Index: gcc/gcov-io.c
===================================================================
--- gcc/gcov-io.c	(revision 210660)
+++ gcc/gcov-io.c	(working copy)
@@ -64,7 +64,11 @@ GCOV_LINKAGE struct gcov_var
 } gcov_var;
 
 /* Save the current position in the gcov file.  */
-static inline gcov_position_t
+/* We need to expose this function when compiling for gcov-tool.  */
+#ifndef IN_GCOV_TOOL
+static inline
+#endif
+gcov_position_t
 gcov_position (void)
 {
   gcc_assert (gcov_var.mode > 0); 
@@ -72,7 +76,11 @@ gcov_position (void)
 }
 
 /* Return nonzero if the error flag is set.  */
-static inline int 
+/* We need to expose this function when compiling for gcov-tool.  */
+#ifndef IN_GCOV_TOOL
+static inline
+#endif
+int
 gcov_is_error (void)
 {
   return gcov_var.file ? gcov_var.error : 1;
@@ -560,11 +568,13 @@ gcov_read_counter (void)
   return value;
 }
 
+/* We need to expose the below function when compiling for gcov-tool.  */
+
+#if !IN_LIBGCOV || defined (IN_GCOV_TOOL)
 /* Read string from coverage file. Returns a pointer to a static
    buffer, or NULL on empty string. You must copy the string before
    calling another gcov function.  */
 
-#if !IN_LIBGCOV
 GCOV_LINKAGE const char *
 gcov_read_string (void)
 {
@@ -641,7 +651,9 @@ gcov_read_summary (struct gcov_summary *summary)
     }
 }
 
-#if !IN_LIBGCOV
+/* We need to expose the below function when compiling for gcov-tool.  */
+
+#if !IN_LIBGCOV || defined (IN_GCOV_TOOL)
 /* Reset to a known position.  BASE should have been obtained from
    gcov_position, LENGTH should be a record length.  */
 
Index: gcc/gcov-io.h
===================================================================
--- gcc/gcov-io.h	(revision 210660)
+++ gcc/gcov-io.h	(working copy)
@@ -240,50 +240,29 @@ typedef unsigned HOST_WIDEST_INT gcov_type_unsigne
 
 
 /* Counters that are collected.  */
-#define GCOV_COUNTER_ARCS 	0  /* Arc transitions.  */
-#define GCOV_COUNTERS_SUMMABLE	1  /* Counters which can be
-				      summaried.  */
-#define GCOV_FIRST_VALUE_COUNTER 1 /* The first of counters used for value
-				      profiling.  They must form a consecutive
-				      interval and their order must match
-				      the order of HIST_TYPEs in
-				      value-prof.h.  */
-#define GCOV_COUNTER_V_INTERVAL	1  /* Histogram of value inside an interval.  */
-#define GCOV_COUNTER_V_POW2	2  /* Histogram of exact power2 logarithm
-				      of a value.  */
-#define GCOV_COUNTER_V_SINGLE	3  /* The most common value of expression.  */
-#define GCOV_COUNTER_V_DELTA	4  /* The most common difference between
-				      consecutive values of expression.  */
 
-#define GCOV_COUNTER_V_INDIR	5  /* The most common indirect address */
-#define GCOV_COUNTER_AVERAGE	6  /* Compute average value passed to the
-				      counter.  */
-#define GCOV_COUNTER_IOR	7  /* IOR of the all values passed to
-				      counter.  */
-#define GCOV_TIME_PROFILER  8 /* Time profile collecting first run of a function */
-#define GCOV_LAST_VALUE_COUNTER 8  /* The last of counters used for value
-				      profiling.  */
-#define GCOV_COUNTERS		9
+#define DEF_GCOV_COUNTER(COUNTER, NAME, MERGE_FN) COUNTER,
+enum {
+#include "gcov-counter.def"
+GCOV_COUNTERS
+};
+#undef DEF_GCOV_COUNTER
 
+/* Counters which can be summaried.  */
+#define GCOV_COUNTERS_SUMMABLE	(GCOV_COUNTER_ARCS + 1)
+
+/* The first of counters used for value profiling.  They must form a
+   consecutive interval and their order must match the order of
+   HIST_TYPEs in value-prof.h.  */
+#define GCOV_FIRST_VALUE_COUNTER GCOV_COUNTERS_SUMMABLE
+
+/* The last of counters used for value profiling.  */
+#define GCOV_LAST_VALUE_COUNTER (GCOV_COUNTERS - 1)
+
 /* Number of counters used for value profiling.  */
 #define GCOV_N_VALUE_COUNTERS \
   (GCOV_LAST_VALUE_COUNTER - GCOV_FIRST_VALUE_COUNTER + 1)
 
-  /* A list of human readable names of the counters */
-#define GCOV_COUNTER_NAMES	{"arcs", "interval", "pow2", "single", \
-              "delta", "indirect_call", "average", "ior", "time_profiler"}
-
-  /* Names of merge functions for counters.  */
-#define GCOV_MERGE_FUNCTIONS	{"__gcov_merge_add",	\
-				 "__gcov_merge_add",	\
-				 "__gcov_merge_add",	\
-				 "__gcov_merge_single",	\
-				 "__gcov_merge_delta",  \
-				 "__gcov_merge_single", \
-				 "__gcov_merge_add",	\
-				 "__gcov_merge_ior",  \
-         "__gcov_merge_time_profile" }
-
 /* Convert a counter index to a tag.  */
 #define GCOV_TAG_FOR_COUNTER(COUNT)				\
 	(GCOV_TAG_COUNTER_BASE + ((gcov_unsigned_t)(COUNT) << 17))
Index: gcc/gcov-dump.c
===================================================================
--- gcc/gcov-dump.c	(revision 210660)
+++ gcc/gcov-dump.c	(working copy)
@@ -422,7 +422,11 @@ static void
 tag_counters (const char *filename ATTRIBUTE_UNUSED,
 	      unsigned tag ATTRIBUTE_UNUSED, unsigned length ATTRIBUTE_UNUSED)
 {
-  static const char *const counter_names[] = GCOV_COUNTER_NAMES;
+#define DEF_GCOV_COUNTER(COUNTER, NAME, MERGE_FN) NAME,
+  static const char *const counter_names[] = {
+#include "gcov-counter.def"
+};
+#undef DEF_GCOV_COUNTER
   unsigned n_counts = GCOV_TAG_COUNTER_NUM (length);
 
   printf (" %s %u counts",
Index: gcc/coverage.c
===================================================================
--- gcc/coverage.c	(revision 210660)
+++ gcc/coverage.c	(working copy)
@@ -120,9 +120,20 @@ static unsigned bbg_file_stamp;
 static char *da_file_name;
 
 /* The names of merge functions for counters.  */
-static const char *const ctr_merge_functions[GCOV_COUNTERS] = GCOV_MERGE_FUNCTIONS;
-static const char *const ctr_names[GCOV_COUNTERS] = GCOV_COUNTER_NAMES;
+#define STR(str) #str
+#define DEF_GCOV_COUNTER(COUNTER, NAME, FN_TYPE) STR(__gcov_merge ## FN_TYPE),
+static const char *const ctr_merge_functions[GCOV_COUNTERS] = {
+#include "gcov-counter.def"
+};
+#undef DEF_GCOV_COUNTER
+#undef STR
 
