private void EmitBranchToNewBlock(string blockName)
{
var newBlock = InstructionBuilder.InsertBlock.ContainingFunction.AppendBasicBlock(blockName);
InstructionBuilder.Branch(newBlock);
InstructionBuilder.PositionAtEnd(newBlock);
}
private Function DefineFunction(Function function, ExpressionContext body)
{
if (!function.IsDeclaration)
{
throw new ArgumentException($"Function {function.Name} cannot be redefined", nameof(function));
}
var basicBlock = function.AppendBasicBlock("entry");
InstructionBuilder.PositionAtEnd(basicBlock);
NamedValues.Clear( );
foreach (var arg in function.Parameters)
{
NamedValues[arg.Name] = arg;
}
var funcReturn = body.Accept(this);
if (funcReturn == null)
{
function.EraseFromParent( );
return(null);
}
InstructionBuilder.Return(funcReturn);
function.Verify( );
return(function);
}
public override Value Visit(FunctionDefinition definition)
{
var function = GetOrDeclareFunction(definition.Signature);
if (!function.IsDeclaration)
{
throw new CodeGeneratorException($"Function {function.Name} cannot be redefined in the same module");
}
try
{
var entryBlock = function.AppendBasicBlock("entry");
InstructionBuilder.PositionAtEnd(entryBlock);
using (NamedValues.EnterScope( ))
{
foreach (var param in definition.Signature.Parameters)
{
NamedValues[param.Name] = function.Parameters[param.Index];
}
var funcReturn = definition.Body.Accept(this);
InstructionBuilder.Return(funcReturn);
function.Verify( );
FunctionPassManager.Run(function);
return(function);
}
}
catch (CodeGeneratorException)
{
function.EraseFromParent( );
throw;
}
}
private void EmitBranchToNewBlock(string blockName)
{
var newBlock = InstructionBuilder.InsertFunction?.AppendBasicBlock(blockName)
?? throw new InternalCodeGeneratorException("ICE: Expected an insertion block attached to a function at this point");
InstructionBuilder.Branch(newBlock);
InstructionBuilder.PositionAtEnd(newBlock);
}
public override Value Visit(ConditionalExpression conditionalExpression)
{
var result = LookupVariable(conditionalExpression.ResultVariable.Name);
EmitLocation(conditionalExpression);
var condition = conditionalExpression.Condition.Accept(this);
if (condition == null)
{
return(null);
}
EmitLocation(conditionalExpression);
var condBool = InstructionBuilder.Compare(RealPredicate.OrderedAndNotEqual, condition, Context.CreateConstant(0.0))
.RegisterName("ifcond");
var function = InstructionBuilder.InsertBlock.ContainingFunction;
var thenBlock = function.AppendBasicBlock("then");
var elseBlock = function.AppendBasicBlock("else");
var continueBlock = function.AppendBasicBlock("ifcont");
InstructionBuilder.Branch(condBool, thenBlock, elseBlock);
// generate then block instructions
InstructionBuilder.PositionAtEnd(thenBlock);
var thenValue = conditionalExpression.ThenExpression.Accept(this);
if (thenValue == null)
{
return(null);
}
InstructionBuilder.Store(thenValue, result);
InstructionBuilder.Branch(continueBlock);
// generate else block
InstructionBuilder.PositionAtEnd(elseBlock);
var elseValue = conditionalExpression.ElseExpression.Accept(this);
if (elseValue == null)
{
return(null);
}
InstructionBuilder.Store(elseValue, result);
InstructionBuilder.Branch(continueBlock);
// generate continue block
InstructionBuilder.PositionAtEnd(continueBlock);
// since the Alloca is created as a non-opaque pointer it is OK to just use the
// ElementType. If full opaque pointer support was used, then the Lookup map
// would need to include the type of the value allocated.
