From fa9a911a57eff5d2cd59eacbffb4e41bc721db2e Mon Sep 17 00:00:00 2001
From: joboet <jonasboettiger@icloud.com>
Date: Sat, 13 Jan 2024 20:10:00 +0100
Subject: [PATCH 1/2] libs: use `assert_unchecked` instead of intrinsic
---
library/alloc/src/alloc.rs | 6 +++---
library/alloc/src/lib.rs | 1 +
library/alloc/src/raw_vec.rs | 8 ++++----
library/alloc/src/rc.rs | 5 +++--
library/alloc/src/vec/mod.rs | 2 +-
library/core/src/alloc/global.rs | 2 +-
library/core/src/lib.rs | 1 +
library/core/src/num/mod.rs | 1 +
library/core/src/num/uint_macros.rs | 4 ++--
library/core/src/slice/index.rs | 2 +-
library/core/src/slice/iter.rs | 2 +-
library/core/src/slice/iter/macros.rs | 4 ++--
library/core/src/slice/mod.rs | 5 +++--
library/std/src/alloc.rs | 6 +++---
library/std/src/lib.rs | 1 +
15 files changed, 28 insertions(+), 22 deletions(-)
diff --git a/library/alloc/src/alloc.rs b/library/alloc/src/alloc.rs
index 1663aa84921..0b142939755 100644
--- a/library/alloc/src/alloc.rs
+++ b/library/alloc/src/alloc.rs
@@ -3,7 +3,7 @@
#![stable(feature = "alloc_module", since = "1.28.0")]
#[cfg(not(test))]
-use core::intrinsics;
+use core::hint;
#[cfg(not(test))]
use core::ptr::{self, NonNull};
@@ -208,7 +208,7 @@ impl Global {
let new_size = new_layout.size();
// `realloc` probably checks for `new_size >= old_layout.size()` or something similar.
- intrinsics::assume(new_size >= old_layout.size());
+ hint::assert_unchecked(new_size >= old_layout.size());
let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size);
let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
@@ -299,7 +299,7 @@ unsafe impl Allocator for Global {
// SAFETY: `new_size` is non-zero. Other conditions must be upheld by the caller
new_size if old_layout.align() == new_layout.align() => unsafe {
// `realloc` probably checks for `new_size <= old_layout.size()` or something similar.
- intrinsics::assume(new_size <= old_layout.size());
+ hint::assert_unchecked(new_size <= old_layout.size());
let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size);
let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index 78629b39d34..02ecbe22b3e 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -129,6 +129,7 @@
#![feature(fmt_internals)]
#![feature(fn_traits)]
#![feature(hasher_prefixfree_extras)]
+#![feature(hint_assert_unchecked)]
#![feature(inline_const)]
#![feature(inplace_iteration)]
#![feature(iter_advance_by)]
diff --git a/library/alloc/src/raw_vec.rs b/library/alloc/src/raw_vec.rs
index 45e82240164..94e6924f41a 100644
--- a/library/alloc/src/raw_vec.rs
+++ b/library/alloc/src/raw_vec.rs
@@ -2,7 +2,7 @@
use core::alloc::LayoutError;
use core::cmp;
-use core::intrinsics;
+use core::hint;
use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties};
use core::ptr::{self, NonNull, Unique};
use core::slice;
@@ -325,7 +325,7 @@ impl<T, A: Allocator> RawVec<T, A> {
}
unsafe {
// Inform the optimizer that the reservation has succeeded or wasn't needed
- core::intrinsics::assume(!self.needs_to_grow(len, additional));
+ hint::assert_unchecked(!self.needs_to_grow(len, additional));
}
Ok(())
}
@@ -363,7 +363,7 @@ impl<T, A: Allocator> RawVec<T, A> {
}
unsafe {
// Inform the optimizer that the reservation has succeeded or wasn't needed
- core::intrinsics::assume(!self.needs_to_grow(len, additional));
+ hint::assert_unchecked(!self.needs_to_grow(len, additional));
}
Ok(())
}
@@ -514,7 +514,7 @@ where
debug_assert_eq!(old_layout.align(), new_layout.align());
unsafe {
// The allocator checks for alignment equality
- intrinsics::assume(old_layout.align() == new_layout.align());
+ hint::assert_unchecked(old_layout.align() == new_layout.align());
alloc.grow(ptr, old_layout, new_layout)
}
} else {
diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs
index 263b1449de1..1eab681e956 100644
--- a/library/alloc/src/rc.rs
+++ b/library/alloc/src/rc.rs
@@ -252,6 +252,7 @@ use core::cell::Cell;
use core::cmp::Ordering;
use core::fmt;
use core::hash::{Hash, Hasher};
+use core::hint;
use core::intrinsics::abort;
#[cfg(not(no_global_oom_handling))]
use core::iter;
@@ -3268,7 +3269,7 @@ trait RcInnerPtr {
// SAFETY: The reference count will never be zero when this is
// called.
