R/ARMeilleure/Instructions/InstEmitFlow32.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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2.4 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 InstEmit32
{
public static void B(ArmEmitterContext context)
{
IOpCode32BImm op = (IOpCode32BImm)context.CurrOp;
context.Branch(context.GetLabel((ulong)op.Immediate));
}
public static void Bl(ArmEmitterContext context)
{
Blx(context, x: false);
}
public static void Blx(ArmEmitterContext context)
{
Blx(context, x: true);
}
private static void Blx(ArmEmitterContext context, bool x)
{
IOpCode32BImm op = (IOpCode32BImm)context.CurrOp;
uint pc = op.GetPc();
bool isThumb = IsThumb(context.CurrOp);
uint currentPc = isThumb
? pc | 1
: pc - 4;
SetIntA32(context, GetBankedRegisterAlias(context.Mode, RegisterAlias.Aarch32Lr), Const(currentPc));
// If x is true, then this is a branch with link and exchange.
// In this case we need to swap the mode between Arm <-> Thumb.
if (x)
{
SetFlag(context, PState.TFlag, Const(isThumb ? 0 : 1));
}
EmitCall(context, (ulong)op.Immediate);
}
public static void Blxr(ArmEmitterContext context)
{
IOpCode32BReg op = (IOpCode32BReg)context.CurrOp;
uint pc = op.GetPc();
Operand addr = context.Copy(GetIntA32(context, op.Rm));
Operand bitOne = context.BitwiseAnd(addr, Const(1));
bool isThumb = IsThumb(context.CurrOp);
uint currentPc = isThumb
? pc | 1
: pc - 4;
SetIntA32(context, GetBankedRegisterAlias(context.Mode, RegisterAlias.Aarch32Lr), Const(currentPc));
SetFlag(context, PState.TFlag, bitOne);
EmitVirtualCall(context, addr);
}
public static void Bx(ArmEmitterContext context)
{
IOpCode32BReg op = (IOpCode32BReg)context.CurrOp;
EmitBxWritePc(context, GetIntA32(context, op.Rm), op.Rm);
}
}
}