Adjust the parser so that the value of TK_ISNOT is similar to the value of

TK_IS.  This helps the compiler generate faster switch() statements on the
Expr.op fields when there are cases for TK_ISNOT and other common operators.

FossilOrigin-Name: 34f05c3d89b2dd15e4b0d1ba292df7de3dfc54b505c0ba145cc3db52cf020845

2 files changed, 11 insertions, 2 deletions

diff --git a/src/parse.y b/src/parse.y
index 90277f9c0..de8282e81 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -236,11 +236,13 @@ columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,A,Y);}
 // improve performance and reduce the executable size.  The goal here is
 // to get the "jump" operations in ISNULL through ESCAPE to have numeric
 // values that are early enough so that all jump operations are clustered
-// at the beginning.
+// at the beginning.  Also, operators like NE and EQ need to be adjacent,
+// and all of the comparison operators need to be clustered together.
+// Various assert() statements throughout the code enforce these restrictions.
 //
 %token ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST.
 %token CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL.
-%token OR AND NOT IS MATCH LIKE_KW BETWEEN IN ISNULL NOTNULL NE EQ.
+%token OR AND NOT IS ISNOT MATCH LIKE_KW BETWEEN IN ISNULL NOTNULL NE EQ.
 %token GT LE LT GE ESCAPE.
 
 // The following directive causes tokens ABORT, AFTER, ASC, etc. to
diff --git a/src/whereexpr.c b/src/whereexpr.c
index 41d6ac9f0..ae1c838c0 100644
--- a/src/whereexpr.c
+++ b/src/whereexpr.c
@@ -435,6 +435,13 @@ static int isAuxiliaryVtabOperator(
         }
       }
     }
+  }else if( pExpr->op>=TK_EQ ){
+    /* Comparison operators are a common case.  Save a few comparisons for
+    ** that common case by terminating early. */
+    assert( TK_NE < TK_EQ );
+    assert( TK_ISNOT < TK_EQ );
+    assert( TK_NOTNULL < TK_EQ );
+    return 0;
   }else if( pExpr->op==TK_NE || pExpr->op==TK_ISNOT || pExpr->op==TK_NOTNULL ){
     int res = 0;
     Expr *pLeft = pExpr->pLeft;