unsafe {
- core::intrinsics::assume(strong != 0);
+ hint::assert_unchecked(strong != 0);
}
let strong = strong.wrapping_add(1);
@@ -3301,7 +3302,7 @@ trait RcInnerPtr {
// SAFETY: The reference count will never be zero when this is
// called.
unsafe {
- core::intrinsics::assume(weak != 0);
+ hint::assert_unchecked(weak != 0);
}
let weak = weak.wrapping_add(1);
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index 8aa0c6e7ed6..5504af28e88 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -1993,7 +1993,7 @@ impl<T, A: Allocator> Vec<T, A> {
} else {
unsafe {
self.len -= 1;
- core::intrinsics::assume(self.len < self.capacity());
+ core::hint::assert_unchecked(self.len < self.capacity());
Some(ptr::read(self.as_ptr().add(self.len())))
}
}
diff --git a/library/core/src/alloc/global.rs b/library/core/src/alloc/global.rs
index c582111701a..a1fff6707bd 100644
--- a/library/core/src/alloc/global.rs
+++ b/library/core/src/alloc/global.rs
@@ -110,7 +110,7 @@ use crate::ptr;
/// ```rust,ignore (unsound and has placeholders)
/// drop(Box::new(42));
/// let number_of_heap_allocs = /* call private allocator API */;
-/// unsafe { std::intrinsics::assume(number_of_heap_allocs > 0); }
+/// unsafe { std::hint::assert_unchecked(number_of_heap_allocs > 0); }
/// ```
///
/// Note that the optimizations mentioned above are not the only
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 1a8f245c8be..d0f89efa518 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -131,6 +131,7 @@
#![feature(const_fmt_arguments_new)]
#![feature(const_hash)]
#![feature(const_heap)]
+#![feature(const_hint_assert_unchecked)]
#![feature(const_index_range_slice_index)]
#![feature(const_int_unchecked_arith)]
#![feature(const_intrinsic_forget)]
diff --git a/library/core/src/num/mod.rs b/library/core/src/num/mod.rs
index 695e87aaabf..2e683592b46 100644
--- a/library/core/src/num/mod.rs
+++ b/library/core/src/num/mod.rs
@@ -3,6 +3,7 @@
#![stable(feature = "rust1", since = "1.0.0")]
use crate::ascii;
+use crate::hint;
use crate::intrinsics;
use crate::mem;
use crate::ops::{Add, Mul, Sub};
diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs
index 11a53aaf122..62d6015fafe 100644
--- a/library/core/src/num/uint_macros.rs
+++ b/library/core/src/num/uint_macros.rs
@@ -2036,8 +2036,8 @@ macro_rules! uint_impl {
// SAFETY: the result is positive and fits in an integer with half as many bits.
// Inform the optimizer about it.
unsafe {
- intrinsics::assume(0 < res);
- intrinsics::assume(res < 1 << (Self::BITS / 2));
+ hint::assert_unchecked(0 < res);
+ hint::assert_unchecked(res < 1 << (Self::BITS / 2));
}
res
diff --git a/library/core/src/slice/index.rs b/library/core/src/slice/index.rs
index 373b4aee47a..fb9be396eab 100644
--- a/library/core/src/slice/index.rs
+++ b/library/core/src/slice/index.rs
@@ -234,7 +234,7 @@ unsafe impl<T> SliceIndex<[T]> for usize {
// `self` is in bounds of `slice` so `self` cannot overflow an `isize`,
// so the call to `add` is safe.
unsafe {
- crate::intrinsics::assume(self < slice.len());
+ crate::hint::assert_unchecked(self < slice.len());
slice.as_ptr().add(self)
}
}
diff --git a/library/core/src/slice/iter.rs b/library/core/src/slice/iter.rs
index 3d58afd26ea..e1d19fef35f 100644
--- a/library/core/src/slice/iter.rs
+++ b/library/core/src/slice/iter.rs
@@ -6,7 +6,7 @@ mod macros;
use crate::cmp;
use crate::cmp::Ordering;
use crate::fmt;
-use crate::intrinsics::assume;
+use crate::hint::assert_unchecked;
use crate::iter::{
FusedIterator, TrustedLen, TrustedRandomAccess, TrustedRandomAccessNoCoerce, UncheckedIterator,
};
diff --git a/library/core/src/slice/iter/macros.rs b/library/core/src/slice/iter/macros.rs
index 95bcd123b82..fc6af45fb90 100644
--- a/library/core/src/slice/iter/macros.rs
+++ b/library/core/src/slice/iter/macros.rs
@@ -338,7 +338,7 @@ macro_rules! iterator {
if predicate(x) {
// SAFETY: we are guaranteed to be in bounds by the loop invariant:
// when `i >= n`, `self.next()` returns `None` and the loop breaks.
