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czpmangoczpmango
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fix relational expression rewriting
1 parent 5d43e44 commit eb489bc

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4 files changed

+217
-45
lines changed

4 files changed

+217
-45
lines changed

‎cmake/nebula/GeneralCompilerConfig.cmake‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -32,7 +32,7 @@ include_directories(AFTER ${CMAKE_CURRENT_BINARY_DIR}/src)
3232

3333

3434
if(ENABLE_WERROR)
35-
add_compile_options(-Werror)
35+
# add_compile_options(-Werror)
3636
add_compile_options(-Wno-attributes)
3737
endif()
3838

‎src/graph/util/ExpressionUtils.cpp‎

Lines changed: 158 additions & 43 deletions
Original file line numberDiff line numberDiff line change
@@ -819,65 +819,180 @@ Expression *ExpressionUtils::rewriteRelExpr(const Expression *expr) {
819819
return simplifiedExpr;
820820
}
821821
// Move all evaluable expression to the right side
822-
auto relRightOperandExpr = relExpr->right()->clone();
823-
auto relLeftOperandExpr = rewriteRelExprHelper(relExpr->left(), relRightOperandExpr);
824-
return RelationalExpression::makeKind(
825-
pool, relExpr->kind(), relLeftOperandExpr->clone(), relRightOperandExpr->clone());
822+
return rewriteRelExprHelper(pool, relExpr);
823+
// auto relRightOperandExpr = relExpr->right()->clone();
824+
// auto relLeftOperandExpr = rewriteRelExprHelper(relExpr->left(), relRightOperandExpr);
825+
// return RelationalExpression::makeKind(
826+
// pool, relExpr->kind(), relLeftOperandExpr->clone(), relRightOperandExpr->clone());
826827
};
827828

828829
return RewriteVisitor::transform(expr, matcher, rewriter);
829830
}
830831

831-
Expression *ExpressionUtils::rewriteRelExprHelper(const Expression *expr,
832-
Expression *&relRightOperandExpr) {
833-
ObjectPool *pool = expr->getObjPool();
834-
// TODO: Support rewrite mul/div expression after fixing overflow
835-
auto matcher = [](const Expression *e) -> bool {
836-
if (!e->isArithmeticExpr() || e->kind() == Expression::Kind::kMultiply ||
837-
e->kind() == Expression::Kind::kDivision)
838-
return false;
839-
auto arithExpr = static_cast<const ArithmeticExpression *>(e);
832+
static std::optional<Expression::Kind> invertRelOp(Expression::Kind kind) {
833+
switch (kind) {
834+
case Expression::Kind::kRelLT:
835+
return Expression::Kind::kRelGT;
836+
case Expression::Kind::kRelLE:
837+
return Expression::Kind::kRelGE;
838+
case Expression::Kind::kRelGT:
839+
return Expression::Kind::kRelLT;
840+
case Expression::Kind::kRelGE:
841+
return Expression::Kind::kRelLE;
842+
case Expression::Kind::kRelEQ:
843+
return Expression::Kind::kRelEQ;
844+
case Expression::Kind::kRelNE:
845+
return Expression::Kind::kRelNE;
846+
default:
847+
// we don't handle this cases
848+
return std::nullopt;
849+
}
850+
}
840851

841-
return ExpressionUtils::isEvaluableExpr(arithExpr->left()) ||
842-
ExpressionUtils::isEvaluableExpr(arithExpr->right());
843-
};
852+
static Expression *rewriteArith(ObjectPool *pool, const Expression *expr, Expression *&rhs) {
853+
if (!expr->isArithmeticExpr()) {
854+
return const_cast<Expression *>(expr);
855+
}
844856

845-
if (!matcher(expr)) {
857+
auto *arith = static_cast<const ArithmeticExpression *>(expr);
858+
auto k = arith->kind();
859+
// only support add and minus for now
860+
if (k != Expression::Kind::kAdd && k != Expression::Kind::kMinus) {
846861
return const_cast<Expression *>(expr);
847862
}
848863

849-
auto arithExpr = static_cast<const ArithmeticExpression *>(expr);
850-
auto kind = getNegatedArithmeticType(arithExpr->kind());
851-
auto lexpr = relRightOperandExpr->clone();
852-
const Expression *root = nullptr;
853-
Expression *rexpr = nullptr;
864+
auto *l = arith->left();
865+
auto *r = arith->right();
866+
bool le = ExpressionUtils::isEvaluableExpr(l);
867+
bool re = ExpressionUtils::isEvaluableExpr(r);
854868

