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- /*##############################################################################
- HPCC SYSTEMS software Copyright (C) 2012 HPCC Systems®.
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
- http://www.apache.org/licenses/LICENSE-2.0
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
- ############################################################################## */
- #include "platform.h"
- #include "jlib.hpp"
- #include "jmisc.hpp"
- #include "jstream.ipp"
- #include "hql.hpp"
- #include "hqlcse.ipp"
- #include "hqlutil.hpp"
- #include "hqlcpputil.hpp"
- #include "hqlthql.hpp"
- #include "hqlcatom.hpp"
- #include "hqlfold.hpp"
- #include "hqlpmap.hpp"
- #include "hqlopt.hpp"
- #include "hqlcerrors.hpp"
- #include "hqlttcpp.ipp"
- #ifdef _DEBUG
- //#define TRACE_CSE
- #endif
- //The following allows x != y and x == y to be commoned up. It works, but currently disabled
- //because cse doesn't preserve short circuit of AND and OR, and some examples mean it will do more
- //work because the alias will always be evaluated. (e.g., salt1.xhql)
- //Really aliases need to be functional and executed on demand or something similar.
- //#define OPTIMIZE_INVERSE
- //---------------------------------------------------------------------------
- inline bool canWrapWithCSE(IHqlExpression * expr)
- {
- switch (expr->getOperator())
- {
- case no_mapto:
- return false;
- }
- return true;
- }
- bool canCreateTemporary(IHqlExpression * expr)
- {
- switch (expr->getOperator())
- {
- case no_range:
- case no_rangefrom:
- case no_rangeto:
- case no_rangecommon:
- case no_constant:
- case no_all:
- case no_mapto:
- case no_record:
- case no_attr:
- case no_attr_expr:
- case no_attr_link:
- case no_joined:
- case no_sizeof:
- case no_offsetof:
- case no_newtransform:
- case no_transform:
- case no_assign:
- case no_assignall:
- case no_left:
- case no_right:
- case no_self:
- case no_top:
- case no_activetable:
- case no_alias:
- case no_skip:
- case no_assert:
- case no_counter:
- case no_sortlist:
- case no_matched:
- case no_matchtext:
- case no_matchunicode:
- case no_matchposition:
- case no_matchlength:
- case no_matchattr:
- case no_matchrow:
- case no_matchutf8:
- case no_recordlist:
- case no_transformlist:
- case no_rowvalue:
- case no_pipe:
- case no_colon:
- case no_globalscope:
- case no_subgraph:
- case no_forcelocal:
- case no_forcenolocal:
- case no_allnodes:
- case no_thisnode:
- case no_libraryscopeinstance:
- case no_loopbody:
- case no_external:
- return false;
- }
- ITypeInfo * type = expr->queryType();
- if (!type)
- return false;
- switch (type->getTypeCode())
- {
- case type_transform:
- case type_null:
- case type_void:
- case type_rule:
- case type_pattern:
- case type_token:
- case type_event:
- return false;
- default:
- return true;
- }
- }
- //---------------------------------------------------------------------------
- /*
- Cse spotting...
- * Don't remove named symbols from items that aren't transformed.
- * Common items up regardless of the named symbol used to reference it.
- */
- CseSpotterInfo::CseSpotterInfo(IHqlExpression * expr) : NewTransformInfo(expr)
- {
- numRefs = 0;
- numAssociatedRefs = 0;
- alreadyAliased = false;
- canAlias = false;
- dontTransform = false;
- dontTransformSelector = false;
- treatAsAliased = false;
- inverse = NULL;
- annotatedExpr = NULL;
- }
- //worth aliasing if referenced more than once, and used more than once in the expressions that are going to be evaluated now
- bool CseSpotterInfo::worthAliasingOnOwn()
- {
- return numRefs > 1 && (numRefs != numAssociatedRefs);
- }
- bool CseSpotterInfo::worthAliasing()
- {
- if (!inverse)
- return worthAliasingOnOwn();
- //no_not will always traverse the inverse (at least once), so don't sum the two counts - just use the non inverted count
- if (original->getOperator() == no_not)
- return worthAliasingOnOwn() || inverse->worthAliasingOnOwn();
- if (inverse->original->getOperator() == no_not)
- return worthAliasingOnOwn();
- unsigned totalRefs = numRefs + inverse->numRefs;
- unsigned totalAssociatedRefs = numAssociatedRefs + inverse->numAssociatedRefs;
- if ((totalRefs > 1) && (totalRefs != totalAssociatedRefs))
- return true;
- return false;
- }
- //Do we create an alias for this node, or the other one?
- bool CseSpotterInfo::useInverseForAlias()
- {
- if (!inverse)
- return false;
- if (numRefs == numAssociatedRefs)
- return true;
- node_operator op = original->getOperator();
- switch (op)
- {
- case no_not:
- case no_ne:
- case no_notin:
- case no_notbetween:
- return inverse->worthAliasingOnOwn();
- }
- node_operator invOp = inverse->original->getOperator();
- switch (invOp)
- {
- case no_not: return false; //No otherwise we'll expand recursively!
