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Add+Use mir::BinOp::Cmp

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This commit is contained in:
Scott McMurray 2023-03-05 20:19:41 -08:00
parent 744c664ba2
commit 3da115a93b
35 changed files with 521 additions and 119 deletions
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3
compiler/rustc_codegen_cranelift/src/codegen_i128.rs
View file

@ -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!(),
}

24
compiler/rustc_codegen_cranelift/src/num.rs
View file

@ -40,6 +40,22 @@ pub(crate) fn bin_op_to_intcc(bin_op: BinOp, signed: bool) -> Option<IntCC> {
})
}
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
// <https://github.com/bytecodealliance/wasmtime/blob/8052bb9e3b792503b225f2a5b2ba3bc023bff462/cranelift/codegen/src/prelude_opt.isle#L41-L47>
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);
}
};

4
compiler/rustc_codegen_gcc/src/common.rs
View file

@ -94,6 +94,10 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
self.const_int(self.type_i32(), i as i64)
}
fn const_i8(&self, i: i8) -> RValue<'gcc> {
self.const_int(self.type_i8(), i as i64)
}
fn const_u32(&self, i: u32) -> RValue<'gcc> {
self.const_uint(self.type_u32(), i as u64)
}

4
compiler/rustc_codegen_llvm/src/common.rs
View file

@ -160,6 +160,10 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
self.const_int(self.type_i32(), i as i64)
}
fn const_i8(&self, i: i8) -> &'ll Value {
self.const_int(self.type_i8(), i as i64)
}
fn const_u32(&self, i: u32) -> &'ll Value {
self.const_uint(self.type_i32(), i as u64)
}

30
compiler/rustc_codegen_ssa/src/mir/rvalue.rs
View file

@ -7,6 +7,7 @@ use crate::common::{self, IntPredicate};
use crate::traits::*;
use crate::MemFlags;
use rustc_hir as hir;
use rustc_middle::mir;
use rustc_middle::mir::Operand;
use rustc_middle::ty::cast::{CastTy, IntTy};
@ -882,6 +883,35 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
bx.icmp(base::bin_op_to_icmp_predicate(op.to_hir_binop(), is_signed), lhs, rhs)
}
}
mir::BinOp::Cmp => {
use std::cmp::Ordering;
debug_assert!(!is_float);
let pred = |op| base::bin_op_to_icmp_predicate(op, is_signed);
if bx.cx().tcx().sess.opts.optimize == OptLevel::No {
// FIXME: This actually generates tighter assembly, and is a classic trick
// <https://graphics.stanford.edu/~seander/bithacks.html#CopyIntegerSign>
// However, as of 2023-11 it optimizes worse in things like derived
// `PartialOrd`, so only use it in debug for now. Once LLVM can handle it
// better (see <https://github.com/llvm/llvm-project/issues/73417>), it'll
// be worth trying it in optimized builds as well.
let is_gt = bx.icmp(pred(hir::BinOpKind::Gt), lhs, rhs);
let gtext = bx.zext(is_gt, bx.type_i8());
let is_lt = bx.icmp(pred(hir::BinOpKind::Lt), lhs, rhs);
let ltext = bx.zext(is_lt, bx.type_i8());
bx.unchecked_ssub(gtext, ltext)
} else {
// These operations are those expected by `tests/codegen/integer-cmp.rs`,
// from <https://github.com/rust-lang/rust/pull/63767>.
let is_lt = bx.icmp(pred(hir::BinOpKind::Lt), lhs, rhs);
let is_ne = bx.icmp(pred(hir::BinOpKind::Ne), lhs, rhs);
let ge = bx.select(
is_ne,
bx.cx().const_i8(Ordering::Greater as i8),
bx.cx().const_i8(Ordering::Equal as i8),
);
bx.select(is_lt, bx.cx().const_i8(Ordering::Less as i8), ge)
}
}
}
}

1
compiler/rustc_codegen_ssa/src/traits/consts.rs
View file

@ -19,6 +19,7 @@ pub trait ConstMethods<'tcx>: BackendTypes {
fn const_bool(&self, val: bool) -> Self::Value;
fn const_i16(&self, i: i16) -> Self::Value;
fn const_i32(&self, i: i32) -> Self::Value;
fn const_i8(&self, i: i8) -> Self::Value;
fn const_u32(&self, i: u32) -> Self::Value;
fn const_u64(&self, i: u64) -> Self::Value;
fn const_u128(&self, i: u128) -> Self::Value;

