diff options
| -rw-r--r-- | compiler/rustc_hir_analysis/src/check/intrinsic.rs | 2 | ||||
| -rw-r--r-- | library/core/src/intrinsics.rs | 36 |
2 files changed, 24 insertions, 14 deletions
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsic.rs b/compiler/rustc_hir_analysis/src/check/intrinsic.rs index f0f6bfff64a..fcc0ec69d5e 100644 --- a/compiler/rustc_hir_analysis/src/check/intrinsic.rs +++ b/compiler/rustc_hir_analysis/src/check/intrinsic.rs @@ -407,7 +407,7 @@ pub fn check_intrinsic_type( } sym::float_to_int_unchecked => (2, 0, vec![param(0)], param(1)), - sym::assume => (0, 0, vec![tcx.types.bool], Ty::new_unit(tcx)), + sym::assume => (0, 1, vec![tcx.types.bool], Ty::new_unit(tcx)), sym::likely => (0, 0, vec![tcx.types.bool], tcx.types.bool), sym::unlikely => (0, 0, vec![tcx.types.bool], tcx.types.bool), diff --git a/library/core/src/intrinsics.rs b/library/core/src/intrinsics.rs index fc6c1eab803..7b73396afc6 100644 --- a/library/core/src/intrinsics.rs +++ b/library/core/src/intrinsics.rs @@ -937,20 +937,30 @@ extern "rust-intrinsic" { #[rustc_nounwind] pub fn unreachable() -> !; - /// Informs the optimizer that a condition is always true. - /// If the condition is false, the behavior is undefined. - /// - /// No code is generated for this intrinsic, but the optimizer will try - /// to preserve it (and its condition) between passes, which may interfere - /// with optimization of surrounding code and reduce performance. It should - /// not be used if the invariant can be discovered by the optimizer on its - /// own, or if it does not enable any significant optimizations. - /// - /// This intrinsic does not have a stable counterpart. - #[rustc_const_stable(feature = "const_assume", since = "1.77.0")] - #[rustc_nounwind] - pub fn assume(b: bool); +} + +/// Informs the optimizer that a condition is always true. +/// If the condition is false, the behavior is undefined. +/// +/// No code is generated for this intrinsic, but the optimizer will try +/// to preserve it (and its condition) between passes, which may interfere +/// with optimization of surrounding code and reduce performance. It should +/// not be used if the invariant can be discovered by the optimizer on its +/// own, or if it does not enable any significant optimizations. +/// +/// This intrinsic does not have a stable counterpart. +#[rustc_const_stable(feature = "const_assume", since = "1.77.0")] +#[rustc_nounwind] +#[unstable(feature = "core_intrinsics", issue = "none")] +#[cfg_attr(not(bootstrap), rustc_intrinsic)] +pub const unsafe fn assume(b: bool) { + if !b { + // SAFETY: the caller must guarantee the argument is never `false` + unsafe { unreachable() } + } +} +extern "rust-intrinsic" { /// Hints to the compiler that branch condition is likely to be true. /// Returns the value passed to it. /// |