- case no_ne:
- case no_notin:
- case no_notbetween:
- return !worthAliasingOnOwn();
- }
- return op > invOp;
- }
- static HqlTransformerInfo cseSpotterInfo("CseSpotter");
- CseSpotter::CseSpotter(bool _spotCseInIfDatasetConditions)
- : NewHqlTransformer(cseSpotterInfo), spotCseInIfDatasetConditions(_spotCseInIfDatasetConditions)
- {
- canAlias = true;
- isAssociated = false;
- spottedCandidate = false;
- invariantSelector = NULL;
- createLocalAliases = false;
- createdAlias = false;
- }
- void CseSpotter::analyseAssociated(IHqlExpression * expr, unsigned pass)
- {
- isAssociated = true;
- analyse(expr, pass);
- isAssociated = false;
- }
- void CseSpotter::analyseExpr(IHqlExpression * expr)
- {
- CseSpotterInfo * extra = queryBodyExtra(expr);
- if (!extra->annotatedExpr && expr->isAnnotation())
- extra->annotatedExpr = expr;
- if (isAssociated)
- extra->numAssociatedRefs++;
-
- node_operator op = expr->getOperator();
- #ifdef OPTIMIZE_INVERSE
- if (getInverseOp(op) != no_none)
- {
- OwnedHqlExpr inverse = getInverse(expr);
- CseSpotterInfo * inverseExtra = queryBodyExtra(inverse);
- extra->inverse = inverseExtra;
- inverseExtra->inverse = extra;
- }
- #endif
-
- if (op == no_alias)
- {
- queryBodyExtra(expr->queryChild(0))->alreadyAliased = true;
- extra->alreadyAliased = true;
- }
- switch (op)
- {
- case no_assign:
- case no_transform:
- case no_newtransform:
- case no_range:
- case no_rangefrom:
- if (expr->isConstant())
- return;
- break;
- case no_constant:
- return;
- }
- if (extra->numRefs++ != 0)
- {
- if (op == no_alias)
- return;
- if (!spottedCandidate && extra->worthAliasing())
- spottedCandidate = true;
- if (canCreateTemporary(expr))
- return;
- //Ugly! This is here as a temporary hack to stop branches of maps being commoned up and always
- //evaluated. The alias spotting and generation really needs to take conditionality into account....
- if (op == no_mapto)
- return;
- }
- if (!containsPotentialCSE(expr))
- return;
- if (canAlias && !expr->isDataset())
- extra->canAlias = true;
- bool savedCanAlias = canAlias;
- if (expr->isDataset() && (op != no_select) && (!spotCseInIfDatasetConditions || (op != no_if)))
- {
- //There is little point looking for CSEs within dataset expressions, because only a very small
- //minority which would correctly cse, and it can cause lots of problems - e.g., join conditions.
- unsigned first = getFirstActivityArgument(expr);
- unsigned num = getNumActivityArguments(expr);
- HqlExprArray children;
- bool defaultCanAlias = canAlias;
- ForEachChild(i, expr)
- {
- IHqlExpression * cur = expr->queryChild(i);
- if (i >= first && i < first+num)
- canAlias = defaultCanAlias;
- else
- canAlias = false;
- analyseExpr(cur);
- }
- }
- else
- PARENT::analyseExpr(expr);
- canAlias = savedCanAlias;
- }
- IHqlExpression * CseSpotter::createAliasOwn(IHqlExpression * expr, CseSpotterInfo * extra)
- {
- #ifdef TRACE_CSE
- StringBuffer s;
- DBGLOG("Create alias for %s (%d refs)", getExprIdentifier(s, expr).str(), extra->numRefs);
- #endif
- extra->alreadyAliased = true;
- if (createLocalAliases)
- return ::createAliasOwn(expr, createLocalAttribute());
- return ::createAliasOwn(expr, NULL);
- }
- IHqlExpression * CseSpotter::createTransformed(IHqlExpression * expr)
- {
- node_operator op = expr->getOperator();
- switch (op)
- {
- case no_matched:
- case no_matchtext:
- case no_matchunicode:
- case no_matchposition:
- case no_matchlength:
- case no_matchrow:
- case no_matchutf8:
- //These actually go wrong if we remove the named symbols, so traverse under no circumstances.
- //others can be traversed to patch up references to datasets that have changed.
- case no_translated:
- return LINK(expr);
- }
- OwnedHqlExpr transformed = PARENT::createTransformed(expr);
- CseSpotterInfo * splitter = queryBodyExtra(expr);
- //MORE: Possibly add a unique number to the alias when this starts worrying about child scopes.
- if (splitter->canAlias && splitter->worthAliasing() && checkPotentialCSE(expr, splitter))
- {
- if (splitter->useInverseForAlias())
- {
- OwnedHqlExpr inverse = getInverse(expr);
- OwnedHqlExpr transformedInverse = transform(inverse);
- return getInverse(transformedInverse);
- }
- createdAlias = true;
- //Use the transformed body to ensure that any cses only create a single instance,
- //But annotate with first annotation spotted, try and retain the symbols to aid debugging.
- LinkedHqlExpr aliasValue = transformed->queryBody();
- // if (splitter->annotatedExpr)
- // aliasValue.setown(splitter->annotatedExpr->cloneAllAnnotations(aliasValue));
- OwnedHqlExpr alias = createAliasOwn(aliasValue.getClear(), splitter);
- return alias.getClear();
- return expr->cloneAllAnnotations(alias);
- }
- return transformed.getClear();
- }
- ANewTransformInfo * CseSpotter::createTransformInfo(IHqlExpression * expr)
- {
- return CREATE_NEWTRANSFORMINFO(CseSpotterInfo, expr);
- }
- bool CseSpotter::containsPotentialCSE(IHqlExpression * expr)
- {
- switch (expr->getOperator())
- {
- case no_record:
- case no_attr:
- case no_attr_expr:
- case no_attr_link:
- case no_joined:
- case no_sizeof:
- case no_offsetof:
- case no_field:
- case no_evaluate: // MORE: This is an example of introducing a new scope...
- case no_translated: // Causes recursion otherwise....
- case no_left:
- case no_right:
- case no_top:
- case no_self:
- case no_selfref:
- case no_activetable:
- case no_filepos:
- case no_file_logicalname:
- case no_matched:
- case no_matchtext:
- case no_matchunicode:
- case no_matchposition:
- case no_matchrow:
- case no_matchlength:
- case no_matchutf8:
- case no_catch:
- case no_projectrow:
- // case no_evalonce:
- return false;
- case no_select:
- return false; //isNewSelector(expr);
- case NO_AGGREGATE:
- //There may possibly be cses, but we would need to do lots of scoping analysis to work out whether they were
- //really common.