7
compiler/rustc_const_eval/src/interpret/operand.rs
View file

@ -235,6 +235,13 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> {
Self::from_scalar(Scalar::from_bool(b), layout)
}
#[inline]
pub fn from_ordering(c: std::cmp::Ordering, tcx: TyCtxt<'tcx>) -> Self {
let ty = tcx.ty_ordering_enum(None);
let layout = tcx.layout_of(ty::ParamEnv::reveal_all().and(ty)).unwrap();
Self::from_scalar(Scalar::from_i8(c as i8), layout)
}
#[inline]
pub fn to_const_int(self) -> ConstInt {
assert!(self.layout.ty.is_integral());

18
compiler/rustc_const_eval/src/interpret/operator.rs
View file

@ -61,6 +61,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}
impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
fn three_way_compare<T: Ord>(&self, lhs: T, rhs: T) -> (ImmTy<'tcx, M::Provenance>, bool) {
let res = Ord::cmp(&lhs, &rhs);
return (ImmTy::from_ordering(res, *self.tcx), false);
}
fn binary_char_op(
&self,
bin_op: mir::BinOp,
@ -69,6 +74,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
) -> (ImmTy<'tcx, M::Provenance>, bool) {
use rustc_middle::mir::BinOp::*;
if bin_op == Cmp {
return self.three_way_compare(l, r);
}
let res = match bin_op {
Eq => l == r,
Ne => l != r,
@ -231,6 +240,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
let r = self.sign_extend(r, right_layout) as i128;
return Ok((ImmTy::from_bool(op(&l, &r), *self.tcx), false));
}
if bin_op == Cmp {
let l = self.sign_extend(l, left_layout) as i128;
let r = self.sign_extend(r, right_layout) as i128;
return Ok(self.three_way_compare(l, r));
}
let op: Option<fn(i128, i128) -> (i128, bool)> = match bin_op {
Div if r == 0 => throw_ub!(DivisionByZero),
Rem if r == 0 => throw_ub!(RemainderByZero),
@ -270,6 +284,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}
}
if bin_op == Cmp {
return Ok(self.three_way_compare(l, r));
}
let val = match bin_op {
Eq => ImmTy::from_bool(l == r, *self.tcx),
Ne => ImmTy::from_bool(l != r, *self.tcx),

9
compiler/rustc_const_eval/src/transform/validate.rs
View file

@ -987,6 +987,15 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
)
}
}
Cmp => {
for x in [a, b] {
check_kinds!(
x,
"Cannot three-way compare non-integer type {:?}",
ty::Char | ty::Uint(..) | ty::Int(..)
)
}
}
AddUnchecked | SubUnchecked | MulUnchecked | Shl | ShlUnchecked | Shr
| ShrUnchecked => {
for x in [a, b] {

4
compiler/rustc_const_eval/src/util/mod.rs
View file

@ -19,7 +19,7 @@ pub fn binop_left_homogeneous(op: mir::BinOp) -> bool {
match op {
Add | AddUnchecked | Sub | SubUnchecked | Mul | MulUnchecked | Div | Rem | BitXor
| BitAnd | BitOr | Offset | Shl | ShlUnchecked | Shr | ShrUnchecked => true,
Eq | Ne | Lt | Le | Gt | Ge => false,
Eq | Ne | Lt | Le | Gt | Ge | Cmp => false,
}
}
@ -30,7 +30,7 @@ pub fn binop_right_homogeneous(op: mir::BinOp) -> bool {
use rustc_middle::mir::BinOp::*;
match op {
Add | AddUnchecked | Sub | SubUnchecked | Mul | MulUnchecked | Div | Rem | BitXor
| BitAnd | BitOr | Eq | Ne | Lt | Le | Gt | Ge => true,
| BitAnd | BitOr | Eq | Ne | Lt | Le | Gt | Ge | Cmp => true,
Offset | Shl | ShlUnchecked | Shr | ShrUnchecked => false,
}
}

1
compiler/rustc_hir/src/lang_items.rs
View file

@ -225,6 +225,7 @@ language_item_table! {
Unpin, sym::unpin, unpin_trait, Target::Trait, GenericRequirement::None;
Pin, sym::pin, pin_type, Target::Struct, GenericRequirement::None;
OrderingEnum, sym::Ordering, ordering_enum, Target::Enum, GenericRequirement::Exact(0);
PartialEq, sym::eq, eq_trait, Target::Trait, GenericRequirement::Exact(1);
PartialOrd, sym::partial_ord, partial_ord_trait, Target::Trait, GenericRequirement::Exact(1);
CVoid, sym::c_void, c_void, Target::Enum, GenericRequirement::None;

