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/* Interprocedural constant propagation
   Copyright (C) 2005 Free Software Foundation, Inc.
   Contributed by Razya Ladelsky <RAZYA@il.ibm.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 2, 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 COPYING.  If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.  */
 
/* Interprocedural constant propagation.
   The aim of interprocedural constant propagation (IPCP) is to find which
   function's argument has the same constant value in each invocation throughout
   the whole program. For example, for an application consisting of two files,
   foo1.c, foo2.c:
 
   foo1.c contains :
 
   int f (int x)
   {
     g (x);
   }
   void main (void)
   {
     f (3);
     h (3);
   }
 
   foo2.c contains :
 
   int h (int y)
   {
     g (y);
   }
   int g (int y)
   {
     printf ("value is %d",y);
   }
 
   The IPCP algorithm will find that g's formal argument y
   is always called with the value 3.
 
   The algorithm used is based on "Interprocedural Constant Propagation",
   by Challahan David, Keith D Cooper, Ken Kennedy, Linda Torczon, Comp86,
   pg 152-161
 
   The optimization is divided into three stages:
 
   First stage - intraprocedural analysis
   =======================================
   This phase computes jump_function and modify information.
 
   A jump function for a callsite represents the values passed as actual
   arguments
   of the callsite. There are three types of values :
   Formal - the caller's formal parameter is passed as an actual argument.
   Constant - a constant is passed as a an actual argument.
   Unknown - neither of the above.
 
   In order to compute the jump functions, we need the modify information for
   the formal parameters of methods.
 
   The jump function info, ipa_jump_func, is defined in ipa_edge
   structure (defined in ipa_prop.h and pointed to by cgraph_node->aux)
   The modify info, ipa_modify, is defined in ipa_node structure
   (defined in ipa_prop.h and pointed to by cgraph_edge->aux).
 
   -ipcp_init_stage() is the first stage driver.
 
   Second stage - interprocedural analysis
   ========================================
   This phase does the interprocedural constant propagation.
   It computes for all formal parameters in the program
   their cval value that may be:
   TOP - unknown.
   BOTTOM - non constant.
   CONSTANT_TYPE - constant value.
 
   Cval of formal f will have a constant value if all callsites to this
   function have the same constant value passed to f.
 
   The cval info, ipcp_formal, is defined in ipa_node structure
   (defined in ipa_prop.h and pointed to by cgraph_edge->aux).
 
   -ipcp_iterate_stage() is the second stage driver.
 
   Third phase - transformation of methods code
   ============================================
   Propagates the constant-valued formals into the function.
   For each method mt, whose parameters are consts, we create a clone/version.
 
   We use two ways to annotate the versioned function with the constant
   formal information:
   1. We insert an assignment statement 'parameter = const' at the beginning
   of the cloned method.
   2. For read-only formals whose address is not taken, we replace all uses
   of the formal with the constant (we provide versioning with an
   ipa_replace_map struct representing the trees we want to replace).
 
   We also need to modify some callsites to call to the cloned methods instead
   of the original ones. For a callsite passing an argument found to be a
   constant by IPCP, there are two different cases to handle:
   1. A constant is passed as an argument.
   2. A parameter (of the caller) passed as an argument (pass through argument).
 
   In the first case, the callsite in the original caller should be redirected
   to call the cloned callee.
   In the second case, both the caller and the callee have clones
   and the callsite of the cloned caller would be redirected to call to
   the cloned callee.
 
   The callgraph is updated accordingly.
 
   This update is done in two stages:
   First all cloned methods are created during a traversal of the callgraph,
   during which all callsites are redirected to call the cloned method.
   Then the callsites are traversed and updated as described above.
 
   -ipcp_insert_stage() is the third phase driver.
 
*/
 
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "target.h"
#include "cgraph.h"
#include "ipa-prop.h"
#include "tree-flow.h"
#include "tree-pass.h"
#include "flags.h"
#include "timevar.h"
#include "diagnostic.h"
 
/* Get orig node field of ipa_node associated with method MT.  */
static inline struct cgraph_node *
ipcp_method_orig_node (struct cgraph_node *mt)
{
  return IPA_NODE_REF (mt)->ipcp_orig_node;
}
 
/* Return true if NODE is a cloned/versioned method.  */
static inline bool
ipcp_method_is_cloned (struct cgraph_node *node)
{
  return (ipcp_method_orig_node (node) != NULL);
}
 
/* Set ORIG_NODE in ipa_node associated with method NODE.  */
static inline void
ipcp_method_set_orig_node (struct cgraph_node *node,
                           struct cgraph_node *orig_node)
{
  IPA_NODE_REF (node)->ipcp_orig_node = orig_node;
}
 
/* Create ipa_node and its data structures for NEW_NODE.
   Set ORIG_NODE as the orig_node field in ipa_node.  */
static void
ipcp_cloned_create (struct cgraph_node *orig_node,
                    struct cgraph_node *new_node)
{
  ipa_node_create (new_node);
  ipcp_method_set_orig_node (new_node, orig_node);
  ipa_method_formal_compute_count (new_node);
  ipa_method_compute_tree_map (new_node);
}
 