return(InstructionBuilder.Load(result.ElementType, result)
.RegisterName("ifresult"));
}
public override Value VisitConditionalExpression([NotNull] ConditionalExpressionContext context)
{
EmitLocation(context);
var condition = context.Condition.Accept(this);
if (condition == null)
{
return(null);
}
var condBool = InstructionBuilder.Compare(RealPredicate.OrderedAndNotEqual, condition, Context.CreateConstant(0.0))
.RegisterName("ifcond");
var function = InstructionBuilder.InsertBlock.ContainingFunction;
var thenBlock = Context.CreateBasicBlock("then", function);
var elseBlock = Context.CreateBasicBlock("else");
var phiMergeBlock = Context.CreateBasicBlock("ifcont");
InstructionBuilder.Branch(condBool, thenBlock, elseBlock);
// generate then block
InstructionBuilder.PositionAtEnd(thenBlock);
var thenValue = context.ThenExpression.Accept(this);
if (thenValue == null)
{
return(null);
}
InstructionBuilder.Branch(phiMergeBlock);
// capture the insert in case generating thenExpression adds new blocks
thenBlock = InstructionBuilder.InsertBlock;
// generate else block
function.BasicBlocks.Add(elseBlock);
InstructionBuilder.PositionAtEnd(elseBlock);
var elseValue = context.ElseExpression.Accept(this);
if (elseValue == null)
{
return(null);
}
InstructionBuilder.Branch(phiMergeBlock);
elseBlock = InstructionBuilder.InsertBlock;
// generate PHI merge block
function.BasicBlocks.Add(phiMergeBlock);
InstructionBuilder.PositionAtEnd(phiMergeBlock);
var phiNode = InstructionBuilder.PhiNode(function.Context.DoubleType)
.RegisterName("iftmp");
phiNode.AddIncoming(thenValue, thenBlock);
phiNode.AddIncoming(elseValue, elseBlock);
return(phiNode);
}
public override Value?Visit(FunctionDefinition definition)
{
definition.ValidateNotNull(nameof(definition));
var function = GetOrDeclareFunction(definition.Signature);
if (!function.IsDeclaration)
{
throw new CodeGeneratorException($"Function {function.Name} cannot be redefined in the same module");
}
try
{
var entryBlock = function.AppendBasicBlock("entry");
InstructionBuilder.PositionAtEnd(entryBlock);
using (NamedValues.EnterScope( ))
{
foreach (var param in definition.Signature.Parameters)
{
var argSlot = InstructionBuilder.Alloca(function.Context.DoubleType)
.RegisterName(param.Name);
InstructionBuilder.Store(function.Parameters[param.Index], argSlot);
NamedValues[param.Name] = argSlot;
}
foreach (LocalVariableDeclaration local in definition.LocalVariables)
{
var localSlot = InstructionBuilder.Alloca(function.Context.DoubleType)
.RegisterName(local.Name);
NamedValues[local.Name] = localSlot;
}
EmitBranchToNewBlock("body");
var funcReturn = definition.Body.Accept(this) ?? throw new CodeGeneratorException(ExpectValidFunc);
InstructionBuilder.Return(funcReturn);
function.Verify( );
FunctionPassManager.Run(function);
if (definition.IsAnonymous)
{
function.AddAttribute(FunctionAttributeIndex.Function, AttributeKind.AlwaysInline)
.Linkage(Linkage.Private);
AnonymousFunctions.Add(function);
}
return(function);
}
}
catch (CodeGeneratorException)
{
function.EraseFromParent( );
throw;
}
}
public override Value Visit(ConditionalExpression conditionalExpression)
{
var condition = conditionalExpression.Condition.Accept(this);
if (condition == null)
{
return(null);
}
var condBool = InstructionBuilder.Compare(RealPredicate.OrderedAndNotEqual, condition, Context.CreateConstant(0.0))
.RegisterName("ifcond");
var function = InstructionBuilder.InsertBlock.ContainingFunction;
var thenBlock = function.AppendBasicBlock("then");
var elseBlock = function.AppendBasicBlock("else");
var continueBlock = function.AppendBasicBlock("ifcont");
InstructionBuilder.Branch(condBool, thenBlock, elseBlock);
// generate then block instructions
InstructionBuilder.PositionAtEnd(thenBlock);
var thenValue = conditionalExpression.ThenExpression.Accept(this);
if (thenValue == null)
{
return(null);
}
InstructionBuilder.Branch(continueBlock);
// capture the insert in case generating else adds new blocks
var thenResultBlock = InstructionBuilder.InsertBlock;
// generate else block
InstructionBuilder.PositionAtEnd(elseBlock);
