/// <summary>
/// Lowers get field operations into separate SSA values.
/// </summary>
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData _,
GetField getField)
{
if (getField.Type is StructureType structureType)
{
foreach (var(_, fieldAccess) in structureType)
{
// Get the source value
var value = context.GetValue(
context.Block,
new FieldRef(
getField.ObjectValue,
new FieldSpan(
getField.FieldSpan.Index + fieldAccess.Index)));
// Bind the mapped SSA value
context.SetValue(
context.Block,
new FieldRef(getField, fieldAccess),
value);
}
context.Remove(getField);
}
else
{
var getFieldValue = context.GetValue(
context.Block,
new FieldRef(getField.ObjectValue, getField.FieldSpan));
context.ReplaceAndRemove(getField, getFieldValue);
}
}
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData _,
Predicate predicate)
{
foreach (var(_, fieldAccess) in predicate.Type as StructureType)
{
// Build a new if predicate which might become dead in the future
var trueValue = context.GetValue(
context.Block,
new FieldRef(predicate.TrueValue, fieldAccess));
var falseValue = context.GetValue(
context.Block,
new FieldRef(predicate.FalseValue, fieldAccess));
var newPredicate = context.Builder.CreatePredicate(
predicate.Location,
predicate.Condition,
trueValue,
falseValue);
// Bind the new if predicate
context.SetValue(
context.Block,
new FieldRef(predicate, fieldAccess),
newPredicate);
}
}
/// <summary>
/// Lowers structure store operations into distinct stores for each field.
/// </summary>
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData _,
Store store)
{
var builder = context.Builder;
foreach (var(_, fieldAccess) in store.Value.Type as StructureType)
{
// Update target address
var address = builder.CreateLoadFieldAddress(
store.Location,
store.Target,
new FieldSpan(fieldAccess));
// Load the currently registered SSA value and store it
var value = context.GetValue(
context.Block,
new FieldRef(store.Value, fieldAccess));
var loweredStore = builder.CreateStore(
store.Location,
address,
value);
context.MarkConverted(loweredStore);
}
context.Remove(store);
}
/// <summary>
/// Converts a store node into an SSA value.
/// </summary>
private static void Convert(
SSARewriterContext <Value> context,
ConstructionData data,
Store store)
{
if (!data.TryGetConverted(store.Target, out var storeRef))
{
return;
}
Value ssaValue = store.Value;
if (!storeRef.IsDirect)
{
ssaValue = context.GetValue(context.Block, storeRef.Source);
ssaValue = context.Builder.CreateSetField(
store.Location,
ssaValue,
storeRef.FieldSpan,
store.Value);
}
context.SetValue(context.Block, storeRef.Source, ssaValue);
context.Remove(store);
}
/// <summary>
/// Lowers set field operations into separate SSA values.
/// </summary>
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData _,
SetField setField)
{
foreach (var(_, fieldAccess) in setField.Type as StructureType)
{
Value value;
if (setField.FieldSpan.Contains(fieldAccess))
{
// Get value from the source value
value = setField.Value;
if (value.Type is StructureType)
{
var getFieldAccess = fieldAccess.Subtract(
setField.FieldSpan.Index);
value = context.GetValue(
context.Block,
new FieldRef(value, getFieldAccess));
}
}
else
{
// Load the currently registered SSA value
value = context.GetValue(
context.Block,
new FieldRef(setField.ObjectValue, fieldAccess));
}
// Bind the mapped SSA value
context.SetValue(
context.Block,
new FieldRef(setField, fieldAccess),
value);
}
context.Remove(setField);
}
/// <summary>
/// Converts a load node into an SSA value.
/// </summary>
private static void Convert(
SSARewriterContext <Value> context,
ConstructionData data,
Load load)
{
if (data.TryGetConverted(load.Source, out var loadRef))
{
var ssaValue = context.GetValue(context.Block, loadRef.Source);
if (!loadRef.IsDirect)
{
ssaValue = context.Builder.CreateGetField(
load.Location,
ssaValue,
loadRef.FieldSpan);
}
context.ReplaceAndRemove(load, ssaValue);
}
else if (!load.Uses.HasAny)
{
context.Remove(load);
}
}
/// <summary>
/// Converts a new get length node into an SSA value.
/// </summary>
private static void Convert <TConstructionData>(
SSARewriterContext <Value> context,
TConstructionData data,
GetViewLength getViewLength)
where TConstructionData : IConstructionData
{
if (!data.TryGetConverted(getViewLength.View, out var getRef))
{
return;
}
// Get the SSA structure value
var ssaValue = context.GetValue(context.Block, getRef.Source);
// Get the view length from the first field (index 0) of the wrapped
// array structure
ssaValue = context.Builder.CreateGetField(
getViewLength.Location,
ssaValue,
new FieldSpan(new FieldAccess(0)));
context.ReplaceAndRemove(getViewLength, ssaValue);
}