- return false;
- case no_assign:
- case no_assignall:
- case no_transform:
- case no_newtransform:
- case no_range:
- case no_rangefrom:
- case no_rangeto:
- case no_rangecommon:
- case no_skip:
- return true;
- case no_compound_diskread:
- case no_compound_indexread:
- case no_compound_disknormalize:
- case no_compound_diskaggregate:
- case no_compound_diskcount:
- case no_compound_diskgroupaggregate:
- case no_compound_indexnormalize:
- case no_compound_indexaggregate:
- case no_compound_indexcount:
- case no_compound_indexgroupaggregate:
- case no_compound_childread:
- case no_compound_childnormalize:
- case no_compound_childaggregate:
- case no_compound_childcount:
- case no_compound_childgroupaggregate:
- case no_compound_selectnew:
- case no_compound_inline:
- return false;
- #if 0
- //Strictly speaking, we shouldn't common up conditional expressions, but it generally provides such a reduction in code
- //that it will stay enabled until I come up with a better scheme.
- case no_if:
- case no_rejected:
- case no_which:
- case no_case:
- case no_map:
- return false;
- #endif
- }
- ITypeInfo * type = expr->queryType();
- if (type && type->getTypeCode() == type_void)
- return false;
- return !expr->isConstant();// || expr->isDataset() || expr->isDatarow();
- }
- bool CseSpotter::checkPotentialCSE(IHqlExpression * expr, CseSpotterInfo * extra)
- {
- if (extra->alreadyAliased)
- return false;
- if (!expr->isPure())
- return false;
- if (!canCreateTemporary(expr))
- return false;
- if (invariantSelector && exprReferencesDataset(expr, invariantSelector))
- return false;
-
- switch (expr->getOperator())
- {
- case no_eq:
- case no_ne:
- case no_gt:
- case no_ge:
- case no_lt:
- case no_le:
- {
- //Don't combine integer comparisons into a CSE - not worth it...
- ITypeInfo * type = expr->queryChild(0)->queryType();
- switch (type->getTypeCode())
- {
- case type_boolean:
- case type_int:
- return false;
- }
- return true;
- }
- case no_not:
- {
- IHqlExpression * child = expr->queryChild(0);
- if (queryBodyExtra(child)->isAliased())
- return false;
- break;
- }
- case no_charlen:
- {
- IHqlExpression * child = expr->queryChild(0);
- if (queryBodyExtra(child)->isAliased() || child->getOperator() == no_select)
- {
- type_t tc = child->queryType()->getTypeCode();
- switch (tc)
- {
- case type_varstring:
- case type_varunicode:
- return true;
- }
- //prevent (trivial-cast)length(x) from being serialized etc.
- extra->treatAsAliased = true;
- return false;
- }
- break;
- }
- case no_field:
- throwUnexpected();
- case no_select:
- //MORE: ds[n].x would probably be worth cseing.
- return false;
- case no_list:
- case no_datasetlist:
- case no_getresult: // these are commoned up in the code generator, so don't do it twice.
- case no_getgraphresult:
- case no_getgraphloopresult:
- case no_translated: // Causes recursion otherwise....
- case no_random:
- return false;
- case no_call:
- case no_externalcall:
- case no_libraryinput:
- case no_counter:
- return true;
- case no_substring:
- {
- SubStringHelper helper(expr);
- return !helper.canGenerateInline();
- }
- case no_cast:
- case no_implicitcast:
- {
- ITypeInfo * exprType = expr->queryType();
- if (exprType->getTypeCode() == type_set)
- return false;
- IHqlExpression * uncast = expr->queryChild(0);
- if (uncast->queryValue())
- return false;
- //Ignore integral casts of items that have already been aliased
- if (queryBodyExtra(uncast)->isAliased())
- {
- if (exprType->isInteger() && uncast->queryType()->isInteger())
- {
- if (extra->numRefs < 5)
- return false;
- }
- }
- break;
- }
- //Following are all source datasets - no point in commoning them up
- //although probably exceptions e.g., table(,pipe)
- case no_none:
- case no_null:
- case no_anon:
- case no_pseudods:
- case no_all:
- // case no_table: - normally work commoning up
- case no_temptable:
- case no_inlinetable:
- case no_xmlproject:
- case no_datasetfromrow:
- case no_datasetfromdictionary:
- case no_preservemeta:
- case no_dataset_alias:
- case no_workunit_dataset:
- case no_left:
- case no_right:
- case no_top:
- case no_self:
- case no_selfref:
- case no_keyindex:
- case no_newkeyindex:
- case no_fail:
- case no_activetable:
- case no_soapcall:
- case no_newsoapcall:
- case no_id2blob:
- case no_embedbody:
- case no_rows:
- return false;
- }
- if (!expr->queryType())
- return false;
- return (expr->numChildren() > 0);
- }
- IHqlExpression * CseSpotter::transform(IHqlExpression * expr)
- {
- return PARENT::transform(expr);
- }
- IHqlExpression * CseSpotter::queryAlreadyTransformed(IHqlExpression * expr)
- {
- CseSpotterInfo * extra = queryBodyExtra(expr);
- if (extra->dontTransform)
- return expr;
- IHqlExpression * ret = PARENT::queryAlreadyTransformed(expr);
- if (!ret)
- {
- IHqlExpression * body = expr->queryBody();
- if (body != expr)
- {
- ret = PARENT::queryAlreadyTransformed(body);
- if (ret == body)
- return NULL;
- }
- }
- return ret;
- }
- IHqlExpression * CseSpotter::queryAlreadyTransformedSelector(IHqlExpression * expr)
- {
- CseSpotterInfo * extra = queryBodyExtra(expr);
- if (extra->dontTransformSelector)
- return expr;
- return PARENT::queryAlreadyTransformedSelector(expr);
- }
- void CseSpotter::stopTransformation(IHqlExpression * expr)
- {
- IHqlExpression * normalized = expr->queryNormalizedSelector();
- queryBodyExtra(expr)->dontTransform = true;
- queryBodyExtra(normalized)->dontTransformSelector = true;
- }
- //---------------------------------------------------------------------------
- static HqlTransformerInfo conjunctionTransformerInfo("ConjunctionTransformer");
- ConjunctionTransformer::ConjunctionTransformer() : NewHqlTransformer(conjunctionTransformerInfo)
- {
- }
- IHqlExpression * ConjunctionTransformer::createTransformed(IHqlExpression * expr)
- {
- node_operator op = expr->getOperator();
- OwnedHqlExpr transformed;
- switch (op)
- {
- case no_matched:
- case no_matchtext:
- case no_matchunicode:
- case no_matchlength:
- case no_matchposition:
- case no_matchrow:
- case no_matchutf8:
- return LINK(expr);
- //not so sure why the following causes problems - because the tables get changed I think.
