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Overview
Comment:Size reduction and performance improvement in the stack-popping logic of the Lemon-generated parser.
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SHA1: 9748c48a4fbd5c06208bbf80e7bfcb159ec026d9
User & Date: drh 2015-11-09 14:11:37.997
Context
2015-11-09
15:06
Avoid recursion in the yy_find_shift_action() routine of the Lemon-generated parser, so that routine can be inlined, for a size reduction and performance increase. (check-in: 0557a179f9 user: drh tags: trunk)
14:11
Size reduction and performance improvement in the stack-popping logic of the Lemon-generated parser. (check-in: 9748c48a4f user: drh tags: trunk)
12:47
Fix incorrect WHERE clause in sqldiff, as reported on the mailing list by Youcef Hilem. (check-in: e0ed4c3e37 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/lempar.c.
︙︙
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}

/*
** Pop the parser's stack once.
**
** If there is a destructor routine associated with the token which
** is popped from the stack, then call it.
**
** Return the major token number for the symbol popped.
*/
static int yy_pop_parser_stack(yyParser *pParser){
  YYCODETYPE yymajor;
  yyStackEntry *yytos = &pParser->yystack[pParser->yyidx];

  /* There is no mechanism by which the parser stack can be popped below
  ** empty in SQLite.  */
  assert( pParser->yyidx>=0 );

#ifndef NDEBUG
  if( yyTraceFILE && pParser->yyidx>=0 ){
    fprintf(yyTraceFILE,"%sPopping %s\n",
      yyTracePrompt,
      yyTokenName[yytos->major]);
  }
#endif
  yymajor = yytos->major;
  yy_destructor(pParser, yymajor, &yytos->minor);
  pParser->yyidx--;
  return yymajor;
}

/* 
** Deallocate and destroy a parser.  Destructors are all called for
** all stack elements before shutting the parser down.
**
** Inputs:








<
<

|
<
|
<
<
<

>

|





<
|
<
<








328
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}

/*
** Pop the parser's stack once.
**
** If there is a destructor routine associated with the token which
** is popped from the stack, then call it.


*/
static void yy_pop_parser_stack(yyParser *pParser){

  yyStackEntry *yytos;



  assert( pParser->yyidx>=0 );
  yytos = &pParser->yystack[pParser->yyidx--];
#ifndef NDEBUG
  if( yyTraceFILE ){
    fprintf(yyTraceFILE,"%sPopping %s\n",
      yyTracePrompt,
      yyTokenName[yytos->major]);
  }
#endif

  yy_destructor(pParser, yytos->major, &yytos->minor);


}

/* 
** Deallocate and destroy a parser.  Destructors are all called for
** all stack elements before shutting the parser down.
**
** Inputs:
︙︙
Changes to tool/lempar.c.
︙︙
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323
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328
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}

/*
** Pop the parser's stack once.
**
** If there is a destructor routine associated with the token which
** is popped from the stack, then call it.
**
** Return the major token number for the symbol popped.
*/
static int yy_pop_parser_stack(yyParser *pParser){
  YYCODETYPE yymajor;
  yyStackEntry *yytos = &pParser->yystack[pParser->yyidx];

  if( pParser->yyidx<0 ) return 0;
#ifndef NDEBUG
  if( yyTraceFILE && pParser->yyidx>=0 ){
    fprintf(yyTraceFILE,"%sPopping %s\n",
      yyTracePrompt,
      yyTokenName[yytos->major]);
  }
#endif
  yymajor = yytos->major;
  yy_destructor(pParser, yymajor, &yytos->minor);
  pParser->yyidx--;
  return yymajor;
}

/* 
** Deallocate and destroy a parser.  Destructors are all called for
** all stack elements before shutting the parser down.
**
** Inputs:








<
<

|
<
|
|
|

|





<
|
<
<








322
323
324
325
326
327
328


329
330

331
332
333
334
335
336
337
338
339
340

341


342
343
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345
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347
348

}

/*
** Pop the parser's stack once.
**
** If there is a destructor routine associated with the token which
** is popped from the stack, then call it.


*/
static void yy_pop_parser_stack(yyParser *pParser){

  yyStackEntry *yytos;
  assert( pParser->yyidx>=0 );
  yytos = &pParser->yystack[pParser->yyidx--];
#ifndef NDEBUG
  if( yyTraceFILE ){
    fprintf(yyTraceFILE,"%sPopping %s\n",
      yyTracePrompt,
      yyTokenName[yytos->major]);
  }
#endif

  yy_destructor(pParser, yytos->major, &yytos->minor);


}

/* 
** Deallocate and destroy a parser.  Destructors are all called for
** all stack elements before shutting the parser down.
**
** Inputs:
︙︙