Exemplo n.º 1
0
        public override void Transform(Context context, TransformContext transformContext)
        {
            //Debug.Assert(context.ConditionCode != ConditionCode.Equal);

            var operand1 = context.Operand1;
            var operand2 = context.Operand2;
            var target   = context.BranchTargets[0];

            var branch         = context.ConditionCode;
            var branchUnsigned = context.ConditionCode.GetUnsigned();

            var nextBlock = transformContext.Split(context);
            var newBlocks = transformContext.CreateNewBlockContexts(4, context.Label);

            // no branch
            TransformContext.UpdatePHIInstructionTargets(nextBlock.Block.NextBlocks, context.Block, nextBlock.Block);

            // Branch
            TransformContext.UpdatePHIInstructionTarget(target, context.Block, newBlocks[3].Block);

            var op0Low  = transformContext.AllocateVirtualRegister32();
            var op0High = transformContext.AllocateVirtualRegister32();
            var op1Low  = transformContext.AllocateVirtualRegister32();
            var op1High = transformContext.AllocateVirtualRegister32();

            context.SetInstruction(IRInstruction.GetLow32, op0Low, operand1);
            context.AppendInstruction(IRInstruction.GetHigh32, op0High, operand1);
            context.AppendInstruction(IRInstruction.GetLow32, op1Low, operand2);
            context.AppendInstruction(IRInstruction.GetHigh32, op1High, operand2);

            // Compare high (equal)
            context.AppendInstruction(IRInstruction.Branch32, ConditionCode.Equal, null, op0High, op1High, newBlocks[1].Block);
            context.AppendInstruction(IRInstruction.Jmp, newBlocks[0].Block);

            // Compare high
            newBlocks[0].AppendInstruction(IRInstruction.Branch32, branch, null, op0High, op1High, newBlocks[3].Block);
            newBlocks[0].AppendInstruction(IRInstruction.Jmp, newBlocks[2].Block);

            // Compare low
            newBlocks[1].AppendInstruction(IRInstruction.Branch32, branchUnsigned, null, op0Low, op1Low, newBlocks[3].Block);
            newBlocks[1].AppendInstruction(IRInstruction.Jmp, newBlocks[2].Block);

            // No branch
            newBlocks[2].AppendInstruction(IRInstruction.Jmp, nextBlock.Block);

            // Branch
            newBlocks[3].AppendInstruction(IRInstruction.Jmp, target);
        }