/* Return cval_type field of CVAL.  */
static inline enum cvalue_type
ipcp_cval_get_cvalue_type (struct ipcp_formal *cval)
{
  return cval->cval_type;
}
 
/* Return scale for MT.  */
static inline gcov_type
ipcp_method_get_scale (struct cgraph_node *mt)
{
  return IPA_NODE_REF (mt)->count_scale;
}
 
/* Set COUNT as scale for MT.  */
static inline void
ipcp_method_set_scale (struct cgraph_node *node, gcov_type count)
{
  IPA_NODE_REF (node)->count_scale = count;
}
 
/* Set TYPE as cval_type field of CVAL.  */
static inline void
ipcp_cval_set_cvalue_type (struct ipcp_formal *cval, enum cvalue_type type)
{
  cval->cval_type = type;
}
 
/* Return cvalue field of CVAL.  */
static inline union parameter_info *
ipcp_cval_get_cvalue (struct ipcp_formal *cval)
{
  return &(cval->cvalue);
}
 
/* Set VALUE as cvalue field  CVAL.  */
static inline void
ipcp_cval_set_cvalue (struct ipcp_formal *cval, union parameter_info *value,
                      enum cvalue_type type)
{
  if (type == CONST_VALUE || type == CONST_VALUE_REF)
    cval->cvalue.value =  value->value;
}
 
/* Return whether TYPE is a constant type.  */
static bool
ipcp_type_is_const (enum cvalue_type type)
{
  if (type == CONST_VALUE || type == CONST_VALUE_REF)
    return true;
  else
    return false;
}
 
/* Return true if CONST_VAL1 and CONST_VAL2 are equal.  */
static inline bool
ipcp_cval_equal_cvalues (union parameter_info *const_val1,
                         union parameter_info *const_val2,
                         enum cvalue_type type1, enum cvalue_type type2)
{
  gcc_assert (ipcp_type_is_const (type1) && ipcp_type_is_const (type2));
  if (type1 != type2)
    return false;
 
  if (operand_equal_p (const_val1->value, const_val2->value, 0))
    return true;
 
  return false;
}
 
/* Compute Meet arithmetics:
   Meet (BOTTOM, x) = BOTTOM
   Meet (TOP,x) = x
   Meet (const_a,const_b) = BOTTOM,  if const_a != const_b.
   MEET (const_a,const_b) = const_a, if const_a == const_b.*/
static void
ipcp_cval_meet (struct ipcp_formal *cval, struct ipcp_formal *cval1,
                struct ipcp_formal *cval2)
{
  if (ipcp_cval_get_cvalue_type (cval1) == BOTTOM
      || ipcp_cval_get_cvalue_type (cval2) == BOTTOM)
    {
      ipcp_cval_set_cvalue_type (cval, BOTTOM);
      return;
    }
  if (ipcp_cval_get_cvalue_type (cval1) == TOP)
    {
      ipcp_cval_set_cvalue_type (cval, ipcp_cval_get_cvalue_type (cval2));
      ipcp_cval_set_cvalue (cval, ipcp_cval_get_cvalue (cval2),
                            ipcp_cval_get_cvalue_type (cval2));
      return;
    }
  if (ipcp_cval_get_cvalue_type (cval2) == TOP)
    {
      ipcp_cval_set_cvalue_type (cval, ipcp_cval_get_cvalue_type (cval1));
      ipcp_cval_set_cvalue (cval, ipcp_cval_get_cvalue (cval1),
                            ipcp_cval_get_cvalue_type (cval1));
      return;
    }
  if (!ipcp_cval_equal_cvalues (ipcp_cval_get_cvalue (cval1),
                                ipcp_cval_get_cvalue (cval2),
                                ipcp_cval_get_cvalue_type (cval1),
                                ipcp_cval_get_cvalue_type (cval2)))
    {
      ipcp_cval_set_cvalue_type (cval, BOTTOM);
      return;
    }
  ipcp_cval_set_cvalue_type (cval, ipcp_cval_get_cvalue_type (cval1));
  ipcp_cval_set_cvalue (cval, ipcp_cval_get_cvalue (cval1),
                        ipcp_cval_get_cvalue_type (cval1));
}
 
/* Return cval structure for the formal at index INFO_TYPE in MT.  */
static inline struct ipcp_formal *
ipcp_method_cval (struct cgraph_node *mt, int info_type)
{
  return &(IPA_NODE_REF (mt)->ipcp_cval[info_type]);
}
 
