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using ARMeilleure.Decoders;
using ARMeilleure.IntermediateRepresentation;
using ARMeilleure.Translation;
using static ARMeilleure.Instructions.InstEmitHelper;
using static ARMeilleure.IntermediateRepresentation.Operand.Factory;
namespace ARMeilleure.Instructions
{
static partial class InstEmit
{
public static void Sdiv(ArmEmitterContext context) => EmitDiv(context, unsigned: false);
public static void Udiv(ArmEmitterContext context) => EmitDiv(context, unsigned: true);
private static void EmitDiv(ArmEmitterContext context, bool unsigned)
{
OpCodeAluBinary op = (OpCodeAluBinary)context.CurrOp;
// If Rm == 0, Rd = 0 (division by zero).
Operand n = GetIntOrZR(context, op.Rn);
Operand m = GetIntOrZR(context, op.Rm);
Operand divisorIsZero = context.ICompareEqual(m, Const(m.Type, 0));
Operand lblBadDiv = Label();
Operand lblEnd = Label();
context.BranchIfTrue(lblBadDiv, divisorIsZero);
if (!unsigned)
{
// If Rn == INT_MIN && Rm == -1, Rd = INT_MIN (overflow).
bool is32Bits = op.RegisterSize == RegisterSize.Int32;
Operand intMin = is32Bits ? Const(int.MinValue) : Const(long.MinValue);
Operand minus1 = is32Bits ? Const(-1) : Const(-1L);
Operand nIsIntMin = context.ICompareEqual(n, intMin);
Operand mIsMinus1 = context.ICompareEqual(m, minus1);
Operand lblGoodDiv = Label();
context.BranchIfFalse(lblGoodDiv, context.BitwiseAnd(nIsIntMin, mIsMinus1));
SetAluDOrZR(context, intMin);
context.Branch(lblEnd);
context.MarkLabel(lblGoodDiv);
}
Operand d = unsigned
? context.DivideUI(n, m)
: context.Divide (n, m);
SetAluDOrZR(context, d);
context.Branch(lblEnd);
context.MarkLabel(lblBadDiv);
SetAluDOrZR(context, Const(op.GetOperandType(), 0));
context.MarkLabel(lblEnd);
}
}
}
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