osprey/ipa/main/analyze/ipa_feedback.cxx

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/*
 * Copyright 2003, 2004, 2005, 2006 PathScale, Inc.  All Rights Reserved.
 */

/*

  Copyright (C) 2000, 2001 Silicon Graphics, Inc.  All Rights Reserved.

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2 of the GNU General Public License as
  published by the Free Software Foundation.

  This program is distributed in the hope that it would be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

  Further, this software is distributed without any warranty that it is
  free of the rightful claim of any third person regarding infringement 
  or the like.  Any license provided herein, whether implied or 
  otherwise, applies only to this software file.  Patent licenses, if 
  any, provided herein do not apply to combinations of this program with 
  other software, or any other product whatsoever.  

  You should have received a copy of the GNU General Public License along
  with this program; if not, write the Free Software Foundation, Inc., 59
  Temple Place - Suite 330, Boston MA 02111-1307, USA.

  Contact information:  Silicon Graphics, Inc., 1600 Amphitheatre Pky,
  Mountain View, CA 94043, or:

  http://www.sgi.com

  For further information regarding this notice, see:

  http://oss.sgi.com/projects/GenInfo/NoticeExplan

*/


// ====================================================================
// ====================================================================
//
// Module: ipa_feedback.cxx
//
// Revision history:
//  03-Sep-97 - Original Version
//
// Description:
//
// Create an output file(s) containing useful information derived during 
// various phases of Interprocedural Analysis. These files contain very
// helpful IPA-derived info such as: 
//
//    o  global variable and function names whose access can be optimized 
//       via compiler directives (e.g. #pragma section_gp, #pragma hidden,
//       #pragma internal, #pragma inline, #pragma noinline ).
//
//    o  names of functions that IPA analysis found to be 'dead' ( but not
//       due to inlining ). Such functions are never called or they are
//       called within other functions which are in turn never called, etc
//
//    o  names of global variables that IPA analysis found to be unused,
//       e.g. written but not read, etc.
//       
// ====================================================================
// ====================================================================


#include "defs.h"
#include "cxx_memory.h"
#include "cxx_hash.h"
#include "erglob.h"
#include "glob.h"
#include "mempool.h"
#include "tracing.h"
#include "strtab.h"
#include "stab.h"
#include "ipa_feedback.h"

extern IPA_FEEDBACK_STRINGS *IPA_Fbk_Strings;

// Wrapper routine to allow C programs in ipa/common to access string hashing
extern "C" INT32 C_Emit_id_string( const char *name );


// ====================================================================
//
// Hash table for strings in the feedback string table.
//
// ====================================================================

// We avoid all duplicates:
typedef class USER_HASH_TABLE < char*, INT32, String_Hash, String_Equal >
  IPA_FEEDBACK_HASH_TBL;
IPA_FEEDBACK_HASH_TBL *IPA_Feedback_Hash_Tbl;

// ====================================================================
//
// IPA_FEEDBACK_STRINGS::IPA_FEEDBACK_STRINGS
// 
// Constructor: Initialize to reflect a new string pool 
//
// ====================================================================

IPA_FEEDBACK_STRINGS::IPA_FEEDBACK_STRINGS ( MEM_POOL* str_pool )
{
  _str_pool_max  =  FBK_STR_POOL_INIT_SIZE;
  _str_pool_size = 0;
  _str_pool      = str_pool;
  _str_pool_base = MEM_POOL_Alloc ( _str_pool,
        sizeof(char)*FBK_STR_POOL_INIT_SIZE );
   if( _str_pool_base == NULL ) {
     ErrMsg ( EC_No_Mem, "IPA Feedback string pool unavail" );
   }
}

// ====================================================================
//
// IPA_FEEDBACK_HASHES::IPA_FEEDBACK_HASHES
// 
// Constructor: Initialize to reflect a string hash table
//
// ====================================================================

IPA_FEEDBACK_HASHES::IPA_FEEDBACK_HASHES ( MEM_POOL* str_hash_tbl )
{
  // Initialize the string hash table:

  IPA_Feedback_Hash_Tbl = 
            CXX_NEW ( IPA_FEEDBACK_HASH_TBL ( FBK_HASH_TAB_SIZE, str_hash_tbl ),
                      str_hash_tbl );
}

// ====================================================================
//
// IPA_FEEDBACK_STRINGS::Add_string
// 
// Add a string to an IPA feedback string pool. The string has been  
// previously checked for duplication.
//
// ====================================================================

INT32
IPA_FEEDBACK_STRINGS::Add_id_string ( const char *s )
{
  INT32 len = strlen(s);
  INT32 loc;

  // Expand the string pool if required

  if ( _str_pool_size == 0 ) _str_pool_size = 1;
  if ( _str_pool_max <= _str_pool_size + len+1 ) {
  _str_pool_base = MEM_POOL_Realloc ( _str_pool, _str_pool_base, 
           sizeof(char)*_str_pool_max, 
           sizeof(char)*(_str_pool_size + len+1+FBK_STR_POOL_INIT_SIZE) );
  if ( _str_pool_base == NULL ) {
    ErrMsg ( EC_No_Mem, "IPA Feedback string pool realloc fails " );
  }
  _str_pool_max = _str_pool_size + len+1+FBK_STR_POOL_INIT_SIZE;
  }

  // Add the new string:
  strcpy ( ((char *)_str_pool_base)+_str_pool_size, s );
  loc = _str_pool_size;
  _str_pool_size += len+1;

  return loc;
}

// ====================================================================
//
// IPA_FEEDBACK_STRINGS::Emit_id_string
//
// Emit a name to an IPA feedback string pool and returns its index.
// A hash table (above) is used to avoid any duplication.
//
// WARNING:  The hash table implementation used stores the string
// pointer as the key rather than the string itself.  So the name
// entered must not be a string which will be overwritten before being
// done with the hash table.
//
// ====================================================================

INT32
IPA_FEEDBACK_STRINGS::Emit_id_string ( const char *name )
{
  // check 1st for duplicate and recycle index if found
  INT32 index = IPA_Feedback_Hash_Tbl->Find ( (char *)name );

  if ( index == 0 ) {
    // no duplicate found - add a new string
    index = IPA_FEEDBACK_STRINGS::Add_id_string ( (char *)name );
    IPA_Feedback_Hash_Tbl->Enter ( (char *)name, index );
    return index;
  }
  else {
    return -index;
  }
}

// ====================================================================
//
// C_Emit_id_string
//
// A wrapper routine to allow the C programs in /common portion of ipa
// source tree to call the string hashing mechanisms to eliminate dups.
//
// WARNING:  The hash table implementation used stores the string
// pointer as the key rather than the string itself.  So the name
// entered must not be a string which will be overwritten before being
// done with the hash table. Separate phases of IPA do free up memory so
// this is a problem if trying to extend hash tables/string pools across
// phases.
//
// ====================================================================
#ifdef TODO

INT32
C_Emit_id_string ( const char *name )
{
  return ( IPA_Fbk_Strings->Emit_id_string( name ) );
}

#endif

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