SQLite

Check-in [70fe8ec2]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Reduce the size of the parser tables generated by Lemon by splitting the yyRuleInfo structure into separate yyRuleInfoLhs and yyRuleInfoNRhs arrays.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256: 70fe8ec2ae3099b8773834c7ac2e56768addbecd57956ac523e71a7dc264049c
User & Date: drh 2018-12-03 23:57:27
Context
2018-12-04
13:51
Small performance increase in sqlite3_step() for the common case where it returns SQLITE_ROW. (check-in: 89344826 user: drh tags: trunk)
01:18
Attempt to make the parser a little faster by storing the ON and USING clause in a single OnUsing object. (Leaf check-in: 6770ed08 user: drh tags: on-using-opt)
2018-12-03
23:57
Reduce the size of the parser tables generated by Lemon by splitting the yyRuleInfo structure into separate yyRuleInfoLhs and yyRuleInfoNRhs arrays. (check-in: 70fe8ec2 user: drh tags: trunk)
17:40
Remove the unused sqlite3Fts5UnicodeNCat() function. (check-in: 7149dacf user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to tool/lemon.c.
︙︙
4586
4587
4588
4589
4590
4591
4592
4593

4594
4595
4596
4597
4598


4599




4600
4601
4602
4603
4604
4605
4606

  }
  tplt_xfer(lemp->name,in,out,&lineno);

  /* Generate code which executes whenever the parser stack overflows */
  tplt_print(out,lemp,lemp->overflow,&lineno);
  tplt_xfer(lemp->name,in,out,&lineno);

  /* Generate the table of rule information

  **
  ** Note: This code depends on the fact that rules are number
  ** sequentually beginning with 0.
  */
  for(i=0, rp=lemp->rule; rp; rp=rp->next, i++){


    fprintf(out,"  { %4d, %4d }, /* (%d) ",rp->lhs->index,-rp->nrhs,i);




    rule_print(out, rp);
    fprintf(out," */\n"); lineno++;
  }
  tplt_xfer(lemp->name,in,out,&lineno);

  /* Generate code which execution during each REDUCE action */
  i = 0;








|
>





>
>
|
>
>
>
>








4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613

  }
  tplt_xfer(lemp->name,in,out,&lineno);

  /* Generate code which executes whenever the parser stack overflows */
  tplt_print(out,lemp,lemp->overflow,&lineno);
  tplt_xfer(lemp->name,in,out,&lineno);

  /* Generate the tables of rule information.  yyRuleInfoLhs[] and
  ** yyRuleInfoNRhs[].
  **
  ** Note: This code depends on the fact that rules are number
  ** sequentually beginning with 0.
  */
  for(i=0, rp=lemp->rule; rp; rp=rp->next, i++){
    fprintf(out,"  %4d,  /* (%d) ", rp->lhs->index, i);
     rule_print(out, rp);
    fprintf(out," */\n"); lineno++;
  }
  tplt_xfer(lemp->name,in,out,&lineno);
  for(i=0, rp=lemp->rule; rp; rp=rp->next, i++){
    fprintf(out,"  %3d,  /* (%d) ", -rp->nrhs, i);
    rule_print(out, rp);
    fprintf(out," */\n"); lineno++;
  }
  tplt_xfer(lemp->name,in,out,&lineno);

  /* Generate code which execution during each REDUCE action */
  i = 0;
︙︙
Changes to tool/lempar.c.
︙︙
682
683
684
685
686
687
688
689
690
691
692


693
694

695
696
697
698
699
700
701
702

  yytos = yypParser->yytos;
  yytos->stateno = yyNewState;
  yytos->major = yyMajor;
  yytos->minor.yy0 = yyMinor;
  yyTraceShift(yypParser, yyNewState, "Shift");
}

/* The following table contains information about every rule that
** is used during the reduce.
*/
static const struct {


  YYCODETYPE lhs;       /* Symbol on the left-hand side of the rule */
  signed char nrhs;     /* Negative of the number of RHS symbols in the rule */

} yyRuleInfo[] = {
%%
};

static void yy_accept(yyParser*);  /* Forward Declaration */

/*
** Perform a reduce action and the shift that must immediately








|
|
<
|
>
>
|
|
>
|








682
683
684
685
686
687
688
689
690

691
692
693
694
695
696
697
698
699
700
701
702
703
704

  yytos = yypParser->yytos;
  yytos->stateno = yyNewState;
  yytos->major = yyMajor;
  yytos->minor.yy0 = yyMinor;
  yyTraceShift(yypParser, yyNewState, "Shift");
}

/* For rule J, yyRuleInfoLhs[J] contains the symbol on the left-hand side
** of that rule */

static const YYCODETYPE yyRuleInfoLhs[] = {
%%
};