var elseValue = conditionalExpression.ElseExpression.Accept(this);
if (elseValue == null)
{
return(null);
}
InstructionBuilder.Branch(continueBlock);
var elseResultBlock = InstructionBuilder.InsertBlock;
// generate continue block
InstructionBuilder.PositionAtEnd(continueBlock);
var phiNode = InstructionBuilder.PhiNode(function.Context.DoubleType)
.RegisterName("ifresult");
phiNode.AddIncoming((thenValue, thenResultBlock), (elseValue, elseResultBlock));
return(phiNode);
}
private (Function Function, int JitHandle) DefineFunction(Function function, ExpressionContext body)
{
if (!function.IsDeclaration)
{
throw new ArgumentException($"Function {function.Name} cannot be redefined", nameof(function));
}
var basicBlock = function.AppendBasicBlock("entry");
InstructionBuilder.PositionAtEnd(basicBlock);
NamedValues.Clear( );
foreach (var arg in function.Parameters)
{
var argSlot = CreateEntryBlockAlloca(function, arg.Name);
InstructionBuilder.Store(arg, argSlot);
NamedValues[arg.Name] = argSlot;
}
var funcReturn = body.Accept(this);
if (funcReturn == null)
{
function.EraseFromParent( );
return(null, default);
/*
* // Output for-loop as:
* // ...
* // start = startexpr
* // goto loop
* // loop:
* // variable = phi [start, loopheader], [nextvariable, loopend]
* // ...
* // bodyexpr
* // ...
* // loopend:
* // step = stepexpr
* // nextvariable = variable + step
* // endcond = endexpr
* // br endcond, loop, endloop
* // outloop:
*/
public override Value VisitForExpression([NotNull] ForExpressionContext context)
{
var function = InstructionBuilder.InsertBlock.ContainingFunction;
string varName = context.Initializer.Name;
var allocaVar = CreateEntryBlockAlloca(function, varName);
// Emit the start code first, without 'variable' in scope.
Value startVal = null;
if (context.Initializer.Value != null)
{
startVal = context.Initializer.Value.Accept(this);
if (startVal == null)
{
return(null);
}
}
else
{
startVal = Context.CreateConstant(0.0);
}
// store the value into allocated location
InstructionBuilder.Store(startVal, allocaVar);
// Make the new basic block for the loop header, inserting after current
// block.
var preHeaderBlock = InstructionBuilder.InsertBlock;
var loopBlock = Context.CreateBasicBlock("loop", function);
// Insert an explicit fall through from the current block to the loopBlock.
InstructionBuilder.Branch(loopBlock);
// Start insertion in loopBlock.
InstructionBuilder.PositionAtEnd(loopBlock);
// Start the PHI node with an entry for Start.
var variable = InstructionBuilder.PhiNode(Context.DoubleType)
.RegisterName(varName);
variable.AddIncoming(startVal, preHeaderBlock);
// Within the loop, the variable is defined equal to the PHI node. If it
// shadows an existing variable, we have to restore it, so save it now.
NamedValues.TryGetValue(varName, out Alloca oldValue);
NamedValues[varName] = allocaVar;
// Emit the body of the loop. This, like any other expr, can change the
// current BB. Note that we ignore the value computed by the body, but don't
// allow an error.
if (context.BodyExpression.Accept(this) == null)
{
return(null);
}
Value stepValue = Context.CreateConstant(1.0);
// DEBUG: How does ANTLR represent optional context (Null or IsEmpty == true)
if (context.StepExpression != null)
{
stepValue = context.StepExpression.Accept(this);
if (stepValue == null)
{
return(null);
}
}
// Compute the end condition.
Value endCondition = context.EndExpression.Accept(this);
if (endCondition == null)
{
return(null);
}
var curVar = InstructionBuilder.Load(allocaVar)
.RegisterName(varName);
var nextVar = InstructionBuilder.FAdd(curVar, stepValue)
.RegisterName("nextvar");
InstructionBuilder.Store(nextVar, allocaVar);
// Convert condition to a bool by comparing non-equal to 0.0.
endCondition = InstructionBuilder.Compare(RealPredicate.OrderedAndNotEqual, endCondition, Context.CreateConstant(1.0))
.RegisterName("loopcond");
// Create the "after loop" block and insert it.
var loopEndBlock = InstructionBuilder.InsertBlock;
var afterBlock = Context.CreateBasicBlock("afterloop", function);
// Insert the conditional branch into the end of LoopEndBB.
