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#include "codetree.hh"
namespace
{
using namespace FUNCTIONPARSERTYPES;
using namespace FPoptimizer_CodeTree;
/***************************/
/* LOGIC (AND, OR, NOT) */
/***************************/
struct ComparisonSetBase
{
enum { Lt_Mask = 0x1, // 1=less
Eq_Mask = 0x2, // 2=equal
Le_Mask = 0x3, // 1+2 = Less or Equal
Gt_Mask = 0x4, // 4=greater
Ne_Mask = 0x5, // 4+1 = Greater or Less, i.e. Not equal
Ge_Mask = 0x6 }; // 4+2 = Greater or Equal
static int Swap_Mask(int m) { return (m&Eq_Mask)
| ((m&Lt_Mask) ? Gt_Mask : 0)
| ((m&Gt_Mask) ? Lt_Mask : 0); }
enum RelationshipResult
{
Ok,
BecomeZero,
BecomeOne,
Suboptimal
};
enum ConditionType
{
cond_or,
cond_and,
cond_mul,
cond_add
};
};
template<typename Value_t>
struct ComparisonSet: public ComparisonSetBase /* For optimizing And, Or */
{
struct Comparison
{
CodeTree<Value_t> a;
CodeTree<Value_t> b;
int relationship;
Comparison() : a(),b(), relationship() {}
};
std::vector<Comparison> relationships;
struct Item
{
CodeTree<Value_t> value;
bool negated;
Item() : value(), negated(false) {}
};
std::vector<Item> plain_set;
int const_offset;
ComparisonSet():
relationships(),
plain_set(),
const_offset(0)
{
}
RelationshipResult AddItem(
const CodeTree<Value_t>& a,
bool negated,
ConditionType type)
{
for(size_t c=0; c<plain_set.size(); ++c)
if(plain_set[c].value.IsIdenticalTo(a))
{
if(negated != plain_set[c].negated)
{
switch(type)
{
case cond_or:
return BecomeOne;
case cond_add:
plain_set.erase(plain_set.begin() + c);
const_offset += 1;
return Suboptimal;
case cond_and:
case cond_mul:
return BecomeZero;
}
}
return Suboptimal;
}
Item pole;
pole.value = a;
pole.negated = negated;
plain_set.push_back(pole);
return Ok;
}
/* Note: Trees are passed by-value so we can use swap() on them safely. */
RelationshipResult AddRelationship
(CodeTree<Value_t> a,
CodeTree<Value_t> b,
int reltype,
ConditionType type)
{
switch(type)
{
case cond_or:
if(reltype == 7) return BecomeOne;
break;
case cond_add:
if(reltype == 7) { const_offset += 1; return Suboptimal; }
break;
case cond_and:
case cond_mul:
if(reltype == 0) return BecomeZero;
break;
}
if(!(a.GetHash() < b.GetHash()))
{
a.swap(b);
reltype = Swap_Mask(reltype);
}
for(size_t c=0; c<relationships.size(); ++c)
{
if(relationships[c].a.IsIdenticalTo(a)
&& relationships[c].b.IsIdenticalTo(b))
{
switch(type)
{
case cond_or:
{
int newrel = relationships[c].relationship | reltype;
if(newrel == 7) return BecomeOne;
relationships[c].relationship = newrel;
break;
}
case cond_and:
case cond_mul:
{
int newrel = relationships[c].relationship & reltype;
if(newrel == 0) return BecomeZero;
relationships[c].relationship = newrel;
break;
}
case cond_add:
{
int newrel_or = relationships[c].relationship | reltype;
int newrel_and = relationships[c].relationship & reltype;
if(newrel_or == 5 // < + >
&& newrel_and == 0)
{
// (x<y) + (x>y) = x!=y
relationships[c].relationship = Ne_Mask;
return Suboptimal;
}
if(newrel_or == 7
&& newrel_and == 0)
{
// (x<y) + (x>=y) = 1
// (x<=y) + (x>y) = 1
// (x=y) + (x!=y) = 1
const_offset += 1;
relationships.erase(relationships.begin()+c);
return Suboptimal;
}
if(newrel_or == 7
&& newrel_and == Eq_Mask)
{
// (x<=y) + (x>=y) = 1 + (x=y)
relationships[c].relationship = Eq_Mask;
const_offset += 1;
return Suboptimal;
}
continue;
}
}
return Suboptimal;
}
}
Comparison comp;
comp.a = a;
comp.b = b;
comp.relationship = reltype;
relationships.push_back(comp);
return Ok;
}
};
template<typename Value_t, typename CondType> /* ComparisonSet::ConditionType */
bool ConstantFolding_LogicCommon(
CodeTree<Value_t>& tree, CondType cond_type, bool is_logical)
{
bool should_regenerate = false;
ComparisonSet<Value_t> comp;
for(size_t a=0; a<tree.GetParamCount(); ++a)
{
typename ComparisonSetBase::RelationshipResult
change = ComparisonSetBase::Ok;
const CodeTree<Value_t>& atree = tree.GetParam(a);
switch(atree.GetOpcode())
{
case cEqual:
change = comp.AddRelationship(atree.GetParam(0), atree.GetParam(1), ComparisonSetBase::Eq_Mask, cond_type);
break;
case cNEqual:
change = comp.AddRelationship(atree.GetParam(0), atree.GetParam(1), ComparisonSetBase::Ne_Mask, cond_type);
break;
case cLess:
change = comp.AddRelationship(atree.GetParam(0), atree.GetParam(1), ComparisonSetBase::Lt_Mask, cond_type);
break;
case cLessOrEq:
