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Merge pull request #1976 from pavgust/fix/hashcons-perf

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C++: HashCons: Further performance improvements
This commit is contained in:
Robert Marsh
2019-09-23 06:37:03 -07:00
committed by GitHub
parent a0ecbc555d 1c971d3f88
commit 90c91a78f8
1 changed files with 27 additions and 18 deletions
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45
cpp/ql/src/semmle/code/cpp/valuenumbering/HashCons.qll
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@@ -729,6 +729,18 @@ private predicate mk_AlignofExpr(HashCons child, AlignofExprOperator e) {
child = hashCons(e.getAChild())
}
/**
* Gets the hash cons of field initializer expressions [0..i), where i > 0, for
* the class aggregate literal `cal` of type `c`, where `head` is the hash cons
* of the i'th initializer expression.
*/
HC_Fields aggInitExprsUpTo(ClassAggregateLiteral cal, Class c, int i) {
exists(Field f, HashCons head, HC_Fields tail |
result = HC_FieldCons(c, i - 1, f, head, tail) and
mk_FieldCons(c, i - 1, f, head, tail, cal)
)
}
private predicate mk_FieldCons(
Class c, int i, Field f, HashCons hc, HC_Fields hcf, ClassAggregateLiteral cal
) {
@@ -738,12 +750,8 @@ private predicate mk_FieldCons(
e = cal.getFieldExpr(f).getFullyConverted() and
f.getInitializationOrder() = i and
(
exists(HashCons head, Field f2, HC_Fields tail |
hc = hashCons(e) and
hcf = HC_FieldCons(c, i - 1, f2, head, tail) and
f2.getInitializationOrder() = i - 1 and
mk_FieldCons(c, i - 1, f2, head, tail, cal)
)
hc = hashCons(e) and
hcf = aggInitExprsUpTo(cal, c, i)
or
hc = hashCons(e) and
i = 0 and
@@ -766,14 +774,7 @@ private predicate mk_ClassAggregateLiteral(Class c, HC_Fields hcf, ClassAggregat
analyzableClassAggregateLiteral(cal) and
c = cal.getUnspecifiedType() and
(
exists(HC_Fields tail, Expr e, Field f, int numChildren, HashCons eCons |
f.getInitializationOrder() = cal.getNumChild() - 1 and
e = cal.getFieldExpr(f).getFullyConverted() and
eCons = hashCons(e) and
numChildren = cal.getNumChild() and
hcf = HC_FieldCons(c, numChildren - 1, f, eCons, tail) and
mk_FieldCons(c, numChildren - 1, f, eCons, tail, cal)
)
hcf = aggInitExprsUpTo(cal, c, cal.getNumChild())
or
cal.getNumChild() = 0 and
hcf = HC_EmptyFields(c)
@@ -785,15 +786,23 @@ private predicate analyzableArrayAggregateLiteral(ArrayAggregateLiteral aal) {
strictcount(aal.getUnspecifiedType()) = 1
}
/**
* Gets the hash cons of array elements in [0..i), where i > 0, for
* the array aggregate literal `aal` of type `t`.
*/
private HC_Array arrayElemsUpTo(ArrayAggregateLiteral aal, Type t, int i) {
exists(HC_Array tail, HashCons head |
result = HC_ArrayCons(t, i - 1, head, tail) and
mk_ArrayCons(t, i - 1, head, tail, aal)
)
}
private predicate mk_ArrayCons(Type t, int i, HashCons hc, HC_Array hca, ArrayAggregateLiteral aal) {
analyzableArrayAggregateLiteral(aal) and
t = aal.getUnspecifiedType() and
hc = hashCons(aal.getChild(i)) and
(
exists(HC_Array tail, HashCons head |
hca = HC_ArrayCons(t, i - 1, head, tail) and
mk_ArrayCons(t, i - 1, head, tail, aal)
)
hca = arrayElemsUpTo(aal, t, i)
or
i = 0 and
hca = HC_EmptyArray(t)