/* Given the jump function (TYPE, INFO_TYPE), compute a new value of CVAL.
   If TYPE is FORMAL_IPA_TYPE, the cval of the corresponding formal is
   drawn from MT.  */
static void
ipcp_cval_compute (struct ipcp_formal *cval, struct cgraph_node *mt,
                   enum jump_func_type type, union parameter_info *info_type)
{
  if (type == UNKNOWN_IPATYPE)
    ipcp_cval_set_cvalue_type (cval, BOTTOM);
  else if (type == CONST_IPATYPE)
    {
      ipcp_cval_set_cvalue_type (cval, CONST_VALUE);
      ipcp_cval_set_cvalue (cval, info_type, CONST_VALUE);
    }
  else if (type == CONST_IPATYPE_REF)
    {
      ipcp_cval_set_cvalue_type (cval, CONST_VALUE_REF);
      ipcp_cval_set_cvalue (cval, info_type, CONST_VALUE_REF);
    }
  else if (type == FORMAL_IPATYPE)
    {
      enum cvalue_type type =
        ipcp_cval_get_cvalue_type (ipcp_method_cval
                                   (mt, info_type->formal_id));
      ipcp_cval_set_cvalue_type (cval, type);
      ipcp_cval_set_cvalue (cval,
                            ipcp_cval_get_cvalue (ipcp_method_cval
                                                  (mt, info_type->formal_id)),
                            type);
    }
}
 
/* True when CVAL1 and CVAL2 values are not the same.  */
static bool
ipcp_cval_changed (struct ipcp_formal *cval1, struct ipcp_formal *cval2)
{
  if (ipcp_cval_get_cvalue_type (cval1) == ipcp_cval_get_cvalue_type (cval2))
    {
      if (ipcp_cval_get_cvalue_type (cval1) != CONST_VALUE &&
          ipcp_cval_get_cvalue_type (cval1) != CONST_VALUE_REF)
        return false;
      if (ipcp_cval_equal_cvalues (ipcp_cval_get_cvalue (cval1),
                                   ipcp_cval_get_cvalue (cval2),
                                   ipcp_cval_get_cvalue_type (cval1),
                                   ipcp_cval_get_cvalue_type (cval2)))
        return false;
    }
  return true;
}
 
/* Create cval structure for method MT.  */
static inline void
ipcp_formal_create (struct cgraph_node *mt)
{
  IPA_NODE_REF (mt)->ipcp_cval =
    xcalloc (ipa_method_formal_count (mt), sizeof (struct ipcp_formal));
}
 
/* Set cval structure of I-th formal of MT to CVAL.  */
static inline void
ipcp_method_cval_set (struct cgraph_node *mt, int i, struct ipcp_formal *cval)
{
  IPA_NODE_REF (mt)->ipcp_cval[i].cval_type = cval->cval_type;
  ipcp_cval_set_cvalue (ipcp_method_cval (mt, i),
                        ipcp_cval_get_cvalue (cval), cval->cval_type);
}
 
/* Set type of cval structure of formal I of MT to CVAL_TYPE1.  */
static inline void
ipcp_method_cval_set_cvalue_type (struct cgraph_node *mt, int i,
                                  enum cvalue_type cval_type1)
{
  IPA_NODE_REF (mt)->ipcp_cval[i].cval_type = cval_type1;
}
 
/* Print ipcp_cval data structures to F.  */
static void
ipcp_method_cval_print (FILE * f)
{
  struct cgraph_node *node;
  int i, count;
  tree cvalue;
 
  fprintf (f, "\nCVAL PRINT\n");
  for (node = cgraph_nodes; node; node = node->next)
    {
      fprintf (f, "Printing cvals %s:\n", cgraph_node_name (node));
      count = ipa_method_formal_count (node);
      for (i = 0; i < count; i++)
        {
          if (ipcp_cval_get_cvalue_type (ipcp_method_cval (node, i))
              == CONST_VALUE
              || ipcp_cval_get_cvalue_type (ipcp_method_cval (node, i)) ==
              CONST_VALUE_REF)
            {
              fprintf (f, " param [%d]: ", i);
              fprintf (f, "type is CONST ");
              cvalue =
                ipcp_cval_get_cvalue (ipcp_method_cval (node, i))->
                  value;
              print_generic_expr (f, cvalue, 0);
              fprintf (f, "\n");
            }
          else if (ipcp_method_cval (node, i)->cval_type == TOP)
            fprintf (f, "param [%d]: type is TOP  \n", i);
          else
            fprintf (f, "param [%d]: type is BOTTOM  \n", i);
        }
    }
}
 
/* Initialize ipcp_cval array of MT with TOP values.
   All cvals for a method's formal parameters are initialized to BOTTOM
   The currently supported types are integer types, real types and
   Fortran constants (i.e. references to constants defined as
   const_decls). All other types are not analyzed and therefore are
   assigned with BOTTOM.  */
static void
ipcp_method_cval_init (struct cgraph_node *mt)
{
  int i;
  tree parm_tree;
 
  ipcp_formal_create (mt);
  for (i = 0; i < ipa_method_formal_count (mt); i++)
    {
      parm_tree = ipa_method_get_tree (mt, i);
      if (INTEGRAL_TYPE_P (TREE_TYPE (parm_tree))
          || SCALAR_FLOAT_TYPE_P (TREE_TYPE (parm_tree))
          || POINTER_TYPE_P (TREE_TYPE (parm_tree)))
        ipcp_method_cval_set_cvalue_type (mt, i, TOP);
      else
        ipcp_method_cval_set_cvalue_type (mt, i, BOTTOM);
    }
}
 