change = comp.AddRelationship(atree.GetParam(0), atree.GetParam(1), ComparisonSetBase::Le_Mask, cond_type);
break;
case cGreater:
change = comp.AddRelationship(atree.GetParam(0), atree.GetParam(1), ComparisonSetBase::Gt_Mask, cond_type);
break;
case cGreaterOrEq:
change = comp.AddRelationship(atree.GetParam(0), atree.GetParam(1), ComparisonSetBase::Ge_Mask, cond_type);
break;
case cNot:
change = comp.AddItem(atree.GetParam(0), true, cond_type);
break;
case cNotNot:
change = comp.AddItem(atree.GetParam(0), false, cond_type);
break;
default:
if(is_logical || IsLogicalValue(atree))
change = comp.AddItem(atree, false, cond_type);
}
switch(change)
{
ReplaceTreeWithZero:
tree.ReplaceWithImmed(0);
return true;
ReplaceTreeWithOne:
tree.ReplaceWithImmed(1);
return true;
case ComparisonSetBase::Ok: // ok
break;
case ComparisonSetBase::BecomeZero: // whole set was invalidated
goto ReplaceTreeWithZero;
case ComparisonSetBase::BecomeOne: // whole set was validated
goto ReplaceTreeWithOne;
case ComparisonSetBase::Suboptimal: // something was changed
should_regenerate = true;
break;
}
}
if(should_regenerate)
{
#ifdef DEBUG_SUBSTITUTIONS
std::cout << "Before ConstantFolding_LogicCommon: "; DumpTree(tree);
std::cout << "\n";
#endif
if(is_logical)
{
tree.DelParams(); // delete all params
}
else
{
// Delete only logical params
for(size_t a=tree.GetParamCount(); a-- > 0; )
{
const CodeTree<Value_t>& atree = tree.GetParam(a);
if(IsLogicalValue(atree))
tree.DelParam(a);
}
}
for(size_t a=0; a<comp.plain_set.size(); ++a)
{
if(comp.plain_set[a].negated)
{
CodeTree<Value_t> r;
r.SetOpcode(cNot);
r.AddParamMove(comp.plain_set[a].value);
r.Rehash();
tree.AddParamMove(r);
}
else if(!is_logical)
{
CodeTree<Value_t> r;
r.SetOpcode(cNotNot);
r.AddParamMove(comp.plain_set[a].value);
r.Rehash();
tree.AddParamMove(r);
}
else
tree.AddParamMove(comp.plain_set[a].value);
}
for(size_t a=0; a<comp.relationships.size(); ++a)
{
CodeTree<Value_t> r;
r.SetOpcode(cNop); // dummy
switch(comp.relationships[a].relationship)
{
case ComparisonSetBase::Lt_Mask: r.SetOpcode( cLess ); break;
case ComparisonSetBase::Eq_Mask: r.SetOpcode( cEqual ); break;
case ComparisonSetBase::Gt_Mask: r.SetOpcode( cGreater ); break;
case ComparisonSetBase::Le_Mask: r.SetOpcode( cLessOrEq ); break;
case ComparisonSetBase::Ne_Mask: r.SetOpcode( cNEqual ); break;
case ComparisonSetBase::Ge_Mask: r.SetOpcode( cGreaterOrEq ); break;
}
r.AddParamMove(comp.relationships[a].a);
r.AddParamMove(comp.relationships[a].b);
r.Rehash();
tree.AddParamMove(r);
}
if(comp.const_offset != 0)
tree.AddParam( CodeTreeImmed( Value_t(comp.const_offset) ) );
#ifdef DEBUG_SUBSTITUTIONS
std::cout << "After ConstantFolding_LogicCommon: "; DumpTree(tree);
std::cout << "\n";
#endif
return true;
}
/*
Note: One thing this does not yet do, is to detect chains
such as x=y & y=z & x=z, which could be optimized
to x=y & x=z.
*/
return false;
}
/* ConstantFolding_AndLogic:
* (x > y) & (x >= y) --> (x > y)
* (x <= y) & (x >= y) --> (x = y)
* (x <= y) & (x > y) --> 0
* !x & !!x --> 0
* etc.
*/
template<typename Value_t>
bool ConstantFolding_AndLogic(CodeTree<Value_t>& tree)
{
assert(tree.GetOpcode() == cAnd || tree.GetOpcode() == cAbsAnd);
return ConstantFolding_LogicCommon(tree, ComparisonSetBase::cond_and, true );
}
/* ConstantFolding_OrLogic:
* (x > y) | (x >= y) --> (x >= y)
* (x <= y) | (x >= y) --> 1
* (x <= y) | (x > y) --> 1
* !x | !!x --> 1
* etc.
*/
template<typename Value_t>
bool ConstantFolding_OrLogic(CodeTree<Value_t>& tree)
{
assert(tree.GetOpcode() == cOr || tree.GetOpcode() == cAbsOr);
return ConstantFolding_LogicCommon(tree, ComparisonSetBase::cond_or, true );
}
/* ConstantFolding_AddLogic:
* (x <= y) + (x >= y) --> (x = y) + 1
* !x + !!x --> 1
* etc.
*/
template<typename Value_t>
bool ConstantFolding_AddLogicItems(CodeTree<Value_t>& tree)
{
assert(tree.GetOpcode() == cAdd);
return ConstantFolding_LogicCommon(tree, ComparisonSetBase::cond_add, false );
}
/* ConstantFolding_MulLogic:
* (x <= y) * (x >= y) --> (x = y)
* (x > y) * (x >= y) --> (x > y)
* !x * !!x --> 0
* etc.
*/
template<typename Value_t>
bool ConstantFolding_MulLogicItems(CodeTree<Value_t>& tree)
{
assert(tree.GetOpcode() == cMul);
return ConstantFolding_LogicCommon(tree, ComparisonSetBase::cond_mul, false );
}
}
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