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scottmcmscottmcm
committed
Add mir::BinOp::Cmp 
1 parent 7b56ce0 commit c6193ce

34 files changed

+479
-221
lines changed

‎compiler/rustc_codegen_cranelift/src/codegen_i128.rs

+2-1
Original file line numberDiff line numberDiff line change
@@ -68,7 +68,7 @@ pub(crate) fn maybe_codegen<'tcx>(
6868
Some(CValue::by_val(ret_val, lhs.layout()))
6969
}
7070
}
71-
BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne => None,
71+
BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne | BinOp::Cmp => None,
7272
BinOp::Shl | BinOp::ShlUnchecked | BinOp::Shr | BinOp::ShrUnchecked => None,
7373
}
7474
}
@@ -134,6 +134,7 @@ pub(crate) fn maybe_codegen_checked<'tcx>(
134134
BinOp::AddUnchecked | BinOp::SubUnchecked | BinOp::MulUnchecked => unreachable!(),
135135
BinOp::Offset => unreachable!("offset should only be used on pointers, not 128bit ints"),
136136
BinOp::Div | BinOp::Rem => unreachable!(),
137+
BinOp::Cmp => unreachable!(),
137138
BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne => unreachable!(),
138139
BinOp::Shl | BinOp::ShlUnchecked | BinOp::Shr | BinOp::ShrUnchecked => unreachable!(),
139140
}

‎compiler/rustc_codegen_cranelift/src/num.rs

+23-2
Original file line numberDiff line numberDiff line change
@@ -40,13 +40,34 @@ pub(crate) fn bin_op_to_intcc(bin_op: BinOp, signed: bool) -> Option<IntCC> {
4040
})
4141
}
4242

43+
fn codegen_three_way_compare<'tcx>(
44+
fx: &mut FunctionCx<'_, '_, 'tcx>,
45+
signed: bool,
46+
lhs: Value,
47+
rhs: Value,
48+
) -> CValue<'tcx> {
49+
let gt_cc = crate::num::bin_op_to_intcc(BinOp::Gt, signed).unwrap();
50+
let lt_cc = crate::num::bin_op_to_intcc(BinOp::Lt, signed).unwrap();
51+
let gt = fx.bcx.ins().icmp(gt_cc, lhs, rhs);
52+
let lt = fx.bcx.ins().icmp(lt_cc, lhs, rhs);
53+
// Cranelift no longer has a single-bit type, so the comparison results
54+
// are already `I8`s, which we can subtract to get the -1/0/+1 we want.
55+
// See <https://github.com/bytecodealliance/wasmtime/pull/5031>.
56+
let val = fx.bcx.ins().isub(gt, lt);
57+
CValue::by_val(val, fx.layout_of(fx.tcx.types.i8))
58+
}
59+
4360
fn codegen_compare_bin_op<'tcx>(
4461
fx: &mut FunctionCx<'_, '_, 'tcx>,
4562
bin_op: BinOp,
4663
signed: bool,
4764
lhs: Value,
4865
rhs: Value,
4966
) -> CValue<'tcx> {
67+
if bin_op == BinOp::Cmp {
68+
return codegen_three_way_compare(fx, signed, lhs, rhs);
69+
}
70+
5071
let intcc = crate::num::bin_op_to_intcc(bin_op, signed).unwrap();
5172
let val = fx.bcx.ins().icmp(intcc, lhs, rhs);
5273
CValue::by_val(val, fx.layout_of(fx.tcx.types.bool))
@@ -59,7 +80,7 @@ pub(crate) fn codegen_binop<'tcx>(
5980
in_rhs: CValue<'tcx>,
6081
) -> CValue<'tcx> {
6182
match bin_op {
62-
BinOp::Eq | BinOp::Lt | BinOp::Le | BinOp::Ne | BinOp::Ge | BinOp::Gt => {
83+
BinOp::Eq | BinOp::Lt | BinOp::Le | BinOp::Ne | BinOp::Ge | BinOp::Gt | BinOp::Cmp => {
6384
match in_lhs.layout().ty.kind() {
6485
ty::Bool | ty::Uint(_) | ty::Int(_) | ty::Char => {
6586
let signed = type_sign(in_lhs.layout().ty);
@@ -160,7 +181,7 @@ pub(crate) fn codegen_int_binop<'tcx>(
160181
}
161182
BinOp::Offset => unreachable!("Offset is not an integer operation"),
162183
// Compare binops handles by `codegen_binop`.
163-
BinOp::Eq | BinOp::Ne | BinOp::Lt | BinOp::Le | BinOp::Gt | BinOp::Ge => {
184+
BinOp::Eq | BinOp::Ne | BinOp::Lt | BinOp::Le | BinOp::Gt | BinOp::Ge | BinOp::Cmp => {
164185
unreachable!("{:?}({:?}, {:?})", bin_op, in_lhs.layout().ty, in_rhs.layout().ty);
165186
}
166187
};

