Performance improvements on the main loop of the LEMON-generated parser.

FossilOrigin-Name: fec1ebadeb9d6b55b19a1c159c543fd7ae67b3307c4caee4d2541bd783630e23

diff --git a/manifest b/manifest
index c39c2e57ca587a45038c92977d8789a77e01743e..fbd61bf9a30aa20680848a5b9ee1e3b0c49c6631 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Enhance\sLEMON\sto\strack\swhich\ssymbols\sactually\scarry\ssemantic\scontent.\nOutput\sthe\slist\sof\ssymbols\sthat\sdo\snot\scarry\scontent\sat\sthe\send\sof\sthe\nreport,\sbut\sdo\snot\s(yet)\sdo\sanything\selse\swith\sthe\sinformation.
-D 2018-04-21T20:24:19.958
+C Performance\simprovements\son\sthe\smain\sloop\sof\sthe\sLEMON-generated\sparser.
+D 2018-04-21T22:40:08.247
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 5ce9343cba9c189046f1afe6d2bcc1f68079439febc05267b98aec6ecc752439
@@ -1645,7 +1645,7 @@ F tool/genfkey.test 4196a8928b78f51d54ef58e99e99401ab2f0a7e5
 F tool/getlock.c f4c39b651370156cae979501a7b156bdba50e7ce
 F tool/kvtest-speed.sh 4761a9c4b3530907562314d7757995787f7aef8f
 F tool/lemon.c 33892e2a243865f73e6c6e7cecce3c6eb4bb95db4a3d9d86d146c8064feb92fd
-F tool/lempar.c 8ce83cbec62cba95819760de2ebab98a1b0d00861af5876bd456a29e1158229d
+F tool/lempar.c 01f28a4d245f0ea480fab1147c1244fe50434cea924ce258b3e8570a6340a0d3
 F tool/libvers.c caafc3b689638a1d88d44bc5f526c2278760d9b9
 F tool/loadfts.c c3c64e4d5e90e8ba41159232c2189dba4be7b862
 F tool/logest.c 11346aa019e2e77a00902aa7d0cabd27bd2e8cca
@@ -1725,7 +1725,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P b78005b6d41640203c163ffde4faf9336f11f47f42e8b7fe10b95415bbaed028
-R bdad1972dfc51eb7c1aa0a96e8529d8a
+P dcf2bafc159179859b91ffea3a4ebd70b5ca6de9e1d515eaf9afde8cfff26c6c
+R 30c687ea8cbf9562ea971a83f0b60716
 U drh
-Z c5d80323466004edd7fb02f443feea52
+Z 5f81242a2fad2cc1a6991b9a8c5f4a01

diff --git a/manifest.uuid b/manifest.uuid
index 1fc92158dc6fea755b6348aedfda08382e95e436..febf97a27e9edb15461e895bba5a17b4c053f530 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-dcf2bafc159179859b91ffea3a4ebd70b5ca6de9e1d515eaf9afde8cfff26c6c
\ No newline at end of file
+fec1ebadeb9d6b55b19a1c159c543fd7ae67b3307c4caee4d2541bd783630e23
\ No newline at end of file

diff --git a/tool/lempar.c b/tool/lempar.c
index fcc47f9bed4b294fbeb7049752b8a17acbdc6667..d2b700a8cfc0e03b9adc0d56451a110e6c974d60 100644 (file)
--- a/tool/lempar.c
+++ b/tool/lempar.c
@@ -505,13 +505,12 @@ int ParseCoverage(FILE *out){
 ** Find the appropriate action for a parser given the terminal
 ** look-ahead token iLookAhead.
 */
-static unsigned int yy_find_shift_action(
-  yyParser *pParser,        /* The parser */
-  YYCODETYPE iLookAhead     /* The look-ahead token */
+static YYACTIONTYPE yy_find_shift_action(
+  YYCODETYPE iLookAhead,    /* The look-ahead token */
+  YYACTIONTYPE stateno      /* Current state number */
 ){
   int i;
-  int stateno = pParser->yytos->stateno;
- 
+
   if( stateno>YY_MAX_SHIFT ) return stateno;
   assert( stateno <= YY_SHIFT_COUNT );
 #if defined(YYCOVERAGE)
@@ -575,7 +574,7 @@ static unsigned int yy_find_shift_action(
 ** look-ahead token iLookAhead.
 */
 static int yy_find_reduce_action(
-  int stateno,              /* Current state number */
+  YYACTIONTYPE stateno,     /* Current state number */
   YYCODETYPE iLookAhead     /* The look-ahead token */
 ){
   int i;
@@ -647,8 +646,8 @@ static void yyTraceShift(yyParser *yypParser, int yyNewState, const char *zTag){
 */
 static void yy_shift(
   yyParser *yypParser,          /* The parser to be shifted */
-  int yyNewState,               /* The new state to shift in */
-  int yyMajor,                  /* The major token to shift in */
+  YYACTIONTYPE yyNewState,      /* The new state to shift in */
+  YYCODETYPE yyMajor,           /* The major token to shift in */
   ParseTOKENTYPE yyMinor        /* The minor token to shift in */
 ){
   yyStackEntry *yytos;
@@ -678,8 +677,8 @@ static void yy_shift(
     yyNewState += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE;
   }
   yytos = yypParser->yytos;
-  yytos->stateno = (YYACTIONTYPE)yyNewState;
-  yytos->major = (YYCODETYPE)yyMajor;
+  yytos->stateno = yyNewState;
+  yytos->major = yyMajor;
   yytos->minor.yy0 = yyMinor;
   yyTraceShift(yypParser, yyNewState, "Shift");
 }
@@ -706,7 +705,7 @@ static void yy_accept(yyParser*);  /* Forward Declaration */
 ** only called from one place, optimizing compilers will in-line it, which
 ** means that the extra parameters have no performance impact.
 */
-static void yy_reduce(
+static YYACTIONTYPE yy_reduce(
   yyParser *yypParser,         /* The parser */
   unsigned int yyruleno,       /* Number of the rule by which to reduce */
   int yyLookahead,             /* Lookahead token, or YYNOCODE if none */
@@ -748,13 +747,13 @@ static void yy_reduce(
 #if YYSTACKDEPTH>0 
     if( yypParser->yytos>=yypParser->yystackEnd ){
       yyStackOverflow(yypParser);
-      return;
+      return YY_ACCEPT_ACTION;
     }
 #else
     if( yypParser->yytos>=&yypParser->yystack[yypParser->yystksz-1] ){
       if( yyGrowStack(yypParser) ){
         yyStackOverflow(yypParser);
-        return;
+        return YY_ACCEPT_ACTION;
       }
       yymsp = yypParser->yytos;
     }
@@ -791,6 +790,7 @@ static void yy_reduce(
   yymsp->stateno = (YYACTIONTYPE)yyact;
   yymsp->major = (YYCODETYPE)yygoto;
   yyTraceShift(yypParser, yyact, "... then shift");
+  return yyact;
 }
 
