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In the LEMON-generated parser, rearrange the meanings of integer action codes

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so that reduce actions occur last.  This means that the most common case
(reduce actions) can be recognized with a single comparison operation, thus
speeding up the main parser loop, slightly.

FossilOrigin-Name: 7bfe7a360261ac7227840db49487c2f0fe338a2f1b868fcaada1e04a8d2b8f7a
This commit is contained in:
drh 2017-12-24 23:38:10 +00:00
parent e58f74f680
commit 5c8241b875
4 changed files with 81 additions and 55 deletions
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18
manifest
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@ -1,5 +1,5 @@
C Improved\sparser\stracing\soutput.
D 2017-12-24T17:06:41.289
C In\sthe\sLEMON-generated\sparser,\srearrange\sthe\smeanings\sof\sinteger\saction\scodes\nso\sthat\sreduce\sactions\soccur\slast.\s\sThis\smeans\sthat\sthe\smost\scommon\scase\n(reduce\sactions)\scan\sbe\srecognized\swith\sa\ssingle\scomparison\soperation,\sthus\nspeeding\sup\sthe\smain\sparser\sloop,\sslightly.
D 2017-12-24T23:38:10.370
F Makefile.in ceb40bfcb30ebba8e1202b34c56ff7e13e112f9809e2381d99be32c2726058f5
F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
F Makefile.msc 6480671f7c129e61208d69492b3c71ce4310d49fceac83cfb17f1c081e242b69
@ -1608,8 +1608,8 @@ F tool/genfkey.README cf68fddd4643bbe3ff8e31b8b6d8b0a1b85e20f4
F tool/genfkey.test 4196a8928b78f51d54ef58e99e99401ab2f0a7e5
F tool/getlock.c f4c39b651370156cae979501a7b156bdba50e7ce
F tool/kvtest-speed.sh 4761a9c4b3530907562314d7757995787f7aef8f
F tool/lemon.c e6056373044d55296d21f81467dba7632bbb81dc49af072b3f0e76338771497e
F tool/lempar.c a427c2375df118fa52e69174ffbbf9e26878096f0a109df6b77062d6032afe18
F tool/lemon.c 7c6919d98e459c0f8a3673be64b03425553733dba01c12939b2fadc30e4e2804
F tool/lempar.c c8dd4dcf0bca9d7c27c62f7df12882c30db749cd9bb83d6f71796b9fabb94f6c
F tool/libvers.c caafc3b689638a1d88d44bc5f526c2278760d9b9
F tool/loadfts.c c3c64e4d5e90e8ba41159232c2189dba4be7b862
F tool/logest.c 11346aa019e2e77a00902aa7d0cabd27bd2e8cca
@ -1687,11 +1687,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
P 07c773148d8db185fa54991df09298b64f4fef28879e6c9395759265e8183977
Q +c4951833c2b976223c2393d82fd2606068c71cd19612ca9df4e26debab980e32
R 3f4f31cde41f94adafa8015552d0561b
T *branch * lemon-improvements
T *sym-lemon-improvements *
T -sym-trunk *
P 25be5750545b7b0ed9e1a1baca31611b354519688f875aa1590b21bb6ff42f1b
R 02413a9b8686f5cb855fd9a72c28a347
U drh
Z 3f6d9f274761457d9d7dcc3ca6c0270c
Z a4798d5b361261f3f5c39967bad11abf

2
manifest.uuid
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@ -1 +1 @@
25be5750545b7b0ed9e1a1baca31611b354519688f875aa1590b21bb6ff42f1b
7bfe7a360261ac7227840db49487c2f0fe338a2f1b868fcaada1e04a8d2b8f7a

100
tool/lemon.c
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@ -384,6 +384,12 @@ struct lemon {
int nrule; /* Number of rules */