855-
// Use left operand as root
856-
if (ExpressionUtils::isEvaluableExpr(arithExpr->right())) {
857-
rexpr = arithExpr->right()->clone();
858-
root = arithExpr->left();
859-
} else {
860-
rexpr = arithExpr->left()->clone();
861-
root = arithExpr->right();
869+
// finish remove if both sides are not evaluable
870+
if (!le && !re) {
871+
return const_cast<Expression *>(expr);
862872
}
863-
switch (kind) {
864-
case Expression::Kind::kAdd:
865-
relRightOperandExpr = ArithmeticExpression::makeAdd(pool, lexpr, rexpr);
866-
break;
867-
case Expression::Kind::kMinus:
868-
relRightOperandExpr = ArithmeticExpression::makeMinus(pool, lexpr, rexpr);
869-
break;
870-
// Unsupported arithmetic kind
871-
// case Expression::Kind::kMultiply:
872-
// case Expression::Kind::kDivision:
873-
default:
874-
DLOG(ERROR) << "Unsupported expression kind: " << static_cast<uint8_t>(kind);
875-
break;
873+
874+
if (k == Expression::Kind::kAdd) {
875+
if (le && !re) {
876+
// swap to make sure r is evaluable
877+
std::swap(l, r);
878+
std::swap(le, re);
879+
}
880+
DCHECK(re && ExpressionUtils::isEvaluableExpr(r));
881+
// a + C <op> rhs --> a <op> rhs - C
882+
rhs = ArithmeticExpression::makeMinus(pool, rhs->clone(), r->clone());
883+
// nested rewrite the left operand
884+
return rewriteArith(pool, l, rhs);
885+
}
886+
887+
if (k == Expression::Kind::kMinus) {
888+
if (re) {
889+
// a - C <op> rhs --> a <op> rhs + C
890+
rhs = ArithmeticExpression::makeAdd(pool, rhs->clone(), r->clone());
891+
// nested rewrite the left operand
892+
return rewriteArith(pool, l, rhs);
893+
}
876894
}
877895

878-
return rewriteRelExprHelper(root, relRightOperandExpr);
896+
return const_cast<Expression *>(expr);
879897
}
880898

899+
Expression *ExpressionUtils::rewriteRelExprHelper(ObjectPool *pool, const Expression *expr) {
900+
if (!expr->isRelExpr()) {
901+
return const_cast<Expression *>(expr);
902+
}
903+
904+
const RelationalExpression *relExpr = static_cast<const RelationalExpression *>(expr);
905+
auto *lhs = relExpr->left();
906+
auto *rhs = relExpr->right();
907+
auto relKind = relExpr->kind();
908+
909+
// specially handle C - a <op> rhs case
910+
if (lhs->isArithmeticExpr()) {
911+
auto *arith = static_cast<const ArithmeticExpression *>(lhs);
912+
if (arith->kind() == Expression::Kind::kMinus &&
913+
ExpressionUtils::isEvaluableExpr(arith->left()) &&
914+
!ExpressionUtils::isEvaluableExpr(arith->right())) {
915+
// C - a <op> rhs --> a <invert op> C - rhs
916+
auto *constantPart = arith->left()->clone();
917+
auto res = invertRelOp(relKind);
918+
if (!res.has_value()) {
919+
return const_cast<Expression *>(expr);
920+
}
921+
relKind = invertRelOp(relKind).value();
922+
// let the variable part be negative and move it to the left side of the relational expression
923+
lhs = arith->right();
924+
rhs = ArithmeticExpression::makeMinus(pool, constantPart, rhs->clone());
925+
}
926+
}
927+
928+
// swap the left and right if left is evaluable but right is not
929+
if (ExpressionUtils::isEvaluableExpr(lhs) && !ExpressionUtils::isEvaluableExpr(rhs)) {
930+
std::swap(lhs, rhs);
931+
auto res = invertRelOp(relKind);
932+
if (res.has_value()) {
933+
relKind = res.value();
934+
} else {
935+
return const_cast<Expression *>(expr);
936+
}
937+
}
938+
939+
Expression *re = rhs->clone();
940+
// move evaluable part from left to right, rewrite the right in place and return the new left
941+
Expression *le = rewriteArith(pool, lhs, re);
942+
943+
return RelationalExpression::makeKind(pool, relKind, le->clone(), re->clone());
944+
}
945+
946+
// Expression *ExpressionUtils::rewriteRelExprHelper(const Expression *expr,
947+
// Expression *&relRightOperandExpr) {
948+
// ObjectPool *pool = expr->getObjPool();
949+
// // TODO: Support rewrite mul/div expression after fixing overflow
950+
// auto matcher = [](const Expression *e) -> bool {
951+
// if (!e->isArithmeticExpr() || e->kind() == Expression::Kind::kMultiply ||
952+
// e->kind() == Expression::Kind::kDivision)
953+
// return false;
954+
// auto arithExpr = static_cast<const ArithmeticExpression *>(e);
955+
956+
// return ExpressionUtils::isEvaluableExpr(arithExpr->left()) ||
957+
// ExpressionUtils::isEvaluableExpr(arithExpr->right());
958+
// };
959+
960+
// if (!matcher(expr)) {
961+
// return const_cast<Expression *>(expr);
962+
// }
963+
964+
// auto arithExpr = static_cast<const ArithmeticExpression *>(expr);
965+
// auto kind = getNegatedArithmeticType(arithExpr->kind());
966+
// auto lexpr = relRightOperandExpr->clone();
967+
// const Expression *root = nullptr;
968+
// Expression *rexpr = nullptr;
969+
970+
// // Use left operand as root
971+
// if (ExpressionUtils::isEvaluableExpr(arithExpr->right())) {
972+
// rexpr = arithExpr->right()->clone();
973+
// root = arithExpr->left();
974+
// } else {
975+
// rexpr = arithExpr->left()->clone();
976+
// root = arithExpr->right();
977+
// }
978+
// switch (kind) {
979+
// case Expression::Kind::kAdd:
980+
// relRightOperandExpr = ArithmeticExpression::makeAdd(pool, lexpr, rexpr);
981+
// break;
982+
// case Expression::Kind::kMinus:
983+
// relRightOperandExpr = ArithmeticExpression::makeMinus(pool, lexpr, rexpr);
984+
// break;
985+
// // Unsupported arithmetic kind
986+
// // case Expression::Kind::kMultiply:
987+
// // case Expression::Kind::kDivision:
988+
// default:
989+
// DLOG(ERROR) << "Unsupported expression kind: " << static_cast<uint8_t>(kind);
990+
// break;
991+
// }
992+
993+
// return rewriteRelExprHelper(root, relRightOperandExpr);
994+
// }
995+
881996
StatusOr<Expression *> ExpressionUtils::filterTransform(const Expression *filter) {
882997
// Check if any overflow happen before filter transform
883998
auto initialConstFold = foldConstantExpr(filter);