+#define DEF_GCOV_COUNTER(COUNTER, NAME, FN_TYPE) NAME,
+static const char *const ctr_names[GCOV_COUNTERS] = {
+#include "gcov-counter.def"
+};
+#undef DEF_GCOV_COUNTER
+
 /* Forward declarations.  */
 static void read_counts_file (void);
 static tree build_var (tree, tree, int);
Index: gcc/gcov-tool.c
===================================================================
--- gcc/gcov-tool.c	(revision 0)
+++ gcc/gcov-tool.c	(revision 0)
@@ -0,0 +1,466 @@
+/* Gcc offline profile processing tool support. */
+/* Compile this one with gcc.  */
+/* Copyright (C) 2014 Free Software Foundation, Inc.
+   Contributed by Rong Xu <xur@google.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "intl.h"
+#include "diagnostic.h"
+#include "version.h"
+#include "gcov-io.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <ftw.h>
+#include <getopt.h>
+
+extern int gcov_profile_merge (struct gcov_info*, struct gcov_info*, int, int);
+extern int gcov_profile_normalize (struct gcov_info*, gcov_type);
+extern int gcov_profile_scale (struct gcov_info*, float, int, int);
+extern struct gcov_info* gcov_read_profile_dir (const char*, int);
+extern void gcov_exit (void);
+extern void set_gcov_list (struct gcov_info *);
+extern void gcov_set_verbose (void);
+
+static int verbose;
+
+/* Remove file NAME if it has a gcda suffix. */
+
+static int
+unlink_gcda_file (const char *name,
+                  const struct stat *status ATTRIBUTE_UNUSED,
+                  int type ATTRIBUTE_UNUSED,
+                  struct FTW *ftwbuf ATTRIBUTE_UNUSED)
+{
+  int ret = 0;
+  int len = strlen (name);
+  int len1 = strlen (GCOV_DATA_SUFFIX);
+
+  if (len > len1 && !strncmp (len -len1 + name, GCOV_DATA_SUFFIX, len1))
+    remove (name);
+
+  if (ret)
+    {
+      fnotice (stderr, "error in removing %s\n", name);
+      exit (FATAL_EXIT_CODE);
+    }
+
+  return ret;
+}
+
+/* Remove the gcda files in PATH recursively.  */
+
+static int
+unlink_profile_dir (const char *path)
+{
+    return nftw(path, unlink_gcda_file, 64, FTW_DEPTH | FTW_PHYS);
+}
+
+/* Merging profile D1 and D2 with weight as W1 and W2, respectively.
+   The result profile is written to directory OUT.
+   Return 0 on success.  */
+
+static int
+profile_merge (const char *d1, const char *d2, const char *out, int w1, int w2)
+{
+  char *pwd;
+  int ret;
+  struct gcov_info * d1_profile;
+  struct gcov_info * d2_profile;
+
+
+  d1_profile = gcov_read_profile_dir (d1, 0);
+  if (!d1_profile)
+    return 1;
+
+  if (d2)
+    {
+      d2_profile = gcov_read_profile_dir (d2, 0);
+      if (!d2_profile)
+        return 1;
+
+      /* The actual merge: we overwrite to d1_profile.  */
+      ret = gcov_profile_merge (d1_profile, d2_profile, w1, w2);
+
+      if (ret)
+        return ret;
+    }
+
+  /* Output new profile.  */
+  unlink_profile_dir (out);
+  mkdir (out, 0755);
+  pwd = getcwd (NULL, 0);
+  gcc_assert (pwd);
+  ret = chdir (out);
+  gcc_assert (ret == 0);
+
+  set_gcov_list (d1_profile);
+  gcov_exit ();
+
+  ret = chdir (pwd);
+  free (pwd);
+  return 0;
+}
+
+/* Usage message for profile merge.  */
+
+static void
+print_merge_usage_message (int error_p)
+{
+  FILE *file = error_p ? stderr : stdout;
+
+  fnotice (file, "  merge [options] <dir1> <dir2>         Merge coverage file contents\n");
+  fnotice (file, "    -v, --verbose                       Verbose mode\n");
+  fnotice (file, "    -o, --output <dir>                  Output directory\n");
+  fnotice (file, "    -w, --weight <w1,w2>                Set weights (float point values)\n");
+}
+
+static const struct option merge_options[] =
+{
+  { "verbose",                no_argument,       NULL, 'v' },
+  { "output",                 required_argument, NULL, 'o' },
+  { "weight",                 required_argument, NULL, 'w' },
+  { 0, 0, 0, 0 }
+};
+
+/* Print merge usage and exit.  */
+
+static void
+merge_usage (void)
+{
+  fnotice (stderr, "Merge subcomand usage:");
+  print_merge_usage_message (true);
+  exit (FATAL_EXIT_CODE);
+}
+
+/* Driver for profile merge sub-command.  */
+
+static int
+do_merge (int argc, char **argv)
+{
+  int opt;
+  int ret;
+  const char *output_dir = 0;
+  int w1 = 1, w2 = 1;
+
+  optind = 0;
+  while ((opt = getopt_long (argc, argv, "vo:w:", merge_options, NULL)) != -1)
+    {
+      switch (opt)
+        {
+        case 'v':
+          verbose = 1;
+          gcov_set_verbose ();
+          break;
+        case 'o':
+          output_dir = optarg;
+          break;
+        case 'w':
+          sscanf (optarg, "%d,%d", &w1, &w2);
+          if (w1 < 0 || w2 < 0)
+            {
+              fnotice (stderr, "weights need to be non-negative\n");
+              exit (FATAL_EXIT_CODE);
+            }
+          break;
+        default:
+          merge_usage ();
+        }
+    }
+
+  if (output_dir == NULL)
+    output_dir = "merged_profile";
+
+  if (argc - optind == 2)
+    ret = profile_merge (argv[optind], argv[optind+1], output_dir, w1, w2);
+  else
+    merge_usage ();
+
+  return ret;
+}
+
+/* If N_VAL is no-zero, normalize the profile by setting the largest counter
+   counter value to N_VAL and scale others counters proportionally.
+   Otherwise, multiply the all counters by SCALE.  */
+
+static int
+profile_rewrite (const char *d1, const char *out, long long n_val,
+                 float scale, int n, int d)
+{
+  char *pwd;
+  int ret;
+  struct gcov_info * d1_profile;
+
+
+  d1_profile = gcov_read_profile_dir (d1, 0);
+  if (!d1_profile)
+    return 1;
+
+  /* Output new profile.  */
+  unlink_profile_dir (out);
+  mkdir (out, 0755);
+  pwd = getcwd (NULL, 0);
+  gcc_assert (pwd);
+  ret = chdir (out);
+  gcc_assert (ret == 0);
+
+  if (n_val)
+    gcov_profile_normalize (d1_profile, (gcov_type) n_val);
+  else
+    gcov_profile_scale (d1_profile, scale, n, d);
+
+  set_gcov_list (d1_profile);
+  gcov_exit ();
+
+  ret = chdir (pwd);
+  free (pwd);
+  return 0;
+}
+
+/* Usage function for profile rewrite.  */
+
+static void
+print_rewrite_usage_message (int error_p)
+{
+  FILE *file = error_p ? stderr : stdout;
+
+  fnotice (file, "  rewrite [options] <dir>               Rewrite coverage file contents\n");
+  fnotice (file, "    -v, --verbose                       Verbose mode\n");
+  fnotice (file, "    -o, --output <dir>                  Output directory\n");
+  fnotice (file, "    -s, --scale <float or simple-frac>  Scale the profile counters\n");
+  fnotice (file, "    -n, --normalize <long long>         Normalize the profile\n");
+}
+
+static const struct option rewrite_options[] =
+{
+  { "verbose",                no_argument,       NULL, 'v' },
+  { "output",                 required_argument, NULL, 'o' },
+  { "scale",                  required_argument, NULL, 's' },
+  { "normalize",              required_argument, NULL, 'n' },
+  { 0, 0, 0, 0 }
+};
+
+/* Print profile rewrite usage and exit.  */
+
+static void
+rewrite_usage (void)
+{
+  fnotice (stderr, "Rewrite subcommand usage:");
+  print_rewrite_usage_message (true);
+  exit (FATAL_EXIT_CODE);
+}
+
+/* Driver for profile rewrite sub-command. */
+
+static int
+do_rewrite (int argc, char **argv)
+{
+  int opt;
+  int ret;
+  const char *output_dir = 0;
+  long long normalize_val = 0;
+  float scale = 0.0;
+  int numerator = 1;
+  int denominator = 1;
+  int do_scaling = 0;
+
+  optind = 0;
+  while ((opt = getopt_long (argc, argv, "vo:s:n:", rewrite_options, NULL)) != -1)
+    {
+      switch (opt)
+        {
+        case 'v':
+          verbose = 1;
+          gcov_set_verbose ();
+          break;
+        case 'o':
+          output_dir = optarg;
+          break;
+        case 'n':
+          if (!do_scaling)
+            normalize_val = atoll (optarg);
+          else
+            fnotice (stderr, "scaling cannot co-exist with normalization,"
+                " skipping\n");
+          break;
+        case 's':
+          ret = 0;
+          do_scaling = 1;
+          if (strstr (optarg, "/"))
+            {
+              ret = sscanf (optarg, "%d/%d", &numerator, &denominator);
+              if (ret == 2)
+                {
+                  gcc_assert (numerator >= 0);
+                  gcc_assert (denominator > 0);
+                }
+            }
+          if (ret != 2)
+            {
+              ret = sscanf (optarg, "%f", &scale);
+              gcc_assert (ret == 1);
+              denominator = 0;
+            }
+
+          if (scale < 0.0)
+            {
+              fnotice (stderr, "scale needs to be non-negative\n");
+              exit (FATAL_EXIT_CODE);
+            }
+          if (normalize_val != 0)
+            {
+              fnotice (stderr, "normalization cannot co-exist with scaling\n");
+              normalize_val = 0;
+            }
+          break;
+        default:
+          rewrite_usage ();
+        }
+    }
+
+  if (output_dir == NULL)
+    output_dir = "rewrite_profile";
+
+  if (argc - optind == 1)
+    {
+      if (denominator > 0)
+        ret = profile_rewrite (argv[optind],  output_dir, 0, 0.0, numerator, denominator);
+      else
+        ret = profile_rewrite (argv[optind],  output_dir, normalize_val, scale, 0, 0);
+    }
+  else
+    rewrite_usage ();
+
+  return ret;
+}
+
+/* Print a usage message and exit.  If ERROR_P is nonzero, this is an error,
+   otherwise the output of --help.  */
+
+static void
+print_usage (int error_p)
+{
+  FILE *file = error_p ? stderr : stdout;
+  int status = error_p ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE;
+
+  fnotice (file, "Usage: %s [OPTION]... SUB_COMMAND [OPTION]...\n\n", progname);
+  fnotice (file, "Offline tool to handle gcda counts\n\n");
+  fnotice (file, "  -h, --help                            Print this help, then exit\n");
+  fnotice (file, "  -v, --version                         Print version number, then exit\n");
+  print_merge_usage_message (error_p);
+  print_rewrite_usage_message (error_p);
+  fnotice (file, "\nFor bug reporting instructions, please see:\n%s.\n",
+           bug_report_url);
+  exit (status);
+}
+
+/* Print version information and exit.  */
+
+static void
+print_version (void)
+{
+  fnotice (stdout, "%s %s%s\n", progname, pkgversion_string, version_string);
+  fnotice (stdout, "Copyright %s 2014 Free Software Foundation, Inc.\n",
+           _("(C)"));
+  fnotice (stdout,
+           _("This is free software; see the source for copying conditions.\n"
+             "There is NO warranty; not even for MERCHANTABILITY or \n"
+             "FITNESS FOR A PARTICULAR PURPOSE.\n\n"));
+  exit (SUCCESS_EXIT_CODE);
+}
+
+static const struct option options[] =
+{
+  { "help",                 no_argument,       NULL, 'h' },
+  { "version",              no_argument,       NULL, 'v' },
+  { 0, 0, 0, 0 }
+};
+
+/* Process args, return index to first non-arg.  */
+
+static int
+process_args (int argc, char **argv)
+{
+  int opt;
+
+  while ((opt = getopt_long (argc, argv, "+hv", options, NULL)) != -1)
+    {
+      switch (opt)
+        {
+        case 'h':
+          print_usage (false);
+          /* Print_usage will exit.  */
+        case 'v':
+          print_version ();
+          /* Print_version will exit.  */
+        default:
+          print_usage (true);
+          /* Print_usage will exit.  */
+        }
+    }
+
+  return optind;
+}
+
+/* Main function for gcov-tool.  */
+
+int
+main (int argc, char **argv)
+{
+  const char *p;
+  const char *sub_command;
+
+  p = argv[0] + strlen (argv[0]);
+  while (p != argv[0] && !IS_DIR_SEPARATOR (p[-1]))
+    --p;
+  progname = p;
+
+  xmalloc_set_program_name (progname);
+
+  /* Unlock the stdio streams.  */
+  unlock_std_streams ();
+
+  gcc_init_libintl ();
+
+  diagnostic_initialize (global_dc, 0);
+
+  /* Handle response files.  */
+  expandargv (&argc, &argv);
+
+  process_args (argc, argv);
+  if (optind >= argc)
+    print_usage (true);
+
+  sub_command = argv[optind];
+
+  if (!strcmp (sub_command, "merge"))
+    return do_merge (argc - optind, argv + optind);
+  else if (!strcmp (sub_command, "rewrite"))
+    return do_rewrite (argc - optind, argv + optind);
+
+  print_usage (true);
+}
Index: gcc/Makefile.in
===================================================================
--- gcc/Makefile.in	(revision 210660)
+++ gcc/Makefile.in	(working copy)
@@ -123,7 +123,8 @@ SUBDIRS =@subdirs@ build
 