 /*
@@ -888,7 +888,7 @@ void Parse(
   ParseARG_PDECL               /* Optional %extra_argument parameter */
 ){
   YYMINORTYPE yyminorunion;
-  unsigned int yyact;   /* The parser action. */
+  YYACTIONTYPE yyact;   /* The parser action. */
 #if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
   int yyendofinput;     /* True if we are at the end of input */
 #endif
@@ -904,32 +904,40 @@ void Parse(
   yyendofinput = (yymajor==0);
 #endif
 
+  yyact = yypParser->yytos->stateno;
 #ifndef NDEBUG
   if( yyTraceFILE ){
-    int stateno = yypParser->yytos->stateno;
-    if( stateno < YY_MIN_REDUCE ){
+    if( yyact < YY_MIN_REDUCE ){
       fprintf(yyTraceFILE,"%sInput '%s' in state %d\n",
-              yyTracePrompt,yyTokenName[yymajor],stateno);
+              yyTracePrompt,yyTokenName[yymajor],yyact);
     }else{
       fprintf(yyTraceFILE,"%sInput '%s' with pending reduce %d\n",
-              yyTracePrompt,yyTokenName[yymajor],stateno-YY_MIN_REDUCE);
+              yyTracePrompt,yyTokenName[yymajor],yyact-YY_MIN_REDUCE);
     }
   }
 #endif
 
   do{
-    yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor);
+    assert( yyact==yypParser->yytos->stateno );
+    yyact = yy_find_shift_action(yymajor,yyact);
     if( yyact >= YY_MIN_REDUCE ){
-      yy_reduce(yypParser,yyact-YY_MIN_REDUCE,yymajor,yyminor ParseCTX_PARAM);
+      yyact = yy_reduce(yypParser,yyact-YY_MIN_REDUCE,yymajor,
+                        yyminor ParseCTX_PARAM);
     }else if( yyact <= YY_MAX_SHIFTREDUCE ){
       yy_shift(yypParser,yyact,yymajor,yyminor);
 #ifndef YYNOERRORRECOVERY
       yypParser->yyerrcnt--;
 #endif
-      yymajor = YYNOCODE;
+      break;
     }else if( yyact==YY_ACCEPT_ACTION ){
-      yypParser->yytos--;
-      yy_accept(yypParser);
+      /* YY_ACCEPT_ACTION also happens on a stack overflow.  We distingush
+      ** the two cases by observing that on a true accept, there should be
+      ** a single token left on the stack, whereas on a stack overflow,
+      ** the stack has been popped (by yyStackOverflow()) to be empty */
+      if( yypParser->yytos > yypParser->yystack ){
+        yypParser->yytos--;
+        yy_accept(yypParser);
+      }
       return;
     }else{
       assert( yyact == YY_ERROR_ACTION );
@@ -997,6 +1005,8 @@ void Parse(
       }
       yypParser->yyerrcnt = 3;
       yyerrorhit = 1;
+      if( yymajor==YYNOCODE ) break;
+      yyact = yypParser->yytos->stateno;
 #elif defined(YYNOERRORRECOVERY)
       /* If the YYNOERRORRECOVERY macro is defined, then do not attempt to
       ** do any kind of error recovery.  Instead, simply invoke the syntax
@@ -1007,8 +1017,7 @@ void Parse(
       */
       yy_syntax_error(yypParser,yymajor, yyminor);
       yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
-      yymajor = YYNOCODE;
-      
+      break;
 #else  /* YYERRORSYMBOL is not defined */
       /* This is what we do if the grammar does not define ERROR:
       **
@@ -1030,10 +1039,10 @@ void Parse(
         yypParser->yyerrcnt = -1;
 #endif
       }
-      yymajor = YYNOCODE;
+      break;
 #endif
     }
-  }while( yymajor!=YYNOCODE && yypParser->yytos>yypParser->yystack );
+  }while( yypParser->yytos>yypParser->yystack );
 #ifndef NDEBUG
   if( yyTraceFILE ){
     yyStackEntry *i;