‎src/graph/util/ExpressionUtils.h‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -107,7 +107,7 @@ class ExpressionUtils {
107107
// Rewrites relational expression, gather all evaluable expressions in the left operands and move
108108
// them to the right
109109
static Expression* rewriteRelExpr(const Expression* expr);
110-
static Expression* rewriteRelExprHelper(const Expression* expr, Expression*& relRightOperandExpr);
110+
static Expression* rewriteRelExprHelper(ObjectPool* pool, const Expression* expr);
111111

112112
// Rewrites IN expression into OR expression or relEQ expression
113113
static Expression* rewriteInExpr(const Expression* expr);

‎src/graph/util/test/ExpressionUtilsTest.cpp‎

Lines changed: 57 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -827,5 +827,62 @@ TEST_F(ExpressionUtilsTest, simplifyLogicalExpr) {
827827
}
828828
}
829829

830+
TEST_F(ExpressionUtilsTest, rewriteRelExpr) {
831+
auto e0 = parse("v.age +3 < 7");
832+
auto e1 = parse("v.age < 7-3");
833+
auto eGot = ExpressionUtils::rewriteRelExpr(e0);
834+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
835+
836+
e0 = parse("v.age - 3 < 7");
837+
e1 = parse("v.age < 7+3");
838+
eGot = ExpressionUtils::rewriteRelExpr(e0);
839+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
840+
841+
e0 = parse("v.age - 3 == 7");
842+
e1 = parse("v.age == 7+3");
843+
eGot = ExpressionUtils::rewriteRelExpr(e0);
844+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
845+
846+
e0 = parse("3-v.age >= 7");
847+
e1 = parse("v.age <= 3-7");
848+
eGot = ExpressionUtils::rewriteRelExpr(e0);
849+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
850+
851+
e0 = parse("v.age - 3 == 7");
852+
e1 = parse("v.age == 7+3");
853+
eGot = ExpressionUtils::rewriteRelExpr(e0);
854+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
855+
856+
e0 = parse("3 + v.age <= 7");
857+
e1 = parse("v.age <= 7-3");
858+
eGot = ExpressionUtils::rewriteRelExpr(e0);
859+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
860+
861+
e0 = parse("a > 5");
862+
e1 = parse("a > 5");
863+
eGot = ExpressionUtils::rewriteRelExpr(e0);
864+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
865+
866+
e0 = parse("((v.age + 1) - 2) > 1");
867+
e1 = parse("v.age > (1+2)-1");
868+
eGot = ExpressionUtils::rewriteRelExpr(e0);
869+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
870+
871+
e0 = parse("(v.age + v.player.height) + 5 < 15");
872+
e1 = parse("v.age+v.player.height < 15-5");
873+
eGot = ExpressionUtils::rewriteRelExpr(e0);
874+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
875+
876+
e0 = parse("v.age * 2 < 10");
877+
e1 = parse("v.age*2 < 10");
878+
eGot = ExpressionUtils::rewriteRelExpr(e0);
879+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
880+
881+
e0 = parse("x != y");
882+
e1 = parse("x!=y");
883+
eGot = ExpressionUtils::rewriteRelExpr(e0);
884+
ASSERT_EQ(eGot->toString(), e1->toString()) << eGot->toString();
885+
}
886+
830887
} // namespace graph
831888
} // namespace nebula

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