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Overview
Comment: | Further improvements to the Lemon-generated code for yy_reduce(). |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | parser-performance |
Files: | files | file ages | folders |
SHA1: |
ef95a7d6490e33a9af4bc7b4b622de73 |
User & Date: | drh 2016-02-17 01:46:19.413 |
Context
2016-02-17
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04:33 | Enhance Lemon so that if reduce code contains a comment of the form "/*A-overwrites-X*/" then a LHS label A is allowed to overwrite the RHS label X. (check-in: 5cfe9545d4 user: drh tags: parser-performance) | |
01:46 | Further improvements to the Lemon-generated code for yy_reduce(). (check-in: ef95a7d649 user: drh tags: parser-performance) | |
01:18 | In Lemon, add the ability for the left-most RHS label to be the same as the LHS label, causing the LHS values to be written directly into the stack. (check-in: 4bb94c7c4c user: drh tags: parser-performance) | |
Changes
Changes to src/parse.y.
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159 160 161 162 163 164 165 | ///////////////////// The CREATE TABLE statement //////////////////////////// // cmd ::= create_table create_table_args. create_table ::= createkw temp(T) TABLE ifnotexists(E) nm(Y) dbnm(Z). { sqlite3StartTable(pParse,&Y,&Z,T,0,0,E); } | | < < | | 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 | ///////////////////// The CREATE TABLE statement //////////////////////////// // cmd ::= create_table create_table_args. create_table ::= createkw temp(T) TABLE ifnotexists(E) nm(Y) dbnm(Z). { sqlite3StartTable(pParse,&Y,&Z,T,0,0,E); } createkw(A) ::= CREATE(A). {disableLookaside(pParse);} %type ifnotexists {int} ifnotexists(A) ::= . {A = 0;} ifnotexists(A) ::= IF NOT EXISTS. {A = 1;} %type temp {int} %ifndef SQLITE_OMIT_TEMPDB temp(A) ::= TEMP. {A = 1;} %endif SQLITE_OMIT_TEMPDB |
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Changes to tool/lemon.c.
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3465 3466 3467 3468 3469 3470 3471 3472 | return z; } /* ** zCode is a string that is the action associated with a rule. Expand ** the symbols in this string so that the refer to elements of the parser ** stack. */ | > > > | > | 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 | return z; } /* ** zCode is a string that is the action associated with a rule. Expand ** the symbols in this string so that the refer to elements of the parser ** stack. ** ** Return 1 if the expanded code requires that "yylhsminor" local variable ** to be defined. */ PRIVATE int translate_code(struct lemon *lemp, struct rule *rp){ char *cp, *xp; int i; int rc = 0; /* True if yylhsminor is used */ char lhsused = 0; /* True if the LHS element has been used */ char lhsdirect; /* True if LHS writes directly into stack */ char used[MAXRHS]; /* True for each RHS element which is used */ char zLhs[50]; /* Convert the LHS symbol into this string */ for(i=0; i<rp->nrhs; i++) used[i] = 0; lhsused = 0; |
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3519 3520 3521 3522 3523 3524 3525 | } }else{ lhsdirect = 0; } if( lhsdirect ){ sprintf(zLhs, "yymsp[%d].minor.yy%d",1-rp->nrhs,rp->lhs->dtnum); }else{ | < < | | 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 | } }else{ lhsdirect = 0; } if( lhsdirect ){ sprintf(zLhs, "yymsp[%d].minor.yy%d",1-rp->nrhs,rp->lhs->dtnum); }else{ rc = 1; sprintf(zLhs, "yylhsminor.yy%d",rp->lhs->dtnum); } append_str(0,0,0,0); /* This const cast is wrong but harmless, if we're careful. */ for(cp=(char *)rp->code; *cp; cp++){ |
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3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 | append_str(zLhs, 0, 0, 0); append_str(";\n", 0, 0, 0); } /* Suffix code generation complete */ cp = append_str(0,0,0,0); if( cp ) rp->codeSuffix = Strsafe(cp); } /* ** Generate code which executes when the rule "rp" is reduced. Write ** the code to "out". Make sure lineno stays up-to-date. */ PRIVATE void emit_code( | > > | 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 | append_str(zLhs, 0, 0, 0); append_str(";\n", 0, 0, 0); } /* Suffix code generation complete */ cp = append_str(0,0,0,0); if( cp ) rp->codeSuffix = Strsafe(cp); return rc; } /* ** Generate code which executes when the rule "rp" is reduced. Write ** the code to "out". Make sure lineno stays up-to-date. */ PRIVATE void emit_code( |
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4294 4295 4296 4297 4298 4299 4300 4301 | */ for(rp=lemp->rule; rp; rp=rp->next){ fprintf(out," { %d, %d },\n",rp->lhs->index,rp->nrhs); lineno++; } tplt_xfer(lemp->name,in,out,&lineno); /* Generate code which execution during each REDUCE action */ for(rp=lemp->rule; rp; rp=rp->next){ | > | > > > | 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 | */ for(rp=lemp->rule; rp; rp=rp->next){ fprintf(out," { %d, %d },\n",rp->lhs->index,rp->nrhs); lineno++; } tplt_xfer(lemp->name,in,out,&lineno); /* Generate code which execution during each REDUCE action */ i = 0; for(rp=lemp->rule; rp; rp=rp->next){ i += translate_code(lemp, rp); } if( i ){ fprintf(out," YYMINORTYPE yylhsminor;\n"); lineno++; } /* First output rules other than the default: rule */ for(rp=lemp->rule; rp; rp=rp->next){ struct rule *rp2; /* Other rules with the same action */ if( rp->code==0 ) continue; if( rp->code[0]=='\n' && rp->code[1]==0 ) continue; /* Will be default: */ fprintf(out," case %d: /* ", rp->index); |
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Changes to tool/lempar.c.
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622 623 624 625 626 627 628 | if( yyTraceFILE && yyruleno>=0 && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){ yysize = yyRuleInfo[yyruleno].nrhs; fprintf(yyTraceFILE, "%sReduce [%s], go to state %d.\n", yyTracePrompt, yyRuleName[yyruleno], yymsp[-yysize].stateno); } #endif /* NDEBUG */ | < | 622 623 624 625 626 627 628 629 630 631 632 633 634 635 | if( yyTraceFILE && yyruleno>=0 && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){ yysize = yyRuleInfo[yyruleno].nrhs; fprintf(yyTraceFILE, "%sReduce [%s], go to state %d.\n", yyTracePrompt, yyRuleName[yyruleno], yymsp[-yysize].stateno); } #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( yypParser->yyidx>yypParser->yyidxMax ){ |
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