Add debug_assert_nounwind to unchecked_{add,sub,neg,mul,shl,shr} methods (haunted PR) #117494
+735
−159
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -510,9 +510,15 @@ macro_rules! int_impl { | ||
| #[inline(always)] | ||
| #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces | ||
| pub const unsafe fn unchecked_add(self, rhs: Self) -> Self { | ||
| debug_assert_nounwind!( | ||
| !self.overflowing_add(rhs).1, | ||
| concat!(stringify!($SelfT), "::unchecked_add cannot overflow"), | ||
| ); | ||
| // SAFETY: this is guaranteed to be safe by the caller. | ||
| unsafe { | ||
| let lhs = self; | ||
| intrinsics::unchecked_add(lhs, rhs) | ||
| } | ||
| } | ||
|
|
||
| /// Checked addition with an unsigned integer. Computes `self + rhs`, | ||
| @@ -648,9 +654,15 @@ macro_rules! int_impl { | ||
| #[inline(always)] | ||
| #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces | ||
| pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self { | ||
| debug_assert_nounwind!( | ||
| !self.overflowing_sub(rhs).1, | ||
| concat!(stringify!($SelfT), "::unchecked_sub cannot overflow"), | ||
| ); | ||
| // SAFETY: this is guaranteed to be safe by the caller. | ||
| unsafe { | ||
| let lhs = self; | ||
| intrinsics::unchecked_sub(lhs, rhs) | ||
| } | ||
| } | ||
|
|
||
| /// Checked subtraction with an unsigned integer. Computes `self - rhs`, | ||
| @@ -786,9 +798,15 @@ macro_rules! int_impl { | ||
| #[inline(always)] | ||
| #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces | ||
| pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self { | ||
| debug_assert_nounwind!( | ||
| !self.overflowing_mul(rhs).1, | ||
| concat!(stringify!($SelfT), "::unchecked_mul cannot overflow"), | ||
| ); | ||
| // SAFETY: this is guaranteed to be safe by the caller. | ||
| unsafe { | ||
| let lhs = self; | ||
| intrinsics::unchecked_mul(lhs, rhs) | ||
| } | ||
| } | ||
|
|
||
| /// Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0` | ||
| @@ -1125,9 +1143,15 @@ macro_rules! int_impl { | ||
| #[inline(always)] | ||
| #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces | ||
| pub const unsafe fn unchecked_neg(self) -> Self { | ||
| debug_assert_nounwind!( | ||
| !self.overflowing_neg().1, | ||
| concat!(stringify!($SelfT), "::unchecked_neg cannot overflow"), | ||
| ); | ||
| // SAFETY: this is guaranteed to be safe by the caller. | ||
| unsafe { | ||
| let n = self; | ||
| intrinsics::unchecked_sub(0, n) | ||
| } | ||
| } | ||
|
|
||
| /// Strict negation. Computes `-self`, panicking if `self == MIN`. | ||
| @@ -1179,7 +1203,7 @@ macro_rules! int_impl { | ||
| #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] | ||
| #[must_use = "this returns the result of the operation, \ | ||
| without modifying the original"] | ||
| #[inline(always)] | ||
|
There was a problem hiding this comment. FYI, functions which are My PR to stop this behavior of There was a problem hiding this comment. So, I initially added this after the stuff I mentioned here, but I did just leave it based upon assumptions that are probably wrong, so, I can remove it. Note that this does show up for the other unchecked operations and that shift is the only one marking them without always. |
||
| pub const fn checked_shl(self, rhs: u32) -> Option<Self> { | ||
| let (a, b) = self.overflowing_shl(rhs); | ||
| if unlikely!(b) { None } else { Some(a) } | ||
| @@ -1241,10 +1265,17 @@ macro_rules! int_impl { | ||
| #[inline(always)] | ||
| #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces | ||
| pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self { | ||
| debug_assert_nounwind!( | ||
| rhs < Self::BITS, | ||
| concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"), | ||
| ); | ||
| // SAFETY: this is guaranteed to be safe by the caller. | ||
| // Any legal shift amount is losslessly representable in the self type. | ||
| unsafe { | ||
| let lhs = self; | ||
| let rhs = conv_rhs_for_unchecked_shift!($SelfT, rhs); | ||
| intrinsics::unchecked_shl(lhs, rhs) | ||
| } | ||
| } | ||
|
|
||
| /// Checked shift right. Computes `self >> rhs`, returning `None` if `rhs` is | ||
| @@ -1262,7 +1293,7 @@ macro_rules! int_impl { | ||
| #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] | ||
| #[must_use = "this returns the result of the operation, \ | ||
| without modifying the original"] | ||
| #[inline(always)] | ||
| pub const fn checked_shr(self, rhs: u32) -> Option<Self> { | ||
| let (a, b) = self.overflowing_shr(rhs); | ||
| if unlikely!(b) { None } else { Some(a) } | ||
| @@ -1324,10 +1355,17 @@ macro_rules! int_impl { | ||
| #[inline(always)] | ||
| #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces | ||
| pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self { | ||
| debug_assert_nounwind!( | ||
| rhs < Self::BITS, | ||
| concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"), | ||
| ); | ||
| // SAFETY: this is guaranteed to be safe by the caller. | ||
| // Any legal shift amount is losslessly representable in the self type. | ||
| unsafe { | ||
| let lhs = self; | ||
| let rhs = conv_rhs_for_unchecked_shift!($SelfT, rhs); | ||
| intrinsics::unchecked_shr(lhs, rhs) | ||
| } | ||
| } | ||
|
|
||
| /// Checked absolute value. Computes `self.abs()`, returning `None` if | ||
| @@ -1991,7 +2029,10 @@ macro_rules! int_impl { | ||
| // SAFETY: the masking by the bitsize of the type ensures that we do not shift | ||
| // out of bounds | ||
| unsafe { | ||
| // FIXME: we can't optimize out the extra check here, | ||
| // so, we can't just call the method for now | ||
| let rhs = conv_rhs_for_unchecked_shift!($SelfT, rhs & (Self::BITS - 1)); | ||
| intrinsics::unchecked_shl(self, rhs) | ||
| } | ||
| } | ||
|
|
||
| @@ -2021,7 +2062,10 @@ macro_rules! int_impl { | ||
| // SAFETY: the masking by the bitsize of the type ensures that we do not shift | ||
| // out of bounds | ||
| unsafe { | ||
| // FIXME: we can't optimize out the extra check here, | ||
| // so, we can't just call the method for now | ||
| let rhs = conv_rhs_for_unchecked_shift!($SelfT, rhs & (Self::BITS - 1)); | ||
| intrinsics::unchecked_shr(self, rhs) | ||
| } | ||
| } | ||
|
|
||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
This extra
letis going to cause more LLVM IR to be generated in order to have debuginfo for it. I learned about this unfortunate behavior only recently:rust/library/core/src/intrinsics.rs
Lines 2688 to 2691 in 8f359be
I wish I had a way to tell rustc that we don't need variable-level debuginfo for a span of code, but here we are.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Ugh, I didn't realise it got all the way to the LLVM IR level. It's unfortunate, but I'll remove the extra lets from these operations. (Will wait until current perf run finishes before doing this.)