Rollup merge of rust-lang#151527 - tgross35:f16-fixme-cleanup, r=folkertdev

Clean up or resolve cfg-related instances of `FIXME(f16_f128)`

* Replace target-specific config that has a `FIXME` with `cfg(target_has_reliable_f*)`
* Take care of trivial intrinsic-related FIXMEs
* Split `FIXME(f16_f128)` into `FIXME(f16)`, `FIXME(f128)`, or `FIXME(f16,f128)` to more clearly identify what they block

The individual commit messages have more details.

Author: JonathanBrouwer

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -665,8 +665,8 @@ impl MsvcBasicName for ty::UintTy {
 
 impl MsvcBasicName for ty::FloatTy {
     fn msvc_basic_name(self) -> &'static str {
-        // FIXME(f16_f128): `f16` and `f128` have no MSVC representation. We could improve the
-        // debuginfo. See: <https://github.com/rust-lang/rust/issues/121837>
+        // FIXME(f128): `f128` has no MSVC representation. We could improve the debuginfo.
+        // See: <https://github.com/rust-lang/rust/issues/121837>
         match self {
             ty::FloatTy::F16 => {
                 bug!("`f16` should have been handled in `build_basic_type_di_node`")

compiler/rustc_target/src/asm/riscv.rs

@@ -47,7 +47,7 @@ impl RiscVInlineAsmRegClass {
                     types! { _: I8, I16, I32, F16, F32; }
                 }
             }
-            // FIXME(f16_f128): Add `q: F128;` once LLVM support the `Q` extension.
+            // FIXME(f128): Add `q: F128;` once LLVM support the `Q` extension.
             Self::freg => types! { f: F16, F32; d: F64; },
             Self::vreg => &[],
         }

library/core/src/convert/num.rs

@@ -154,7 +154,7 @@ impl_from!(i16 => isize, #[stable(feature = "lossless_iusize_conv", since = "1.2
 // * 53 bits in f64
 // * 113 bits in f128
 // Lossy float conversions are not implemented at this time.
-// FIXME(f16_f128): The `f16`/`f128` impls `#[stable]` attributes should be changed to reference
+// FIXME(f16,f128): The `f16`/`f128` impls `#[stable]` attributes should be changed to reference
 // `f16`/`f128` when they are stabilised (trait impls have to have a `#[stable]` attribute, but none
 // of the `f16`/`f128` impls can be used on stable as the `f16` and `f128` types are unstable).
 
@@ -168,7 +168,7 @@ impl_from!(i16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0"
 impl_from!(i16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
 impl_from!(i32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
 impl_from!(i32 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
-// FIXME(f16_f128): This impl would allow using `f128` on stable before it is stabilised.
+// FIXME(f128): This impl would allow using `f128` on stable before it is stabilised.
 // impl_from!(i64 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
 
 // unsigned integer -> float
@@ -181,11 +181,11 @@ impl_from!(u16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0"
 impl_from!(u16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
 impl_from!(u32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
 impl_from!(u32 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
-// FIXME(f16_f128): This impl would allow using `f128` on stable before it is stabilised.
+// FIXME(f128): This impl would allow using `f128` on stable before it is stabilised.
 // impl_from!(u64 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
 
 // float -> float
-// FIXME(f16_f128): adding additional `From<{float}>` impls to `f32` breaks inference. See
+// FIXME(f16,f128): adding additional `From<{float}>` impls to `f32` breaks inference. See
 // <https://github.com/rust-lang/rust/issues/123831>
 impl_from!(f16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
 impl_from!(f16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);

library/core/src/fmt/float.rs

@@ -236,7 +236,7 @@ floating! { f32 f64 }
 #[cfg(target_has_reliable_f16)]
 floating! { f16 }
 
-// FIXME(f16_f128): A fallback is used when the backend+target does not support f16 well, in order
+// FIXME(f16): A fallback is used when the backend+target does not support f16 well, in order
 // to avoid ICEs.
 
 #[cfg(not(target_has_reliable_f16))]

library/core/src/num/dec2flt/mod.rs

@@ -179,7 +179,7 @@ from_str_float_impl!(f16);
 from_str_float_impl!(f32);
 from_str_float_impl!(f64);
 
-// FIXME(f16_f128): A fallback is used when the backend+target does not support f16 well, in order
+// FIXME(f16): A fallback is used when the backend+target does not support f16 well, in order
 // to avoid ICEs.
 
 #[cfg(not(target_has_reliable_f16))]

library/core/src/num/f128.rs

@@ -137,10 +137,8 @@ pub mod consts {
     pub const LN_10: f128 = 2.30258509299404568401799145468436420760110148862877297603333_f128;
 }
 
