Make missed precondition-free float intrinsics safe

Author: clarfonthey

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -90,6 +90,10 @@ fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -> hi
         | sym::contract_check_ensures
         | sym::contract_check_requires
         | sym::contract_checks
+        | sym::copysignf16
+        | sym::copysignf32
+        | sym::copysignf64
+        | sym::copysignf128
         | sym::cosf16
         | sym::cosf32
         | sym::cosf64
@@ -106,6 +110,10 @@ fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -> hi
         | sym::expf32
         | sym::expf64
         | sym::expf128
+        | sym::fabsf16
+        | sym::fabsf32
+        | sym::fabsf64
+        | sym::fabsf128
         | sym::fadd_algebraic
         | sym::fdiv_algebraic
         | sym::floorf16

library/core/src/intrinsics/mod.rs

@@ -3170,7 +3170,7 @@ pub const fn maximumf128(x: f128, y: f128) -> f128 {
 /// [`f16::abs`](../../std/primitive.f16.html#method.abs)
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub const unsafe fn fabsf16(x: f16) -> f16;
+pub const fn fabsf16(x: f16) -> f16;
 
 /// Returns the absolute value of an `f32`.
 ///
@@ -3179,7 +3179,7 @@ pub const unsafe fn fabsf16(x: f16) -> f16;
 #[rustc_nounwind]
 #[rustc_intrinsic_const_stable_indirect]
 #[rustc_intrinsic]
-pub const unsafe fn fabsf32(x: f32) -> f32;
+pub const fn fabsf32(x: f32) -> f32;
 
 /// Returns the absolute value of an `f64`.
 ///
@@ -3188,23 +3188,23 @@ pub const unsafe fn fabsf32(x: f32) -> f32;
 #[rustc_nounwind]
 #[rustc_intrinsic_const_stable_indirect]
 #[rustc_intrinsic]
-pub const unsafe fn fabsf64(x: f64) -> f64;
+pub const fn fabsf64(x: f64) -> f64;
 
 /// Returns the absolute value of an `f128`.
 ///
 /// The stabilized version of this intrinsic is
 /// [`f128::abs`](../../std/primitive.f128.html#method.abs)
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub const unsafe fn fabsf128(x: f128) -> f128;
+pub const fn fabsf128(x: f128) -> f128;
 
 /// Copies the sign from `y` to `x` for `f16` values.
 ///
 /// The stabilized version of this intrinsic is
 /// [`f16::copysign`](../../std/primitive.f16.html#method.copysign)
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub const unsafe fn copysignf16(x: f16, y: f16) -> f16;
+pub const fn copysignf16(x: f16, y: f16) -> f16;
 
 /// Copies the sign from `y` to `x` for `f32` values.
 ///
@@ -3213,23 +3213,23 @@ pub const unsafe fn copysignf16(x: f16, y: f16) -> f16;
 #[rustc_nounwind]
 #[rustc_intrinsic_const_stable_indirect]
 #[rustc_intrinsic]
-pub const unsafe fn copysignf32(x: f32, y: f32) -> f32;
+pub const fn copysignf32(x: f32, y: f32) -> f32;
 /// Copies the sign from `y` to `x` for `f64` values.
 ///
 /// The stabilized version of this intrinsic is
 /// [`f64::copysign`](../../std/primitive.f64.html#method.copysign)
 #[rustc_nounwind]
 #[rustc_intrinsic_const_stable_indirect]
 #[rustc_intrinsic]
-pub const unsafe fn copysignf64(x: f64, y: f64) -> f64;
+pub const fn copysignf64(x: f64, y: f64) -> f64;
 
 /// Copies the sign from `y` to `x` for `f128` values.
 ///
 /// The stabilized version of this intrinsic is
 /// [`f128::copysign`](../../std/primitive.f128.html#method.copysign)
 #[rustc_nounwind]
 #[rustc_intrinsic]
-pub const unsafe fn copysignf128(x: f128, y: f128) -> f128;
+pub const fn copysignf128(x: f128, y: f128) -> f128;
 
 /// Generates the LLVM body for the automatic differentiation of `f` using Enzyme,
 /// with `df` as the derivative function and `args` as its arguments.

library/core/src/num/f128.rs

@@ -1366,8 +1366,7 @@ impl f128 {
     #[rustc_const_unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     pub const fn copysign(self, sign: f128) -> f128 {
-        // SAFETY: this is actually a safe intrinsic
-        unsafe { intrinsics::copysignf128(self, sign) }
+        intrinsics::copysignf128(self, sign)
     }
 
     /// Float addition that allows optimizations based on algebraic rules.

library/core/src/num/f16.rs

@@ -1343,8 +1343,7 @@ impl f16 {
     #[rustc_const_unstable(feature = "f16", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     pub const fn copysign(self, sign: f16) -> f16 {
-        // SAFETY: this is actually a safe intrinsic
-        unsafe { intrinsics::copysignf16(self, sign) }
+        intrinsics::copysignf16(self, sign)
     }
 
     /// Float addition that allows optimizations based on algebraic rules.

library/core/src/num/f32.rs

@@ -1449,8 +1449,7 @@ impl f32 {
     #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
     #[inline]
     pub const fn abs(self) -> f32 {
-        // SAFETY: this is actually a safe intrinsic
-        unsafe { intrinsics::fabsf32(self) }
+        intrinsics::fabsf32(self)
     }
 
     /// Returns a number that represents the sign of `self`.
@@ -1508,8 +1507,7 @@ impl f32 {
     #[stable(feature = "copysign", since = "1.35.0")]
     #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
     pub const fn copysign(self, sign: f32) -> f32 {
-        // SAFETY: this is actually a safe intrinsic
-        unsafe { intrinsics::copysignf32(self, sign) }
+        intrinsics::copysignf32(self, sign)
     }
 
     /// Float addition that allows optimizations based on algebraic rules.

library/core/src/num/f64.rs

@@ -1447,8 +1447,7 @@ impl f64 {
     #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
     #[inline]
     pub const fn abs(self) -> f64 {
-        // SAFETY: this is actually a safe intrinsic
-        unsafe { intrinsics::fabsf64(self) }
+        intrinsics::fabsf64(self)
     }
 
     /// Returns a number that represents the sign of `self`.
@@ -1506,8 +1505,7 @@ impl f64 {
     #[rustc_const_stable(feature = "const_float_methods", since = "1.85.0")]
     #[inline]
     pub const fn copysign(self, sign: f64) -> f64 {
-        // SAFETY: this is actually a safe intrinsic
-        unsafe { intrinsics::copysignf64(self, sign) }
+        intrinsics::copysignf64(self, sign)
     }
 
     /// Float addition that allows optimizations based on algebraic rules.