- case no_filepos:
- case no_file_logicalname:
- case no_sizeof:
- case no_offsetof:
- return LINK(expr);
- case no_and:
- case no_or:
- {
- IHqlExpression * left = expr->queryChild(0);
- if (left->getOperator() == op)
- {
- HqlExprArray args, transformedArgs;
- left->unwindList(args, op);
- ForEachItemIn(i, args)
- transformedArgs.append(*transform(&args.item(i)));
- transformedArgs.append(*transform(expr->queryChild(1)));
- transformed.setown(createLeftBinaryList(op, transformedArgs));
- // return expr->cloneAllAnnotations(transformed);
- }
- break;
- }
- }
- if (!transformed)
- transformed.setown(NewHqlTransformer::createTransformed(expr));
- return transformed.getClear();
- }
- //---------------------------------------------------------------------------
- #ifdef NEW_CSE_PROCESSING
- inline bool canInsertCodeAlias(IHqlExpression * expr)
- {
- switch (expr->getOperator())
- {
- case no_range:
- case no_rangefrom:
- case no_rangeto:
- case no_rangecommon:
- case no_mapto:
- case no_recordlist:
- case no_transformlist:
- case no_rowvalue:
- case no_sortlist:
- return false;
- default:
- return true;
- }
- }
- static HqlTransformerInfo cseScopeTransformerInfo("CseScopeTransformer");
- CseScopeTransformer::CseScopeTransformer()
- : NewHqlTransformer(cseScopeTransformerInfo)
- {
- activeParent = NULL;
- seq = 0;
- conditionDepth = 0;
- }
- void CseScopeTransformer::analyseExpr(IHqlExpression * expr)
- {
- expr = expr->queryBody();
- if (!containsNonGlobalAlias(expr))
- return;
- node_operator op = expr->getOperator();
- CseScopeInfo * splitter = queryExtra(expr);
- if (splitter->seq)
- {
- splitter->hasSharedParent = true;
- splitter->addParent(activeParent);
- return;
- }
- splitter->firstParent = activeParent;
- splitter->seq = ++seq;
- splitter->isUnconditional = (conditionDepth == 0);
- {
- IHqlExpression * savedParent = activeParent;
- activeParent = expr;
- switch (op)
- {
- case no_if:
- case no_or:
- case no_and:
- case no_case:
- {
- analyseExpr(expr->queryChild(0));
- conditionDepth++;
- ForEachChildFrom(i, expr, 1)
- analyseExpr(expr->queryChild(i));
- conditionDepth--;
- break;
- }
- default:
- NewHqlTransformer::analyseExpr(expr);
- break;
- }
- activeParent = savedParent;
- }
- //Add here so the cse are in the correct order to cope with dependencies...
- if (op == no_alias)
- {
- assertex(!expr->hasAttribute(globalAtom));
- allCSEs.append(*LINK(splitter));
- }
- }
- bool CseScopeTransformer::attachCSEs(IHqlExpression * root)
- {
- bool changed = false;
- ForEachItemIn(idx, allCSEs)
- {
- CseScopeInfo& cur = allCSEs.item(idx);
- IHqlExpression * aliasLocation = findAliasLocation(&cur);
- if (!aliasLocation && cur.isUnconditional)
- aliasLocation = root;
- if (aliasLocation && aliasLocation != cur.original)
- {
- queryExtra(aliasLocation)->aliasesToDefine.append(*LINK(cur.original));
- changed = true;
- }
- }
- return changed;
- }
- IHqlExpression * CseScopeTransformer::createTransformed(IHqlExpression * expr)
- {
- //Can't short-circuit transformation if (!containsAlias(expr)) because it means references to transformed datasets won't get patched up
- IHqlExpression * body = expr->queryBody(true);
- if (body != expr)
- {
- OwnedHqlExpr ret = transform(body);
- return expr->cloneAnnotation(ret);
- }
- //slight difference from before...