 # Selection of languages to be made.
 CONFIG_LANGUAGES = @all_selected_languages@
-LANGUAGES = c gcov$(exeext) gcov-dump$(exeext) $(CONFIG_LANGUAGES)
+LANGUAGES = c gcov$(exeext) gcov-dump$(exeext) gcov-tool$(exeext) \
+            $(CONFIG_LANGUAGES)
 
 # Default values for variables overridden in Makefile fragments.
 # CFLAGS is for the user to override to, e.g., do a cross build with -O2.
@@ -196,6 +197,9 @@ GCC_WARN_CXXFLAGS = $(LOOSE_WARN) $($(@D)-warn) $(
 # flex output may yield harmless "no previous prototype" warnings
 build/gengtype-lex.o-warn = -Wno-error
 gengtype-lex.o-warn = -Wno-error
+libgcov-util.o-warn = -Wno-error
+libgcov-driver-tool.o-warn = -Wno-error
+libgcov-merge-tool.o-warn = -Wno-error
 
 # All warnings have to be shut off in stage1 if the compiler used then
 # isn't gcc; configure determines that.  WARN_CFLAGS will be either
@@ -769,6 +773,7 @@ GCC_INSTALL_NAME := $(shell echo gcc|sed '$(progra
 GCC_TARGET_INSTALL_NAME := $(target_noncanonical)-$(shell echo gcc|sed '$(program_transform_name)')
 CPP_INSTALL_NAME := $(shell echo cpp|sed '$(program_transform_name)')
 GCOV_INSTALL_NAME := $(shell echo gcov|sed '$(program_transform_name)')
+GCOV_TOOL_INSTALL_NAME := $(shell echo gcov-tool|sed '$(program_transform_name)')
 
 # Setup the testing framework, if you have one
 EXPECT = `if [ -f $${rootme}/../expect/expect ] ; then \
@@ -890,7 +895,7 @@ BASIC_BLOCK_H = basic-block.h $(PREDICT_H) $(VEC_H
 GIMPLE_H = gimple.h gimple.def gsstruct.def pointer-set.h $(VEC_H) \
 	$(GGC_H) $(BASIC_BLOCK_H) $(TREE_H) tree-ssa-operands.h \
 	tree-ssa-alias.h $(INTERNAL_FN_H) $(HASH_TABLE_H) is-a.h
-GCOV_IO_H = gcov-io.h gcov-iov.h auto-host.h
+GCOV_IO_H = gcov-io.h gcov-iov.h auto-host.h gcov-counter.def
 RECOG_H = recog.h
 EMIT_RTL_H = emit-rtl.h
 FLAGS_H = flags.h flag-types.h $(OPTIONS_H)
@@ -1490,7 +1495,7 @@ ALL_HOST_FRONTEND_OBJS = $(foreach v,$(CONFIG_LANG
 ALL_HOST_BACKEND_OBJS = $(GCC_OBJS) $(OBJS) $(OBJS-libcommon) \
   $(OBJS-libcommon-target) @TREEBROWSER@ main.o c-family/cppspec.o \
   $(COLLECT2_OBJS) $(EXTRA_GCC_OBJS) $(GCOV_OBJS) $(GCOV_DUMP_OBJS) \
-  lto-wrapper.o
+  $(GCOV_TOOL_OBJS) lto-wrapper.o
 
 # This lists all host object files, whether they are included in this
 # compilation or not.
@@ -1515,6 +1520,7 @@ MOSTLYCLEANFILES = insn-flags.h insn-config.h insn
  $(SPECS) collect2$(exeext) gcc-ar$(exeext) gcc-nm$(exeext) \
  gcc-ranlib$(exeext) \
  gcov-iov$(build_exeext) gcov$(exeext) gcov-dump$(exeext) \
+ gcov-tool$(exeect) \
  gengtype$(exeext) *.[0-9][0-9].* *.[si] *-checksum.c libbackend.a \
  libcommon-target.a libcommon.a libgcc.mk
 
@@ -2572,6 +2578,22 @@ GCOV_DUMP_OBJS = gcov-dump.o
 gcov-dump$(exeext): $(GCOV_DUMP_OBJS) $(LIBDEPS)
 	+$(LINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) $(GCOV_DUMP_OBJS) \
 		$(LIBS) -o $@
+
+GCOV_TOOL_DEP_FILES = $(srcdir)/../libgcc/libgcov-util.c gcov-io.c $(GCOV_IO_H) \
+  $(srcdir)/../libgcc/libgcov-driver.c $(srcdir)/../libgcc/libgcov-driver-system.c \
+  $(srcdir)/../libgcc/libgcov-merge.c \
+  $(SYSTEM_H) coretypes.h $(TM_H) $(CONFIG_H) version.h intl.h $(DIAGNOSTIC_H)
+libgcov-util.o: $(srcdir)/../libgcc/libgcov-util.c $(GCOV_TOOL_DEP_FILES)
+	+$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) -o $@ $<
+libgcov-driver-tool.o: $(srcdir)/../libgcc/libgcov-driver.c $(GCOV_TOOL_DEP_FILES)
+	+$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
+	  -DIN_GCOV_TOOL=1 -o $@ $<
+libgcov-merge-tool.o: $(srcdir)/../libgcc/libgcov-merge.c $(GCOV_TOOL_DEP_FILES)
+	+$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
+	  -DIN_GCOV_TOOL=1 -o $@ $<
+GCOV_TOOL_OBJS = gcov-tool.o libgcov-util.o libgcov-driver-tool.o libgcov-merge-tool.o
+gcov-tool$(exeext): $(GCOV_TOOL_OBJS) $(LIBDEPS)
+	+$(LINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) $(GCOV_TOOL_OBJS) $(LIBS) -o $@
 #
 # Build the include directories.  The stamp files are stmp-* rather than
 # s-* so that mostlyclean does not force the include directory to
@@ -2800,7 +2822,7 @@ TEXI_GCC_FILES = gcc.texi gcc-common.texi gcc-vers
 	 contribute.texi compat.texi funding.texi gnu.texi gpl_v3.texi	\
 	 fdl.texi contrib.texi cppenv.texi cppopts.texi avr-mmcu.texi	\
 	 implement-c.texi implement-cxx.texi arm-neon-intrinsics.texi	\
-	 arm-acle-intrinsics.texi
+	 arm-acle-intrinsics.texi gcov-tool.texi
 
