// TODO:
// 1. If first branch is to the next basic block,
// then swap branch condition, replace branch target with jump target, and remove jump instruction.
// part of code: ConditionCode = GetOppositeConditionCode(ConditionCode);
// 2. If the basic block contains only a single jump instruction, rewrite all jumps to avoid it.
protected override void Run()
{
var trace = CreateTrace();
for (int f = 0; f < BasicBlocks.Count - 1; f++)
{
var from = BasicBlocks[f];
var next = BasicBlocks[f + 1];
Context context = new Context(InstructionSet, from, from.EndIndex);
context.GotoPrevious();
while (context.IsEmpty)
{
context.GotoPrevious();
}
if (context.Instruction.FlowControl != FlowControl.UnconditionalBranch)
continue;
Debug.Assert(context.Instruction.FlowControl == FlowControl.UnconditionalBranch);
Debug.Assert(context.BranchTargets.Length == 1);
var target = context.BranchTargets[0];
if (next.Label != target)
continue;
context.Remove();
}
}
/// <summary>
/// Replaces the intrinsic call site
/// </summary>
/// <param name="context">The context.</param>
/// <param name="typeSystem">The type system.</param>
void IIntrinsicMethod.ReplaceIntrinsicCall(Context context, ITypeSystem typeSystem, IList<RuntimeParameter> parameters)
{
// TODO
context.Remove();
}
/// <summary>
/// Visitation function for SwitchInstruction.
/// </summary>
/// <param name="context">The context.</param>
void IIRVisitor.Switch(Context context)
{
int[] targets = context.BranchTargets;
Operand operand = context.Operand1;
context.Remove();
for (int i = 0; i < targets.Length - 1; ++i)
{
context.AppendInstruction(X86.Cmp, null, operand, Operand.CreateConstant(BuiltInSigType.IntPtr, i));
context.AppendInstruction(X86.Branch, ConditionCode.Equal);
context.SetBranch(targets[i]);
}
}
/// <summary>
/// Empties the block of all instructions.
/// </summary>
/// <param name="block">The block.</param>
protected void EmptyBlockOfAllInstructions(BasicBlock block)
{
var ctx = new Context(InstructionSet, block);
Debug.Assert(ctx.IsBlockStartInstruction);
ctx.GotoNext();
while (!ctx.IsBlockEndInstruction)
{
if (!ctx.IsEmpty)
{
ctx.Remove();
}
ctx.GotoNext();
}
}
/// <summary>
/// Visitation function for Return.
/// </summary>
/// <param name="context">The context.</param>
void IIRVisitor.Return(Context context)
{
Debug.Assert(context.BranchTargets != null);
if (context.Operand1 != null)
{
// HACK - to support test suit on windows
//if (context.Operand1.IsR)
//{
// Operand stack = methodCompiler.StackLayout.AddStackLocal(context.Operand1.Type);
// Context before = context.InsertBefore();
// architecture.InsertMoveInstruction(before, stack, context.Operand1);
// before.AppendInstruction(X86.Fld, null, stack);
//}
var returnOperand = context.Operand1;
context.Remove();
CallingConvention.SetReturnValue(TypeLayout, context, returnOperand);
context.AppendInstruction(X86.Jmp);
context.SetBranch(Int32.MaxValue);
}
else
{
context.SetInstruction(X86.Jmp);
context.SetBranch(Int32.MaxValue);
}
}
/// <summary>
/// Visitation function for <see cref="IX86Visitor.Movzx"/> instructions.
/// </summary>
/// <param name="context">The context.</param>
void IX86Visitor.Movzx(Context context)
{
// Movsx can not use ESI or EDI registers
if (context.Operand1.IsCPURegister && (context.Operand1.Register == GeneralPurposeRegister.ESI || context.Operand1.Register == GeneralPurposeRegister.EDI))
{
Debug.Assert(context.Result.IsCPURegister);
Operand dest = context.Result;
Operand source = context.Operand1;
if (source.Register != dest.Register)
{
context.SetInstruction(X86.Mov, dest, source);
}
else
{
context.Remove();
}
if (dest.IsShort || dest.IsChar)
{
context.AppendInstruction(X86.And, dest, dest, Operand.CreateConstantUnsignedInt(TypeSystem, (uint)0xffff));
}
else if (dest.IsByte || dest.IsBoolean)
{
context.AppendInstruction(X86.And, dest, dest, Operand.CreateConstantUnsignedInt(TypeSystem, (uint)0xff));
}
}
}
/// <summary>
/// Visitation function for <see cref="IX86Visitor.Movsx"/> instructions.
/// </summary>
/// <param name="context">The context.</param>
void IX86Visitor.Movsx(Context context)
{
// Movsx can not use ESI or EDI registers
if (context.Operand1.IsCPURegister && (context.Operand1.Register == GeneralPurposeRegister.ESI || context.Operand1.Register == GeneralPurposeRegister.EDI))
{
Operand dest = context.Result;
Operand source = context.Operand1;
if (source.Register != dest.Register)
{
context.SetInstruction(X86.Mov, dest, source);
}
else
{
context.Remove();
}
if (source.IsShort || source.IsChar)
{
context.AppendInstruction(X86.And, dest, dest, Operand.CreateConstantUnsignedInt(MethodCompiler.TypeSystem, (uint)0x0000ffff));
context.AppendInstruction(X86.Xor, dest, dest, Operand.CreateConstantUnsignedInt(MethodCompiler.TypeSystem, (uint)0x00010000));
context.AppendInstruction(X86.Sub, dest, dest, Operand.CreateConstantUnsignedInt(MethodCompiler.TypeSystem, (uint)0x00010000));
}
else if (source.IsByte || source.IsBoolean)
{
context.AppendInstruction(X86.And, dest, dest, Operand.CreateConstantUnsignedInt(MethodCompiler.TypeSystem, (uint)0x000000ff));
context.AppendInstruction(X86.Xor, dest, dest, Operand.CreateConstantUnsignedInt(MethodCompiler.TypeSystem, (uint)0x00000100));
context.AppendInstruction(X86.Sub, dest, dest, Operand.CreateConstantUnsignedInt(MethodCompiler.TypeSystem, (uint)0x00000100));
}
}
}
/// <summary>
/// Visitation function for SwitchInstruction.
/// </summary>
/// <param name="context">The context.</param>
void IR.IIRVisitor.SwitchInstruction(Context context)
{
IBranch branch = context.Branch;
Operand operand = context.Operand1;
context.Remove();
for (int i = 0; i < branch.Targets.Length - 1; ++i)
{
context.AppendInstruction(Instruction.CmpInstruction, operand, new ConstantOperand(BuiltInSigType.IntPtr, i));
context.AppendInstruction(Instruction.BranchInstruction, IR.ConditionCode.Equal);
context.SetBranch(branch.Targets[i]);
}
}
/// <summary>
/// Processes the phi instruction.
/// </summary>
/// <param name="block">The block.</param>
/// <param name="context">The context.</param>
private void ProcessPhiInstruction(BasicBlock block, Context context)
{
for (var predecessorIndex = 0; predecessorIndex < block.PreviousBlocks.Count; ++predecessorIndex)
{
var predecessor = block.PreviousBlocks[predecessorIndex];
var operand = context.GetOperand(predecessorIndex);
this.InsertCopyStatement(predecessor, context.Result, operand);
}
context.Remove();
}
