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);
}
public static void EmitDiv(ArmEmitterContext context, bool unsigned)
{
Operand n = GetAluN(context);
Operand m = GetAluM(context);
Operand zero = Const(m.Type, 0);
Operand divisorIsZero = context.ICompareEqual(m, zero);
Operand lblBadDiv = Label();
Operand lblEnd = Label();
context.BranchIfTrue(lblBadDiv, divisorIsZero);
if (!unsigned)
{
// ARM64 behaviour: If Rn == INT_MIN && Rm == -1, Rd = INT_MIN (overflow).
// TODO: tests to ensure A32 works the same
Operand intMin = Const(int.MinValue);
Operand minus1 = Const(-1);
Operand nIsIntMin = context.ICompareEqual(n, intMin);
Operand mIsMinus1 = context.ICompareEqual(m, minus1);
Operand lblGoodDiv = Label();
context.BranchIfFalse(lblGoodDiv, context.BitwiseAnd(nIsIntMin, mIsMinus1));
EmitAluStore(context, intMin);
context.Branch(lblEnd);
context.MarkLabel(lblGoodDiv);
}
Operand res = unsigned
? context.DivideUI(n, m)
: context.Divide(n, m);
EmitAluStore(context, res);
context.Branch(lblEnd);
context.MarkLabel(lblBadDiv);
EmitAluStore(context, zero);
context.MarkLabel(lblEnd);
}