 # we explicitly use $(srcdir)/doc/tm.texi here to avoid confusion with
 # the generated tm.texi; the latter might have a more recent timestamp,
@@ -3208,6 +3230,13 @@ install-common: native lang.install-common install
 	    rm -f $(DESTDIR)$(bindir)/$(GCOV_INSTALL_NAME)$(exeext); \
 	    $(INSTALL_PROGRAM) gcov$(exeext) $(DESTDIR)$(bindir)/$(GCOV_INSTALL_NAME)$(exeext); \
 	fi
+# Install gcov-tool if it was compiled.
+	-if [ -f gcov-tool$(exeext) ]; \
+	then \
+	    rm -f $(DESTDIR)$(bindir)/$(GCOV_TOOL_INSTALL_NAME)$(exeext); \
+	    $(INSTALL_PROGRAM) \
+	    gcov-tool$(exeext) $(DESTDIR)$(bindir)/$(GCOV_TOOL_INSTALL_NAME)$(exeext); \
+	fi
 
 # Install the driver program as $(target_noncanonical)-gcc,
 # $(target_noncanonical)-gcc-$(version), and also as gcc if native.
Index: gcc/gcov-counter.def
===================================================================
--- gcc/gcov-counter.def	(revision 0)
+++ gcc/gcov-counter.def	(revision 0)
@@ -0,0 +1,54 @@
+/* Definitions for the gcov counters in the GNU compiler.
+   Copyright (C) 2001-2014 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* Before including this file, define a macro:
+
+     DEF_GCOV_COUNTER(COUNTER, NAME, FN_TYPE)
+
+   This macro will be expanded to all supported gcov counters, their
+   names, or the type of handler functions.  FN_TYPE will be
+   expanded to a handler function, like in gcov_merge, it is
+   expanded to __gcov_merge ## FN_TYPE.  */
+
+/* Arc transitions.  */
+DEF_GCOV_COUNTER(GCOV_COUNTER_ARCS, "arcs", _add)
+
+/* Histogram of value inside an interval.  */
+DEF_GCOV_COUNTER(GCOV_COUNTER_V_INTERVAL, "interval", _add)
+
+/* Histogram of exact power2 logarithm of a value.  */
+DEF_GCOV_COUNTER(GCOV_COUNTER_V_POW2, "pow2", _add)
+
+/* The most common value of expression.  */
+DEF_GCOV_COUNTER(GCOV_COUNTER_V_SINGLE, "single", _single)
+
+/* The most common difference between consecutive values of expression.  */
+DEF_GCOV_COUNTER(GCOV_COUNTER_V_DELTA, "delta", _delta)
+
+/* The most common indirect address.  */
+DEF_GCOV_COUNTER(GCOV_COUNTER_V_INDIR, "indirect_call", _single)
+
+/* Compute average value passed to the counter.  */
+DEF_GCOV_COUNTER(GCOV_COUNTER_AVERAGE, "average", _add)
+
+/* IOR of the all values passed to counter.  */
+DEF_GCOV_COUNTER(GCOV_COUNTER_IOR, "ior", _ior)
+
+/* Time profile collecting first run of a function */
+DEF_GCOV_COUNTER(GCOV_TIME_PROFILER, "time_profiler", _time_profile)
Index: libgcc/libgcov-driver.c
===================================================================
--- libgcc/libgcov-driver.c	(revision 210652)
+++ libgcc/libgcov-driver.c	(working copy)
@@ -77,7 +77,11 @@ set_gcov_list (struct gcov_info *head)
 }
 
 /* Size of the longest file name. */
-static size_t gcov_max_filename = 0;
+/* We need to expose this static variable when compiling for gcov-tool.  */
+#ifndef IN_GCOV_TOOL
+static
+#endif
+size_t gcov_max_filename = 0;
 
 /* Flag when the profile has already been dumped via __gcov_dump().  */
 static int gcov_dump_complete;
Index: libgcc/libgcov-merge.c
===================================================================
--- libgcc/libgcov-merge.c	(revision 210652)
+++ libgcc/libgcov-merge.c	(working copy)
@@ -53,7 +53,7 @@ void
 __gcov_merge_add (gcov_type *counters, unsigned n_counters)
 {
   for (; n_counters; counters++, n_counters--)
-    *counters += gcov_read_counter ();
+    *counters += gcov_get_counter ();
 }
 #endif /* L_gcov_merge_add */
 
@@ -65,7 +65,7 @@ void
 __gcov_merge_ior (gcov_type *counters, unsigned n_counters)
 {
   for (; n_counters; counters++, n_counters--)
-    *counters |= gcov_read_counter ();
+    *counters |= gcov_get_counter ();
 }
 #endif
 
@@ -81,7 +81,7 @@ __gcov_merge_time_profile (gcov_type *counters, un
 
   for (i = 0; i < n_counters; i++)
     {
-      value = gcov_read_counter ();
+      value = gcov_get_counter ();
 
       if (value && (!counters[i] || value < counters[i]))
         counters[i] = value;
@@ -109,9 +109,9 @@ __gcov_merge_single (gcov_type *counters, unsigned
   n_measures = n_counters / 3;
   for (i = 0; i < n_measures; i++, counters += 3)
     {
-      value = gcov_read_counter ();
-      counter = gcov_read_counter ();
-      all = gcov_read_counter ();
+      value = gcov_get_counter_target ();
+      counter = gcov_get_counter ();
+      all = gcov_get_counter ();
 
       if (counters[0] == value)
         counters[1] += counter;
@@ -148,10 +148,10 @@ __gcov_merge_delta (gcov_type *counters, unsigned
   n_measures = n_counters / 4;
   for (i = 0; i < n_measures; i++, counters += 4)
     {
-      /* last = */ gcov_read_counter ();
-      value = gcov_read_counter ();
-      counter = gcov_read_counter ();
-      all = gcov_read_counter ();
+      /* last = */ gcov_get_counter ();
+      value = gcov_get_counter_target ();
+      counter = gcov_get_counter ();
+      all = gcov_get_counter ();
 
