protected internal override void VisitStObj(StObj inst)
{
base.VisitStObj(inst);
if (EarlyExpressionTransforms.StObjToStLoc(inst, context))
{
context.RequestRerun();
return;
}
TransformAssignment.HandleCompoundAssign(inst, context);
}
protected internal override void VisitCall(Call inst)
{
var expr = EarlyExpressionTransforms.HandleCall(inst, context);
if (expr != null)
{
// The resulting expression may trigger further rules, so continue visiting the replacement:
expr.AcceptVisitor(this);
}
else
{
base.VisitCall(inst);
TransformAssignment.HandleCompoundAssign(inst, context);
}
}
protected internal override void VisitLdObj(LdObj inst)
{
base.VisitLdObj(inst);
EarlyExpressionTransforms.AddressOfLdLocToLdLoca(inst, context);
if (EarlyExpressionTransforms.LdObjToLdLoc(inst, context))
{
return;
}
if (TransformDecimalFieldToConstant(inst, out LdcDecimal decimalConstant))
{
context.Step("TransformDecimalFieldToConstant", inst);
inst.ReplaceWith(decimalConstant);
return;
}
}
protected internal override void VisitStObj(StObj inst)
{
if (IsDisplayClassFieldAccess(inst.Target, out var v, out var displayClass, out var field)) {
VariableToDeclare vd = displayClass.VariablesToDeclare[(IField)field.MemberDefinition];
if (vd.CanPropagate && vd.Initializers.Contains(inst)) {
if (inst.Parent is Block containingBlock) {
context.Step($"Remove initializer of {v.Name}.{vd.Name} due to propagation", inst);
containingBlock.Instructions.Remove(inst);
return;
}
}
}
base.VisitStObj(inst);
EarlyExpressionTransforms.StObjToStLoc(inst, context);
}
protected internal override void VisitStObj(StObj inst)
{
base.VisitStObj(inst);
if (EarlyExpressionTransforms.StObjToStLoc(inst, context))
{
context.RequestRerun();
return;
}
if (inst.Value is BinaryNumericInstruction binary &&
binary.Left.MatchLdObj(out ILInstruction target, out IType t) &&
inst.Target.Match(target).Success &&
SemanticHelper.IsPure(target.Flags) &&
CompoundAssignmentInstruction.IsBinaryCompatibleWithType(binary, t))
{
context.Step("compound assignment", inst);
// stobj(target, binary.op(ldobj(target), ...))
// => compound.op(target, ...)
inst.ReplaceWith(new CompoundAssignmentInstruction(
binary, binary.Left, binary.Right,
t, CompoundAssignmentType.EvaluatesToNewValue));
}
}
protected internal override void VisitStObj(StObj inst)
{
inst.Value.AcceptVisitor(this);
if (inst.Parent is Block)
{
if (IsParameterAssignment(inst, out var displayClass, out var field, out var parameter))
{
context.Step($"Detected parameter assignment {parameter.Name}", inst);
displayClass.Variables.Add((IField)field.MemberDefinition, parameter);
instructionsToRemove.Add(inst);
return;
}
if (IsDisplayClassAssignment(inst, out displayClass, out field, out var variable))
{
context.Step($"Detected display-class assignment {variable.Name}", inst);
displayClass.Variables.Add((IField)field.MemberDefinition, variable);
instructionsToRemove.Add(inst);
return;
}
}
inst.Target.AcceptVisitor(this);
EarlyExpressionTransforms.StObjToStLoc(inst, context);
}
protected internal override void VisitLdObj(LdObj inst)
{
base.VisitLdObj(inst);
EarlyExpressionTransforms.LdObjToLdLoc(inst, context);
}
protected internal override void VisitComp(Comp inst)
{
// "logic.not(arg)" is sugar for "comp(arg != ldc.i4 0)"
if (inst.MatchLogicNot(out var arg))
{
VisitLogicNot(inst, arg);
return;
}
else if (inst.Kind == ComparisonKind.Inequality && inst.LiftingKind == ComparisonLiftingKind.None &&
inst.Right.MatchLdcI4(0) && (IfInstruction.IsInConditionSlot(inst) || inst.Left is Comp)
)
{
// if (comp(x != 0)) ==> if (x)
// comp(comp(...) != 0) => comp(...)
context.Step("Remove redundant comp(... != 0)", inst);
inst.Left.AddILRange(inst);
inst.ReplaceWith(inst.Left);
inst.Left.AcceptVisitor(this);
return;
}
base.VisitComp(inst);
if (inst.IsLifted)
{
return;
}
EarlyExpressionTransforms.FixComparisonKindLdNull(inst, context);
var rightWithoutConv = inst.Right.UnwrapConv(ConversionKind.SignExtend).UnwrapConv(ConversionKind.ZeroExtend);
if (rightWithoutConv.MatchLdcI4(0) &&
inst.Sign == Sign.Unsigned &&
(inst.Kind == ComparisonKind.GreaterThan || inst.Kind == ComparisonKind.LessThanOrEqual))
{
if (inst.Kind == ComparisonKind.GreaterThan)
{
context.Step("comp.unsigned(left > ldc.i4 0) => comp(left != ldc.i4 0)", inst);
inst.Kind = ComparisonKind.Inequality;
VisitComp(inst);
return;
}
else if (inst.Kind == ComparisonKind.LessThanOrEqual)
{
context.Step("comp.unsigned(left <= ldc.i4 0) => comp(left == ldc.i4 0)", inst);
inst.Kind = ComparisonKind.Equality;
VisitComp(inst);
return;
}
}
else if (rightWithoutConv.MatchLdcI4(0) && inst.Kind.IsEqualityOrInequality())
{
if (inst.Left.MatchLdLen(StackType.I, out ILInstruction array))
{
// comp.unsigned(ldlen array == conv i4->i(ldc.i4 0))
// => comp(ldlen.i4 array == ldc.i4 0)
// This is a special case where the C# compiler doesn't generate conv.i4 after ldlen.
context.Step("comp(ldlen.i4 array == ldc.i4 0)", inst);
inst.InputType = StackType.I4;
inst.Left.ReplaceWith(new LdLen(StackType.I4, array).WithILRange(inst.Left));
inst.Right = rightWithoutConv;
}
else if (inst.Left is Conv conv && conv.TargetType == PrimitiveType.I && conv.Argument.ResultType == StackType.O)
{
// C++/CLI sometimes uses this weird comparison with null:
context.Step("comp(conv o->i (ldloc obj) == conv i4->i <sign extend>(ldc.i4 0))", inst);
// -> comp(ldloc obj == ldnull)
inst.InputType = StackType.O;
inst.Left = conv.Argument;
inst.Right = new LdNull().WithILRange(inst.Right);
inst.Right.AddILRange(rightWithoutConv);
}
}
}
