Make float abs, copysign and signum const too

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -95,6 +95,12 @@ pub(crate) fn eval_nullary_intrinsic<'tcx>(
     })
 }
 
+enum FloatBinIntrinsic {
+    Min,
+    Max,
+    Copysign,
+}
+
 impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     /// Returns `true` if emulation happened.
     /// Here we implement the intrinsics that are common to all Miri instances; individual machines can add their own
@@ -438,21 +444,54 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 self.write_scalar(Scalar::from_target_usize(align.bytes(), self), dest)?;
             }
 
-            sym::minnumf16 | sym::maxnumf16 => {
-                let is_max = intrinsic_name == sym::maxnumf16;
-                self.float_min_max_intrinsic::<rustc_apfloat::ieee::Half>(is_max, args, dest)?;
+            sym::minnumf16 | sym::maxnumf16 | sym::copysignf16 => {
+                let op = match intrinsic_name {
+                    sym::minnumf16 => FloatBinIntrinsic::Min,
+                    sym::maxnumf16 => FloatBinIntrinsic::Max,
+                    sym::copysignf16 => FloatBinIntrinsic::Copysign,
+                    _ => bug!(),
+                };
+                self.float_bin_op_intrinsic::<rustc_apfloat::ieee::Half>(op, args, dest)?;
+            }
+            sym::minnumf32 | sym::maxnumf32 | sym::copysignf32 => {
+                let op = match intrinsic_name {
+                    sym::minnumf32 => FloatBinIntrinsic::Min,
+                    sym::maxnumf32 => FloatBinIntrinsic::Max,
+                    sym::copysignf32 => FloatBinIntrinsic::Copysign,
+                    _ => bug!(),
+                };
+                self.float_bin_op_intrinsic::<rustc_apfloat::ieee::Single>(op, args, dest)?;
+            }
+            sym::minnumf64 | sym::maxnumf64 | sym::copysignf64 => {
+                let op = match intrinsic_name {
+                    sym::minnumf64 => FloatBinIntrinsic::Min,
+                    sym::maxnumf64 => FloatBinIntrinsic::Max,
+                    sym::copysignf64 => FloatBinIntrinsic::Copysign,
+                    _ => bug!(),
+                };
+                self.float_bin_op_intrinsic::<rustc_apfloat::ieee::Double>(op, args, dest)?;
+            }
+            sym::minnumf128 | sym::maxnumf128 | sym::copysignf128 => {
+                let op = match intrinsic_name {
+                    sym::minnumf128 => FloatBinIntrinsic::Min,
+                    sym::maxnumf128 => FloatBinIntrinsic::Max,
+                    sym::copysignf128 => FloatBinIntrinsic::Copysign,
+                    _ => bug!(),
+                };
+                self.float_bin_op_intrinsic::<rustc_apfloat::ieee::Quad>(op, args, dest)?;
+            }
+
+            sym::fabsf16 => {
+                self.float_abs_intrinsic::<rustc_apfloat::ieee::Half>(args, dest)?;
             }
-            sym::minnumf32 | sym::maxnumf32 => {
-                let is_max = intrinsic_name == sym::maxnumf32;
-                self.float_min_max_intrinsic::<rustc_apfloat::ieee::Single>(is_max, args, dest)?;
+            sym::fabsf32 => {
+                self.float_abs_intrinsic::<rustc_apfloat::ieee::Single>(args, dest)?;
             }
-            sym::minnumf64 | sym::maxnumf64 => {
-                let is_max = intrinsic_name == sym::maxnumf64;
-                self.float_min_max_intrinsic::<rustc_apfloat::ieee::Double>(is_max, args, dest)?;
+            sym::fabsf64 => {
+                self.float_abs_intrinsic::<rustc_apfloat::ieee::Double>(args, dest)?;
             }
-            sym::minnumf128 | sym::maxnumf128 => {
-                let is_max = intrinsic_name == sym::maxnumf128;
-                self.float_min_max_intrinsic::<rustc_apfloat::ieee::Quad>(is_max, args, dest)?;
+            sym::fabsf128 => {
+                self.float_abs_intrinsic::<rustc_apfloat::ieee::Quad>(args, dest)?;
             }
 
             // Unsupported intrinsic: skip the return_to_block below.
@@ -715,9 +754,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         interp_ok(Scalar::from_bool(lhs_bytes == rhs_bytes))
     }
 