5
compiler/rustc_hir_analysis/src/check/intrinsic.rs
View file

@ -107,6 +107,7 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -
| sym::cttz
| sym::bswap
| sym::bitreverse
| sym::three_way_compare
| sym::discriminant_value
| sym::type_id
| sym::likely
@ -418,6 +419,10 @@ pub fn check_intrinsic_type(
| sym::bswap
| sym::bitreverse => (1, 0, vec![param(0)], param(0)),
sym::three_way_compare => {
(1, 0, vec![param(0), param(0)], tcx.ty_ordering_enum(Some(span)))
}
sym::add_with_overflow | sym::sub_with_overflow | sym::mul_with_overflow => {
(1, 0, vec![param(0), param(0)], Ty::new_tup(tcx, &[param(0), tcx.types.bool]))
}

2
compiler/rustc_middle/src/mir/syntax.rs
View file

@ -1444,6 +1444,8 @@ pub enum BinOp {
Ge,
/// The `>` operator (greater than)
Gt,
/// The `<=>` operator (three-way comparison, like `Ord::cmp`)
Cmp,
/// The `ptr.offset` operator
Offset,
}

8
compiler/rustc_middle/src/mir/tcx.rs
View file

@ -276,6 +276,11 @@ impl<'tcx> BinOp {
&BinOp::Eq | &BinOp::Lt | &BinOp::Le | &BinOp::Ne | &BinOp::Ge | &BinOp::Gt => {
tcx.types.bool
}
&BinOp::Cmp => {
// these should be integer-like types of the same size.
assert_eq!(lhs_ty, rhs_ty);
tcx.ty_ordering_enum(None)
}
}
}
}
@ -312,7 +317,8 @@ impl BinOp {
BinOp::Gt => hir::BinOpKind::Gt,
BinOp::Le => hir::BinOpKind::Le,
BinOp::Ge => hir::BinOpKind::Ge,
BinOp::AddUnchecked
BinOp::Cmp
| BinOp::AddUnchecked
| BinOp::SubUnchecked
| BinOp::MulUnchecked
| BinOp::ShlUnchecked

7
compiler/rustc_middle/src/ty/context.rs
View file

@ -905,6 +905,13 @@ impl<'tcx> TyCtxt<'tcx> {
self.get_lang_items(())
}
/// Gets a `Ty` representing the [`LangItem::OrderingEnum`]
#[track_caller]
pub fn ty_ordering_enum(self, span: Option<Span>) -> Ty<'tcx> {
let ordering_enum = self.require_lang_item(hir::LangItem::OrderingEnum, span);
self.type_of(ordering_enum).no_bound_vars().unwrap()
}
/// Obtain the given diagnostic item's `DefId`. Use `is_diagnostic_item` if you just want to
/// compare against another `DefId`, since `is_diagnostic_item` is cheaper.
pub fn get_diagnostic_item(self, name: Symbol) -> Option<DefId> {

2
compiler/rustc_mir_transform/src/lower_intrinsics.rs
View file

@ -90,6 +90,7 @@ impl<'tcx> MirPass<'tcx> for LowerIntrinsics {
sym::wrapping_add
| sym::wrapping_sub
| sym::wrapping_mul
| sym::three_way_compare
| sym::unchecked_add
| sym::unchecked_sub
| sym::unchecked_mul
@ -109,6 +110,7 @@ impl<'tcx> MirPass<'tcx> for LowerIntrinsics {
sym::wrapping_add => BinOp::Add,
sym::wrapping_sub => BinOp::Sub,
sym::wrapping_mul => BinOp::Mul,
sym::three_way_compare => BinOp::Cmp,
sym::unchecked_add => BinOp::AddUnchecked,
sym::unchecked_sub => BinOp::SubUnchecked,
sym::unchecked_mul => BinOp::MulUnchecked,

1
compiler/rustc_mir_transform/src/promote_consts.rs
View file

@ -525,6 +525,7 @@ impl<'tcx> Validator<'_, 'tcx> {
| BinOp::Lt
| BinOp::Ge
| BinOp::Gt
| BinOp::Cmp
| BinOp::Offset
| BinOp::Add
| BinOp::AddUnchecked