- IHqlExpression * transformed = NewHqlTransformer::createTransformed(expr);
- CseScopeInfo * splitter = queryExtra(expr);
- if (splitter->aliasesToDefine.ordinality())
- {
- HqlExprArray args;
- args.append(*transformed);
- ForEachItemIn(idx, splitter->aliasesToDefine)
- {
- IHqlExpression * value = &splitter->aliasesToDefine.item(idx);
- args.append(*transform(value));
- }
- if (expr->isDataset())
- transformed = createDataset(no_alias_scope, args);
- else if (expr->isDatarow())
- transformed = createRow(no_alias_scope, args);
- else
- transformed = createValue(no_alias_scope, transformed->getType(), args);
- }
- return transformed;
- }
- ANewTransformInfo * CseScopeTransformer::createTransformInfo(IHqlExpression * expr)
- {
- return CREATE_NEWTRANSFORMINFO(CseScopeInfo, expr);
- }
- //First find the highest shared parent node (or this if no parents are shared)
- CseScopeInfo * CseScopeTransformer::calcCommonLocation(CseScopeInfo * extra)
- {
- if (extra->calcedCommonLocation)
- return extra->commonLocation;
- CseScopeInfo * commonLocation = extra;
- if (extra->firstParent)
- {
- CseScopeInfo * firstParentExtra = queryExtra(extra->firstParent);
- CseScopeInfo * commonParent = calcCommonLocation(firstParentExtra);
- if ((extra->parents.ordinality() == 0) && (!firstParentExtra->hasSharedParent || extra->firstParent->getOperator() == no_alias))
- // if ((extra->parents.ordinality() == 0) && !firstParentExtra->hasSharedParent)
- {
- //assertex(commonParent == firstParentExtra);
- //commonParent = extra;
- }
- else
- {
- extra->hasSharedParent = true;
- commonLocation = commonParent;
- ForEachItemIn(i, extra->parents)
- {
- CseScopeInfo * nextExtra = calcCommonLocation(queryExtra(extra->parents.item(i)));
- if (nextExtra->isUnconditional)
- extra->isUnconditional = true;
- commonLocation = findCommonPath(commonLocation, nextExtra);
- if (!commonLocation && extra->isUnconditional)
- break;
- }
- }
- }
- else
- {
- if (extra->hasSharedParent)
- commonLocation = NULL;
- }
- extra->calcedCommonLocation = true;
- extra->commonLocation = commonLocation;
- return commonLocation;
- }
- IHqlExpression * CseScopeTransformer::findAliasLocation(CseScopeInfo * extra)
- {
- CseScopeInfo * best = calcCommonLocation(extra);
- loop
- {
- if (!best)
- return NULL;
- IHqlExpression * bestLocation = best->original;
- if (canInsertCodeAlias(bestLocation))
- return bestLocation;
- best = selectParent(best);
- }
- }
- CseScopeInfo * CseScopeTransformer::selectParent(CseScopeInfo * info)
- {
- if (info->hasSharedParent)
- return info->commonLocation;
- if (!info->firstParent)
- return NULL;
- return queryExtra(info->firstParent);
- }
- CseScopeInfo * CseScopeTransformer::findCommonPath(CseScopeInfo * left, CseScopeInfo * right)
- {
- loop
- {
- if (!left || !right)
- return NULL;
- if (left == right)
- return left;
- if (left->seq > right->seq)
- left = selectParent(left);
- else
- right = selectParent(right);
- }
- }
- #else
- CSEentry::CSEentry(IHqlExpression * _value, PathArray & _path)
- {
- value.set(_value);
- unsigned depth=_path.ordinality();
- path.ensure(depth);
- ForEachItemIn(idx, _path)
- path.append(_path.item(idx));
- ensurePathValid();
- }
- void CSEentry::ensurePathValid()
- {
- //It is not valid to insert a no_code_alias at certain points....
- while (path.ordinality())
- {
- switch (path.tos().getOperator())
- {
- case no_range:
- case no_rangefrom:
- case no_rangeto:
- case no_rangecommon:
- case no_mapto:
- case no_recordlist:
- case no_transformlist:
- case no_rowvalue:
- case no_sortlist:
- path.pop();
- break;
- default:
- return;
- }
- }
- }
- void CSEentry::findCommonPath(PathArray & otherPath)
- {
- unsigned prevPath = path.ordinality();
- unsigned maxPath = path.ordinality();
- if (maxPath > otherPath.ordinality())
- maxPath = otherPath.ordinality();
- unsigned idx;
- for (idx = 0; idx < maxPath; idx++)
- {
- IHqlExpression * l = &path.item(idx);
- IHqlExpression * r = &otherPath.item(idx);
- if (l != r)
- break;
- }
- //Ensure the new location is valid for receiving the CSE
- while (idx != 0)
- {
- if (canWrapWithCSE(&path.item(idx-1)))
- break;
- idx--;
- }
- path.trunc(idx);
- if (prevPath != path.ordinality())
- {
- ForEachItemIn(idx2, dependsOn)
- dependsOn.item(idx2).findCommonPath(path);
- }
- ensurePathValid();
- }
- static HqlTransformerInfo cseScopeTransformerInfo("CseScopeTransformer");
- CseScopeTransformer::CseScopeTransformer()
- : NewHqlTransformer(cseScopeTransformerInfo)
- {
- }
- void CseScopeTransformer::analyseExpr(IHqlExpression * expr)
- {
- expr = expr->queryBody();
- if (!containsNonGlobalAlias(expr))
- return;
- CSEentry * cse = NULL;
- node_operator op = expr->getOperator();
- if (op == no_alias)
- {
- assertex(!expr->hasAttribute(globalAtom));
- CseScopeInfo * splitter = queryExtra(expr);
- //PrintLog("splitter: %s", expr->toString(StringBuffer()).str());
- if (splitter->cseUse)
- {
- //Find the common path, and map the alias.
- CSEentry * cse = splitter->cseUse;
- cse->findCommonPath(path);
- if (activeCSE.ordinality())
- activeCSE.tos().dependsOn.append(*LINK(cse));
- return;
- }
- cse = new CSEentry(expr, path);
- splitter->cseUse.setown(cse);
- if (activeCSE.ordinality())
- activeCSE.tos().dependsOn.append(*LINK(cse));
- activeCSE.append(*LINK(cse));
- }
- #if 0
- if ((op == no_transform) || (op == no_newtransform))
- {
- //For a transform add each assignment as a path point - so the aliases for assignments don't end up
- //before aliases for skip attributes.
- path.append(*expr);
- ForEachChild(i, expr)
- {
- IHqlExpression * cur = expr->queryChild(i);
- analyseExpr(cur);
- path.append(*cur);
- }
- ForEachChild(i2, expr)
- path.pop();
- path.pop();
- }
- else
- #endif
- {
- path.append(*expr);
- NewHqlTransformer::analyseExpr(expr);
- path.pop();
- }
- //Add here so the cse are in the correct order to cope with dependencies...