-    fn float_min_max_intrinsic<F>(
+    fn float_bin_op_intrinsic<F>(
         &mut self,
-        is_max: bool,
+        op: FloatBinIntrinsic,
         args: &[OpTy<'tcx, M::Provenance>],
         dest: &MPlaceTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx, ()>
@@ -726,8 +765,26 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     {
         let a: F = self.read_scalar(&args[0])?.to_float()?;
         let b: F = self.read_scalar(&args[1])?.to_float()?;
-        let res = if is_max { a.max(b) } else { a.min(b) };
-        self.write_scalar(adjust_nan(self, res, &[a, b]), dest)?;
+        let res = match op {
+            FloatBinIntrinsic::Min => adjust_nan(self, a.min(b), &[a, b]),
+            FloatBinIntrinsic::Max => adjust_nan(self, a.max(b), &[a, b]),
+            FloatBinIntrinsic::Copysign => a.copy_sign(b), // bitwise, no NaN adjustments
+        };
+        self.write_scalar(res, dest)?;
+        interp_ok(())
+    }
+
+    fn float_abs_intrinsic<F>(
+        &mut self,
+        args: &[OpTy<'tcx, M::Provenance>],
+        dest: &MPlaceTy<'tcx, M::Provenance>,
+    ) -> InterpResult<'tcx, ()>
+    where
+        F: rustc_apfloat::Float + rustc_apfloat::FloatConvert<F> + Into<Scalar<M::Provenance>>,
+    {
+        let x: F = self.read_scalar(&args[0])?.to_float()?;
+        // bitwise, no NaN adjustments
+        self.write_scalar(x.abs(), dest)?;
         interp_ok(())
     }
 }

library/core/src/intrinsics.rs

@@ -1795,56 +1795,6 @@ extern "rust-intrinsic" {
     #[rustc_nounwind]
     pub fn fmaf128(a: f128, b: f128, c: f128) -> f128;
 
-    /// Returns the absolute value of an `f16`.
-    ///
-    /// The stabilized version of this intrinsic is
-    /// [`f16::abs`](../../std/primitive.f16.html#method.abs)
-    #[rustc_nounwind]
-    pub fn fabsf16(x: f16) -> f16;
-    /// Returns the absolute value of an `f32`.
-    ///
-    /// The stabilized version of this intrinsic is
-    /// [`f32::abs`](../../std/primitive.f32.html#method.abs)
-    #[rustc_nounwind]
-    pub fn fabsf32(x: f32) -> f32;
-    /// Returns the absolute value of an `f64`.
-    ///
-    /// The stabilized version of this intrinsic is
-    /// [`f64::abs`](../../std/primitive.f64.html#method.abs)
-    #[rustc_nounwind]
-    pub 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]
-    pub 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]
-    pub fn copysignf16(x: f16, y: f16) -> f16;
-    /// Copies the sign from `y` to `x` for `f32` values.
-    ///
-    /// The stabilized version of this intrinsic is
-    /// [`f32::copysign`](../../std/primitive.f32.html#method.copysign)
-    #[rustc_nounwind]
-    pub 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]
-    pub 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]
-    pub fn copysignf128(x: f128, y: f128) -> f128;
-
     /// Returns the largest integer less than or equal to an `f16`.
     ///
     /// The stabilized version of this intrinsic is
@@ -3539,6 +3489,105 @@ pub const fn maxnumf128(_x: f128, _y: f128) -> f128 {
     unimplemented!();
 }
 