1
compiler/rustc_smir/src/rustc_smir/convert/mir.rs
View file

@ -493,6 +493,7 @@ impl<'tcx> Stable<'tcx> for mir::BinOp {
BinOp::Ne => stable_mir::mir::BinOp::Ne,
BinOp::Ge => stable_mir::mir::BinOp::Ge,
BinOp::Gt => stable_mir::mir::BinOp::Gt,
BinOp::Cmp => stable_mir::mir::BinOp::Cmp,
BinOp::Offset => stable_mir::mir::BinOp::Offset,
}
}

1
compiler/rustc_span/src/symbol.rs
View file

@ -1785,6 +1785,7 @@ symbols! {
thread,
thread_local,
thread_local_macro,
three_way_compare,
thumb2,
thumb_mode: "thumb-mode",
tmm_reg,

2
compiler/rustc_ty_utils/src/consts.rs
View file

@ -82,7 +82,7 @@ fn check_binop(op: mir::BinOp) -> bool {
match op {
Add | AddUnchecked | Sub | SubUnchecked | Mul | MulUnchecked | Div | Rem | BitXor
| BitAnd | BitOr | Shl | ShlUnchecked | Shr | ShrUnchecked | Eq | Lt | Le | Ne | Ge
| Gt => true,
| Gt | Cmp => true,
Offset => false,
}
}

4
compiler/stable_mir/src/mir/body.rs
View file

@ -329,6 +329,7 @@ pub enum BinOp {
Ne,
Ge,
Gt,
Cmp,
Offset,
}
@ -368,6 +369,9 @@ impl BinOp {
assert!(lhs_kind.is_primitive() || lhs_kind.is_raw_ptr() || lhs_kind.is_fn_ptr());
Ty::bool_ty()
}
BinOp::Cmp => {
unimplemented!("Should cmp::Ordering be a RigidTy?");
}
}
}
}

8
library/core/src/cmp.rs
View file

@ -376,6 +376,7 @@ pub struct AssertParamIsEq<T: Eq + ?Sized> {
/// ```
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
#[stable(feature = "rust1", since = "1.0.0")]
#[cfg_attr(not(bootstrap), lang = "Ordering")]
#[repr(i8)]
pub enum Ordering {
/// An ordering where a compared value is less than another.
@ -1563,12 +1564,19 @@ mod impls {
impl Ord for $t {
#[inline]
fn cmp(&self, other: &$t) -> Ordering {
#[cfg(bootstrap)]
{
// The order here is important to generate more optimal assembly.
// See <https://github.com/rust-lang/rust/issues/63758> for more info.
if *self < *other { Less }
else if *self == *other { Equal }
else { Greater }
}
#[cfg(not(bootstrap))]
{
crate::intrinsics::three_way_compare(*self, *other)
}
}
}
)*)
}

12
library/core/src/intrinsics.rs
View file

@ -2146,6 +2146,18 @@ extern "rust-intrinsic" {
#[rustc_nounwind]
pub fn bitreverse<T: Copy>(x: T) -> T;
/// Does a three-way comparison between the two integer arguments.
///
/// This is included as an intrinsic as it's useful to let it be one thing
/// in MIR, rather than the multiple checks and switches that make its IR
/// large and difficult to optimize.
///
/// The stabilized version of this intrinsic is [`Ord::cmp`].
#[cfg(not(bootstrap))]
#[rustc_const_unstable(feature = "const_three_way_compare", issue = "none")]
#[rustc_safe_intrinsic]
pub fn three_way_compare<T: Copy>(lhs: T, rhs: T) -> crate::cmp::Ordering;
/// Performs checked integer addition.
///
/// Note that, unlike most intrinsics, this is safe to call;

19
library/core/tests/intrinsics.rs
View file

@ -99,3 +99,22 @@ fn test_const_deallocate_at_runtime() {
const_deallocate(core::ptr::null_mut(), 1, 1); // nop
}
}
#[cfg(not(bootstrap))]
#[test]
fn test_three_way_compare_in_const_contexts() {
use core::cmp::Ordering::*;
use core::intrinsics::three_way_compare;
const {
assert!(Less as i8 == three_way_compare(123_u16, 456) as _);
assert!(Equal as i8 == three_way_compare(456_u16, 456) as _);
assert!(Greater as i8 == three_way_compare(789_u16, 456) as _);
assert!(Less as i8 == three_way_compare('A', 'B') as _);
assert!(Equal as i8 == three_way_compare('B', 'B') as _);
assert!(Greater as i8 == three_way_compare('C', 'B') as _);
assert!(Less as i8 == three_way_compare(-123_i16, 456) as _);
assert!(Equal as i8 == three_way_compare(456_i16, 456) as _);
assert!(Greater as i8 == three_way_compare(123_i16, -456) as _);
}
}