       if (counters[1] == value)
         counters[2] += counter;
Index: libgcc/libgcov-util.c
===================================================================
--- libgcc/libgcov-util.c	(revision 0)
+++ libgcc/libgcov-util.c	(revision 0)
@@ -0,0 +1,856 @@
+/* Utility functions for reading gcda files into in-memory
+   gcov_info structures and offline profile processing. */
+/* Copyright (C) 2014 Free Software Foundation, Inc.
+   Contributed by Rong Xu <xur@google.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+
+#define IN_GCOV_TOOL 1
+
+#include "libgcov.h"
+#include "intl.h"
+#include "diagnostic.h"
+#include "version.h"
+#include "demangle.h"
+
+/* Borrowed from basic-block.h.  */
+#define RDIV(X,Y) (((X) + (Y) / 2) / (Y))
+
+extern gcov_position_t gcov_position();
+extern int gcov_is_error();
+extern gcov_unsigned_t gcov_max_filename;
+
+/* Verbose mode for debug.  */
+static int verbose;
+
+/* Set verbose flag.  */
+void gcov_set_verbose (void)
+{
+  verbose = 1;
+}
+
+/* The following part is to read Gcda and reconstruct GCOV_INFO.  */
+
+#include "obstack.h"
+#include <unistd.h>
+#include <ftw.h>
+
+static void tag_function (unsigned, unsigned);
+static void tag_blocks (unsigned, unsigned);
+static void tag_arcs (unsigned, unsigned);
+static void tag_lines (unsigned, unsigned);
+static void tag_counters (unsigned, unsigned);
+static void tag_summary (unsigned, unsigned);
+
+/* The gcov_info for the first module.  */
+static struct gcov_info *curr_gcov_info;
+/* The gcov_info being processed.  */
+static struct gcov_info *gcov_info_head;
+/* This variable contains all the functions in current module.  */
+static struct obstack fn_info;
+/* The function being processed.  */
+static struct gcov_fn_info *curr_fn_info;
+/* The number of functions seen so far.  */
+static unsigned num_fn_info;
+/* This variable contains all the counters for current module.  */
+static int k_ctrs_mask[GCOV_COUNTERS];
+/* The kind of counters that have been seen.  */
+static struct gcov_ctr_info k_ctrs[GCOV_COUNTERS];
+/* Number of kind of counters that have been seen.  */
+static int k_ctrs_types;
+/* The longest length of all the filenames.  */
+static int max_filename_len;
+
+/* Merge functions for counters.  */
+#define DEF_GCOV_COUNTER(COUNTER, NAME, FN_TYPE) __gcov_merge ## FN_TYPE,
+static gcov_merge_fn ctr_merge_functions[GCOV_COUNTERS] = {
+#include "gcov-counter.def"
+};
+#undef DEF_GCOV_COUNTER
+
+/* Set the ctrs field in gcov_fn_info object FN_INFO.  */
+
+static void
+set_fn_ctrs (struct gcov_fn_info *fn_info)
+{
+  int j = 0, i;
+
+  for (i = 0; i < GCOV_COUNTERS; i++)
+    {
+      if (k_ctrs_mask[i] == 0)
+        continue;
+      fn_info->ctrs[j].num = k_ctrs[i].num;
+      fn_info->ctrs[j].values = k_ctrs[i].values;
+      j++;
+    }
+  if (k_ctrs_types == 0)
+    k_ctrs_types = j;
+  else
+    gcc_assert (j == k_ctrs_types);
+}
+
+/* For each tag in gcda file, we have an entry here.
+   TAG is the tag value; NAME is the tag name; and
+   PROC is the handler function.  */
+
+typedef struct tag_format
+{
+    unsigned tag;
+    char const *name;
+    void (*proc) (unsigned, unsigned);
+} tag_format_t;
+
+/* Handler table for various Tags.  */
+
+static const tag_format_t tag_table[] =
+{
+  {0, "NOP", NULL},
+  {0, "UNKNOWN", NULL},
+  {0, "COUNTERS", tag_counters},
+  {GCOV_TAG_FUNCTION, "FUNCTION", tag_function},
+  {GCOV_TAG_BLOCKS, "BLOCKS", tag_blocks},
+  {GCOV_TAG_ARCS, "ARCS", tag_arcs},
+  {GCOV_TAG_LINES, "LINES", tag_lines},
+  {GCOV_TAG_OBJECT_SUMMARY, "OBJECT_SUMMARY", tag_summary},
+  {GCOV_TAG_PROGRAM_SUMMARY, "PROGRAM_SUMMARY", tag_summary},
+  {0, NULL, NULL}
+};
+
+/* Handler for reading function tag.  */
+
+static void
+tag_function (unsigned tag ATTRIBUTE_UNUSED, unsigned length ATTRIBUTE_UNUSED)
+{
+  int i;
+
+  /* write out previous fn_info.  */
+  if (num_fn_info)
+    {
+      set_fn_ctrs (curr_fn_info);
+      obstack_ptr_grow (&fn_info, curr_fn_info);
+    }
+
+  /* Here we over allocate a bit, using GCOV_COUNTERS instead of the actual active
+     counter types.  */
+  curr_fn_info = (struct gcov_fn_info *) xcalloc (sizeof (struct gcov_fn_info)
+                   + GCOV_COUNTERS * sizeof (struct gcov_ctr_info), 1);
+
+  for (i = 0; i < GCOV_COUNTERS; i++)
+     k_ctrs[i].num = 0;
+  k_ctrs_types = 0;
+
+  curr_fn_info->key = curr_gcov_info;
+  curr_fn_info->ident = gcov_read_unsigned ();
+  curr_fn_info->lineno_checksum = gcov_read_unsigned ();
+  curr_fn_info->cfg_checksum = gcov_read_unsigned ();
+  num_fn_info++;
+
+  if (verbose)
+    fnotice (stdout, "tag one function id=%d\n", curr_fn_info->ident);
+}
+
+/* Handler for reading block tag.  */
+
+static void
+tag_blocks (unsigned tag ATTRIBUTE_UNUSED, unsigned length ATTRIBUTE_UNUSED)
+{
+  /* TBD: gcov-tool currently does not handle gcno files. Assert here.  */
+  gcc_unreachable ();
+}
+
+/* Handler for reading flow arc tag.  */
+
+static void
+tag_arcs (unsigned tag ATTRIBUTE_UNUSED, unsigned length ATTRIBUTE_UNUSED)
+{
+  /* TBD: gcov-tool currently does not handle gcno files. Assert here.  */
+  gcc_unreachable ();
+}
+
+/* Handler for reading line tag.  */
+
+static void
+tag_lines (unsigned tag ATTRIBUTE_UNUSED, unsigned length ATTRIBUTE_UNUSED)
+{
+  /* TBD: gcov-tool currently does not handle gcno files. Assert here.  */
+  gcc_unreachable ();
+}
+
+/* Handler for reading counters array tag with value as TAG and length of LENGTH.  */
+
+static void
+tag_counters (unsigned tag, unsigned length)
+{
+  unsigned n_counts = GCOV_TAG_COUNTER_NUM (length);
+  gcov_type *values;
+  unsigned ix;
+  unsigned tag_ix;
+
+  tag_ix = GCOV_COUNTER_FOR_TAG (tag);
+  gcc_assert (tag_ix < GCOV_COUNTERS);
+  k_ctrs_mask [tag_ix] = 1;
+  gcc_assert (k_ctrs[tag_ix].num == 0);
+  k_ctrs[tag_ix].num = n_counts;
+
+  k_ctrs[tag_ix].values = values = (gcov_type *) xmalloc (n_counts * sizeof (gcov_type));
+  gcc_assert (values);
+
+  for (ix = 0; ix != n_counts; ix++)
+    values[ix] = gcov_read_counter ();
+}
+
+/* Handler for reading summary tag.  */
+
+static void
+tag_summary (unsigned tag ATTRIBUTE_UNUSED, unsigned length ATTRIBUTE_UNUSED)
+{
+  struct gcov_summary summary;
+
+  gcov_read_summary (&summary);
+}
+
+/* This function is called at the end of reading a gcda file.
+   It flushes the contents in curr_fn_info to gcov_info object OBJ_INFO.  */
+
+static void
+read_gcda_finalize (struct gcov_info *obj_info)
+{
+  int i;
+
+  set_fn_ctrs (curr_fn_info);
+  obstack_ptr_grow (&fn_info, curr_fn_info);
+
+  /* We set the following fields: merge, n_functions, and functions.  */
+  obj_info->n_functions = num_fn_info;
+  obj_info->functions = (const struct gcov_fn_info**) obstack_finish (&fn_info);
+
+  /* wrap all the counter array.  */
+  for (i=0; i< GCOV_COUNTERS; i++)
+    {
+      if (k_ctrs_mask[i])
+        obj_info->merge[i] = ctr_merge_functions[i];
+    }
+}
+
+/* Read the content of a gcda file FILENAME, and return a gcov_info data structure.
+   Program level summary CURRENT_SUMMARY will also be updated.  */
+
+static struct gcov_info *
+read_gcda_file (const char *filename)
+{
+  unsigned tags[4];
+  unsigned depth = 0;
+  unsigned magic, version;
+  struct gcov_info *obj_info;
+  int i;
+
+  for (i=0; i< GCOV_COUNTERS; i++)
+    k_ctrs_mask[i] = 0;
+  k_ctrs_types = 0;
+
+  if (!gcov_open (filename))
+    {
+      fnotice (stderr, "%s:cannot open\n", filename);
+      return NULL;
+    }
+
+  /* Read magic.  */
+  magic = gcov_read_unsigned ();
+  if (magic != GCOV_DATA_MAGIC)
+    {
+      fnotice (stderr, "%s:not a gcov data file\n", filename);
+      gcov_close ();
+      return NULL;
+    }
+
+  /* Read version.  */
+  version = gcov_read_unsigned ();
+  if (version != GCOV_VERSION)
+    {
+      fnotice (stderr, "%s:incorrect gcov version %d vs %d \n", filename, version, GCOV_VERSION);
+      gcov_close ();
+      return NULL;
+    }
+
+  /* Instantiate a gcov_info object.  */
+  curr_gcov_info = obj_info = (struct gcov_info *) xcalloc (sizeof (struct gcov_info) +
+             sizeof (struct gcov_ctr_info) * GCOV_COUNTERS, 1);
+
+  obj_info->version = version;
+  obstack_init (&fn_info);
+  num_fn_info = 0;
+  curr_fn_info = 0;
+  {
+    char *str_dup = (char*) xmalloc (strlen (filename) + 1);
+    int len;
+
+    strcpy (str_dup, filename);
+    obj_info->filename = str_dup;
+    if ((len = strlen (filename)) > max_filename_len)
+      max_filename_len = len;
+  }
+
+  /* Read stamp.  */
+  obj_info->stamp = gcov_read_unsigned ();
+
+  while (1)
+    {
+      gcov_position_t base;
+      unsigned tag, length;
+      tag_format_t const *format;
+      unsigned tag_depth;
+      int error;
+      unsigned mask;
+
+      tag = gcov_read_unsigned ();
+      if (!tag)
+	break;
+      length = gcov_read_unsigned ();
+      base = gcov_position ();
+      mask = GCOV_TAG_MASK (tag) >> 1;
+      for (tag_depth = 4; mask; mask >>= 8)
+	{
+	  if (((mask & 0xff) != 0xff))
+	    {
+	      warning (0, "%s:tag `%08x' is invalid\n", filename, tag);
+	      break;
+	    }
+	  tag_depth--;
+	}
+      for (format = tag_table; format->name; format++)
+	if (format->tag == tag)
+	  goto found;
+      format = &tag_table[GCOV_TAG_IS_COUNTER (tag) ? 2 : 1];
+    found:;
+      if (tag)
+	{
+	  if (depth && depth < tag_depth)
+	    {
+	      if (!GCOV_TAG_IS_SUBTAG (tags[depth - 1], tag))
+		warning (0, "%s:tag `%08x' is incorrectly nested\n",
+			filename, tag);
+	    }
+	  depth = tag_depth;
+	  tags[depth - 1] = tag;
+	}
+
+      if (format->proc)
+        {
+	  unsigned long actual_length;
+
+	  (*format->proc) (tag, length);
+
+	  actual_length = gcov_position () - base;
+	  if (actual_length > length)
+	    warning (0, "%s:record size mismatch %lu bytes overread\n",
+		    filename, actual_length - length);
+	  else if (length > actual_length)
+	    warning (0, "%s:record size mismatch %lu bytes unread\n",
+		    filename, length - actual_length);
+	}
+
+      gcov_sync (base, length);
+      if ((error = gcov_is_error ()))
+	{
+	  warning (0, error < 0 ? "%s:counter overflow at %lu\n" :
+		                  "%s:read error at %lu\n", filename,
+		  (long unsigned) gcov_position ());
+	  break;
+	}
+    }
+
+  read_gcda_finalize (obj_info);
+  gcov_close ();
+
+  return obj_info;
+}
+
+/* This will be called by ftw(). It opens and read a gcda file FILENAME.
+   Return a non-zero value to stop the tree walk.  */
+
+static int
+ftw_read_file (const char *filename,
+               const struct stat *status ATTRIBUTE_UNUSED,
+               int type)
+{
+  int filename_len;
+  int suffix_len;
+  struct gcov_info *obj_info;
+
+  /* Only read regular files.  */
+  if (type != FTW_F)
+    return 0;
+
+  filename_len = strlen (filename);
+  suffix_len = strlen (GCOV_DATA_SUFFIX);
+
+  if (filename_len <= suffix_len)
+    return 0;
+
+  if (strcmp(filename + filename_len - suffix_len, GCOV_DATA_SUFFIX))
+    return 0;
+
+   if (verbose)
+    fnotice (stderr, "reading file: %s\n", filename);
+
+  obj_info = read_gcda_file (filename);
+
+  obj_info->next = gcov_info_head;
+  gcov_info_head = obj_info;
+
+  return 0;
+}
+
+/* Initializer for reading a profile dir.  */
+
+static inline void
+read_profile_dir_init (void)
+{
+  gcov_info_head = 0;
+}
+
+/* Driver for read a profile directory and convert into gcov_info list in memory.
+   Return NULL on error,
+   Return the head of gcov_info list on success.
+   Note the file static variable GCOV_MAX_FILENAME is also set.  */
+
+struct gcov_info *
+gcov_read_profile_dir (const char* dir_name, int recompute_summary ATTRIBUTE_UNUSED)
+{
+  char *pwd;
+  int ret;
+
+  read_profile_dir_init ();
+
+  if (access (dir_name, R_OK) != 0)
+    {
+      fnotice (stderr, "cannot access directory %s\n", dir_name);
+      return NULL;
+    }
+  pwd = getcwd (NULL, 0);
+  gcc_assert (pwd);
+  ret = chdir (dir_name);
+  if (ret !=0)
+    {
