rjx-mirror/ARMeilleure/Instructions/InstEmitFlow.cs
Ficture Seven 2421186d97
Generalize tail continues (#1298)
* Generalize tail continues

* Fix DecodeBasicBlock

`Next` and `Branch` would be null, which is not the state expected by
the branch instructions. They end up branching or falling into a block
which is never populated by the `Translator`. This causes an assert to
be fired when building the CFG.

* Clean up Decode overloads

* Do not synchronize when branching into exit block

If we're branching into an exit block, that exit block will tail
continue into another translation which already has a synchronization.

* Remove A32 predicate tail continue

If `block` is not an exit block then the `block.Next` must exist (as
per the last instruction of `block`).

* Throw if decoded 0 blocks

Address gdkchan's feedback

* Rebuild block list instead of setting to null

Address gdkchan's feedback
2020-06-18 13:37:21 +10:00

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3.4 KiB
C#

using ARMeilleure.Decoders;
using ARMeilleure.IntermediateRepresentation;
using ARMeilleure.State;
using ARMeilleure.Translation;
using static ARMeilleure.Instructions.InstEmitFlowHelper;
using static ARMeilleure.Instructions.InstEmitHelper;
using static ARMeilleure.IntermediateRepresentation.OperandHelper;
namespace ARMeilleure.Instructions
{
static partial class InstEmit
{
public static void B(ArmEmitterContext context)
{
OpCodeBImmAl op = (OpCodeBImmAl)context.CurrOp;
context.Branch(context.GetLabel((ulong)op.Immediate));
}
public static void B_Cond(ArmEmitterContext context)
{
OpCodeBImmCond op = (OpCodeBImmCond)context.CurrOp;
EmitBranch(context, op.Cond);
}
public static void Bl(ArmEmitterContext context)
{
OpCodeBImmAl op = (OpCodeBImmAl)context.CurrOp;
context.Copy(GetIntOrZR(context, RegisterAlias.Lr), Const(op.Address + 4));
EmitCall(context, (ulong)op.Immediate);
}
public static void Blr(ArmEmitterContext context)
{
OpCodeBReg op = (OpCodeBReg)context.CurrOp;
Operand n = context.Copy(GetIntOrZR(context, op.Rn));
context.Copy(GetIntOrZR(context, RegisterAlias.Lr), Const(op.Address + 4));
EmitVirtualCall(context, n);
}
public static void Br(ArmEmitterContext context)
{
OpCodeBReg op = (OpCodeBReg)context.CurrOp;
EmitVirtualJump(context, GetIntOrZR(context, op.Rn), op.Rn == RegisterAlias.Lr);
}
public static void Cbnz(ArmEmitterContext context) => EmitCb(context, onNotZero: true);
public static void Cbz(ArmEmitterContext context) => EmitCb(context, onNotZero: false);
private static void EmitCb(ArmEmitterContext context, bool onNotZero)
{
OpCodeBImmCmp op = (OpCodeBImmCmp)context.CurrOp;
EmitBranch(context, GetIntOrZR(context, op.Rt), onNotZero);
}
public static void Ret(ArmEmitterContext context)
{
OpCodeBReg op = (OpCodeBReg)context.CurrOp;
context.Return(GetIntOrZR(context, op.Rn));
}
public static void Tbnz(ArmEmitterContext context) => EmitTb(context, onNotZero: true);
public static void Tbz(ArmEmitterContext context) => EmitTb(context, onNotZero: false);
private static void EmitTb(ArmEmitterContext context, bool onNotZero)
{
OpCodeBImmTest op = (OpCodeBImmTest)context.CurrOp;
Operand value = context.BitwiseAnd(GetIntOrZR(context, op.Rt), Const(1L << op.Bit));
EmitBranch(context, value, onNotZero);
}
private static void EmitBranch(ArmEmitterContext context, Condition cond)
{
OpCodeBImm op = (OpCodeBImm)context.CurrOp;
EmitCondBranch(context, context.GetLabel((ulong)op.Immediate), cond);
}
private static void EmitBranch(ArmEmitterContext context, Operand value, bool onNotZero)
{
OpCodeBImm op = (OpCodeBImm)context.CurrOp;
Operand lblTarget = context.GetLabel((ulong)op.Immediate);
if (onNotZero)
{
context.BranchIfTrue(lblTarget, value);
}
else
{
context.BranchIfFalse(lblTarget, value);
}
}
}
}