InstructionBuilder.Branch(endCondition, loopBlock, afterBlock);
InstructionBuilder.PositionAtEnd(afterBlock);
// Add a new entry to the PHI node for the backedge.
variable.AddIncoming(nextVar, loopEndBlock);
// Restore the unshadowed variable.
if (oldValue != null)
{
NamedValues[varName] = oldValue;
}
else
{
NamedValues.Remove(varName);
}
// for expr always returns 0.0 for consistency, there is no 'void'
return(Context.DoubleType.GetNullValue( ));
}
public override Value?Visit(ForInExpression forInExpression)
{
forInExpression.ValidateNotNull(nameof(forInExpression));
EmitLocation(forInExpression);
var function = InstructionBuilder.InsertFunction;
if (function is null)
{
throw new InternalCodeGeneratorException("ICE: Expected block attached to a function at this point");
}
string varName = forInExpression.LoopVariable.Name;
Alloca allocaVar = LookupVariable(varName);
// Emit the start code first, without 'variable' in scope.
Value?startVal;
if (forInExpression.LoopVariable.Initializer != null)
{
startVal = forInExpression.LoopVariable.Initializer.Accept(this);
if (startVal is null)
{
return(null);
}
}
else
{
startVal = Context.CreateConstant(0.0);
}
// store the value into allocated location
InstructionBuilder.Store(startVal, allocaVar);
// Make the new basic block for the loop header.
var loopBlock = function.AppendBasicBlock("loop");
// Insert an explicit fall through from the current block to the loopBlock.
InstructionBuilder.Branch(loopBlock);
// Start insertion in loopBlock.
InstructionBuilder.PositionAtEnd(loopBlock);
// Within the loop, the variable is defined equal to the PHI node.
// So, push a new scope for it and any values the body might set
using (NamedValues.EnterScope( ))
{
EmitBranchToNewBlock("ForInScope");
// Emit the body of the loop. This, like any other expression, can change the
// current BB. Note that we ignore the value computed by the body, but don't
// allow an error.
if (forInExpression.Body.Accept(this) == null)
{
return(null);
}
Value?stepValue = forInExpression.Step.Accept(this);
if (stepValue == null)
{
return(null);
}
// Compute the end condition.
Value?endCondition = forInExpression.Condition.Accept(this);
if (endCondition == null)
{
return(null);
}
// since the Alloca is created as a non-opaque pointer it is OK to just use the
// ElementType. If full opaque pointer support was used, then the Lookup map
// would need to include the type of the value allocated.
var curVar = InstructionBuilder.Load(allocaVar.ElementType, allocaVar)
.RegisterName(varName);
var nextVar = InstructionBuilder.FAdd(curVar, stepValue)
.RegisterName("nextvar");
InstructionBuilder.Store(nextVar, allocaVar);
// Convert condition to a bool by comparing non-equal to 0.0.
endCondition = InstructionBuilder.Compare(RealPredicate.OrderedAndNotEqual, endCondition, Context.CreateConstant(0.0))
.RegisterName("loopcond");
// Create the "after loop" block and insert it.
var afterBlock = function.AppendBasicBlock("afterloop");
// Insert the conditional branch into the end of LoopEndBB.