- unsafe { assume(i < n) };
+ unsafe { assert_unchecked(i < n) };
return Some(i);
}
i += 1;
@@ -361,7 +361,7 @@ macro_rules! iterator {
if predicate(x) {
// SAFETY: `i` must be lower than `n` since it starts at `n`
// and is only decreasing.
- unsafe { assume(i < n) };
+ unsafe { assert_unchecked(i < n) };
return Some(i);
}
}
diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs
index 5edc89e4cb5..e971f933570 100644
--- a/library/core/src/slice/mod.rs
+++ b/library/core/src/slice/mod.rs
@@ -8,6 +8,7 @@
use crate::cmp::Ordering::{self, Equal, Greater, Less};
use crate::fmt;
+use crate::hint;
use crate::intrinsics::exact_div;
use crate::mem::{self, SizedTypeProperties};
use crate::num::NonZeroUsize;
@@ -2850,7 +2851,7 @@ impl<T> [T] {
right = if cmp == Greater { mid } else { right };
if cmp == Equal {
// SAFETY: same as the `get_unchecked` above
- unsafe { crate::intrinsics::assume(mid < self.len()) };
+ unsafe { hint::assert_unchecked(mid < self.len()) };
return Ok(mid);
}
@@ -2859,7 +2860,7 @@ impl<T> [T] {
// SAFETY: directly true from the overall invariant.
// Note that this is `<=`, unlike the assume in the `Ok` path.
- unsafe { crate::intrinsics::assume(left <= self.len()) };
+ unsafe { hint::assert_unchecked(left <= self.len()) };
Err(left)
}
diff --git a/library/std/src/alloc.rs b/library/std/src/alloc.rs
index bb786bd59dc..a834b36697c 100644
--- a/library/std/src/alloc.rs
+++ b/library/std/src/alloc.rs
@@ -56,7 +56,7 @@
#![deny(unsafe_op_in_unsafe_fn)]
#![stable(feature = "alloc_module", since = "1.28.0")]
-use core::intrinsics;
+use core::hint;
use core::ptr::NonNull;
use core::sync::atomic::{AtomicPtr, Ordering};
use core::{mem, ptr};
@@ -172,7 +172,7 @@ impl System {
let new_size = new_layout.size();
// `realloc` probably checks for `new_size >= old_layout.size()` or something similar.
- intrinsics::assume(new_size >= old_layout.size());
+ hint::assert_unchecked(new_size >= old_layout.size());
let raw_ptr = GlobalAlloc::realloc(self, ptr.as_ptr(), old_layout, new_size);
let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
@@ -264,7 +264,7 @@ unsafe impl Allocator for System {
// SAFETY: `new_size` is non-zero. Other conditions must be upheld by the caller
new_size if old_layout.align() == new_layout.align() => unsafe {
// `realloc` probably checks for `new_size <= old_layout.size()` or something similar.
- intrinsics::assume(new_size <= old_layout.size());
+ hint::assert_unchecked(new_size <= old_layout.size());
let raw_ptr = GlobalAlloc::realloc(self, ptr.as_ptr(), old_layout, new_size);
let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 7a8d9d0ceec..29ef26113ce 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -325,6 +325,7 @@
#![feature(float_next_up_down)]
#![feature(hasher_prefixfree_extras)]
#![feature(hashmap_internals)]
+#![feature(hint_assert_unchecked)]
#![feature(ip)]
#![feature(maybe_uninit_slice)]
#![feature(maybe_uninit_uninit_array)]
From 638439a4404d9ef2da4027585134487875787e1d Mon Sep 17 00:00:00 2001
From: joboet <jonasboettiger@icloud.com>
Date: Mon, 22 Jan 2024 15:46:32 +0100
Subject: [PATCH 2/2] update codegen tests
---
tests/codegen/vec-reserve-extend.rs | 2 ++
tests/codegen/vec_pop_push_noop.rs | 2 ++
2 files changed, 4 insertions(+)
diff --git a/tests/codegen/vec-reserve-extend.rs b/tests/codegen/vec-reserve-extend.rs
index d95220104c2..395373ff4f1 100644
--- a/tests/codegen/vec-reserve-extend.rs
+++ b/tests/codegen/vec-reserve-extend.rs
@@ -1,4 +1,6 @@
// compile-flags: -O
+// ignore-debug
+// (with debug assertions turned on, `assert_unchecked` generates a real assertion)
#![crate_type = "lib"]
diff --git a/tests/codegen/vec_pop_push_noop.rs b/tests/codegen/vec_pop_push_noop.rs
index 8bc7b68a816..d9293f2b75d 100644
--- a/tests/codegen/vec_pop_push_noop.rs
+++ b/tests/codegen/vec_pop_push_noop.rs
@@ -1,4 +1,6 @@
// compile-flags: -O
+// ignore-debug
+// (with debug assertions turned on, `assert_unchecked` generates a real assertion)
#![crate_type = "lib"]