+/// Returns the absolute value of an `f16`.
+///
+/// The stabilized version of this intrinsic is
+/// [`f16::abs`](../../std/primitive.f16.html#method.abs)
+#[rustc_nounwind]
+// #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+#[rustc_const_unstable(feature = "f16", issue = "116909")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const unsafe fn fabsf16(_x: f16) -> f16 {
+    unimplemented!();
+}
+
+/// Returns the absolute value of an `f32`.
+///
+/// The stabilized version of this intrinsic is
+/// [`f32::abs`](../../std/primitive.f32.html#method.abs)
+#[rustc_nounwind]
+#[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const unsafe fn fabsf32(_x: f32) -> f32 {
+    unimplemented!();
+}
+
+/// Returns the absolute value of an `f64`.
+///
+/// The stabilized version of this intrinsic is
+/// [`f64::abs`](../../std/primitive.f64.html#method.abs)
+#[rustc_nounwind]
+#[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const unsafe fn fabsf64(_x: f64) -> f64 {
+    unimplemented!();
+}
+
+/// 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_const_unstable(feature = "const_float_methods", issue = "130843")]
+#[rustc_const_unstable(feature = "f128", issue = "116909")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const unsafe fn fabsf128(_x: f128) -> f128 {
+    unimplemented!();
+}
+
+/// 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_const_unstable(feature = "const_float_methods", issue = "130843")]
+#[rustc_const_unstable(feature = "f16", issue = "116909")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const unsafe fn copysignf16(_x: f16, _y: f16) -> f16 {
+    unimplemented!();
+}
+
+/// Copies the sign from `y` to `x` for `f32` values.
+///
+/// The stabilized version of this intrinsic is
+/// [`f32::copysign`](../../std/primitive.f32.html#method.copysign)
+#[rustc_nounwind]
+#[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const unsafe fn copysignf32(_x: f32, _y: f32) -> f32 {
+    unimplemented!();
+}
+/// 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_const_unstable(feature = "const_float_methods", issue = "130843")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const unsafe fn copysignf64(_x: f64, _y: f64) -> f64 {
+    unimplemented!();
+}
+
+/// 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_const_unstable(feature = "const_float_methods", issue = "130843")]
+#[rustc_const_unstable(feature = "f128", issue = "116909")]
+#[rustc_intrinsic]
+#[rustc_intrinsic_must_be_overridden]
+pub const unsafe fn copysignf128(_x: f128, _y: f128) -> f128 {
+    unimplemented!();
+}
+
 /// Inform Miri that a given pointer definitely has a certain alignment.
 #[cfg(miri)]
 pub(crate) const fn miri_promise_symbolic_alignment(ptr: *const (), align: usize) {

library/std/src/f128.rs

@@ -210,8 +210,10 @@ impl f128 {
     #[inline]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f128", issue = "116909")]
+    // #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn abs(self) -> Self {
+    pub const fn abs(self) -> Self {
         // FIXME(f16_f128): replace with `intrinsics::fabsf128` when available
         // We don't do this now because LLVM has lowering bugs for f128 math.
         Self::from_bits(self.to_bits() & !(1 << 127))
@@ -240,8 +242,10 @@ impl f128 {
     #[inline]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f128", issue = "116909")]
+    // #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn signum(self) -> f128 {
+    pub const fn signum(self) -> f128 {
         if self.is_nan() { Self::NAN } else { 1.0_f128.copysign(self) }
     }
 
@@ -278,8 +282,10 @@ impl f128 {
     #[inline]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f128", issue = "116909")]
+    // #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+    #[rustc_const_unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn copysign(self, sign: f128) -> f128 {
+    pub const fn copysign(self, sign: f128) -> f128 {
         unsafe { intrinsics::copysignf128(self, sign) }
     }
 

library/std/src/f16.rs

@@ -210,8 +210,10 @@ impl f16 {
     #[inline]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f16", issue = "116909")]
+    // #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn abs(self) -> Self {
+    pub const fn abs(self) -> Self {
         // FIXME(f16_f128): replace with `intrinsics::fabsf16` when available
         Self::from_bits(self.to_bits() & !(1 << 15))
     }
@@ -239,8 +241,10 @@ impl f16 {
     #[inline]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f16", issue = "116909")]
+    // #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn signum(self) -> f16 {
+    pub const fn signum(self) -> f16 {
         if self.is_nan() { Self::NAN } else { 1.0_f16.copysign(self) }
     }
 
@@ -277,8 +281,10 @@ impl f16 {
     #[inline]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f16", issue = "116909")]
+    // #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+    #[rustc_const_unstable(feature = "f16", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn copysign(self, sign: f16) -> f16 {
+    pub const fn copysign(self, sign: f16) -> f16 {
         unsafe { intrinsics::copysignf16(self, sign) }
     }
 

library/std/src/f32.rs

@@ -194,8 +194,9 @@ impl f32 {
     #[rustc_allow_incoherent_impl]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
     #[inline]
-    pub fn abs(self) -> f32 {
+    pub const fn abs(self) -> f32 {
         unsafe { intrinsics::fabsf32(self) }
     }
 
@@ -218,8 +219,9 @@ impl f32 {
     #[rustc_allow_incoherent_impl]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
     #[inline]
-    pub fn signum(self) -> f32 {
+    pub const fn signum(self) -> f32 {
         if self.is_nan() { Self::NAN } else { 1.0_f32.copysign(self) }
     }
 
@@ -253,7 +255,8 @@ impl f32 {
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[inline]
     #[stable(feature = "copysign", since = "1.35.0")]
-    pub fn copysign(self, sign: f32) -> f32 {
+    #[rustc_const_unstable(feature = "const_float_methods", issue = "130843")]
+    pub const fn copysign(self, sign: f32) -> f32 {
         unsafe { intrinsics::copysignf32(self, sign) }
     }