InstructionBuilder.Branch(endCondition, loopBlock, afterBlock);
InstructionBuilder.PositionAtEnd(afterBlock);
// for expression always returns 0.0 for consistency, there is no 'void'
return(Context.DoubleType.GetNullValue( ));
}
}
public override Value?Visit(ConditionalExpression conditionalExpression)
{
conditionalExpression.ValidateNotNull(nameof(conditionalExpression));
var result = LookupVariable(conditionalExpression.ResultVariable.Name);
EmitLocation(conditionalExpression);
var condition = conditionalExpression.Condition.Accept(this);
if (condition == null)
{
return(null);
}
EmitLocation(conditionalExpression);
var condBool = InstructionBuilder.Compare(RealPredicate.OrderedAndNotEqual, condition, Context.CreateConstant(0.0))
.RegisterName("ifcond");
var function = InstructionBuilder.InsertFunction;
if (function is null)
{
throw new InternalCodeGeneratorException("ICE: expected block that is attached to a function at this point");
}
var thenBlock = function.AppendBasicBlock("then");
var elseBlock = function.AppendBasicBlock("else");
var continueBlock = function.AppendBasicBlock("ifcont");
InstructionBuilder.Branch(condBool, thenBlock, elseBlock);
// generate then block instructions
InstructionBuilder.PositionAtEnd(thenBlock);
// InstructionBuilder.InserBlock after this point is !null
Debug.Assert(InstructionBuilder.InsertBlock != null, "expected non-null InsertBlock");
var thenValue = conditionalExpression.ThenExpression.Accept(this);
if (thenValue == null)
{
return(null);
}
InstructionBuilder.Store(thenValue, result);
InstructionBuilder.Branch(continueBlock);
// generate else block
InstructionBuilder.PositionAtEnd(elseBlock);
var elseValue = conditionalExpression.ElseExpression.Accept(this);
if (elseValue == null)
{
return(null);
}
InstructionBuilder.Store(elseValue, result);
InstructionBuilder.Branch(continueBlock);
// generate continue block
InstructionBuilder.PositionAtEnd(continueBlock);
// since the Alloca is created as a non-opaque pointer it is OK to just use the
// ElementType. If full opaque pointer support was used, then the Lookup map
// would need to include the type of the value allocated.
return(InstructionBuilder.Load(result.ElementType, result)
.RegisterName("ifresult"));
}
public override Value?Visit(FunctionDefinition definition)
{
definition.ValidateNotNull(nameof(definition));
var function = GetOrDeclareFunction(definition.Signature);
if (!function.IsDeclaration)
{
throw new CodeGeneratorException($"Function {function.Name} cannot be redefined in the same module");
}
Debug.Assert(function.DISubProgram != null, "Expected function with non-null DISubProgram");
LexicalBlocks.Push(function.DISubProgram);
try
{
var entryBlock = function.AppendBasicBlock("entry");
InstructionBuilder.PositionAtEnd(entryBlock);
// Unset the location for the prologue emission (leading instructions with no
// location in a function are considered part of the prologue and the debugger
// will run past them when breaking on a function)
EmitLocation(null);
using (NamedValues.EnterScope( ))
{
foreach (var param in definition.Signature.Parameters)
{
var argSlot = InstructionBuilder.Alloca(function.Context.DoubleType)
.RegisterName(param.Name);
AddDebugInfoForAlloca(argSlot, function, param);
InstructionBuilder.Store(function.Parameters[param.Index], argSlot);
NamedValues[param.Name] = argSlot;
}
foreach (LocalVariableDeclaration local in definition.LocalVariables)
{
var localSlot = InstructionBuilder.Alloca(function.Context.DoubleType)
.RegisterName(local.Name);
AddDebugInfoForAlloca(localSlot, function, local);
NamedValues[local.Name] = localSlot;
}
EmitBranchToNewBlock("body");
var funcReturn = definition.Body.Accept(this) ?? throw new CodeGeneratorException(ExpectValidFunc);
InstructionBuilder.Return(funcReturn);
Module.DIBuilder.Finish(function.DISubProgram);
function.Verify( );
FunctionPassManager.Run(function);
if (definition.IsAnonymous)
{
function.AddAttribute(FunctionAttributeIndex.Function, AttributeKind.AlwaysInline)
.Linkage(Linkage.Private);
AnonymousFunctions.Add(function);
}
return(function);
}
}
catch (CodeGeneratorException)
{
function.EraseFromParent( );
throw;
}
}
public override Value Visit(ForInExpression forInExpression)
{
var function = InstructionBuilder.InsertBlock.ContainingFunction;
string varName = forInExpression.LoopVariable.Name;
// Emit the start code first, without 'variable' in scope.
Value startVal;
if (forInExpression.LoopVariable.Initializer != null)
{
startVal = forInExpression.LoopVariable.Initializer.Accept(this);
if (startVal == null)
{
return(null);
}
}
else
{
startVal = Context.CreateConstant(0.0);
}
// Make the new basic block for the loop header, inserting after current
// block.
var preHeaderBlock = InstructionBuilder.InsertBlock;
var loopBlock = function.AppendBasicBlock("loop");
// Insert an explicit fall through from the current block to the loopBlock.