+      fnotice (stderr, "%s is not a directory\n", dir_name);
+      return NULL;
+    }
+  ftw (".", ftw_read_file, 50);
+  ret = chdir (pwd);
+  free (pwd);
+
+
+  /* gcov_max_filename is defined in libgcov.c that records the
+     max filename len. We need to set it here to allocate the
+     array for dumping.  */
+  gcov_max_filename = max_filename_len;
+
+  return gcov_info_head;;
+}
+
+/* This part of the code is to merge profile counters.  */
+
+static gcov_type *gcov_value_buf;
+static gcov_unsigned_t gcov_value_buf_size;
+static gcov_unsigned_t gcov_value_buf_pos;
+static unsigned gcov_merge_weight;
+
+/* Read a counter value from gcov_value_buf array.  */
+
+gcov_type
+gcov_read_counter_mem (void)
+{
+  gcov_type ret;
+  gcc_assert (gcov_value_buf_pos < gcov_value_buf_size);
+  ret = *(gcov_value_buf + gcov_value_buf_pos);
+  ++gcov_value_buf_pos;
+  return ret;
+}
+
+/* Return the recorded merge weight.  */
+
+unsigned
+gcov_get_merge_weight (void)
+{
+  return gcov_merge_weight;
+}
+
+/* A wrapper function for merge functions. It sets up the
+   value buffer and weights and then calls the merge function.  */
+
+static void
+merge_wrapper (gcov_merge_fn f, gcov_type *v1, gcov_unsigned_t n,
+               gcov_type *v2, unsigned w)
+{
+  gcov_value_buf = v2;
+  gcov_value_buf_pos = 0;
+  gcov_value_buf_size = n;
+  gcov_merge_weight = w;
+  (*f) (v1, n);
+}
+
+/* Offline tool to manipulate profile data.
+   This tool targets on matched profiles. But it has some tolerance on
+   unmatched profiles.
+   When merging p1 to p2 (p2 is the dst),
+   * m.gcda in p1 but not in p2: append m.gcda to p2 with specified weight;
+     emit warning
+   * m.gcda in p2 but not in p1: keep m.gcda in p2 and multiply by
+     specified weight; emit warning.
+   * m.gcda in both p1 and p2:
+   ** p1->m.gcda->f checksum matches p2->m.gcda->f: simple merge.
+   ** p1->m.gcda->f checksum does not matches p2->m.gcda->f: keep
+      p2->m.gcda->f and
+      drop p1->m.gcda->f. A warning is emitted.  */
+
+/* Add INFO2's counter to INFO1, multiplying by weight W.  */
+
+static int
+gcov_merge (struct gcov_info *info1, struct gcov_info *info2, int w)
+{
+  unsigned f_ix;
+  unsigned n_functions = info1->n_functions;
+  int has_mismatch = 0;
+
+  gcc_assert (info2->n_functions == n_functions);
+  for (f_ix = 0; f_ix < n_functions; f_ix++)
+    {
+      unsigned t_ix;
+      const struct gcov_fn_info *gfi_ptr1 = info1->functions[f_ix];
+      const struct gcov_fn_info *gfi_ptr2 = info2->functions[f_ix];
+      const struct gcov_ctr_info *ci_ptr1, *ci_ptr2;
+
+      if (!gfi_ptr1 || gfi_ptr1->key != info1)
+        continue;
+      if (!gfi_ptr2 || gfi_ptr2->key != info2)
+        continue;
+
+      if (gfi_ptr1->cfg_checksum != gfi_ptr2->cfg_checksum)
+        {
+          fnotice (stderr, "in %s, cfg_checksum mismatch, skipping\n",
+                  info1->filename);
+          has_mismatch = 1;
+          continue;
+        }
+      ci_ptr1 = gfi_ptr1->ctrs;
+      ci_ptr2 = gfi_ptr2->ctrs;
+      for (t_ix = 0; t_ix != GCOV_COUNTERS; t_ix++)
+        {
+          gcov_merge_fn merge1 = info1->merge[t_ix];
+          gcov_merge_fn merge2 = info2->merge[t_ix];
+
+          gcc_assert (merge1 == merge2);
+          if (!merge1)
+            continue;
+          gcc_assert (ci_ptr1->num == ci_ptr2->num);
+          merge_wrapper (merge1, ci_ptr1->values, ci_ptr1->num, ci_ptr2->values, w);
+          ci_ptr1++;
+          ci_ptr2++;
+        }
+    }
+
+  return has_mismatch;
+}
+
+/* Find and return the match gcov_info object for INFO from ARRAY.
+   SIZE is the length of ARRAY.
+   Return NULL if there is no match.  */
+
+static struct gcov_info *
+find_match_gcov_info (struct gcov_info **array, int size, struct gcov_info *info)
+{
+  struct gcov_info *gi_ptr;
+  struct gcov_info *ret = NULL;
+  int i;
+
+  for (i = 0; i < size; i++)
+    {
+      gi_ptr = array[i];
+      if (gi_ptr == 0)
+        continue;
+      if (!strcmp (gi_ptr->filename, info->filename))
+        {
+          ret = gi_ptr;
+          array[i] = 0;
+          break;
+        }
+    }
+
+  if (ret && ret->n_functions != info->n_functions)
+    {
+      fnotice (stderr, "mismatched profiles in %s (%d functions"
+                       " vs %d functions)\n",
+                       ret->filename,
+                       ret->n_functions,
+                       info->n_functions);
+      ret = NULL;
+    }
+  return ret;
+}
+
+/* Merge the list of gcov_info objects from SRC_PROFILE to TGT_PROFILE.
+   Return 0 on success: without mismatch.
+   Reutrn 1 on error.  */
+
+int
+gcov_profile_merge (struct gcov_info *tgt_profile, struct gcov_info *src_profile,
+                    int w1, int w2)
+{
+  struct gcov_info *gi_ptr;
+  struct gcov_info **tgt_infos;
+  struct gcov_info *tgt_tail;
+  struct gcov_info **in_src_not_tgt;
+  unsigned tgt_cnt = 0, src_cnt = 0;
+  unsigned unmatch_info_cnt = 0;
+  unsigned int i;
+
+  for (gi_ptr = tgt_profile; gi_ptr; gi_ptr = gi_ptr->next)
+    tgt_cnt++;
+  for (gi_ptr = src_profile; gi_ptr; gi_ptr = gi_ptr->next)
+    src_cnt++;
+  tgt_infos = (struct gcov_info **) xmalloc (sizeof (struct gcov_info *)
+                 * tgt_cnt);
+  gcc_assert (tgt_infos);
+  in_src_not_tgt = (struct gcov_info **) xmalloc (sizeof (struct gcov_info *)
+                     * src_cnt);
+  gcc_assert (in_src_not_tgt);
+
+  for (gi_ptr = tgt_profile, i = 0; gi_ptr; gi_ptr = gi_ptr->next, i++)
+    tgt_infos[i] = gi_ptr;
+
+  tgt_tail = tgt_infos[tgt_cnt - 1];
+
+  /* First pass on tgt_profile, we multiply w1 to all counters.  */
+  if (w1 > 1)
+    {
+       for (i = 0; i < tgt_cnt; i++)
+         gcov_merge (tgt_infos[i], tgt_infos[i], w1-1);
+    }
+
+  /* Second pass, add src_profile to the tgt_profile.  */
+  for (gi_ptr = src_profile; gi_ptr; gi_ptr = gi_ptr->next)
+    {
+      struct gcov_info *gi_ptr1;
+
+      gi_ptr1 = find_match_gcov_info (tgt_infos, tgt_cnt, gi_ptr);
+      if (gi_ptr1 == NULL)
+        {
+          in_src_not_tgt[unmatch_info_cnt++] = gi_ptr;
+          continue;
+        }
+      gcov_merge (gi_ptr1, gi_ptr, w2);
+    }
+
+  /* For modules in src but not in tgt. We adjust the counter and append.  */
+  for (i = 0; i < unmatch_info_cnt; i++)
+    {
+      gi_ptr = in_src_not_tgt[i];
+      gcov_merge (gi_ptr, gi_ptr, w2 - 1);
+      tgt_tail->next = gi_ptr;
+      tgt_tail = gi_ptr;
+    }
+
+  return 0;
+}
+
+typedef gcov_type (*counter_op_fn) (gcov_type, void*, void*);
+
+/* Performing FN upon arc counters.  */
+
+static void
+__gcov_add_counter_op (gcov_type *counters, unsigned n_counters,
+                       counter_op_fn fn, void *data1, void *data2)
+{
+  for (; n_counters; counters++, n_counters--)
+    {
+      gcov_type val = *counters;
+      *counters = fn(val, data1, data2);
+    }
+}
+
+/* Performing FN upon ior counters.  */
+
+static void
+__gcov_ior_counter_op (gcov_type *counters ATTRIBUTE_UNUSED,
+                       unsigned n_counters ATTRIBUTE_UNUSED,
+                       counter_op_fn fn ATTRIBUTE_UNUSED,
+                       void *data1 ATTRIBUTE_UNUSED,
+                       void *data2 ATTRIBUTE_UNUSED)
+{
+  /* Do nothing.  */
+}
+
+/* Performing FN upon time-profile counters.  */
+
+static void
+__gcov_time_profile_counter_op (gcov_type *counters, unsigned n_counters,
+                                counter_op_fn fn, void *data1, void *data2)
+{
+  __gcov_add_counter_op (counters, n_counters, fn, data1, data2);
+}
+
+/* Performaing FN upon delta counters.  */
+
+static void
+__gcov_delta_counter_op (gcov_type *counters, unsigned n_counters,
+                         counter_op_fn fn, void *data1, void *data2)
+{
+  unsigned i, n_measures;
+
+  gcc_assert (!(n_counters % 4));
+  n_measures = n_counters / 4;
+  for (i = 0; i < n_measures; i++, counters += 4)
+    {
+      counters[2] = fn (counters[2], data1, data2);
+      counters[3] = fn (counters[3], data1, data2);
+    }
+}
+
+/* Performing FN upon single counters.  */
+
+static void
+__gcov_single_counter_op (gcov_type *counters, unsigned n_counters,
+                          counter_op_fn fn, void *data1, void *data2)
+{
+  unsigned i, n_measures;
+
+  gcc_assert (!(n_counters % 3));
+  n_measures = n_counters / 3;
+  for (i = 0; i < n_measures; i++, counters += 3)
+    {
+      counters[1] = fn (counters[1], data1, data2);
+      counters[2] = fn (counters[2], data1, data2);
+    }
+}
+
+/* Scaling the counter value V by multiplying *(float*) DATA1.  */
+
+static gcov_type
+fp_scale (gcov_type v, void *data1, void *data2 ATTRIBUTE_UNUSED)
+{
+  float f = *(float *) data1;
+  return (gcov_type) (v * f);
+}
+
+/* Scaling the counter value V by multiplying DATA2/DATA1.  */
+
+static gcov_type
+int_scale (gcov_type v, void *data1, void *data2)
+{
+  int n = *(int *) data1;
+  int d = *(int *) data2;
+  return (gcov_type) ( RDIV (v,d) * n);
+}
+
+/* Type of function used to process counters.  */
+typedef void (*gcov_counter_fn) (gcov_type *, gcov_unsigned_t,
+                          counter_op_fn, void *, void *);
+
+/* Function array to process profile counters.  */
+#define DEF_GCOV_COUNTER(COUNTER, NAME, FN_TYPE) \
+  __gcov ## FN_TYPE ## _counter_op,
+static gcov_counter_fn ctr_functions[GCOV_COUNTERS] = {
+#include "gcov-counter.def"
+};
+#undef DEF_GCOV_COUNTER
+
+/* Driver for scaling profile counters.  */
+
+int
+gcov_profile_scale (struct gcov_info *profile, float scale_factor, int n, int d)
+{
+  struct gcov_info *gi_ptr;
+  unsigned f_ix;
+
+  if (verbose)
+    fnotice (stdout, "scale_factor is %f or %d/%d\n", scale_factor, n, d);
+
+  /* Scaling the counters.  */
+  for (gi_ptr = profile; gi_ptr; gi_ptr = gi_ptr->next)
+    for (f_ix = 0; f_ix < gi_ptr->n_functions; f_ix++)
+      {
+        unsigned t_ix;
+        const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
+        const struct gcov_ctr_info *ci_ptr;
+
+        if (!gfi_ptr || gfi_ptr->key != gi_ptr)
+          continue;
+
+        ci_ptr = gfi_ptr->ctrs;
+        for (t_ix = 0; t_ix != GCOV_COUNTERS; t_ix++)
+          {
+            gcov_merge_fn merge = gi_ptr->merge[t_ix];
+
+            if (!merge)
+              continue;
+            if (d == 0)
+              (*ctr_functions[t_ix]) (ci_ptr->values, ci_ptr->num,
+                                      fp_scale, &scale_factor, NULL);
+            else
+              (*ctr_functions[t_ix]) (ci_ptr->values, ci_ptr->num,
+                                      int_scale, &n, &d);
+            ci_ptr++;
+          }
+      }
+
+  return 0;
+}
+
+/* Driver to normalize profile counters.  */
+
+int
+gcov_profile_normalize (struct gcov_info *profile, gcov_type max_val)
+{
+  struct gcov_info *gi_ptr;
+  gcov_type curr_max_val = 0;
+  unsigned f_ix;
+  unsigned int i;
+  float scale_factor;
+
+  /* Find the largest count value.  */
+  for (gi_ptr = profile; gi_ptr; gi_ptr = gi_ptr->next)
+    for (f_ix = 0; f_ix < gi_ptr->n_functions; f_ix++)
+      {
+        unsigned t_ix;
+        const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
+        const struct gcov_ctr_info *ci_ptr;
+
+        if (!gfi_ptr || gfi_ptr->key != gi_ptr)
+          continue;
+
+        ci_ptr = gfi_ptr->ctrs;
+        for (t_ix = 0; t_ix < 1; t_ix++)
+          {
+            for (i = 0; i < ci_ptr->num; i++)
+              if (ci_ptr->values[i] > curr_max_val)
+                curr_max_val = ci_ptr->values[i];
+            ci_ptr++;
+          }
+      }
+
+  scale_factor = (float)max_val / curr_max_val;
+  if (verbose)
+    fnotice (stdout, "max_val is %lld\n", (long long) curr_max_val);
+
+  return gcov_profile_scale (profile, scale_factor, 0, 0);
+}
Index: libgcc/libgcov.h
===================================================================
--- libgcc/libgcov.h	(revision 210652)
+++ libgcc/libgcov.h	(working copy)
@@ -33,6 +33,10 @@
 #define xcalloc calloc
 #endif
 
