)
+static bool
+do_tree_profiling (void)
 {
   if (flag_tree_based_profiling
       && (profile_arc_flag || flag_test_coverage || flag_branch_probabilities))
@@ -184,11 +592,26 @@ static FILE *tree_profile_dump_file (void) {
   return dump_file;
 }
 
+static void
+tree_profiling (void)
+{
+  branch_prob ();
+  if (flag_branch_probabilities
+      && flag_profile_values
+      && flag_value_profile_transformations)
+    value_profile_transformations ();
+  /* The above could hose dominator info.  Currently there is
+     none coming in, this is a safety valve.  It should be
+     easy to adjust it, if and when there is some.  */
+  free_dominance_info (CDI_DOMINATORS);
+  free_dominance_info (CDI_POST_DOMINATORS);
+}
+
 struct tree_opt_pass pass_tree_profile = 
 {
   "tree_profile",			/* name */
   do_tree_profiling,			/* gate */
-  branch_prob,				/* execute */
+  tree_profiling,			/* execute */
   NULL,					/* sub */
   NULL,					/* next */
   0,					/* static_pass_number */