1
library/core/tests/lib.rs
View file

@ -21,6 +21,7 @@
#![feature(const_pointer_is_aligned)]
#![feature(const_ptr_as_ref)]
#![feature(const_ptr_write)]
#![cfg_attr(not(bootstrap), feature(const_three_way_compare))]
#![feature(const_trait_impl)]
#![feature(const_likely)]
#![feature(const_location_fields)]

51
tests/assembly/x86_64-cmp.rs Normal file
View file

@ -0,0 +1,51 @@
//@ revisions: DEBUG OPTIM
//@ [DEBUG] compile-flags: -C opt-level=0
//@ [OPTIM] compile-flags: -C opt-level=3
//@ assembly-output: emit-asm
//@ compile-flags: --crate-type=lib -C llvm-args=-x86-asm-syntax=intel
//@ only-x86_64
//@ ignore-sgx
#![feature(core_intrinsics)]
use std::intrinsics::three_way_compare;
#[no_mangle]
// CHECK-LABEL: signed_cmp:
pub fn signed_cmp(a: i16, b: i16) -> std::cmp::Ordering {
// DEBUG: cmp
// DEBUG: setg
// DEBUG: and
// DEBUG: cmp
// DEBUG: setl
// DEBUG: and
// DEBUG: sub
// OPTIM: xor
// OPTIM: cmp
// OPTIM: setne
// OPTIM: mov
// OPTIM: cmovge
// OPTIM: ret
three_way_compare(a, b)
}
#[no_mangle]
// CHECK-LABEL: unsigned_cmp:
pub fn unsigned_cmp(a: u16, b: u16) -> std::cmp::Ordering {
// DEBUG: cmp
// DEBUG: seta
// DEBUG: and
// DEBUG: cmp
// DEBUG: setb
// DEBUG: and
// DEBUG: sub
// OPTIM: xor
// OPTIM: cmp
// OPTIM: setne
// OPTIM: mov
// OPTIM: cmovae
// OPTIM: ret
three_way_compare(a, b)
}

47
tests/codegen/intrinsics/three_way_compare.rs Normal file
View file

@ -0,0 +1,47 @@
//@ revisions: DEBUG OPTIM
//@ [DEBUG] compile-flags: -C opt-level=0
//@ [OPTIM] compile-flags: -C opt-level=3
//@ compile-flags: -C no-prepopulate-passes
#![crate_type = "lib"]
#![feature(core_intrinsics)]
use std::intrinsics::three_way_compare;
#[no_mangle]
// CHECK-LABEL: @signed_cmp
// DEBUG-SAME: (i16 %a, i16 %b)
// OPTIM-SAME: (i16 noundef %a, i16 noundef %b)
pub fn signed_cmp(a: i16, b: i16) -> std::cmp::Ordering {
// DEBUG: %[[GT:.+]] = icmp sgt i16 %a, %b
// DEBUG: %[[ZGT:.+]] = zext i1 %[[GT]] to i8
// DEBUG: %[[LT:.+]] = icmp slt i16 %a, %b
// DEBUG: %[[ZLT:.+]] = zext i1 %[[LT]] to i8
// DEBUG: %[[R:.+]] = sub nsw i8 %[[ZGT]], %[[ZLT]]
// OPTIM: %[[LT:.+]] = icmp slt i16 %a, %b
// OPTIM: %[[NE:.+]] = icmp ne i16 %a, %b
// OPTIM: %[[CGE:.+]] = select i1 %[[NE]], i8 1, i8 0
// OPTIM: %[[CGEL:.+]] = select i1 %[[LT]], i8 -1, i8 %[[CGE]]
// OPTIM: ret i8 %[[CGEL]]
three_way_compare(a, b)
}
#[no_mangle]
// CHECK-LABEL: @unsigned_cmp
// DEBUG-SAME: (i16 %a, i16 %b)
// OPTIM-SAME: (i16 noundef %a, i16 noundef %b)
pub fn unsigned_cmp(a: u16, b: u16) -> std::cmp::Ordering {
// DEBUG: %[[GT:.+]] = icmp ugt i16 %a, %b
// DEBUG: %[[ZGT:.+]] = zext i1 %[[GT]] to i8
// DEBUG: %[[LT:.+]] = icmp ult i16 %a, %b
// DEBUG: %[[ZLT:.+]] = zext i1 %[[LT]] to i8
// DEBUG: %[[R:.+]] = sub nsw i8 %[[ZGT]], %[[ZLT]]
// OPTIM: %[[LT:.+]] = icmp ult i16 %a, %b
// OPTIM: %[[NE:.+]] = icmp ne i16 %a, %b
// OPTIM: %[[CGE:.+]] = select i1 %[[NE]], i8 1, i8 0
// OPTIM: %[[CGEL:.+]] = select i1 %[[LT]], i8 -1, i8 %[[CGE]]
// OPTIM: ret i8 %[[CGEL]]
three_way_compare(a, b)
}