- if (cse)
- {
- allCSEs.append(*LINK(cse));
- activeCSE.pop();
- }
- }
- bool CseScopeTransformer::attachCSEs(IHqlExpression * /*root*/)
- {
- bool changed = false;
- ForEachItemIn(idx, allCSEs)
- {
- CSEentry & cur = allCSEs.item(idx);
- if (cur.path.ordinality())
- {
- IHqlExpression & location = cur.path.tos();
- queryExtra(&location)->cseDefine.append(OLINK(cur));
- changed = true;
- }
- }
- return changed;
- }
- IHqlExpression * CseScopeTransformer::createTransformed(IHqlExpression * expr)
- {
- //Can't short-circuit transformation if (!containsAlias(expr)) because it means references to transformed datasets won't get patched up
- IHqlExpression * body = expr->queryBody(true);
- if (body != expr)
- {
- OwnedHqlExpr ret = transform(body);
- return expr->cloneAnnotation(ret);
- }
- //slight difference from before...
- IHqlExpression * transformed = NewHqlTransformer::createTransformed(expr);
- CseScopeInfo * splitter = queryExtra(expr);
- if (splitter->cseDefine.ordinality())
- {
- HqlExprArray args;
- args.append(*transformed);
- ForEachItemIn(idx, splitter->cseDefine)
- {
- CSEentry & cur = splitter->cseDefine.item(idx);
- args.append(*transform(cur.value));
- }
- if (expr->isDataset())
- transformed = createDataset(no_alias_scope, args);
- else if (expr->isDatarow())
- transformed = createRow(no_alias_scope, args);
- else
- transformed = createValue(no_alias_scope, transformed->getType(), args);
- }
- return transformed;
- }
- ANewTransformInfo * CseScopeTransformer::createTransformInfo(IHqlExpression * expr)
- {
- return CREATE_NEWTRANSFORMINFO(CseScopeInfo, expr);
- }
- #endif
- IHqlExpression * spotScalarCSE(IHqlExpression * expr, IHqlExpression * limit, bool spotCseInIfDatasetConditions)
- {
- if (expr->isConstant())
- return LINK(expr);
- switch (expr->getOperator())
- {
- case no_select:
- if (!isNewSelector(expr))
- return LINK(expr);
- break;
- }
- OwnedHqlExpr transformed = LINK(expr); //removeNamedSymbols(expr);
- bool addedAliases = false;
- //First spot the aliases - so that restructuring the ands doesn't lose any existing aliases.
- {
- CseSpotter spotter(spotCseInIfDatasetConditions);
- spotter.analyse(transformed, 0);
- if (spotter.foundCandidates())
- {
- if (limit)
- spotter.stopTransformation(limit);
- transformed.setown(spotter.transformRoot(transformed));
- addedAliases = spotter.createdNewAliases();
- }
- }
- if (!containsAlias(transformed))
- return transformed.getClear();
- //Transform conjunctions so they are (a AND (b AND (c AND d))) not (((a AND b) AND c) AND d)
- //so that alias scope can be introduced in a better place.
- {
- ConjunctionTransformer tr;
- transformed.setown(tr.transformRoot(transformed));
- }
- if (!addedAliases)
- return transformed.getClear();
- //Now work out where in the tree the aliases should be evaluated.
- {
- CseScopeTransformer scoper;
- scoper.analyse(transformed, 0);
- if (scoper.attachCSEs(transformed))
- transformed.setown(scoper.transformRoot(transformed));
- }
- return transformed.getClear();
- }
- void spotScalarCSE(SharedHqlExpr & expr, SharedHqlExpr & associated, IHqlExpression * limit, IHqlExpression * invariantSelector, bool spotCseInIfDatasetConditions)
- {
- CseSpotter spotter(spotCseInIfDatasetConditions);
- spotter.analyse(expr, 0);
- if (associated)
- spotter.analyseAssociated(associated, 0);
- if (!spotter.foundCandidates())
- return;
- if (limit)
- spotter.stopTransformation(limit);
- if (invariantSelector)
- spotter.setInvariantSelector(invariantSelector);
- expr.setown(spotter.transformRoot(expr));
- associated.setown(spotter.transformRoot(associated));
- }
- void spotScalarCSE(HqlExprArray & exprs, HqlExprArray & associated, IHqlExpression * limit, IHqlExpression * invariantSelector, bool spotCseInIfDatasetConditions)
- {
- CseSpotter spotter(spotCseInIfDatasetConditions);
- spotter.analyseArray(exprs, 0);
- ForEachItemIn(ia, associated)
- spotter.analyseAssociated(&associated.item(ia), 0);
- if (!spotter.foundCandidates())
- return;
- if (limit)
- spotter.stopTransformation(limit);
- if (invariantSelector)
- spotter.setInvariantSelector(invariantSelector);
- HqlExprArray newExprs;
- HqlExprArray newAssociated;
- spotter.transformRoot(exprs, newExprs);
- spotter.transformRoot(associated, newAssociated);
- replaceArray(exprs, newExprs);
- replaceArray(associated, newAssociated);
- }
- //---------------------------------------------------------------------------
- //The TableInvariantTransformer is important for ensuring that getResultXXX code is executed in the code context, amongst other things
- //It must ensure that any global aliases couldn't contain some other global aliases inside a child query, otherwise when the child query is
- //evaluated the result won't be in the correct place.
- //
- //MORE: This could be improved to work out whether it is worth creating an alias (which will then be serialized...)
- //e.g., don't alias i) <alias<n>> +- offset or ii) extension of an alias's size., iii) substring of a fixed size string. iv) length(string
- //however it is pretty good as it stands.