+#ifndef IN_GCOV_TOOL
+/* About the target.  */
+/* This path will be used by libgcov runtime.  */
+
 #include "tconfig.h"
 #include "tsystem.h"
 #include "coretypes.h"
@@ -79,6 +83,83 @@ typedef unsigned gcov_type_unsigned __attribute__
 #define GCOV_LOCKED 0
 #endif
 
+/* "Counts" stored in gcda files can be a real counter value, or
+   an target address. When differentiate these two types because
+   when manipulating counts, we should only change real counter values,
+   rather target addresses.
+   This version is for reading count values in libgcov runtime:
+   we read from gcda files.  */
+static inline gcov_type
+gcov_get_counter (void)
+{
+  return gcov_read_counter ();
+}
+
+/* This version is for reading count target values in libgcov runtime:
+   we read from gcda files.  */
+
+static inline gcov_type
+gcov_get_counter_target (void)
+{
+  return gcov_read_counter ();
+}
+
+#else /* IN_GCOV_TOOL */
+/* About the host.  */
+/* This path will be compiled for the host and linked into
+   gcov-tool binary.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+
+typedef unsigned gcov_unsigned_t;
+typedef unsigned gcov_position_t;
+/* gcov_type is typedef'd elsewhere for the compiler */
+#if defined (HOST_HAS_F_SETLKW)
+#define GCOV_LOCKED 1
+#else
+#define GCOV_LOCKED 0
+#endif
+
+/* Some Macros specific to gcov-tool.  */
+
+#define L_gcov 1
+#define L_gcov_merge_add 1
+#define L_gcov_merge_single 1
+#define L_gcov_merge_delta 1
+#define L_gcov_merge_ior 1
+#define L_gcov_merge_time_profile 1
+
+extern gcov_type gcov_read_counter_mem();
+extern unsigned gcov_get_merge_weight();
+
+/* Rerfer the comment to same functions above. This version is for gcov-tool.
+   We read the value from memory and multiply it by the merge weight.  */
+   
+static inline gcov_type
+gcov_get_counter (void)
+{
+  return gcov_read_counter_mem () * gcov_get_merge_weight ();
+}
+
+/* Rerfer the comment to same functions above. This version is for gcov-tool.
+   We read the value from memory and we do NOT multiply it by the merge
+   weight. */
+
+static inline gcov_type
+gcov_get_counter_target (void)
+{
+  return gcov_read_counter_mem ();
+}
+
+/* Make certian internal functions/variables in libgcov available for
+   gcov-tool access.  */
+#define GCOV_TOOL_LINKAGE 
+
+#endif /* !IN_GCOV_TOOL */
+
 #if defined(inhibit_libc)
 #define IN_LIBGCOV (-1)
 #else
@@ -159,8 +240,13 @@ struct gcov_info
 					  unused) */
   