int nsymbol; /* Number of terminal and nonterminal symbols */
int nterminal; /* Number of terminal symbols */
int minShiftReduce; /* Minimum shift-reduce action value */
int errAction; /* Error action value */
int accAction; /* Accept action value */
int noAction; /* No-op action value */
int minReduce; /* Minimum reduce action */
int maxAction; /* Maximum action value of any kind */
struct symbol **symbols; /* Sorted array of pointers to symbols */
int errorcnt; /* Number of errors */
struct symbol *errsym; /* The error symbol */
@ -3020,6 +3026,27 @@ PRIVATE FILE *file_open(
return fp;
}
/* Print the text of a rule
*/
void rule_print(FILE *out, struct rule *rp){
int i, j;
fprintf(out, "%s",rp->lhs->name);
/* if( rp->lhsalias ) fprintf(out,"(%s)",rp->lhsalias); */
fprintf(out," ::=");
for(i=0; i<rp->nrhs; i++){
struct symbol *sp = rp->rhs[i];
if( sp->type==MULTITERMINAL ){
fprintf(out," %s", sp->subsym[0]->name);
for(j=1; j<sp->nsubsym; j++){
fprintf(out,"|%s", sp->subsym[j]->name);
}
}else{
fprintf(out," %s", sp->name);
}
/* if( rp->rhsalias[i] ) fprintf(out,"(%s)",rp->rhsalias[i]); */
}
}
/* Duplicate the input file without comments and without actions
** on rules */
void Reprint(struct lemon *lemp)
@ -3047,21 +3074,7 @@ void Reprint(struct lemon *lemp)
printf("\n");
}
for(rp=lemp->rule; rp; rp=rp->next){
printf("%s",rp->lhs->name);
/* if( rp->lhsalias ) printf("(%s)",rp->lhsalias); */
printf(" ::=");
for(i=0; i<rp->nrhs; i++){
sp = rp->rhs[i];
if( sp->type==MULTITERMINAL ){
printf(" %s", sp->subsym[0]->name);
for(j=1; j<sp->nsubsym; j++){
printf("|%s", sp->subsym[j]->name);
}
}else{
printf(" %s", sp->name);
}
/* if( rp->rhsalias[i] ) printf("(%s)",rp->rhsalias[i]); */
}
rule_print(stdout, rp);
printf(".");
if( rp->precsym ) printf(" [%s]",rp->precsym->name);
/* if( rp->code ) printf("\n %s",rp->code); */
@ -3321,16 +3334,19 @@ PRIVATE int compute_action(struct lemon *lemp, struct action *ap)
switch( ap->type ){
case SHIFT: act = ap->x.stp->statenum; break;
case SHIFTREDUCE: {
act = ap->x.rp->iRule + lemp->nstate;
/* Since a SHIFT is inherient after a prior REDUCE, convert any
** SHIFTREDUCE action with a nonterminal on the LHS into a simple
** REDUCE action: */
if( ap->sp->index>=lemp->nterminal ) act += lemp->nrule;
if( ap->sp->index>=lemp->nterminal ){
act = lemp->minReduce + ap->x.rp->iRule;
}else{
act = lemp->minShiftReduce + ap->x.rp->iRule;
}
break;
}
case REDUCE: act = ap->x.rp->iRule + lemp->nstate+lemp->nrule; break;
case ERROR: act = lemp->nstate + lemp->nrule*2; break;
case ACCEPT: act = lemp->nstate + lemp->nrule*2 + 1; break;
case REDUCE: act = lemp->minReduce + ap->x.rp->iRule; break;
case ERROR: act = lemp->errAction; break;
case ACCEPT: act = lemp->accAction; break;
default: act = -1; break;
}
return act;
@ -4038,6 +4054,13 @@ void ReportTable(
int mnNtOfst, mxNtOfst;
struct axset *ax;
lemp->minShiftReduce = lemp->nstate;
lemp->errAction = lemp->minShiftReduce + lemp->nrule;
lemp->accAction = lemp->errAction + 1;