‎compiler/rustc_codegen_gcc/src/common.rs

+4
Original file line numberDiff line numberDiff line change
@@ -104,6 +104,10 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
104104
self.const_int(self.type_i32(), i as i64)
105105
}
106106

107+
fn const_i8(&self, i: i8) -> RValue<'gcc> {
108+
self.const_int(self.type_i8(), i as i64)
109+
}
110+
107111
fn const_u32(&self, i: u32) -> RValue<'gcc> {
108112
self.const_uint(self.type_u32(), i as u64)
109113
}

‎compiler/rustc_codegen_llvm/src/common.rs

+4
Original file line numberDiff line numberDiff line change
@@ -158,6 +158,10 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
158158
self.const_int(self.type_i32(), i as i64)
159159
}
160160

161+
fn const_i8(&self, i: i8) -> &'ll Value {
162+
self.const_int(self.type_i8(), i as i64)
163+
}
164+
161165
fn const_u32(&self, i: u32) -> &'ll Value {
162166
self.const_uint(self.type_i32(), i as u64)
163167
}

‎compiler/rustc_codegen_ssa/src/mir/rvalue.rs

+22
Original file line numberDiff line numberDiff line change
@@ -7,6 +7,7 @@ use crate::common::{self, IntPredicate};
77
use crate::traits::*;
88
use crate::MemFlags;
99

10+
use rustc_hir as hir;
1011
use rustc_middle::mir;
1112
use rustc_middle::mir::Operand;
1213
use rustc_middle::ty::cast::{CastTy, IntTy};
@@ -881,6 +882,27 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
881882
bx.icmp(base::bin_op_to_icmp_predicate(op.to_hir_binop(), is_signed), lhs, rhs)
882883
}
883884
}
885+
mir::BinOp::Cmp => {
886+
use std::cmp::Ordering;
887+
debug_assert!(!is_float);
888+
// FIXME: To avoid this PR changing behaviour, the operations used
889+
// here are those from <https://github.com/rust-lang/rust/pull/63767>,
890+
// as tested by `tests/codegen/integer-cmp.rs`.
891+
// Something in future might want to pick different ones. For example,
892+
// maybe the ones from Clang's `<=>` operator in C++20 (see
893+
// <https://github.com/llvm/llvm-project/issues/60012>) or once we
894+
// update to new LLVM, something to take advantage of the new folds in
895+
// <https://github.com/llvm/llvm-project/issues/59666>.
896+
let pred = |op| base::bin_op_to_icmp_predicate(op, is_signed);
897+
let is_lt = bx.icmp(pred(hir::BinOpKind::Lt), lhs, rhs);
898+
let is_ne = bx.icmp(pred(hir::BinOpKind::Ne), lhs, rhs);
899+
let ge = bx.select(
900+
is_ne,
901+
bx.cx().const_i8(Ordering::Greater as i8),
902+
bx.cx().const_i8(Ordering::Equal as i8),
903+
);
904+
bx.select(is_lt, bx.cx().const_i8(Ordering::Less as i8), ge)
905+
}
884906
}
885907
}
886908

‎compiler/rustc_codegen_ssa/src/traits/consts.rs

+1
Original file line numberDiff line numberDiff line change
@@ -19,6 +19,7 @@ pub trait ConstMethods<'tcx>: BackendTypes {
1919
fn const_bool(&self, val: bool) -> Self::Value;
2020
fn const_i16(&self, i: i16) -> Self::Value;
2121
fn const_i32(&self, i: i32) -> Self::Value;
22+
fn const_i8(&self, i: i8) -> Self::Value;
2223
fn const_u32(&self, i: u32) -> Self::Value;
2324
fn const_u64(&self, i: u64) -> Self::Value;
2425
fn const_u128(&self, i: u128) -> Self::Value;

‎compiler/rustc_const_eval/src/interpret/operand.rs

+7
Original file line numberDiff line numberDiff line change
@@ -224,6 +224,13 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> {
224224
Self::from_scalar(Scalar::from_bool(b), layout)
225225
}
226226

