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Factor constant functions out of the inner loop since they are more expensive

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than the extra OP_Copy needed to move the result into place.

FossilOrigin-Name: 80ad317f89c46db0d0d252aefdc036a34a61183d
This commit is contained in:
drh 2017-01-04 04:18:00 +00:00
commit 49c5ab243b
4 changed files with 38 additions and 28 deletions
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16
manifest
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@ -1,5 +1,5 @@
C Use\scompiler\sintrinsic\sfunctions\sfor\ssigned\sinteger\smath\swhen\soverflow\ndetection\sis\sneeded.
D 2017-01-03T21:57:11.355
C Factor\sconstant\sfunctions\sout\sof\sthe\sinner\sloop\ssince\sthey\sare\smore\sexpensive\nthan\sthe\sextra\sOP_Copy\sneeded\sto\smove\sthe\sresult\sinto\splace.
D 2017-01-04T04:18:00.128
F Makefile.in 41bd4cad981487345c4a84081074bcdb876e4b2e
F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
@ -341,7 +341,7 @@ F src/ctime.c 9f2296a4e5d26ebf0e0d95a0af4628f1ea694e7a
F src/date.c dc3f1391d9297f8c748132813aaffcb117090d6e
F src/dbstat.c 19ee7a4e89979d4df8e44cfac7a8f905ec89b77d
F src/delete.c c8bc10d145c9666a34ae906250326fdaa8d58fa5
F src/expr.c 449cbb8b9857ff8eb685b72555086818a178858c
F src/expr.c f06f41e5e5daca10fb090e70a2502dcc0dbc992b
F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
F src/fkey.c 2e9aabe1aee76273aff8a84ee92c464e095400ae
F src/func.c c67273e1ec08abbdcc14c189892a3ff6eeece86b
@ -393,7 +393,7 @@ F src/shell.c 6095531aa900decdaa765e0f3993fba7153c92c1
F src/sqlite.h.in e8e2d108d82647f0a812fdb74accf91c1ec08ddc
F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
F src/sqlite3ext.h 8648034aa702469afb553231677306cc6492a1ae
F src/sqliteInt.h f3450b70cfd99b434304225cf3b95de9cb4a9536
F src/sqliteInt.h 9fdfb8789b27a621f3401468bc1705c32308f877
F src/sqliteLimit.h c0373387c287c8d0932510b5547ecde31b5da247
F src/status.c a9e66593dfb28a9e746cba7153f84d49c1ddc4b1
F src/table.c 5226df15ab9179b9ed558d89575ea0ce37b03fc9
@ -1541,8 +1541,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
P bed0eaa5f50112e64fc97a2afdc9d56cf8f5026a 4c2efd4239bf07eb4b92d4af54edd68ee6312670
R 4be5114c40ec1b8757eebb3b6a7e4284
T +closed 4c2efd4239bf07eb4b92d4af54edd68ee6312670
P d3ac32a6e7f1823450feb3d1089802542090d164 2ab997e47998d261bd6190bbce5c09f3fbd4cfd3
R 2d314fb6a2447c90f8995bffa1ef5d9e
T +closed 2ab997e47998d261bd6190bbce5c09f3fbd4cfd3
U drh
Z 6bd6e679c9840443d9b2f38c8bc4573f
Z 2f6b9afef8397c67d3717af984641685

2
manifest.uuid
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@ -1 +1 @@
d3ac32a6e7f1823450feb3d1089802542090d164
80ad317f89c46db0d0d252aefdc036a34a61183d

46
src/expr.c
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@ -3612,6 +3612,11 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
u8 enc = ENC(db); /* The text encoding used by this database */
CollSeq *pColl = 0; /* A collating sequence */
if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){
/* SQL functions can be expensive. So try to move constant functions
** out of the inner loop, even if that means an extra OP_Copy. */
return sqlite3ExprCodeAtInit(pParse, pExpr, -1);
}
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
if( ExprHasProperty(pExpr, EP_TokenOnly) ){
pFarg = 0;
@ -3992,24 +3997,40 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
/*
** Factor out the code of the given expression to initialization time.
**
** If regDest>=0 then the result is always stored in that register and the
** result is not reusable. If regDest<0 then this routine is free to
** store the value whereever it wants. The register where the expression
** is stored is returned. When regDest<0, two identical expressions will
** code to the same register.
*/
void sqlite3ExprCodeAtInit(
int sqlite3ExprCodeAtInit(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* The expression to code when the VDBE initializes */
int regDest, /* Store the value in this register */
u8 reusable /* True if this expression is reusable */
int regDest /* Store the value in this register */
){
ExprList *p;
assert( ConstFactorOk(pParse) );
p = pParse->pConstExpr;
if( regDest<0 && p ){
struct ExprList_item *pItem;
int i;
for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
if( pItem->reusable && sqlite3ExprCompare(pItem->pExpr,pExpr,-1)==0 ){
return pItem->u.iConstExprReg;
}
}
}
pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
p = sqlite3ExprListAppend(pParse, p, pExpr);
if( p ){
struct ExprList_item *pItem = &p->a[p->nExpr-1];
pItem->reusable = regDest<0;
if( regDest<0 ) regDest = ++pParse->nMem;
pItem->u.iConstExprReg = regDest;
pItem->reusable = reusable;
}
pParse->pConstExpr = p;
return regDest;
}
/*
@ -4032,19 +4053,8 @@ int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
&& pExpr->op!=TK_REGISTER
&& sqlite3ExprIsConstantNotJoin(pExpr)
){
ExprList *p = pParse->pConstExpr;
int i;
*pReg = 0;
if( p ){
struct ExprList_item *pItem;
for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){
if( pItem->reusable && sqlite3ExprCompare(pItem->pExpr,pExpr,-1)==0 ){
return pItem->u.iConstExprReg;
}
}
}
r2 = ++pParse->nMem;
sqlite3ExprCodeAtInit(pParse, pExpr, r2, 1);
r2 = sqlite3ExprCodeAtInit(pParse, pExpr, -1);
}else{
int r1 = sqlite3GetTempReg(pParse);
r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
@ -4098,7 +4108,7 @@ void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){
*/
void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
if( pParse->okConstFactor && sqlite3ExprIsConstant(pExpr) ){
sqlite3ExprCodeAtInit(pParse, pExpr, target, 0);
sqlite3ExprCodeAtInit(pParse, pExpr, target);
}else{
sqlite3ExprCode(pParse, pExpr, target);
}
@ -4170,7 +4180,7 @@ int sqlite3ExprCodeExprList(
sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
}
}else if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
sqlite3ExprCodeAtInit(pParse, pExpr, target+i, 0);
sqlite3ExprCodeAtInit(pParse, pExpr, target+i);
}else{
int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
if( inReg!=target+i ){

2
src/sqliteInt.h
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@ -3716,7 +3716,7 @@ void sqlite3ExprCacheAffinityChange(Parse*, int, int);
void sqlite3ExprCode(Parse*, Expr*, int);
void sqlite3ExprCodeCopy(Parse*, Expr*, int);
void sqlite3ExprCodeFactorable(Parse*, Expr*, int);
void sqlite3ExprCodeAtInit(Parse*, Expr*, int, u8);
int sqlite3ExprCodeAtInit(Parse*, Expr*, int);
int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
int sqlite3ExprCodeTarget(Parse*, Expr*, int);
void sqlite3ExprCodeAndCache(Parse*, Expr*, int);