lemp->noAction = lemp->accAction + 1;
lemp->minReduce = lemp->noAction + 1;
lemp->maxAction = lemp->minReduce + lemp->nrule;
in = tplt_open(lemp);
if( in==0 ) return;
out = file_open(lemp,".c","wb");
@ -4076,7 +4099,7 @@ void ReportTable(
minimum_size_type(0, lemp->nsymbol+1, &szCodeType)); lineno++;
fprintf(out,"#define YYNOCODE %d\n",lemp->nsymbol+1); lineno++;
fprintf(out,"#define YYACTIONTYPE %s\n",
minimum_size_type(0,lemp->nstate+lemp->nrule*2+5,&szActionType)); lineno++;
minimum_size_type(0,lemp->maxAction,&szActionType)); lineno++;
if( lemp->wildcard ){
fprintf(out,"#define YYWILDCARD %d\n",
lemp->wildcard->index); lineno++;
@ -4201,15 +4224,16 @@ void ReportTable(
fprintf(out,"#define YYNSTATE %d\n",lemp->nxstate); lineno++;
fprintf(out,"#define YYNRULE %d\n",lemp->nrule); lineno++;
fprintf(out,"#define YY_MAX_SHIFT %d\n",lemp->nxstate-1); lineno++;
fprintf(out,"#define YY_MIN_SHIFTREDUCE %d\n",lemp->nstate); lineno++;
i = lemp->nstate + lemp->nrule;
i = lemp->minShiftReduce;
fprintf(out,"#define YY_MIN_SHIFTREDUCE %d\n",i); lineno++;
i += lemp->nrule;
fprintf(out,"#define YY_MAX_SHIFTREDUCE %d\n", i-1); lineno++;
fprintf(out,"#define YY_MIN_REDUCE %d\n", i); lineno++;
i = lemp->nstate + lemp->nrule*2;
fprintf(out,"#define YY_ERROR_ACTION %d\n", lemp->errAction); lineno++;
fprintf(out,"#define YY_ACCEPT_ACTION %d\n", lemp->accAction); lineno++;
fprintf(out,"#define YY_NO_ACTION %d\n", lemp->noAction); lineno++;
fprintf(out,"#define YY_MIN_REDUCE %d\n", lemp->minReduce); lineno++;
i = lemp->minReduce + lemp->nrule;
fprintf(out,"#define YY_MAX_REDUCE %d\n", i-1); lineno++;
fprintf(out,"#define YY_ERROR_ACTION %d\n", i); lineno++;
fprintf(out,"#define YY_ACCEPT_ACTION %d\n", i+1); lineno++;
fprintf(out,"#define YY_NO_ACTION %d\n", i+2); lineno++;
tplt_xfer(lemp->name,in,out,&lineno);
/* Now output the action table and its associates:
@ -4231,7 +4255,7 @@ void ReportTable(
fprintf(out,"static const YYACTIONTYPE yy_action[] = {\n"); lineno++;
for(i=j=0; i<n; i++){
int action = acttab_yyaction(pActtab, i);
if( action<0 ) action = lemp->nstate + lemp->nrule + 2;
if( action<0 ) action = lemp->noAction;
if( j==0 ) fprintf(out," /* %5d */ ", i);
fprintf(out, " %4d,", action);
if( j==9 || i==n-1 ){
@ -4320,7 +4344,11 @@ void ReportTable(
for(i=j=0; i<n; i++){
stp = lemp->sorted[i];
if( j==0 ) fprintf(out," /* %5d */ ", i);
fprintf(out, " %4d,", stp->iDfltReduce+lemp->nstate+lemp->nrule);
if( stp->iDfltReduce<0 ){
fprintf(out, " %4d,", lemp->errAction);
}else{
fprintf(out, " %4d,", stp->iDfltReduce + lemp->minReduce);
}
if( j==9 || i==n-1 ){
fprintf(out, "\n"); lineno++;
j = 0;
@ -4401,7 +4429,7 @@ void ReportTable(
if( sp==0 || sp->type==TERMINAL ||
sp->index<=0 || sp->destructor!=0 ) continue;
if( once ){
fprintf(out, " /* Default NON-TERMINAL Destructor */\n"); lineno++;
fprintf(out, " /* Default NON-TERMINAL Destructor */\n");lineno++;
once = 0;
}
fprintf(out," case %d: /* %s */\n", sp->index, sp->name); lineno++;
