diff --git a/src/codegen_i128.rs b/src/codegen_i128.rs index b2bc289a5b6..4a5ef352151 100644 --- a/src/codegen_i128.rs +++ b/src/codegen_i128.rs @@ -68,7 +68,7 @@ pub(crate) fn maybe_codegen<'tcx>( Some(CValue::by_val(ret_val, lhs.layout())) } } - BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne => None, + BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne | BinOp::Cmp => None, BinOp::Shl | BinOp::ShlUnchecked | BinOp::Shr | BinOp::ShrUnchecked => None, } } @@ -134,6 +134,7 @@ pub(crate) fn maybe_codegen_checked<'tcx>( BinOp::AddUnchecked | BinOp::SubUnchecked | BinOp::MulUnchecked => unreachable!(), BinOp::Offset => unreachable!("offset should only be used on pointers, not 128bit ints"), BinOp::Div | BinOp::Rem => unreachable!(), + BinOp::Cmp => unreachable!(), BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne => unreachable!(), BinOp::Shl | BinOp::ShlUnchecked | BinOp::Shr | BinOp::ShrUnchecked => unreachable!(), } diff --git a/src/num.rs b/src/num.rs index 8992f40fb90..796182418ad 100644 --- a/src/num.rs +++ b/src/num.rs @@ -40,6 +40,22 @@ pub(crate) fn bin_op_to_intcc(bin_op: BinOp, signed: bool) -> Option { }) } +fn codegen_three_way_compare<'tcx>( + fx: &mut FunctionCx<'_, '_, 'tcx>, + signed: bool, + lhs: Value, + rhs: Value, +) -> CValue<'tcx> { + // This emits `(lhs > rhs) - (lhs < rhs)`, which is cranelift's preferred form per + // + let gt_cc = crate::num::bin_op_to_intcc(BinOp::Gt, signed).unwrap(); + let lt_cc = crate::num::bin_op_to_intcc(BinOp::Lt, signed).unwrap(); + let gt = fx.bcx.ins().icmp(gt_cc, lhs, rhs); + let lt = fx.bcx.ins().icmp(lt_cc, lhs, rhs); + let val = fx.bcx.ins().isub(gt, lt); + CValue::by_val(val, fx.layout_of(fx.tcx.ty_ordering_enum(Some(fx.mir.span)))) +} + fn codegen_compare_bin_op<'tcx>( fx: &mut FunctionCx<'_, '_, 'tcx>, bin_op: BinOp, @@ -47,6 +63,10 @@ fn codegen_compare_bin_op<'tcx>( lhs: Value, rhs: Value, ) -> CValue<'tcx> { + if bin_op == BinOp::Cmp { + return codegen_three_way_compare(fx, signed, lhs, rhs); + } + let intcc = crate::num::bin_op_to_intcc(bin_op, signed).unwrap(); let val = fx.bcx.ins().icmp(intcc, lhs, rhs); CValue::by_val(val, fx.layout_of(fx.tcx.types.bool)) @@ -59,7 +79,7 @@ pub(crate) fn codegen_binop<'tcx>( in_rhs: CValue<'tcx>, ) -> CValue<'tcx> { match bin_op { - BinOp::Eq | BinOp::Lt | BinOp::Le | BinOp::Ne | BinOp::Ge | BinOp::Gt => { + BinOp::Eq | BinOp::Lt | BinOp::Le | BinOp::Ne | BinOp::Ge | BinOp::Gt | BinOp::Cmp => { match in_lhs.layout().ty.kind() { ty::Bool | ty::Uint(_) | ty::Int(_) | ty::Char => { let signed = type_sign(in_lhs.layout().ty); @@ -160,7 +180,7 @@ pub(crate) fn codegen_int_binop<'tcx>( } BinOp::Offset => unreachable!("Offset is not an integer operation"), // Compare binops handles by `codegen_binop`. - BinOp::Eq | BinOp::Ne | BinOp::Lt | BinOp::Le | BinOp::Gt | BinOp::Ge => { + BinOp::Eq | BinOp::Ne | BinOp::Lt | BinOp::Le | BinOp::Gt | BinOp::Ge | BinOp::Cmp => { unreachable!("{:?}({:?}, {:?})", bin_op, in_lhs.layout().ty, in_rhs.layout().ty); } };