- //ideally it would need information about how many times the expression is likely to be evaluated (e.g., 1/many)
- //so that could be taken into account (e.g, filenames which are 'string' + conditional)
- static bool canHoistInvariant(IHqlExpression * expr)
- {
- if (!canCreateTemporary(expr))
- {
- if ((expr->getOperator() != no_alias) || expr->hasAttribute(globalAtom))
- return false;
- }
- if (!expr->isPure())
- return false;
- if (expr->isFunction())
- return false;
- switch (expr->getOperator())
- {
- case no_list:
- case no_datasetlist:
- case no_createdictionary:
- return false; // probably don't want to hoist these
- }
- return true;
- }
- static HqlTransformerInfo tableInvariantTransformerInfo("TableInvariantTransformer");
- TableInvariantTransformer::TableInvariantTransformer() : NewHqlTransformer(tableInvariantTransformerInfo)
- {
- canAlias = true;
- }
- bool TableInvariantTransformer::isInvariant(IHqlExpression * expr)
- {
- TableInvariantInfo * extra = queryBodyExtra(expr);
- if (extra->cachedInvariant)
- return extra->isInvariant;
- bool invariant = false;
- node_operator op = expr->getOperator();
- switch (op)
- {
- case no_record:
- case no_null:
- case no_activetable:
- case no_activerow:
- case no_left:
- case no_right:
- case no_self:
- case no_top:
- case no_selfref:
- case no_filepos:
- case no_file_logicalname:
- case no_joined:
- case no_offsetof:
- case no_sizeof:
- case NO_AGGREGATE:
- break;
- case no_preservemeta:
- invariant = isInvariant(expr->queryChild(0));
- break;
- case no_workunit_dataset:
- case no_getresult:
- if (expr->hasAttribute(wuidAtom))
- invariant = isInvariant(expr->queryAttribute(wuidAtom));
- else
- invariant = true;
- break;
- case no_constant:
- case no_getgraphresult:
- invariant = true;
- break;
- case no_select:
- {
- if (!expr->isDataset())
- {
- IHqlExpression * ds = expr->queryChild(0);
- if (expr->hasAttribute(newAtom) || ds->isDatarow())
- invariant = isInvariant(ds);
- }
- break;
- }
- case no_newaggregate:
- {
- //Allow these on a very strict subset of the datasets - to ensure that no potential globals can be included in the dataset
- if (!isInvariant(expr->queryChild(0)))
- break;
- switch (querySimpleAggregate(expr, false, true))
- {
- case no_existsgroup:
- case no_countgroup:
- invariant = true;
- break;
- }
- break;
- }
- case no_selectnth:
- switch (expr->queryChild(1)->getOperator())
- {
- case no_constant:
- case no_counter:
- invariant = isInvariant(expr->queryChild(0));
- break;
- }
- break;
- default:
- if (!isContextDependent(expr))
- //MORE: The following line is needed if the xml/parse flags are removed from the context, but it causes problems
- //preventing counts from being hoisted as aliases. That is really correct - but it makes code worse for some examples.
- //if (!isContextDependent(expr) && expr->isIndependentOfScope())
- {
- if (!expr->isAction())// && !expr->isDataset() && !expr->isDatarow())
- {
- invariant = true;
- ForEachChild(i, expr)
- {
- IHqlExpression * cur = expr->queryChild(i);
- if (!isInvariant(cur))
- {
- invariant = false;
- break;
- }
- }
- }
- }
- break;
- }
- extra->cachedInvariant = true;
- extra->isInvariant = invariant;
- return invariant;
- }
- #if 0
- void TableInvariantTransformer::analyseExpr(IHqlExpression * expr)
- {
- expr = expr->queryBody();
- if (alreadyVisited(expr))
- return;
- node_operator op = expr->getOperator();
- switch (op)
- {
- case no_record:
- case no_constant:
- return;
- }
- if (isInvariant(expr) && !expr->isAttribute() && !expr->isConstant() && canHoistInvariant(expr))
- {
- TableInvariantInfo * extra = queryBodyExtra(expr);
- if (op == no_alias)
- {
- if (!expr->hasAttribute(globalAtom))
- extra->createAlias = true;
- }
- else
- extra->createAlias = true;
- return;
- }
- if (op == no_attr_expr)
- analyseChildren(expr);
- else
- NewHqlTransformer::analyseExpr(expr);
- }
- #else
- void TableInvariantTransformer::analyseExpr(IHqlExpression * expr)
- {
- expr = expr->queryBody();
- TableInvariantInfo * extra = queryBodyExtra(expr);
- if (alreadyVisited(expr))
- return;
- //More - these need to be handled properly...
- node_operator op = expr->getOperator();
- switch (op)
- {
- case no_record:
- case no_constant:
- return;
- }
- //We are trying to ensure that any expressions that don't access fields that are dependent on the activeDatasets/context are only
- //evaluated once => check for active dataset rather than any dataset
- bool candidate = false;
- if (!isContextDependent(expr) && !expr->isAttribute())
- {
- if (isInlineTrivialDataset(expr) && !expr->isConstant())
- {
- candidate = (op != no_null);
- }
- else
- {
- if (!containsActiveDataset(expr))
- {
- //MORE: We should be able to hoist constant datasets (e.g., temptables), but it causes problems
- //e.g., stops items it contains from being aliased. So
- if (!expr->isAction() && !expr->isDataset() && !expr->isDatarow())
- {
- switch (op)
- {
- case no_alias:
- if (!expr->hasAttribute(globalAtom))
- extra->createAlias = true;
- return;
- default:
- //MORE: We should be able to hoist constant datasets (e.g., temptables), but it causes problems
- //e.g., stops items it contains from being aliased.
- candidate = !expr->isConstant();
- break;
- }
- }
- }
- }
- if (candidate && canHoistInvariant(expr))
- {
- extra->createAlias = true;
- return;
- }
- }
- if (op == no_attr_expr)
- analyseChildren(expr);
- else
- NewHqlTransformer::analyseExpr(expr);
- }
- #endif
- bool TableInvariantTransformer::isAlwaysAlias(IHqlExpression * expr)
- {
- if (queryBodyExtra(expr)->createAlias)
- return true;
- switch (expr->getOperator())
- {
- case no_alias:
- case no_getresult: // these are commoned up in the code generator, so don't do it twice.
- case no_getgraphresult:
- case no_getgraphloopresult:
- return true;
- }
- return false;
- }
- bool TableInvariantTransformer::isTrivialAlias(IHqlExpression * expr)
- {
- switch (expr->getOperator())
- {
- case no_cast:
- case no_implicitcast:
- //Don't create aliases for items that are simply integral casts of other aliases.