@ -4444,8 +4472,10 @@ void ReportTable(
** Note: This code depends on the fact that rules are number
** sequentually beginning with 0.
*/
for(rp=lemp->rule; rp; rp=rp->next){
fprintf(out," { %d, %d },\n",rp->lhs->index,-rp->nrhs); lineno++;
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);
@ -4711,7 +4741,7 @@ void ResortStates(struct lemon *lemp)
for(i=0; i<lemp->nstate; i++){
stp = lemp->sorted[i];
stp->nTknAct = stp->nNtAct = 0;
stp->iDfltReduce = lemp->nrule; /* Init dflt action to "syntax error" */
stp->iDfltReduce = -1; /* Init dflt action to "syntax error" */
stp->iTknOfst = NO_OFFSET;
stp->iNtOfst = NO_OFFSET;
for(ap=stp->ap; ap; ap=ap->next){
@ -4723,7 +4753,7 @@ void ResortStates(struct lemon *lemp)
stp->nNtAct++;
}else{
assert( stp->autoReduce==0 || stp->pDfltReduce==ap->x.rp );
stp->iDfltReduce = iAction - lemp->nstate - lemp->nrule;
stp->iDfltReduce = iAction;
}
}
}

16
tool/lempar.c
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@ -75,11 +75,11 @@
** YY_MAX_SHIFT Maximum value for shift actions
** YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions
** YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions
** YY_MIN_REDUCE Minimum value for reduce actions
** YY_MAX_REDUCE Maximum value for reduce actions
** YY_ERROR_ACTION The yy_action[] code for syntax error
** YY_ACCEPT_ACTION The yy_action[] code for accept
** YY_NO_ACTION The yy_action[] code for no-op
** YY_MIN_REDUCE Minimum value for reduce actions
** YY_MAX_REDUCE Maximum value for reduce actions
*/
#ifndef INTERFACE
# define INTERFACE 1
@ -115,9 +115,6 @@
** N between YY_MIN_SHIFTREDUCE Shift to an arbitrary state then
** and YY_MAX_SHIFTREDUCE reduce by rule N-YY_MIN_SHIFTREDUCE.
**
** N between YY_MIN_REDUCE Reduce by rule N-YY_MIN_REDUCE
** and YY_MAX_REDUCE
**
** N == YY_ERROR_ACTION A syntax error has occurred.
**
** N == YY_ACCEPT_ACTION The parser accepts its input.
@ -125,6 +122,9 @@
** N == YY_NO_ACTION No such action. Denotes unused
** slots in the yy_action[] table.
**
** N between YY_MIN_REDUCE Reduce by rule N-YY_MIN_REDUCE
** and YY_MAX_REDUCE
**
** The action table is constructed as a single large table named yy_action[].
** Given state S and lookahead X, the action is computed as either:
**
@ -868,14 +868,14 @@ void Parse(
do{
yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor);
if( yyact <= YY_MAX_SHIFTREDUCE ){
if( yyact >= YY_MIN_REDUCE ){
yy_reduce(yypParser,yyact-YY_MIN_REDUCE,yymajor,yyminor);
}else if( yyact <= YY_MAX_SHIFTREDUCE ){
yy_shift(yypParser,yyact,yymajor,yyminor);
#ifndef YYNOERRORRECOVERY
yypParser->yyerrcnt--;
#endif
yymajor = YYNOCODE;
}else if( yyact <= YY_MAX_REDUCE ){
yy_reduce(yypParser,yyact-YY_MIN_REDUCE,yymajor,yyminor);
}else{
assert( yyact == YY_ERROR_ACTION );
yyminorunion.yy0 = yyminor;