Esempio n. 1
0
        private static void EmitLoad(ILEmitterCtx context, AccessType accType, bool pair)
        {
            OpCodeMemEx64 op = (OpCodeMemEx64)context.CurrOp;

            bool ordered   = (accType & AccessType.Ordered) != 0;
            bool exclusive = (accType & AccessType.Exclusive) != 0;

            if (ordered)
            {
                EmitBarrier(context);
            }

            context.EmitLdint(op.Rn);
            context.EmitSttmp();

            if (exclusive)
            {
                context.EmitLdarg(TranslatedSub.StateArgIdx);
                context.EmitLdtmp();

                context.EmitPrivateCall(typeof(CpuThreadState), nameof(CpuThreadState.SetExclusiveAddress));
            }

            void WriteExclusiveValue(string propName)
            {
                if (op.Size < 3)
                {
                    context.Emit(OpCodes.Conv_U8);
                }

                context.EmitSttmp2();
                context.EmitLdarg(TranslatedSub.StateArgIdx);
                context.EmitLdtmp2();

                context.EmitCallPrivatePropSet(typeof(CpuThreadState), propName);

                context.EmitLdtmp2();

                if (op.Size < 3)
                {
                    context.Emit(OpCodes.Conv_U4);
                }
            }

            if (pair)
            {
                //Exclusive loads should be atomic. For pairwise loads, we need to
                //read all the data at once. For a 32-bits pairwise load, we do a
                //simple 64-bits load, for a 128-bits load, we need to call a special
                //method to read 128-bits atomically.
                if (op.Size == 2)
                {
                    context.EmitLdarg(TranslatedSub.MemoryArgIdx);
                    context.EmitLdtmp();

                    EmitReadZxCall(context, 3);

                    context.Emit(OpCodes.Dup);

                    //Mask low half.
                    context.Emit(OpCodes.Conv_U4);

                    if (exclusive)
                    {
                        WriteExclusiveValue(nameof(CpuThreadState.ExclusiveValueLow));
                    }

                    context.EmitStintzr(op.Rt);

                    //Shift high half.
                    context.EmitLsr(32);
                    context.Emit(OpCodes.Conv_U4);

                    if (exclusive)
                    {
                        WriteExclusiveValue(nameof(CpuThreadState.ExclusiveValueHigh));
                    }

                    context.EmitStintzr(op.Rt2);
                }
                else if (op.Size == 3)
                {
                    context.EmitLdarg(TranslatedSub.MemoryArgIdx);
                    context.EmitLdtmp();

                    context.EmitPrivateCall(typeof(MemoryManager), nameof(MemoryManager.AtomicReadInt128));

                    context.Emit(OpCodes.Dup);

                    //Load low part of the vector.
                    context.EmitLdc_I4(0);
                    context.EmitLdc_I4(3);

                    VectorHelper.EmitCall(context, nameof(VectorHelper.VectorExtractIntZx));

                    if (exclusive)
                    {
                        WriteExclusiveValue(nameof(CpuThreadState.ExclusiveValueLow));
                    }

                    context.EmitStintzr(op.Rt);

                    //Load high part of the vector.
                    context.EmitLdc_I4(1);
                    context.EmitLdc_I4(3);

                    VectorHelper.EmitCall(context, nameof(VectorHelper.VectorExtractIntZx));

                    if (exclusive)
                    {
                        WriteExclusiveValue(nameof(CpuThreadState.ExclusiveValueHigh));
                    }

                    context.EmitStintzr(op.Rt2);
                }
                else
                {
                    throw new InvalidOperationException($"Invalid store size of {1 << op.Size} bytes.");
                }
            }
            else
            {
                //8, 16, 32 or 64-bits (non-pairwise) load.
                context.EmitLdarg(TranslatedSub.MemoryArgIdx);
                context.EmitLdtmp();

                EmitReadZxCall(context, op.Size);

                if (exclusive)
                {
                    WriteExclusiveValue(nameof(CpuThreadState.ExclusiveValueLow));
                }

                context.EmitStintzr(op.Rt);
            }
        }