   unsigned n_functions;		/* number of functions */
+
+#ifndef IN_GCOV_TOOL
   const struct gcov_fn_info *const *functions; /* pointer to pointers
-					          to function information  */
+                                                  to function information  */
+#else
+  const struct gcov_fn_info **functions;
+#endif /* !IN_GCOV_TOOL */
 };
 
 /* Register a new object file module.  */
Index: gcc/doc/gcc.texi
===================================================================
--- gcc/doc/gcc.texi	(revision 210660)
+++ gcc/doc/gcc.texi	(working copy)
@@ -66,6 +66,7 @@ Texts being (a) (see below), and with the Back-Cov
 * gcc: (gcc).                  The GNU Compiler Collection.
 * g++: (gcc).                  The GNU C++ compiler.
 * gcov: (gcc) Gcov.            @command{gcov}---a test coverage program.
+* gcov-tool: (gcc) Gcov-tool.  @command{gcov-tool}---an offline gcda profile processing program.
 @end direntry
 This file documents the use of the GNU compilers.
 @sp 1
@@ -138,6 +139,7 @@ Introduction, gccint, GNU Compiler Collection (GCC
 * Objective-C::     GNU Objective-C runtime features.
 * Compatibility::   Binary Compatibility
 * Gcov::            @command{gcov}---a test coverage program.
+* Gcov-tool::       @command{gcov-tool}---an offline gcda profile processing program.
 * Trouble::         If you have trouble using GCC.
 * Bugs::            How, why and where to report bugs.
 * Service::         How To Get Help with GCC
@@ -164,6 +166,7 @@ Introduction, gccint, GNU Compiler Collection (GCC
 @include objc.texi
 @include compat.texi
 @include gcov.texi
+@include gcov-tool.texi
 @include trouble.texi
 @include bugreport.texi
 @include service.texi
Index: gcc/doc/gcov-tool.texi
===================================================================
--- gcc/doc/gcov-tool.texi	(revision 0)
+++ gcc/doc/gcov-tool.texi	(revision 0)
@@ -0,0 +1,173 @@
+@c Copyright (C) 1996-2014 Free Software Foundation, Inc.
+@c This is part of the GCC manual.
+@c For copying conditions, see the file gcc.texi.
+
+@ignore
+@c man begin COPYRIGHT
+Copyright @copyright{} 1996-2014 Free Software Foundation, Inc.
+
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being ``GNU General Public License'' and ``Funding
+Free Software'', the Front-Cover texts being (a) (see below), and with
+the Back-Cover Texts being (b) (see below).  A copy of the license is
+included in the gfdl(7) man page.
+
+(a) The FSF's Front-Cover Text is:
+
+     A GNU Manual
+
+(b) The FSF's Back-Cover Text is:
+
+     You have freedom to copy and modify this GNU Manual, like GNU
+     software.  Copies published by the Free Software Foundation raise
+     funds for GNU development.
+@c man end
+@c Set file name and title for the man page.
+@setfilename gcov-tool
+@settitle offline gcda profile processing tool
+@end ignore
+
+@node Gcov-tool
+@chapter @command{gcov-tool}---an offline gcda profile processing tool
+
+@command{gcov-tool} is a tool you can use in conjunction with GCC to
+manipulate or process gcda profile files offline.
+
+@menu
+* Gcov-tool Intro::             Introduction to gcov-tool.
+* Invoking Gcov-tool::          How to use gcov-tool.
+@end menu
+
+@node Gcov-tool Intro
+@section Introduction to @command{gcov-tool}
+@c man begin DESCRIPTION
+
+@command{gcov-tool} is an offline tool to process gcc's gcda profile files.
+
+Current gcov-tool supports the following functionalities:
+
+@itemize @bullet
+@item
+merge two sets of profiles with weights.
+
+@item
+read one set of profile and rewrite profile contents. One can scale or
+normalize the count values.
+@end itemize
+
+Note that for the merging operation, this profile generated offline may
+contain a slight different values from the online merged profile. Here are
+a list of typical differences:
+
+@itemize @bullet
+@item
+histogram difference: This offline tool recomputes the histogram after merging
+the counters. The resulting histogram, therefore, is precise. The online
+merging does not have this capability -- the histogram is merged from two
+histograms and the result is an approximation.
+
+@item
+summary checksum difference: Summary checksum uses a CRC32 operation. The value
+depends on the link list order of gcov-info objects. This order is different in
+gcov-tool from that in the online merge. It's expected to have different
+summary checksums. It does not really matter as the compiler does not use this
+checksum anywhere.
+
+@item
+value profile counter values difference: Some counter values for value profile
+are runtime dependent, like heap addresses. It's normal to see some difference
+in these kind of counters.
+@end itemize
+
+@c man end
+
+@node Invoking Gcov-tool
+@section Invoking @command{gcov-tool}
+
+@smallexample
+gcov-tool @r{[}@var{global-options}@r{]} SUB_COMMAND
+@r{[}@var{sub_command-options}@r{]} @var{profile_dir}
+@end smallexample
+
+@command{gcov-tool} accepts the following options:
+
+@ignore
+@c man begin SYNOPSIS
+gcov-tool [@option{-v}|@option{--version}] [@option{-h}|@option{--help}]
+
+gcov-tool merge [merge-options] @var{directory1} @var{directory2}
+     [@option{-v}|@option{--verbose}]
+     [@option{-o}|@option{ --output} @var{directory}]
+     [@option{-w}|@option{--weight} @var{w1,w2}]
+
+gcov-tool rewrite [rewrite-options] @var{directory}
+     [@option{-v}|@option{--verbose}]
+     [@option{-o}|@option{--output} @var{directory}]
+     [@option{-s}|@option{--scale} @var{float_or_simple-frac_value}]
+     [@option{-n}|@option{--normalize} @var{long_long_value}]
+@c man end
+@c man begin SEEALSO
+gpl(7), gfdl(7), fsf-funding(7), gcc(1), gcov(1) and the Info entry for
+@file{gcc}.
+@c man end
+@end ignore
+
+@c man begin OPTIONS
+@table @gcctabopt
+@item -h
+@itemx --help
+Display help about using @command{gcov-tool} (on the standard output), and
+exit without doing any further processing.
+
+@item -v
+@itemx --version
+Display the @command{gcov-tool} version number (on the standard output),
+and exit without doing any further processing.
+
+@item merge
+Merge two profile directories.
+
+@table @gcctabopt
+@item -v
+@itemx --verbose
+Set the verbose mode.
+
+@item -o @var{directory}
+@itemx --output @var{directory}
+Set the output profile directory. Default output directory name is
+@var{merged_profile}.
+
+@item -w @var{w1,w2}
+@itemx --weight @var{w1,w2}
+Set the merge weights of the @var{directory1} and @var{directory2},
+respectively. The default weights are 1 for both.
+@end table
+
+@item rewrite
+Read the specified profile directory and rewrite to a new directory.
+
+@table @gcctabopt
+@item -v
+@itemx --verbose
+Set the verbose mode.
+
+@item -o @var{directory}
+@itemx --output @var{directory}
+Set the output profile directory. Default output name is @var{rewrite_profile}.
+
+@item -s @var{float_or_simple-frac_value}
+@itemx --scale @var{float_or_simple-frac_value}
+Scale the profile counters. The specified value can be in floating point value,
+or simple fraction value form, such 1, 2, 2/3, and 5/3.
+
+@item -n @var{long_long_value}
+@itemx --normalize <long_long_value>
+Normalize the profile. The specified value is the max counter value
+in the new profile.
+
+@end table
+@end table
+
+@c man end