/* Create a new assignment statment and make
   it the first statement in the function FN
   tree.
   PARM1 is the lhs of the assignment and
   VAL is the rhs. */
static void
constant_val_insert (tree fn, tree parm1, tree val)
{
  struct function *func;
  tree init_stmt;
  edge e_step;
  edge_iterator ei;
 
  init_stmt = build2 (MODIFY_EXPR, void_type_node, parm1, val);
  func = DECL_STRUCT_FUNCTION (fn);
  cfun = func;
  current_function_decl = fn;
  if (ENTRY_BLOCK_PTR_FOR_FUNCTION (func)->succs)
    FOR_EACH_EDGE (e_step, ei, ENTRY_BLOCK_PTR_FOR_FUNCTION (func)->succs)
      bsi_insert_on_edge_immediate (e_step, init_stmt);
}
 
/* build INTEGER_CST tree with type TREE_TYPE and
   value according to CVALUE. Return the tree.   */
static tree
build_const_val (union parameter_info *cvalue, enum cvalue_type type,
                 tree tree_type)
{
  tree const_val = NULL;
 
  gcc_assert (ipcp_type_is_const (type));
  const_val = fold_convert (tree_type, cvalue->value);
  return const_val;
}
 
/* Build the tree representing the constant and call
   constant_val_insert().  */
static void
ipcp_propagate_const (struct cgraph_node *mt, int param,
                      union parameter_info *cvalue ,enum cvalue_type type)
{
  tree fndecl;
  tree const_val;
  tree parm_tree;
 
  if (dump_file)
    fprintf (dump_file, "propagating const to %s\n", cgraph_node_name (mt));
  fndecl = mt->decl;
  parm_tree = ipa_method_get_tree (mt, param);
  const_val = build_const_val (cvalue, type, TREE_TYPE (parm_tree));
  constant_val_insert (fndecl, parm_tree, const_val);
}
 
/* Compute the proper scale for NODE.  It is the ratio between
   the number of direct calls (represented on the incoming
   cgraph_edges) and sum of all invocations of NODE (represented
   as count in cgraph_node). */
static void
ipcp_method_compute_scale (struct cgraph_node *node)
{
  gcov_type sum;
  struct cgraph_edge *cs;
 
  sum = 0;
  /* Compute sum of all counts of callers. */
  for (cs = node->callers; cs != NULL; cs = cs->next_caller)
    sum += cs->count;
  if (node->count == 0)
    ipcp_method_set_scale (node, 0);
  else
    ipcp_method_set_scale (node, sum * REG_BR_PROB_BASE / node->count);
}
 
/* Initialization and computation of IPCP data structures.
   It is an intraprocedural
   analysis of methods, which gathers information to be propagated
   later on.  */
static void
ipcp_init_stage (void)
{
  struct cgraph_node *node;
  struct cgraph_edge *cs;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      ipa_method_formal_compute_count (node);
      ipa_method_compute_tree_map (node);
      ipcp_method_cval_init (node);
      ipa_method_compute_modify (node);
      ipcp_method_compute_scale (node);
    }
  for (node = cgraph_nodes; node; node = node->next)
    {
      /* building jump functions  */
      for (cs = node->callees; cs; cs = cs->next_callee)
        {
          ipa_callsite_compute_count (cs);
          if (ipa_callsite_param_count (cs)
              != ipa_method_formal_count (cs->callee))
            {
              /* Handle cases of functions with
                 a variable number of parameters.  */
              ipa_callsite_param_count_set (cs, 0);
              ipa_method_formal_count_set (cs->callee, 0);
            }
          else
            ipa_callsite_compute_param (cs);
        }
    }
}
 
/* Return true if there are some formal parameters whose value is TOP.
   Change their values to BOTTOM, since they weren't determined.  */
static bool
ipcp_after_propagate (void)
{
  int i, count;
  struct cgraph_node *node;
  bool prop_again;
 
  prop_again = false;
  for (node = cgraph_nodes; node; node = node->next)
    {
      count = ipa_method_formal_count (node);
      for (i = 0; i < count; i++)
        if (ipcp_cval_get_cvalue_type (ipcp_method_cval (node, i)) == TOP)
          {
            prop_again = true;
            ipcp_method_cval_set_cvalue_type (node, i, BOTTOM);
          }
    }
  return prop_again;
}
 
/* Interprocedural analysis. The algorithm propagates constants from
   the caller's parameters to the callee's arguments.  */
static void
ipcp_propagate_stage (void)
{
  int i;
  struct ipcp_formal cval1 = { 0, {0} }, cval = { 0,{0} };
  struct ipcp_formal *cval2;
  struct cgraph_node *mt, *callee;
  struct cgraph_edge *cs;
  struct ipa_jump_func *jump_func;
  enum jump_func_type type;
  union parameter_info *info_type;
  ipa_methodlist_p wl;
  int count;
 