227+
#[inline]
228+
pub fn from_ordering(c: std::cmp::Ordering, tcx: TyCtxt<'tcx>) -> Self {
229+
let ty = tcx.ty_ordering_enum(None);
230+
let layout = tcx.layout_of(ty::ParamEnv::reveal_all().and(ty)).unwrap();
231+
Self::from_scalar(Scalar::from_i8(c as i8), layout)
232+
}
233+
227234
#[inline]
228235
pub fn to_const_int(self) -> ConstInt {
229236
assert!(self.layout.ty.is_integral());

‎compiler/rustc_const_eval/src/interpret/operator.rs

+18
Original file line numberDiff line numberDiff line change
@@ -61,6 +61,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
6161
}
6262

6363
impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
64+
fn three_way_compare<T: Ord>(&self, lhs: T, rhs: T) -> (ImmTy<'tcx, M::Provenance>, bool) {
65+
let res = Ord::cmp(&lhs, &rhs);
66+
return (ImmTy::from_ordering(res, *self.tcx), false);
67+
}
68+
6469
fn binary_char_op(
6570
&self,
6671
bin_op: mir::BinOp,
@@ -69,6 +74,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
6974
) -> (ImmTy<'tcx, M::Provenance>, bool) {
7075
use rustc_middle::mir::BinOp::*;
7176

77+
if bin_op == Cmp {
78+
return self.three_way_compare(l, r);
79+
}
80+
7281
let res = match bin_op {
7382
Eq => l == r,
7483
Ne => l != r,
@@ -231,6 +240,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
231240
let r = self.sign_extend(r, right_layout) as i128;
232241
return Ok((ImmTy::from_bool(op(&l, &r), *self.tcx), false));
233242
}
243+
if bin_op == Cmp {
244+
let l = self.sign_extend(l, left_layout) as i128;
245+
let r = self.sign_extend(r, right_layout) as i128;
246+
return Ok(self.three_way_compare(l, r));
247+
}
234248
let op: Option<fn(i128, i128) -> (i128, bool)> = match bin_op {
235249
Div if r == 0 => throw_ub!(DivisionByZero),
236250
Rem if r == 0 => throw_ub!(RemainderByZero),
@@ -270,6 +284,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
270284
}
271285
}
272286

287+
if bin_op == Cmp {
288+
return Ok(self.three_way_compare(l, r));
289+
}
290+
273291
let val = match bin_op {
274292
Eq => ImmTy::from_bool(l == r, *self.tcx),
275293
Ne => ImmTy::from_bool(l != r, *self.tcx),

‎compiler/rustc_const_eval/src/transform/promote_consts.rs

+1
Original file line numberDiff line numberDiff line change
@@ -573,6 +573,7 @@ impl<'tcx> Validator<'_, 'tcx> {
573573
| BinOp::Lt
574574
| BinOp::Ge
575575
| BinOp::Gt
576+
| BinOp::Cmp
576577
| BinOp::Offset
577578
| BinOp::Add
578579
| BinOp::AddUnchecked

‎compiler/rustc_const_eval/src/transform/validate.rs

+9
Original file line numberDiff line numberDiff line change
@@ -932,6 +932,15 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
932932
)
933933
}
934934
}
935+
Cmp => {
936+
for x in [a, b] {
937+
check_kinds!(
938+
x,
939+
"Cannot three-way compare non-integer type {:?}",
940+
ty::Char | ty::Uint(..) | ty::Int(..)
941+
)
942+
}
943+
}
935944
AddUnchecked | SubUnchecked | MulUnchecked | Shl | ShlUnchecked | Shr
936945
| ShrUnchecked => {
937946
for x in [a, b] {

‎compiler/rustc_const_eval/src/util/mod.rs

+2-2
Original file line numberDiff line numberDiff line change
@@ -19,7 +19,7 @@ pub(crate) fn binop_left_homogeneous(op: mir::BinOp) -> bool {
1919
match op {
2020
Add | AddUnchecked | Sub | SubUnchecked | Mul | MulUnchecked | Div | Rem | BitXor
2121
| BitAnd | BitOr | Offset | Shl | ShlUnchecked | Shr | ShrUnchecked => true,
22-
Eq | Ne | Lt | Le | Gt | Ge => false,
22+
Eq | Ne | Lt | Le | Gt | Ge | Cmp => false,
2323
}
2424
}
2525