15
tests/mir-opt/lower_intrinsics.rs
View file

@ -229,3 +229,18 @@ pub unsafe fn ptr_offset(p: *const i32, d: isize) -> *const i32 {
core::intrinsics::offset(p, d)
}
// EMIT_MIR lower_intrinsics.three_way_compare_char.LowerIntrinsics.diff
pub fn three_way_compare_char(a: char, b: char) {
let _x = core::intrinsics::three_way_compare(a, b);
}
// EMIT_MIR lower_intrinsics.three_way_compare_signed.LowerIntrinsics.diff
pub fn three_way_compare_signed(a: i16, b: i16) {
core::intrinsics::three_way_compare(a, b);
}
// EMIT_MIR lower_intrinsics.three_way_compare_unsigned.LowerIntrinsics.diff
pub fn three_way_compare_unsigned(a: u32, b: u32) {
let _x = core::intrinsics::three_way_compare(a, b);
}

34
tests/mir-opt/lower_intrinsics.three_way_compare_char.LowerIntrinsics.panic-abort.diff Normal file
View file

@ -0,0 +1,34 @@
- // MIR for `three_way_compare_char` before LowerIntrinsics
+ // MIR for `three_way_compare_char` after LowerIntrinsics
fn three_way_compare_char(_1: char, _2: char) -> () {
debug a => _1;
debug b => _2;
let mut _0: ();
let _3: std::cmp::Ordering;
let mut _4: char;
let mut _5: char;
scope 1 {
debug _x => _3;
}
bb0: {
StorageLive(_3);
StorageLive(_4);
_4 = _1;
StorageLive(_5);
_5 = _2;
- _3 = three_way_compare::<char>(move _4, move _5) -> [return: bb1, unwind unreachable];
+ _3 = Cmp(move _4, move _5);
+ goto -> bb1;
}
bb1: {
StorageDead(_5);
StorageDead(_4);
_0 = const ();
StorageDead(_3);
return;
}
}

34
tests/mir-opt/lower_intrinsics.three_way_compare_char.LowerIntrinsics.panic-unwind.diff Normal file
View file

@ -0,0 +1,34 @@
- // MIR for `three_way_compare_char` before LowerIntrinsics
+ // MIR for `three_way_compare_char` after LowerIntrinsics
fn three_way_compare_char(_1: char, _2: char) -> () {
debug a => _1;
debug b => _2;
let mut _0: ();
let _3: std::cmp::Ordering;
let mut _4: char;
let mut _5: char;
scope 1 {
debug _x => _3;
}
bb0: {
StorageLive(_3);
StorageLive(_4);
_4 = _1;
StorageLive(_5);
_5 = _2;
- _3 = three_way_compare::<char>(move _4, move _5) -> [return: bb1, unwind continue];
+ _3 = Cmp(move _4, move _5);
+ goto -> bb1;
}
bb1: {
StorageDead(_5);
StorageDead(_4);
_0 = const ();
StorageDead(_3);
return;
}
}

31
tests/mir-opt/lower_intrinsics.three_way_compare_signed.LowerIntrinsics.panic-abort.diff Normal file
View file

@ -0,0 +1,31 @@
- // MIR for `three_way_compare_signed` before LowerIntrinsics
+ // MIR for `three_way_compare_signed` after LowerIntrinsics
fn three_way_compare_signed(_1: i16, _2: i16) -> () {
debug a => _1;
debug b => _2;
let mut _0: ();
let _3: std::cmp::Ordering;
let mut _4: i16;
let mut _5: i16;
bb0: {
StorageLive(_3);
StorageLive(_4);
_4 = _1;
StorageLive(_5);
_5 = _2;
- _3 = three_way_compare::<i16>(move _4, move _5) -> [return: bb1, unwind unreachable];
+ _3 = Cmp(move _4, move _5);
+ goto -> bb1;
}
bb1: {
StorageDead(_5);
StorageDead(_4);
StorageDead(_3);
_0 = const ();
return;
}
}