  /* Initialize worklist to contain all methods.  */
  wl = ipa_methodlist_init ();
  while (ipa_methodlist_not_empty (wl))
    {
      mt = ipa_remove_method (&wl);
      for (cs = mt->callees; cs; cs = cs->next_callee)
        {
          callee = ipa_callsite_callee (cs);
          count = ipa_callsite_param_count (cs);
          for (i = 0; i < count; i++)
            {
              jump_func = ipa_callsite_param (cs, i);
              type = get_type (jump_func);
              info_type = ipa_jf_get_info_type (jump_func);
              ipcp_cval_compute (&cval1, mt, type, info_type);
              cval2 = ipcp_method_cval (callee, i);
              ipcp_cval_meet (&cval, &cval1, cval2);
              if (ipcp_cval_changed (&cval, cval2))
                {
                  ipcp_method_cval_set (callee, i, &cval);
                  ipa_add_method (&wl, callee);
                }
            }
        }
    }
}
 
/* Call the constant propagation algorithm and re-call it if necessary
   (if there are undetermined values left).  */
static void
ipcp_iterate_stage (void)
{
  ipcp_propagate_stage ();
  if (ipcp_after_propagate ())
    /* Some cvals have changed from TOP to BOTTOM.
       This change should be propagated.  */
    ipcp_propagate_stage ();
}
 
/* Check conditions to forbid constant insertion to MT.  */
static bool
ipcp_method_dont_insert_const (struct cgraph_node *mt)
{
  /* ??? Handle pending sizes case.  */
  if (DECL_UNINLINABLE (mt->decl))
    return true;
  return false;
}
 
/* Print ipa_jump_func data structures to F.  */
static void
ipcp_callsite_param_print (FILE * f)
{
  struct cgraph_node *node;
  int i, count;
  struct cgraph_edge *cs;
  struct ipa_jump_func *jump_func;
  enum jump_func_type type;
  tree info_type;
 
  fprintf (f, "\nCALLSITE PARAM PRINT\n");
  for (node = cgraph_nodes; node; node = node->next)
    {
      for (cs = node->callees; cs; cs = cs->next_callee)
        {
          fprintf (f, "callsite  %s ", cgraph_node_name (node));
          fprintf (f, "-> %s :: \n", cgraph_node_name (cs->callee));
          count = ipa_callsite_param_count (cs);
          for (i = 0; i < count; i++)
            {
              jump_func = ipa_callsite_param (cs, i);
              type = get_type (jump_func);
 
              fprintf (f, " param %d: ", i);
              if (type == UNKNOWN_IPATYPE)
                fprintf (f, "UNKNOWN\n");
              else if (type == CONST_IPATYPE || type == CONST_IPATYPE_REF)
                {
                  info_type =
                    ipa_jf_get_info_type (jump_func)->value;
                  fprintf (f, "CONST : ");
                  print_generic_expr (f, info_type, 0);
                  fprintf (f, "\n");
                }
              else if (type == FORMAL_IPATYPE)
                {
                  fprintf (f, "FORMAL : ");
                  fprintf (f, "%d\n",
                           ipa_jf_get_info_type (jump_func)->formal_id);
                }
            }
        }
    }
}
 
/* Print count scale data structures.  */
static void
ipcp_method_scale_print (FILE * f)
{
  struct cgraph_node *node;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      fprintf (f, "printing scale for %s: ", cgraph_node_name (node));
      fprintf (f, "value is  " HOST_WIDE_INT_PRINT_DEC
               "  \n", (HOST_WIDE_INT) ipcp_method_get_scale (node));
    }
}
 
/* Print counts of all cgraph nodes.  */
static void
ipcp_profile_mt_count_print (FILE * f)
{
  struct cgraph_node *node;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      fprintf (f, "method %s: ", cgraph_node_name (node));
      fprintf (f, "count is  " HOST_WIDE_INT_PRINT_DEC
               "  \n", (HOST_WIDE_INT) node->count);
    }
}
 
/* Print counts of all cgraph edges.  */
static void
ipcp_profile_cs_count_print (FILE * f)
{
  struct cgraph_node *node;
  struct cgraph_edge *cs;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      for (cs = node->callees; cs; cs = cs->next_callee)
        {
          fprintf (f, "%s -> %s ", cgraph_node_name (cs->caller),
                   cgraph_node_name (cs->callee));
          fprintf (f, "count is  " HOST_WIDE_INT_PRINT_DEC "  \n",
                   (HOST_WIDE_INT) cs->count);
        }
    }
}
 