@@ -30,7 +30,7 @@ pub(crate) fn binop_right_homogeneous(op: mir::BinOp) -> bool {
3030
use rustc_middle::mir::BinOp::*;
3131
match op {
3232
Add | AddUnchecked | Sub | SubUnchecked | Mul | MulUnchecked | Div | Rem | BitXor
33-
| BitAnd | BitOr | Eq | Ne | Lt | Le | Gt | Ge => true,
33+
| BitAnd | BitOr | Eq | Ne | Lt | Le | Gt | Ge | Cmp => true,
3434
Offset | Shl | ShlUnchecked | Shr | ShrUnchecked => false,
3535
}
3636
}

‎compiler/rustc_hir/src/lang_items.rs

+1
Original file line numberDiff line numberDiff line change
@@ -217,6 +217,7 @@ language_item_table! {
217217
Unpin, sym::unpin, unpin_trait, Target::Trait, GenericRequirement::None;
218218
Pin, sym::pin, pin_type, Target::Struct, GenericRequirement::None;
219219

220+
OrderingEnum, sym::Ordering, ordering_enum, Target::Enum, GenericRequirement::Exact(0);
220221
PartialEq, sym::eq, eq_trait, Target::Trait, GenericRequirement::Exact(1);
221222
PartialOrd, sym::partial_ord, partial_ord_trait, Target::Trait, GenericRequirement::Exact(1);
222223
CVoid, sym::c_void, c_void, Target::Enum, GenericRequirement::None;

‎compiler/rustc_hir_analysis/src/check/intrinsic.rs

+5
Original file line numberDiff line numberDiff line change
@@ -98,6 +98,7 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: DefId) -> hir
9898
| sym::cttz
9999
| sym::bswap
100100
| sym::bitreverse
101+
| sym::three_way_compare
101102
| sym::discriminant_value
102103
| sym::type_id
103104
| sym::likely
@@ -325,6 +326,10 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
325326
| sym::bswap
326327
| sym::bitreverse => (1, vec![param(0)], param(0)),
327328

329+
sym::three_way_compare => {
330+
(1, vec![param(0), param(0)], tcx.ty_ordering_enum(Some(it.span)))
331+
}
332+
328333
sym::add_with_overflow | sym::sub_with_overflow | sym::mul_with_overflow => {
329334
(1, vec![param(0), param(0)], Ty::new_tup(tcx, &[param(0), tcx.types.bool]))
330335
}

‎compiler/rustc_middle/src/mir/syntax.rs

+2
Original file line numberDiff line numberDiff line change
@@ -1429,6 +1429,8 @@ pub enum BinOp {
14291429
Ge,
14301430
/// The `>` operator (greater than)
14311431
Gt,
1432+
/// The `<=>` operator (three-way comparison, like `Ord::cmp`)
1433+
Cmp,
14321434
/// The `ptr.offset` operator
14331435
Offset,
14341436
}

‎compiler/rustc_middle/src/mir/tcx.rs

+7-1
Original file line numberDiff line numberDiff line change
@@ -264,6 +264,11 @@ impl<'tcx> BinOp {
264264
&BinOp::Eq | &BinOp::Lt | &BinOp::Le | &BinOp::Ne | &BinOp::Ge | &BinOp::Gt => {
265265
tcx.types.bool
266266
}
267+
&BinOp::Cmp => {
268+
// these should be integer-like types of the same size.
269+
assert_eq!(lhs_ty, rhs_ty);
270+
tcx.ty_ordering_enum(None)
271+
}
267272
}
268273
}
269274
}
@@ -300,7 +305,8 @@ impl BinOp {
300305
BinOp::Gt => hir::BinOpKind::Gt,
301306
BinOp::Le => hir::BinOpKind::Le,
302307
BinOp::Ge => hir::BinOpKind::Ge,
303-
BinOp::AddUnchecked
308+
BinOp::Cmp
309+
| BinOp::AddUnchecked
304310
| BinOp::SubUnchecked
305311
| BinOp::MulUnchecked
306312
| BinOp::ShlUnchecked

‎compiler/rustc_middle/src/ty/context.rs

+7
Original file line numberDiff line numberDiff line change
@@ -784,6 +784,13 @@ impl<'tcx> TyCtxt<'tcx> {
784784
self.get_lang_items(())
785785
}
786786

787+
/// Gets a `Ty` representing the [`LangItem::OrderingEnum`]
788+
#[track_caller]
789+
pub fn ty_ordering_enum(self, span: Option<Span>) -> Ty<'tcx> {
790+
let ordering_enum = self.require_lang_item(hir::LangItem::OrderingEnum, span);
791+
self.type_of(ordering_enum).no_bound_vars().unwrap()
792+
}
793+
787794
/// Obtain the given diagnostic item's `DefId`. Use `is_diagnostic_item` if you just want to
788795
/// compare against another `DefId`, since `is_diagnostic_item` is cheaper.
789796
pub fn get_diagnostic_item(self, name: Symbol) -> Option<DefId> {