InstructionBuilder.Branch(loopBlock);
// Start insertion in loopBlock.
InstructionBuilder.PositionAtEnd(loopBlock);
// Start the PHI node with an entry for Start.
var variable = InstructionBuilder.PhiNode(Context.DoubleType)
.RegisterName(varName);
variable.AddIncoming(startVal, preHeaderBlock);
// Within the loop, the variable is defined equal to the PHI node.
// So, push a new scope for it and any values the body might set
using (NamedValues.EnterScope( ))
{
NamedValues[varName] = variable;
// Emit the body of the loop. This, like any other expression, can change the
// current BB. Note that we ignore the value computed by the body, but don't
// allow an error.
if (forInExpression.Body.Accept(this) == null)
{
return(null);
}
Value stepValue = forInExpression.Step.Accept(this);
if (stepValue == null)
{
return(null);
}
var nextVar = InstructionBuilder.FAdd(variable, stepValue)
.RegisterName("nextvar");
// Compute the end condition.
Value endCondition = forInExpression.Condition.Accept(this);
if (endCondition == null)
{
return(null);
}
// Convert condition to a bool by comparing non-equal to 0.0.
endCondition = InstructionBuilder.Compare(RealPredicate.OrderedAndNotEqual, endCondition, Context.CreateConstant(0.0))
.RegisterName("loopcond");
// capture loop end result block for loop variable PHI node
var loopEndBlock = InstructionBuilder.InsertBlock;
// Create the "after loop" block and insert it.
var afterBlock = function.AppendBasicBlock("afterloop");
// Insert the conditional branch into the end of LoopEndBB.
InstructionBuilder.Branch(endCondition, loopBlock, afterBlock);
InstructionBuilder.PositionAtEnd(afterBlock);
// Add a new entry to the PHI node for the back-edge.
variable.AddIncoming(nextVar, loopEndBlock);
// for expression always returns 0.0 for consistency, there is no 'void'
return(Context.DoubleType.GetNullValue( ));
}
}
private Function DefineFunction(Function function, ExpressionContext body)
{
if (!function.IsDeclaration)
{
throw new ArgumentException($"Function {function.Name} cannot be redefined", nameof(function));
}
var proto = FunctionPrototypes[function.Name];
var basicBlock = function.AppendBasicBlock("entry");
InstructionBuilder.PositionAtEnd(basicBlock);
var diFile = Module.DICompileUnit.File;
var scope = Module.DICompileUnit;
LexicalBlocks.Push(function.DISubProgram);
// Unset the location for the prologue emission (leading instructions with no
// location in a function are considered part of the prologue and the debugger
// will run past them when breaking on a function)
EmitLocation(null);
NamedValues.Clear( );
foreach (var arg in function.Parameters)
{
uint line = ( uint )proto.Parameters[( int )(arg.Index)].Span.StartLine;
uint col = ( uint )proto.Parameters[( int )(arg.Index)].Span.StartColumn;
var argSlot = CreateEntryBlockAlloca(function, arg.Name);
DILocalVariable debugVar = Module.DIBuilder.CreateArgument(function.DISubProgram
, arg.Name
, diFile
, line
, DoubleType
, true
, DebugInfoFlags.None
, checked (( ushort )(arg.Index + 1)) // Debug index starts at 1!
);
Module.DIBuilder.InsertDeclare(argSlot
, debugVar
, new DILocation(Context, line, col, function.DISubProgram)
, InstructionBuilder.InsertBlock
);
InstructionBuilder.Store(arg, argSlot);
NamedValues[arg.Name] = argSlot;
}
var funcReturn = body.Accept(this);
if (funcReturn == null)
{
function.EraseFromParent( );
LexicalBlocks.Pop( );
return(null);
}
InstructionBuilder.Return(funcReturn);
LexicalBlocks.Pop( );
Module.DIBuilder.Finish(function.DISubProgram);
function.Verify( );
Trace.TraceInformation(function.ToString( ));
return(function);
}