/* Print all counts and probabilities of cfg edges of all methods.  */
static void
ipcp_profile_edge_print (FILE * f)
{
  struct cgraph_node *node;
  basic_block bb;
  edge_iterator ei;
  edge e;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      fprintf (f, "method %s: \n", cgraph_node_name (node));
      if (DECL_SAVED_TREE (node->decl))
        {
          bb =
            ENTRY_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION (node->decl));
          fprintf (f, "ENTRY: ");
          fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
                   " %d\n", (HOST_WIDE_INT) bb->count, bb->frequency);
 
          if (bb->succs)
            FOR_EACH_EDGE (e, ei, bb->succs)
            {
              if (e->dest ==
                  EXIT_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION
                                               (node->decl)))
                fprintf (f, "edge ENTRY -> EXIT,  Count");
              else
                fprintf (f, "edge ENTRY -> %d,  Count", e->dest->index);
              fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
                       " Prob %d\n", (HOST_WIDE_INT) e->count,
                       e->probability);
            }
          FOR_EACH_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
          {
            fprintf (f, "bb[%d]: ", bb->index);
            fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
                     " %d\n", (HOST_WIDE_INT) bb->count, bb->frequency);
            FOR_EACH_EDGE (e, ei, bb->succs)
            {
              if (e->dest ==
                  EXIT_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION
                                               (node->decl)))
                fprintf (f, "edge %d -> EXIT,  Count", e->src->index);
              else
                fprintf (f, "edge %d -> %d,  Count", e->src->index,
                         e->dest->index);
              fprintf (f, " " HOST_WIDE_INT_PRINT_DEC " Prob %d\n",
                       (HOST_WIDE_INT) e->count, e->probability);
            }
          }
        }
    }
}
 
/* Print counts and frequencies for all basic blocks of all methods.  */
static void
ipcp_profile_bb_print (FILE * f)
{
  basic_block bb;
  struct cgraph_node *node;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      fprintf (f, "method %s: \n", cgraph_node_name (node));
      if (DECL_SAVED_TREE (node->decl))
        {
          bb =
            ENTRY_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION (node->decl));
          fprintf (f, "ENTRY: Count");
          fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
                   " Frquency  %d\n", (HOST_WIDE_INT) bb->count,
                   bb->frequency);
 
          FOR_EACH_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
          {
            fprintf (f, "bb[%d]: Count", bb->index);
            fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
                     " Frequency %d\n", (HOST_WIDE_INT) bb->count,
                     bb->frequency);
          }
          bb =
            EXIT_BLOCK_PTR_FOR_FUNCTION (DECL_STRUCT_FUNCTION (node->decl));
          fprintf (f, "EXIT: Count");
          fprintf (f, " " HOST_WIDE_INT_PRINT_DEC
                   " Frequency %d\n", (HOST_WIDE_INT) bb->count,
                   bb->frequency);
 
        }
    }
}
 
/* Print all IPCP data structures to F.  */
static void
ipcp_structures_print (FILE * f)
{
  ipcp_method_cval_print (f);
  ipcp_method_scale_print (f);
  ipa_method_tree_print (f);
  ipa_method_modify_print (f);
  ipcp_callsite_param_print (f);
}
 
/* Print profile info for all methods.  */
static void
ipcp_profile_print (FILE * f)
{
  fprintf (f, "\nNODE COUNTS :\n");
  ipcp_profile_mt_count_print (f);
  fprintf (f, "\nCS COUNTS stage:\n");
  ipcp_profile_cs_count_print (f);
  fprintf (f, "\nBB COUNTS and FREQUENCIES :\n");
  ipcp_profile_bb_print (f);
  fprintf (f, "\nCFG EDGES COUNTS and PROBABILITIES :\n");
  ipcp_profile_edge_print (f);
}
 
/* Build and initialize ipa_replace_map struct
   according to TYPE. This struct is read by versioning, which
   operates according to the flags sent.  PARM_TREE is the
   formal's tree found to be constant.  CVALUE represents the constant.  */
static struct ipa_replace_map *
ipcp_replace_map_create (enum cvalue_type type, tree parm_tree,
                         union parameter_info *cvalue)
{
  struct ipa_replace_map *replace_map;
  tree const_val;
 
  replace_map = xcalloc (1, sizeof (struct ipa_replace_map));
  gcc_assert (ipcp_type_is_const (type));
  if (type == CONST_VALUE_REF )
    {
      const_val =
        build_const_val (cvalue, type, TREE_TYPE (TREE_TYPE (parm_tree)));
      replace_map->old_tree = parm_tree;
      replace_map->new_tree = const_val;
      replace_map->replace_p = true;
      replace_map->ref_p = true;
    }
  else if (TREE_READONLY (parm_tree) && !TREE_ADDRESSABLE (parm_tree))
    {
      const_val = build_const_val (cvalue, type, TREE_TYPE (parm_tree));
      replace_map->old_tree = parm_tree;
      replace_map->new_tree = const_val;
      replace_map->replace_p = true;
      replace_map->ref_p = false;
    }
  else
    {
      replace_map->old_tree = NULL;
      replace_map->new_tree = NULL;
      replace_map->replace_p = false;
      replace_map->ref_p = false;
    }
 
  return replace_map;
}
 
/* Return true if this callsite should be redirected to
   the orig callee (instead of the cloned one).  */
static bool
ipcp_redirect (struct cgraph_edge *cs)
{
  struct cgraph_node *caller, *callee, *orig_callee;
  int i, count;
  struct ipa_jump_func *jump_func;
  enum jump_func_type type;
  enum cvalue_type cval_type;
 
