/// <summary>
/// Determines whether a variable should be inlined in non-aggressive mode, even though it is not a generated variable.
/// </summary>
/// <param name="next">The next top-level expression</param>
/// <param name="loadInst">The load within 'next'</param>
/// <param name="inlinedExpression">The expression being inlined</param>
static bool NonAggressiveInlineInto(ILInstruction next, ILInstruction loadInst, ILInstruction inlinedExpression, ILVariable v)
{
Debug.Assert(loadInst.IsDescendantOf(next));
// decide based on the source expression being inlined
switch (inlinedExpression.OpCode)
{
case OpCode.DefaultValue:
case OpCode.StObj:
case OpCode.NumericCompoundAssign:
case OpCode.UserDefinedCompoundAssign:
case OpCode.Await:
return(true);
case OpCode.LdLoc:
if (v.StateMachineField == null && ((LdLoc)inlinedExpression).Variable.StateMachineField != null)
{
// Roslyn likes to put the result of fetching a state machine field into a temporary variable,
// so inline more aggressively in such cases.
return(true);
}
break;
}
var parent = loadInst.Parent;
if (NullableLiftingTransform.MatchNullableCtor(parent, out _, out _))
{
// inline into nullable ctor call in lifted operator
parent = parent.Parent;
}
if (parent is ILiftableInstruction liftable && liftable.IsLifted)
{
return(true); // inline into lifted operators
}
switch (parent.OpCode)
{
case OpCode.NullCoalescingInstruction:
if (NullableType.IsNullable(v.Type))
{
return(true); // inline nullables into ?? operator
}
break;
case OpCode.NullableUnwrap:
return(true); // inline into ?. operator
case OpCode.UserDefinedLogicOperator:
case OpCode.DynamicLogicOperatorInstruction:
return(true); // inline into (left slot of) user-defined && or || operator
case OpCode.DynamicGetMemberInstruction:
case OpCode.DynamicGetIndexInstruction:
case OpCode.LdObj:
if (parent.Parent.OpCode == OpCode.DynamicCompoundAssign)
{
return(true); // inline into dynamic compound assignments
}
break;
}
// decide based on the target into which we are inlining
switch (next.OpCode)
{
case OpCode.Leave:
case OpCode.YieldReturn:
return(parent == next);
case OpCode.IfInstruction:
while (parent.MatchLogicNot(out _))
{
parent = parent.Parent;
}
return(parent == next);
case OpCode.BlockContainer:
if (((BlockContainer)next).EntryPoint.Instructions[0] is SwitchInstruction switchInst)
{
next = switchInst;
goto case OpCode.SwitchInstruction;
}
else
{
return(false);
}
case OpCode.SwitchInstruction:
return(parent == next || (parent.MatchBinaryNumericInstruction(BinaryNumericOperator.Sub) && parent.Parent == next));
default:
return(false);
}
}
/// <summary>
/// Determines whether a variable should be inlined in non-aggressive mode, even though it is not a generated variable.
/// </summary>
/// <param name="next">The next top-level expression</param>
/// <param name="v">The variable being eliminated by inlining.</param>
/// <param name="inlinedExpression">The expression being inlined</param>
static bool NonAggressiveInlineInto(ILInstruction next, FindResult findResult, ILInstruction inlinedExpression, ILVariable v)
{
if (findResult.Type == FindResultType.NamedArgument)
{
var originalStore = (StLoc)inlinedExpression.Parent;
return(!originalStore.ILStackWasEmpty);
}
Debug.Assert(findResult.Type == FindResultType.Found);
var loadInst = findResult.LoadInst;
Debug.Assert(loadInst.IsDescendantOf(next));
// decide based on the source expression being inlined
switch (inlinedExpression.OpCode)
{
case OpCode.DefaultValue:
case OpCode.StObj:
case OpCode.NumericCompoundAssign:
case OpCode.UserDefinedCompoundAssign:
case OpCode.Await:
case OpCode.SwitchInstruction:
return(true);
case OpCode.LdLoc:
if (v.StateMachineField == null && ((LdLoc)inlinedExpression).Variable.StateMachineField != null)
{
// Roslyn likes to put the result of fetching a state machine field into a temporary variable,
// so inline more aggressively in such cases.
return(true);
}
break;
}
if (inlinedExpression.ResultType == StackType.Ref)
{
// VB likes to use ref locals for compound assignment
// (the C# compiler uses ref stack slots instead).
// We want to avoid unnecessary ref locals, so we'll always inline them if possible.