- {
- ITypeInfo * type = expr->queryType();
- if (type->isInteger())
- {
- IHqlExpression * cast = expr->queryChild(0);
- ITypeInfo * castType = cast->queryType();
- if (castType->isInteger() && isAlwaysAlias(cast))
- {
- switch (type->getSize())
- {
- case 1: case 2: case 4: case 8:
- return true;
- }
- }
- }
- break;
- }
- case no_not:
- {
- IHqlExpression * child = expr->queryChild(0);
- if (isAlwaysAlias(child))
- return true;
- break;
- }
- }
- return false;
- }
- IHqlExpression * TableInvariantTransformer::createTransformed(IHqlExpression * expr)
- {
- if (expr->getOperator() == no_alias)
- {
- OwnedHqlExpr newChild = transform(expr->queryChild(0));
- if (newChild->getOperator() == no_alias)
- return newChild.getClear();
- }
- OwnedHqlExpr transformed = NewHqlTransformer::createTransformed(expr);
- if (queryBodyExtra(expr)->createAlias)
- {
- if (!isTrivialAlias(expr))
- {
- OwnedHqlExpr attr = createAttribute(globalAtom);
- if (transformed->getOperator() == no_alias)
- transformed.set(transformed->queryChild(0));
- return createAlias(transformed->queryBody(), attr);
- }
- }
- return transformed.getClear();
- }
- //---------------------------------------------------------------------------
- IHqlExpression * spotTableInvariant(IHqlExpression * expr)
- {
- TableInvariantTransformer transformer;
- transformer.analyse(expr, 0);
- return transformer.transformRoot(expr);
- }
- IHqlExpression * spotTableInvariantChildren(IHqlExpression * expr)
- {
- TableInvariantTransformer transformer;
- ForEachChild(i1, expr)
- transformer.analyse(expr->queryChild(i1), 0);
- return transformer.transformRoot(expr);
- }
- //---------------------------------------------------------------------------
- static HqlTransformerInfo globalAliasTransformerInfo("GlobalAliasTransformer");
- GlobalAliasTransformer::GlobalAliasTransformer() : NewHqlTransformer(globalAliasTransformerInfo)
- {
- insideGlobal = false;
- }
- void GlobalAliasTransformer::analyseExpr(IHqlExpression * expr)
- {
- if (!containsAlias(expr))
- return;
- bool wasInsideGlobal = insideGlobal;
- GlobalAliasInfo * extra = queryBodyExtra(expr);
- extra->numUses++;
- if (expr->getOperator() == no_alias)
- {
- if (expr->hasAttribute(globalAtom))
- {
- // assertex(!containsActiveDataset(expr) || isInlineTrivialDataset(expr));
- if (!insideGlobal)
- extra->isOuter = true;
- }
- if (extra->numUses > 1)
- return;
- if (extra->isOuter)
- insideGlobal = true;
- }
- else
- {
- //ugly, but we need to walk children more than once even if we've already been here.
- //What is important is if visited >1 or occur globally, so can short circuit based on that condition.
- //This currently links too many times because subsequent cse generation may common up multiple uses of the same item
- //but it's not too bad.
- //We could rerun this again if that was a major issue.
- if (insideGlobal)
- {
- if (extra->numUses > 2)
- return; // may need to visit children more than once so that alias is linked twice.
- }
- else
- {
- if (extra->isOuter && (extra->numUses > 2))
- return;
- extra->isOuter = true;
- }
- }
- if (expr->getOperator() == no_attr_expr)
- analyseChildren(expr);
- else
- NewHqlTransformer::analyseExpr(expr);
- insideGlobal = wasInsideGlobal;
- }
- IHqlExpression * GlobalAliasTransformer::createTransformed(IHqlExpression * expr)
- {
- OwnedHqlExpr transformed = NewHqlTransformer::createTransformed(expr);
- if ((expr->getOperator() == no_alias))
- {
- GlobalAliasInfo * extra = queryBodyExtra(expr);
- if (expr->hasAttribute(globalAtom))
- {
- if (!extra->isOuter)
- {
- if (extra->numUses == 1)
- return LINK(transformed->queryChild(0));
- if (!expr->hasAttribute(localAtom))
- return appendLocalAttribute(transformed);
- }
- else if (expr->hasAttribute(localAtom))
- {
- //Should never occur - but just about conceivable that some kind of constant folding
- //might cause a surrounding global alias to be removed.
- return removeLocalAttribute(transformed);
- }
- }
- else
- {
- if ((extra->numUses == 1) && !expr->hasAttribute(internalAtom))
- return LINK(transformed->queryChild(0));
- }
- }
- return transformed.getClear();
- }
- //---------------------------------------------------------------------------
- IHqlExpression * optimizeActivityAliasReferences(IHqlExpression * expr)
- {
- if (!containsAlias(expr))
- return LINK(expr);
- unsigned first = getFirstActivityArgument(expr);
- unsigned last = first + getNumActivityArguments(expr);
- bool foundAlias = false;
- ForEachChild(i1, expr)
- {
- IHqlExpression * cur = expr->queryChild(i1);
- if (((i1 < first) || (i1 >= last)) && containsAlias(cur))
- {
- foundAlias = true;
- break;
- }
- }
- if (!foundAlias)
- return LINK(expr);
- GlobalAliasTransformer transformer;
- ForEachChild(i2, expr)
- {
- IHqlExpression * cur = expr->queryChild(i2);
- if (((i2 < first) || (i2 >= last)) && containsAlias(cur))
- transformer.analyse(cur, 0);
- }
- HqlExprArray args;
- ForEachChild(i3, expr)
- {
- IHqlExpression * cur = expr->queryChild(i3);
- if ((i3 < first) || (i3 >= last))
- args.append(*transformer.transformRoot(cur));
- else
- args.append(*LINK(cur));
- }
- return cloneOrLink(expr, args);
- }
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