/* For rule J, yyRuleInfoNRhs[J] contains the negative of the number
** of symbols on the right-hand side of that rule. */
static const signed char yyRuleInfoNRhs[] = {
%%
};

static void yy_accept(yyParser*);  /* Forward Declaration */

/*
** Perform a reduce action and the shift that must immediately
︙︙
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750

  int yysize;                     /* Amount to pop the stack */
  ParseARG_FETCH
  (void)yyLookahead;
  (void)yyLookaheadToken;
  yymsp = yypParser->yytos;
#ifndef NDEBUG
  if( yyTraceFILE && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
    yysize = yyRuleInfo[yyruleno].nrhs;
    if( yysize ){
      fprintf(yyTraceFILE, "%sReduce %d [%s], go to state %d.\n",
        yyTracePrompt,
        yyruleno, yyRuleName[yyruleno], yymsp[yysize].stateno);
    }else{
      fprintf(yyTraceFILE, "%sReduce %d [%s].\n",
        yyTracePrompt, yyruleno, yyRuleName[yyruleno]);
    }
  }
#endif /* NDEBUG */

  /* Check that the stack is large enough to grow by a single entry
  ** if the RHS of the rule is empty.  This ensures that there is room
  ** enough on the stack to push the LHS value */
  if( yyRuleInfo[yyruleno].nrhs==0 ){
#ifdef YYTRACKMAXSTACKDEPTH
    if( (int)(yypParser->yytos - yypParser->yystack)>yypParser->yyhwm ){
      yypParser->yyhwm++;
      assert( yypParser->yyhwm == (int)(yypParser->yytos - yypParser->yystack));
    }
#endif
#if YYSTACKDEPTH>0 








|














|








723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752

  int yysize;                     /* Amount to pop the stack */
  ParseARG_FETCH
  (void)yyLookahead;
  (void)yyLookaheadToken;
  yymsp = yypParser->yytos;
#ifndef NDEBUG
  if( yyTraceFILE && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
    yysize = yyRuleInfoNRhs[yyruleno];
    if( yysize ){
      fprintf(yyTraceFILE, "%sReduce %d [%s], go to state %d.\n",
        yyTracePrompt,
        yyruleno, yyRuleName[yyruleno], yymsp[yysize].stateno);
    }else{
      fprintf(yyTraceFILE, "%sReduce %d [%s].\n",
        yyTracePrompt, yyruleno, yyRuleName[yyruleno]);
    }
  }
#endif /* NDEBUG */

  /* Check that the stack is large enough to grow by a single entry
  ** if the RHS of the rule is empty.  This ensures that there is room
  ** enough on the stack to push the LHS value */
  if( yyRuleInfoNRhs[yyruleno]==0 ){
#ifdef YYTRACKMAXSTACKDEPTH
    if( (int)(yypParser->yytos - yypParser->yystack)>yypParser->yyhwm ){
      yypParser->yyhwm++;
      assert( yypParser->yyhwm == (int)(yypParser->yytos - yypParser->yystack));
    }
#endif
#if YYSTACKDEPTH>0
︙︙
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794

  **  #line <lineno> <thisfile>
  **     break;
  */
/********** Begin reduce actions **********************************************/
%%
/********** End reduce actions ************************************************/
  };
  assert( yyruleno<sizeof(yyRuleInfo)/sizeof(yyRuleInfo[0]) );
  yygoto = yyRuleInfo[yyruleno].lhs;
  yysize = yyRuleInfo[yyruleno].nrhs;
  yyact = yy_find_reduce_action(yymsp[yysize].stateno,(YYCODETYPE)yygoto);

  /* There are no SHIFTREDUCE actions on nonterminals because the table
  ** generator has simplified them to pure REDUCE actions. */
  assert( !(yyact>YY_MAX_SHIFT && yyact<=YY_MAX_SHIFTREDUCE) );

  /* It is not possible for a REDUCE to be followed by an error */








|
|
|








780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796

  **  #line <lineno> <thisfile>
  **     break;
  */
/********** Begin reduce actions **********************************************/
%%
/********** End reduce actions ************************************************/
  };
  assert( yyruleno<sizeof(yyRuleInfoLhs)/sizeof(yyRuleInfoLhs[0]) );
  yygoto = yyRuleInfoLhs[yyruleno];
  yysize = yyRuleInfoNRhs[yyruleno];
  yyact = yy_find_reduce_action(yymsp[yysize].stateno,(YYCODETYPE)yygoto);

  /* There are no SHIFTREDUCE actions on nonterminals because the table
  ** generator has simplified them to pure REDUCE actions. */
  assert( !(yyact>YY_MAX_SHIFT && yyact<=YY_MAX_SHIFTREDUCE) );

  /* It is not possible for a REDUCE to be followed by an error */
︙︙