return(true);
}
var parent = loadInst.Parent;
if (NullableLiftingTransform.MatchNullableCtor(parent, out _, out _))
{
// inline into nullable ctor call in lifted operator
parent = parent.Parent;
}
if (parent is ILiftableInstruction liftable && liftable.IsLifted)
{
return(true); // inline into lifted operators
}
// decide based on the new parent into which we are inlining:
switch (parent.OpCode)
{
case OpCode.NullCoalescingInstruction:
if (NullableType.IsNullable(v.Type))
{
return(true); // inline nullables into ?? operator
}
break;
case OpCode.NullableUnwrap:
return(true); // inline into ?. operator
case OpCode.UserDefinedLogicOperator:
case OpCode.DynamicLogicOperatorInstruction:
return(true); // inline into (left slot of) user-defined && or || operator
case OpCode.DynamicGetMemberInstruction:
case OpCode.DynamicGetIndexInstruction:
if (parent.Parent.OpCode == OpCode.DynamicCompoundAssign)
{
return(true); // inline into dynamic compound assignments
}
break;
case OpCode.DynamicCompoundAssign:
return(true);
case OpCode.GetPinnableReference:
case OpCode.LocAllocSpan:
return(true); // inline size-expressions into localloc.span
case OpCode.Call:
case OpCode.CallVirt:
// Aggressive inline into property/indexer getter calls for compound assignment calls
// (The compiler generates locals for these because it doesn't want to evalute the args twice for getter+setter)
if (parent.SlotInfo == CompoundAssignmentInstruction.TargetSlot)
{
return(true);
}
if (((CallInstruction)parent).Method is SyntheticRangeIndexAccessor)
{
return(true);
}
break;
case OpCode.CallIndirect when loadInst.SlotInfo == CallIndirect.FunctionPointerSlot:
return(true);
case OpCode.LdElema:
if (((LdElema)parent).WithSystemIndex)
{
return(true);
}
break;
case OpCode.Leave:
case OpCode.YieldReturn:
return(true);
case OpCode.SwitchInstruction:
//case OpCode.BinaryNumericInstruction when parent.SlotInfo == SwitchInstruction.ValueSlot:
case OpCode.StringToInt when parent.SlotInfo == SwitchInstruction.ValueSlot:
return(true);
case OpCode.MatchInstruction when((MatchInstruction)parent).IsDeconstructTuple:
return(true);
}
// decide based on the top-level target instruction into which we are inlining:
switch (next.OpCode)
{
case OpCode.IfInstruction:
while (parent.MatchLogicNot(out _))
{
parent = parent.Parent;
}
return(parent == next);
default:
return(false);
}
}
/// <summary>
/// Determines whether a variable should be inlined in non-aggressive mode, even though it is not a generated variable.
/// </summary>
/// <param name="next">The next top-level expression</param>
/// <param name="v">The variable being eliminated by inlining.</param>
/// <param name="inlinedExpression">The expression being inlined</param>
static bool NonAggressiveInlineInto(ILInstruction next, FindResult findResult, ILInstruction inlinedExpression, ILVariable v)
{
if (findResult.Type == FindResultType.NamedArgument)
{
var originalStore = (StLoc)inlinedExpression.Parent;
return(!originalStore.ILStackWasEmpty);
}
Debug.Assert(findResult.Type == FindResultType.Found);
var loadInst = findResult.LoadInst;
Debug.Assert(loadInst.IsDescendantOf(next));
// decide based on the source expression being inlined
switch (inlinedExpression.OpCode)
{
case OpCode.DefaultValue:
case OpCode.StObj:
case OpCode.NumericCompoundAssign:
case OpCode.UserDefinedCompoundAssign:
case OpCode.Await:
return(true);
case OpCode.LdLoc:
if (v.StateMachineField == null && ((LdLoc)inlinedExpression).Variable.StateMachineField != null)
{
// Roslyn likes to put the result of fetching a state machine field into a temporary variable,
// so inline more aggressively in such cases.
return(true);
}
break;
}
var parent = loadInst.Parent;
if (NullableLiftingTransform.MatchNullableCtor(parent, out _, out _))
{
// inline into nullable ctor call in lifted operator
parent = parent.Parent;
}
if (parent is ILiftableInstruction liftable && liftable.IsLifted)
{
return(true); // inline into lifted operators
}
// decide based on the new parent into which we are inlining:
switch (parent.OpCode)
{
case OpCode.NullCoalescingInstruction:
if (NullableType.IsNullable(v.Type))
{
return(true); // inline nullables into ?? operator
}
break;
case OpCode.NullableUnwrap:
return(true); // inline into ?. operator
case OpCode.UserDefinedLogicOperator:
case OpCode.DynamicLogicOperatorInstruction:
return(true); // inline into (left slot of) user-defined && or || operator
case OpCode.DynamicGetMemberInstruction:
case OpCode.DynamicGetIndexInstruction:
if (parent.Parent.OpCode == OpCode.DynamicCompoundAssign)
{
return(true); // inline into dynamic compound assignments
}
break;
case OpCode.DynamicCompoundAssign:
return(true);
case OpCode.ArrayToPointer:
case OpCode.LocAllocSpan:
return(true); // inline size-expressions into localloc.span
case OpCode.Call:
case OpCode.CallVirt:
// Aggressive inline into property/indexer getter calls for compound assignment calls
// (The compiler generates locals for these because it doesn't want to evalute the args twice for getter+setter)
if (parent.SlotInfo == CompoundAssignmentInstruction.TargetSlot)
{
return(true);
}
break;
}
// decide based on the top-level target instruction into which we are inlining:
switch (next.OpCode)
{
case OpCode.Leave:
case OpCode.YieldReturn:
return(parent == next);
case OpCode.IfInstruction:
while (parent.MatchLogicNot(out _))
{
parent = parent.Parent;
}
return(parent == next);
case OpCode.BlockContainer:
if (((BlockContainer)next).EntryPoint.Instructions[0] is SwitchInstruction switchInst)
{
next = switchInst;
goto case OpCode.SwitchInstruction;
}
else
{
return(false);
}
case OpCode.SwitchInstruction:
if (parent == next)
{
return(true);
}
if (parent.MatchBinaryNumericInstruction(BinaryNumericOperator.Sub) && parent.Parent == next)
{
return(true);
}
if (parent is StringToInt stringToInt && stringToInt.Parent == next)
{
return(true);
}
return(false);
default:
return(false);
}
}