31
tests/mir-opt/lower_intrinsics.three_way_compare_signed.LowerIntrinsics.panic-unwind.diff Normal file
View file

@ -0,0 +1,31 @@
- // MIR for `three_way_compare_signed` before LowerIntrinsics
+ // MIR for `three_way_compare_signed` after LowerIntrinsics
fn three_way_compare_signed(_1: i16, _2: i16) -> () {
debug a => _1;
debug b => _2;
let mut _0: ();
let _3: std::cmp::Ordering;
let mut _4: i16;
let mut _5: i16;
bb0: {
StorageLive(_3);
StorageLive(_4);
_4 = _1;
StorageLive(_5);
_5 = _2;
- _3 = three_way_compare::<i16>(move _4, move _5) -> [return: bb1, unwind continue];
+ _3 = Cmp(move _4, move _5);
+ goto -> bb1;
}
bb1: {
StorageDead(_5);
StorageDead(_4);
StorageDead(_3);
_0 = const ();
return;
}
}

34
tests/mir-opt/lower_intrinsics.three_way_compare_unsigned.LowerIntrinsics.panic-abort.diff Normal file
View file

@ -0,0 +1,34 @@
- // MIR for `three_way_compare_unsigned` before LowerIntrinsics
+ // MIR for `three_way_compare_unsigned` after LowerIntrinsics
fn three_way_compare_unsigned(_1: u32, _2: u32) -> () {
debug a => _1;
debug b => _2;
let mut _0: ();
let _3: std::cmp::Ordering;
let mut _4: u32;
let mut _5: u32;
scope 1 {
debug _x => _3;
}
bb0: {
StorageLive(_3);
StorageLive(_4);
_4 = _1;
StorageLive(_5);
_5 = _2;
- _3 = three_way_compare::<u32>(move _4, move _5) -> [return: bb1, unwind unreachable];
+ _3 = Cmp(move _4, move _5);
+ goto -> bb1;
}
bb1: {
StorageDead(_5);
StorageDead(_4);
_0 = const ();
StorageDead(_3);
return;
}
}

34
tests/mir-opt/lower_intrinsics.three_way_compare_unsigned.LowerIntrinsics.panic-unwind.diff Normal file
View file

@ -0,0 +1,34 @@
- // MIR for `three_way_compare_unsigned` before LowerIntrinsics
+ // MIR for `three_way_compare_unsigned` after LowerIntrinsics
fn three_way_compare_unsigned(_1: u32, _2: u32) -> () {
debug a => _1;
debug b => _2;
let mut _0: ();
let _3: std::cmp::Ordering;
let mut _4: u32;
let mut _5: u32;
scope 1 {
debug _x => _3;
}
bb0: {
StorageLive(_3);
StorageLive(_4);
_4 = _1;
StorageLive(_5);
_5 = _2;
- _3 = three_way_compare::<u32>(move _4, move _5) -> [return: bb1, unwind continue];
+ _3 = Cmp(move _4, move _5);
+ goto -> bb1;
}
bb1: {
StorageDead(_5);
StorageDead(_4);
_0 = const ();
StorageDead(_3);
return;
}
}

151
tests/mir-opt/pre-codegen/derived_ord.{impl#0}-partial_cmp.PreCodegen.after.mir
View file