  caller = cs->caller;
  callee = cs->callee;
  orig_callee = ipcp_method_orig_node (callee);
  count = ipa_method_formal_count (orig_callee);
  for (i = 0; i < count; i++)
    {
      cval_type =
        ipcp_cval_get_cvalue_type (ipcp_method_cval (orig_callee, i));
      if (ipcp_type_is_const (cval_type))
        {
          jump_func = ipa_callsite_param (cs, i);
          type = get_type (jump_func);
          if (type != CONST_IPATYPE
              && type != CONST_IPATYPE_REF)
            return true;
        }
    }
 
  return false;
}
 
/* Fix the callsites and the callgraph after function cloning was done.  */
static void
ipcp_update_callgraph (void)
{
  struct cgraph_node *node, *orig_callee;
  struct cgraph_edge *cs;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      /* want to fix only original nodes  */
      if (ipcp_method_is_cloned (node))
        continue;
      for (cs = node->callees; cs; cs = cs->next_callee)
        if (ipcp_method_is_cloned (cs->callee))
          {
            /* Callee is a cloned node  */
            orig_callee = ipcp_method_orig_node (cs->callee);
            if (ipcp_redirect (cs))
              {
                cgraph_redirect_edge_callee (cs, orig_callee);
                TREE_OPERAND (TREE_OPERAND
                              (get_call_expr_in (cs->call_stmt), 0), 0) =
                  orig_callee->decl;
              }
          }
    }
}
 
/* Update all cfg basic blocks in NODE according to SCALE.  */
static void
ipcp_update_bb_counts (struct cgraph_node *node, gcov_type scale)
{
  basic_block bb;
 
  FOR_ALL_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
    bb->count = bb->count * scale / REG_BR_PROB_BASE;
}
 
/* Update all cfg edges in NODE according to SCALE.  */
static void
ipcp_update_edges_counts (struct cgraph_node *node, gcov_type scale)
{
  basic_block bb;
  edge_iterator ei;
  edge e;
 
  FOR_ALL_BB_FN (bb, DECL_STRUCT_FUNCTION (node->decl))
    FOR_EACH_EDGE (e, ei, bb->succs)
    e->count = e->count * scale / REG_BR_PROB_BASE;
}
 
/* Update profiling info for versioned methods and the
   methods they were versioned from.  */
static void
ipcp_update_profiling (void)
{
  struct cgraph_node *node, *orig_node;
  gcov_type scale, scale_complement;
  struct cgraph_edge *cs;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      if (ipcp_method_is_cloned (node))
        {
          orig_node = ipcp_method_orig_node (node);
          scale = ipcp_method_get_scale (orig_node);
          node->count = orig_node->count * scale / REG_BR_PROB_BASE;
          scale_complement = REG_BR_PROB_BASE - scale;
          orig_node->count =
            orig_node->count * scale_complement / REG_BR_PROB_BASE;
          for (cs = node->callees; cs; cs = cs->next_callee)
            cs->count = cs->count * scale / REG_BR_PROB_BASE;
          for (cs = orig_node->callees; cs; cs = cs->next_callee)
            cs->count = cs->count * scale_complement / REG_BR_PROB_BASE;
          ipcp_update_bb_counts (node, scale);
          ipcp_update_bb_counts (orig_node, scale_complement);
          ipcp_update_edges_counts (node, scale);
          ipcp_update_edges_counts (orig_node, scale_complement);
        }
    }
}
 
/* Propagate the constant parameters found by ipcp_iterate_stage()
   to the function's code.  */
static void
ipcp_insert_stage (void)
{
  struct cgraph_node *node, *node1 = NULL;
  int i, const_param;
  union parameter_info *cvalue;
  varray_type redirect_callers, replace_trees;
  struct cgraph_edge *cs;
  int node_callers, count;
  tree parm_tree;
  enum cvalue_type type;
  struct ipa_replace_map *replace_param;
 
  for (node = cgraph_nodes; node; node = node->next)
    {
      /* Propagation of the constant is forbidden in
         certain conditions.  */
      if (ipcp_method_dont_insert_const (node))
        continue;
      const_param = 0;
      count = ipa_method_formal_count (node);
      for (i = 0; i < count; i++)
        {
          type = ipcp_cval_get_cvalue_type (ipcp_method_cval (node, i));
          if (ipcp_type_is_const (type))
            const_param++;
        }
      if (const_param == 0)
        continue;
      VARRAY_GENERIC_PTR_INIT (replace_trees, const_param, "replace_trees");
      for (i = 0; i < count; i++)
        {
          type = ipcp_cval_get_cvalue_type (ipcp_method_cval (node, i));
          if (ipcp_type_is_const (type))
            {
              cvalue = ipcp_cval_get_cvalue (ipcp_method_cval (node, i));
              parm_tree = ipa_method_get_tree (node, i);
              replace_param =
                ipcp_replace_map_create (type, parm_tree, cvalue);
              VARRAY_PUSH_GENERIC_PTR (replace_trees, replace_param);
            }
        }
      /* Compute how many callers node has.  */
      node_callers = 0;
      for (cs = node->callers; cs != NULL; cs = cs->next_caller)
        node_callers++;
      VARRAY_GENERIC_PTR_INIT (redirect_callers, node_callers,
                               "redirect_callers");
      for (cs = node->callers; cs != NULL; cs = cs->next_caller)
        VARRAY_PUSH_GENERIC_PTR (redirect_callers, cs);
      /* Redirecting all the callers of the node to the
         new versioned node.  */
      node1 =
        cgraph_function_versioning (node, redirect_callers, replace_trees);
      VARRAY_CLEAR (redirect_callers);
      VARRAY_CLEAR (replace_trees);
      if (node1 == NULL)
        continue;
      if (dump_file)
        fprintf (dump_file, "versioned function %s\n",
                 cgraph_node_name (node));
      ipcp_cloned_create (node, node1);
      for (i = 0; i < count; i++)
        {
          type = ipcp_cval_get_cvalue_type (ipcp_method_cval (node, i));
          if (ipcp_type_is_const (type))
            {
              cvalue = ipcp_cval_get_cvalue (ipcp_method_cval (node, i));
              parm_tree = ipa_method_get_tree (node, i);
              if (type != CONST_VALUE_REF
                  && !TREE_READONLY (parm_tree))
                ipcp_propagate_const (node1, i, cvalue, type);
            }
        }
    }
  ipcp_update_callgraph ();
  ipcp_update_profiling ();
}
 
