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 Visit(VariableReferenceExpression reference)
{
var value = LookupVariable(reference.Name);
// 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(value.ElementType, value)
.RegisterName(reference.Name));
}
public override Value VisitVariableExpression([NotNull] VariableExpressionContext context)
{
string varName = context.Name;
if (!NamedValues.TryGetValue(varName, out Alloca value))
{
throw new ArgumentException("Unknown variable name", nameof(context));
}
return(InstructionBuilder.Load(value)
.RegisterName(varName));
}
private static void CreateCopyFunctionBody(BitcodeModule module
, DataLayout layout
, Function copyFunc
, DIFile diFile
, ITypeRef foo
, DebugPointerType fooPtr
, DIType constFooType
)
{
var diBuilder = module.DIBuilder;
copyFunc.Parameters[0].Name = "src";
copyFunc.Parameters[1].Name = "pDst";
// create block for the function body, only need one for this simple sample
var blk = copyFunc.AppendBasicBlock("entry");
// create instruction builder to build the body
var instBuilder = new InstructionBuilder(blk);
// create debug info locals for the arguments
// NOTE: Debug parameter indices are 1 based!
var paramSrc = diBuilder.CreateArgument(copyFunc.DISubProgram, "src", diFile, 11, constFooType, false, 0, 1);
var paramDst = diBuilder.CreateArgument(copyFunc.DISubProgram, "pDst", diFile, 12, fooPtr.DIType, false, 0, 2);
uint ptrAlign = layout.CallFrameAlignmentOf(fooPtr);
// create Locals
// NOTE: There's no debug location attached to these instructions.
// The debug info will come from the declare intrinsic below.
var dstAddr = instBuilder.Alloca(fooPtr)
.RegisterName("pDst.addr")
.Alignment(ptrAlign);
bool param0ByVal = copyFunc.Attributes[FunctionAttributeIndex.Parameter0].Contains(AttributeKind.ByVal);
if (param0ByVal)
{
diBuilder.InsertDeclare(copyFunc.Parameters[0]
, paramSrc
, new DILocation(module.Context, 11, 43, copyFunc.DISubProgram)
, blk
);
}
instBuilder.Store(copyFunc.Parameters[1], dstAddr)
.Alignment(ptrAlign);
// insert declare pseudo instruction to attach debug info to the local declarations
diBuilder.InsertDeclare(dstAddr, paramDst, new DILocation(module.Context, 12, 38, copyFunc.DISubProgram), blk);
if (!param0ByVal)
{
// since the function's LLVM signature uses a pointer, which is copied locally
// inform the debugger to treat it as the value by dereferencing the pointer
diBuilder.InsertDeclare(copyFunc.Parameters[0]
, paramSrc
, diBuilder.CreateExpression(ExpressionOp.deref)
, new DILocation(module.Context, 11, 43, copyFunc.DISubProgram)
, blk
);
}
var loadedDst = instBuilder.Load(dstAddr)
.Alignment(ptrAlign)
.SetDebugLocation(15, 6, copyFunc.DISubProgram);
var dstPtr = instBuilder.BitCast(loadedDst, module.Context.Int8Type.CreatePointerType( ))
.SetDebugLocation(15, 13, copyFunc.DISubProgram);
var srcPtr = instBuilder.BitCast(copyFunc.Parameters[0], module.Context.Int8Type.CreatePointerType( ))
.SetDebugLocation(15, 13, copyFunc.DISubProgram);
uint pointerSize = layout.IntPtrType(module.Context).IntegerBitWidth;
instBuilder.MemCpy(module
, dstPtr
, srcPtr
, module.Context.CreateConstant(pointerSize, layout.ByteSizeOf(foo), false)
, ( int )layout.AbiAlignmentOf(foo)
, false
).SetDebugLocation(15, 13, copyFunc.DISubProgram);
instBuilder.Return( )
.SetDebugLocation(16, 1, copyFunc.DISubProgram);
}
/*
* // 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"));
}