@ -6,37 +6,33 @@ fn <impl at $DIR/derived_ord.rs:6:10: 6:20>::partial_cmp(_1: &MultiField, _2: &M
let mut _0: std::option::Option<std::cmp::Ordering>;
let mut _3: &char;
let mut _4: &char;
let mut _10: std::option::Option<std::cmp::Ordering>;
let mut _8: std::option::Option<std::cmp::Ordering>;
let mut _9: i8;
let mut _10: &i16;
let mut _11: &i16;
let mut _12: &i16;
let _18: std::option::Option<std::cmp::Ordering>;
scope 1 {
debug cmp => _18;
debug cmp => _8;
}
scope 2 (inlined std::cmp::impls::<impl PartialOrd for char>::partial_cmp) {
debug self => _3;
debug other => _4;
let mut _9: std::cmp::Ordering;
let mut _7: std::cmp::Ordering;
scope 3 (inlined std::cmp::impls::<impl Ord for char>::cmp) {
debug self => _3;
debug other => _4;
let mut _5: char;
let mut _6: char;
let mut _7: bool;
let mut _8: bool;
}
}
scope 4 (inlined std::cmp::impls::<impl PartialOrd for i16>::partial_cmp) {
debug self => _11;
debug other => _12;
let mut _17: std::cmp::Ordering;
debug self => _10;
debug other => _11;
let mut _14: std::cmp::Ordering;
scope 5 (inlined std::cmp::impls::<impl Ord for i16>::cmp) {
debug self => _11;
debug other => _12;
debug self => _10;
debug other => _11;
let mut _12: i16;
let mut _13: i16;
let mut _14: i16;
let mut _15: bool;
let mut _16: bool;
}
}
@ -45,115 +41,46 @@ fn <impl at $DIR/derived_ord.rs:6:10: 6:20>::partial_cmp(_1: &MultiField, _2: &M
_3 = &((*_1).0: char);
StorageLive(_4);
_4 = &((*_2).0: char);
StorageLive(_9);
StorageLive(_5);
StorageLive(_6);
StorageLive(_7);
_5 = ((*_1).0: char);
StorageLive(_6);
_6 = ((*_2).0: char);
_7 = Lt(_5, _6);
switchInt(move _7) -> [0: bb1, otherwise: bb10];
_7 = Cmp(move _5, move _6);
StorageDead(_6);
StorageDead(_5);
_8 = Option::<std::cmp::Ordering>::Some(_7);
StorageDead(_4);
StorageDead(_3);
_9 = discriminant(_7);
switchInt(move _9) -> [0: bb1, otherwise: bb2];
}
bb1: {
StorageLive(_8);
_8 = Eq(_5, _6);
switchInt(move _8) -> [0: bb2, otherwise: bb3];
StorageLive(_10);
_10 = &((*_1).1: i16);
StorageLive(_11);
_11 = &((*_2).1: i16);
StorageLive(_14);
StorageLive(_12);
_12 = ((*_1).1: i16);
StorageLive(_13);
_13 = ((*_2).1: i16);
_14 = Cmp(move _12, move _13);
StorageDead(_13);
StorageDead(_12);
_0 = Option::<std::cmp::Ordering>::Some(move _14);
StorageDead(_14);
StorageDead(_11);
StorageDead(_10);
goto -> bb3;
}
bb2: {
_9 = const Greater;
StorageDead(_8);
StorageDead(_7);
StorageDead(_6);
StorageDead(_5);
_10 = Option::<std::cmp::Ordering>::Some(move _9);
StorageDead(_9);
StorageDead(_4);
StorageDead(_3);
goto -> bb11;
_0 = _8;
goto -> bb3;
}
bb3: {
StorageDead(_8);
StorageDead(_7);
StorageDead(_6);
StorageDead(_5);
StorageDead(_9);
StorageDead(_4);
StorageDead(_3);
StorageLive(_11);
_11 = &((*_1).1: i16);
StorageLive(_12);
_12 = &((*_2).1: i16);
StorageLive(_17);
StorageLive(_13);
StorageLive(_14);
StorageLive(_15);
_13 = ((*_1).1: i16);
_14 = ((*_2).1: i16);
_15 = Lt(_13, _14);
switchInt(move _15) -> [0: bb4, otherwise: bb8];
}
bb4: {
StorageLive(_16);
_16 = Eq(_13, _14);
switchInt(move _16) -> [0: bb5, otherwise: bb6];
}
bb5: {
_17 = const Greater;
goto -> bb7;
}
bb6: {
_17 = const Equal;
goto -> bb7;
}
bb7: {
StorageDead(_16);
goto -> bb9;
}
bb8: {
_17 = const Less;
goto -> bb9;
}
bb9: {
StorageDead(_15);
StorageDead(_14);
StorageDead(_13);
_0 = Option::<std::cmp::Ordering>::Some(move _17);
StorageDead(_17);
StorageDead(_12);
StorageDead(_11);
goto -> bb12;
}
bb10: {
_9 = const Less;
StorageDead(_7);
StorageDead(_6);
StorageDead(_5);
_10 = Option::<std::cmp::Ordering>::Some(move _9);
StorageDead(_9);
StorageDead(_4);
StorageDead(_3);
goto -> bb11;
}
bb11: {
StorageLive(_18);
_18 = _10;
_0 = _10;
StorageDead(_18);
goto -> bb12;
}
bb12: {
return;
}
}