/* The IPCP driver.  */
void
ipcp_driver (void)
{
  if (dump_file)
    fprintf (dump_file, "\nIPA constant propagation start:\n");
  ipa_nodes_create ();
  ipa_edges_create ();
  /* 1. Call the init stage to initialize
     the ipa_node and ipa_edge structures.  */
  ipcp_init_stage ();
  if (dump_file)
    {
      fprintf (dump_file, "\nIPA structures before propagation:\n");
      ipcp_structures_print (dump_file);
    }
  /* 2. Do the interprocedural propagation.  */
  ipcp_iterate_stage ();
  if (dump_file)
    {
      fprintf (dump_file, "\nIPA structures after propagation:\n");
      ipcp_structures_print (dump_file);
      fprintf (dump_file, "\nProfiling info before insert stage:\n");
      ipcp_profile_print (dump_file);
    }
  /* 3. Insert the constants found to the functions.  */
  ipcp_insert_stage ();
  if (dump_file)
    {
      fprintf (dump_file, "\nProfiling info after insert stage:\n");
      ipcp_profile_print (dump_file);
    }
  /* Free all IPCP structures.  */
  ipa_free ();
  ipa_nodes_free ();
  ipa_edges_free ();
  if (dump_file)
    fprintf (dump_file, "\nIPA constant propagation end\n");
  cgraph_remove_unreachable_nodes (true, NULL);
}
 
/* Gate for IPCP optimization.  */
static bool
cgraph_gate_cp (void)
{
  return flag_ipa_cp;
}
 
struct tree_opt_pass pass_ipa_cp = {
  "cp",                         /* name */
  cgraph_gate_cp,               /* gate */
  ipcp_driver,                  /* execute */
  NULL,                         /* sub */
  NULL,                         /* next */
  0,                             /* static_pass_number */
  TV_IPA_CONSTANT_PROP,         /* tv_id */
  0,                             /* properties_required */
  PROP_trees,                   /* properties_provided */
  0,                             /* properties_destroyed */
  0,                             /* todo_flags_start */
  TODO_dump_cgraph | TODO_dump_func,    /* todo_flags_finish */
 
};
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[/] [scarts/] [trunk/] [toolchain/] [scarts-gcc/] [gcc-4.1.1/] [gcc/] [ipa-cp.c] - Blame information for rev 14

Line No.	Rev	Author	Line
1	12	jlechner	`/* Interprocedural constant propagation`
2			`Copyright (C) 2005 Free Software Foundation, Inc.`
3			`Contributed by Razya Ladelsky <RAZYA@il.ibm.com>`
4
5			`This file is part of GCC.`
6
7			`GCC is free software; you can redistribute it and/or modify it under`
8			`the terms of the GNU General Public License as published by the Free`
9			`Software Foundation; either version 2, or (at your option) any later`
10			`version.`
11
12			`GCC is distributed in the hope that it will be useful, but WITHOUT ANY`
13			`WARRANTY; without even the implied warranty of MERCHANTABILITY or`
14			`FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License`
15			`for more details.`
16
17			`You should have received a copy of the GNU General Public License`
18			`along with GCC; see the file COPYING. If not, write to the Free`
19			`Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA`
20			`02110-1301, USA. */`
21
22			`/* Interprocedural constant propagation.`
23			`The aim of interprocedural constant propagation (IPCP) is to find which`
24			`function's argument has the same constant value in each invocation throughout`
25			`the whole program. For example, for an application consisting of two files,`
26			`foo1.c, foo2.c:`
27
28			`foo1.c contains :`
29
30			`int f (int x)`
31			`{`
32			`g (x);`
33			`}`
34			`void main (void)`
35			`{`
36			`f (3);`
37			`h (3);`
38			`}`
39
40			`foo2.c contains :`