‎compiler/rustc_mir_transform/src/lower_intrinsics.rs

+2
Original file line numberDiff line numberDiff line change
@@ -81,6 +81,7 @@ impl<'tcx> MirPass<'tcx> for LowerIntrinsics {
8181
sym::wrapping_add
8282
| sym::wrapping_sub
8383
| sym::wrapping_mul
84+
| sym::three_way_compare
8485
| sym::unchecked_add
8586
| sym::unchecked_sub
8687
| sym::unchecked_mul
@@ -100,6 +101,7 @@ impl<'tcx> MirPass<'tcx> for LowerIntrinsics {
100101
sym::wrapping_add => BinOp::Add,
101102
sym::wrapping_sub => BinOp::Sub,
102103
sym::wrapping_mul => BinOp::Mul,
104+
sym::three_way_compare => BinOp::Cmp,
103105
sym::unchecked_add => BinOp::AddUnchecked,
104106
sym::unchecked_sub => BinOp::SubUnchecked,
105107
sym::unchecked_mul => BinOp::MulUnchecked,

‎compiler/rustc_smir/src/rustc_smir/convert/mir.rs

+1
Original file line numberDiff line numberDiff line change
@@ -490,6 +490,7 @@ impl<'tcx> Stable<'tcx> for mir::BinOp {
490490
BinOp::Ne => stable_mir::mir::BinOp::Ne,
491491
BinOp::Ge => stable_mir::mir::BinOp::Ge,
492492
BinOp::Gt => stable_mir::mir::BinOp::Gt,
493+
BinOp::Cmp => stable_mir::mir::BinOp::Cmp,
493494
BinOp::Offset => stable_mir::mir::BinOp::Offset,
494495
}
495496
}

‎compiler/rustc_span/src/symbol.rs

+1
Original file line numberDiff line numberDiff line change
@@ -1658,6 +1658,7 @@ symbols! {
16581658
thread,
16591659
thread_local,
16601660
thread_local_macro,
1661+
three_way_compare,
16611662
thumb2,
16621663
thumb_mode: "thumb-mode",
16631664
tmm_reg,

‎compiler/rustc_ty_utils/src/consts.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -82,7 +82,7 @@ fn check_binop(op: mir::BinOp) -> bool {
8282
match op {
8383
Add | AddUnchecked | Sub | SubUnchecked | Mul | MulUnchecked | Div | Rem | BitXor
8484
| BitAnd | BitOr | Shl | ShlUnchecked | Shr | ShrUnchecked | Eq | Lt | Le | Ne | Ge
85-
| Gt => true,
85+
| Gt | Cmp => true,
8686
Offset => false,
8787
}
8888
}

‎compiler/stable_mir/src/mir/body.rs

+1
Original file line numberDiff line numberDiff line change
@@ -208,6 +208,7 @@ pub enum BinOp {
208208
Ne,
209209
Ge,
210210
Gt,
211+
Cmp,
211212
Offset,
212213
}
213214

‎library/core/src/cmp.rs

+8
Original file line numberDiff line numberDiff line change
@@ -352,6 +352,7 @@ pub struct AssertParamIsEq<T: Eq + ?Sized> {
352352
/// ```
353353
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
354354
#[stable(feature = "rust1", since = "1.0.0")]
355+
#[cfg_attr(not(bootstrap), lang = "Ordering")]
355356
#[repr(i8)]
356357
pub enum Ordering {
357358
/// An ordering where a compared value is less than another.
@@ -1513,12 +1514,19 @@ mod impls {
15131514
impl Ord for $t {
15141515
#[inline]
15151516
fn cmp(&self, other: &$t) -> Ordering {
1517+
#[cfg(bootstrap)]
1518+
{
15161519
// The order here is important to generate more optimal assembly.
15171520
// See <https://github.com/rust-lang/rust/issues/63758> for more info.
15181521
if *self < *other { Less }
15191522
else if *self == *other { Equal }
15201523
else { Greater }
15211524
}
1525+
#[cfg(not(bootstrap))]
1526+
{
1527+
crate::intrinsics::three_way_compare(*self, *other)
1528+
}
1529+
}
15221530
}
15231531
)*)
15241532
}

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