+#[doc(test(attr(feature(cfg_target_has_reliable_f16_f128), allow(internal_features))))]
 impl f128 {
-    // FIXME(f16_f128): almost all methods in this `impl` are missing examples and a const
-    // implementation. Add these once we can run code on all platforms and have f16/f128 in CTFE.
-
     /// The radix or base of the internal representation of `f128`.
     #[unstable(feature = "f128", issue = "116909")]
     pub const RADIX: u32 = 2;
@@ -277,8 +275,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `unordtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let nan = f128::NAN;
     /// let f = 7.0_f128;
@@ -300,8 +297,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let f = 7.0f128;
     /// let inf = f128::INFINITY;
@@ -326,8 +322,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `lttf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let f = 7.0f128;
     /// let inf: f128 = f128::INFINITY;
@@ -355,8 +350,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let min = f128::MIN_POSITIVE; // 3.362103143e-4932f128
     /// let max = f128::MAX;
@@ -386,8 +380,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let min = f128::MIN_POSITIVE; // 3.362103143e-4932f128
     /// let max = f128::MAX;
@@ -419,8 +412,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// use std::num::FpCategory;
     ///
@@ -514,8 +506,7 @@ impl f128 {
     ///
     /// ```rust
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// // f128::EPSILON is the difference between 1.0 and the next number up.
     /// assert_eq!(1.0f128.next_up(), 1.0 + f128::EPSILON);
@@ -569,8 +560,7 @@ impl f128 {
     ///
     /// ```rust
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let x = 1.0f128;
     /// // Clamp value into range [0, 1).
@@ -613,8 +603,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let x = 2.0_f128;
     /// let abs_difference = (x.recip() - (1.0 / x)).abs();
@@ -640,8 +629,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let angle = std::f128::consts::PI;
     ///
@@ -671,8 +659,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let angle = 180.0f128;
     ///
@@ -706,8 +693,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // Using aarch64 because `reliable_f128_math` is needed
-    /// # #[cfg(all(target_arch = "aarch64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128_math)] {
     ///
     /// let x = 1.0f128;
     /// let y = 2.0f128;
@@ -738,8 +724,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // Using aarch64 because `reliable_f128_math` is needed
-    /// # #[cfg(all(target_arch = "aarch64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128_math)] {
     ///
     /// let x = 1.0f128;
     /// let y = 2.0f128;
@@ -771,8 +756,7 @@ impl f128 {
     /// ```
     /// #![feature(f128)]
     /// #![feature(float_minimum_maximum)]
-    /// # // Using aarch64 because `reliable_f128_math` is needed
-    /// # #[cfg(all(target_arch = "aarch64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128_math)] {
     ///
     /// let x = 1.0f128;
     /// let y = 2.0f128;
@@ -804,8 +788,7 @@ impl f128 {
     /// ```
     /// #![feature(f128)]
     /// #![feature(float_minimum_maximum)]
-    /// # // Using aarch64 because `reliable_f128_math` is needed
-    /// # #[cfg(all(target_arch = "aarch64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128_math)] {
     ///
     /// let x = 1.0f128;
     /// let y = 2.0f128;
@@ -831,8 +814,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // Using aarch64 because `reliable_f128_math` is needed
-    /// # #[cfg(all(target_arch = "aarch64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// assert_eq!(1f128.midpoint(4.0), 2.5);
     /// assert_eq!((-5.5f128).midpoint(8.0), 1.25);
@@ -862,8 +844,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `float*itf` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let value = 4.6_f128;
     /// let rounded = unsafe { value.to_int_unchecked::<u16>() };
@@ -906,10 +887,11 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
-    /// # // FIXME(f16_f128): enable this once const casting works
-    /// # // assert_ne!((1f128).to_bits(), 1f128 as u128); // to_bits() is not casting!
+    /// assert_ne!((1f128).to_bits(), 1f128 as u128); // to_bits() is not casting!
     /// assert_eq!((12.5f128).to_bits(), 0x40029000000000000000000000000000);
+    /// # }
     /// ```
     #[inline]
     #[unstable(feature = "f128", issue = "116909")]
@@ -952,8 +934,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// #  // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let v = f128::from_bits(0x40029000000000000000000000000000);
     /// assert_eq!(v, 12.5);
@@ -1064,8 +1045,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let value = f128::from_be_bytes(
     ///     [0x40, 0x02, 0x90, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -1090,8 +1070,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let value = f128::from_le_bytes(
     ///     [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -1123,8 +1102,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `eqtf2` is available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let value = f128::from_ne_bytes(if cfg!(target_endian = "big") {
     ///     [0x40, 0x02, 0x90, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -1257,8 +1235,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # // FIXME(f16_f128): remove when `{eq,gt,unord}tf` are available
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// assert!((-3.0f128).clamp(-2.0, 1.0) == -2.0);
     /// assert!((0.0f128).clamp(-2.0, 1.0) == 0.0);
@@ -1333,7 +1310,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let x = 3.5_f128;
     /// let y = -3.5_f128;
@@ -1349,9 +1326,7 @@ 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 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))
+        intrinsics::fabsf128(self)
     }
 
     /// Returns a number that represents the sign of `self`.
@@ -1364,7 +1339,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let f = 3.5_f128;
     ///
@@ -1400,7 +1375,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
+    /// # #[cfg(target_has_reliable_f128)] {
     ///
     /// let f = 3.5_f128;
     ///
@@ -1477,8 +1452,6 @@ impl f128 {
 }
 
 // Functions in this module fall into `core_float_math`
-// FIXME(f16_f128): all doctests must be gated to platforms that have `long double` === `_Float128`
-// due to https://github.com/llvm/llvm-project/issues/44744. aarch64 linux matches this.
 // #[unstable(feature = "core_float_math", issue = "137578")]
 #[cfg(not(test))]
 #[doc(test(attr(feature(cfg_target_has_reliable_f16_f128), expect(internal_features))))]

library/core/src/num/f16.rs

@@ -134,9 +134,6 @@ pub mod consts {
 
 #[doc(test(attr(feature(cfg_target_has_reliable_f16_f128), allow(internal_features))))]
 impl f16 {
-    // FIXME(f16_f128): almost all methods in this `impl` are missing examples and a const
-    // implementation. Add these once we can run code on all platforms and have f16/f128 in CTFE.
-
     /// The radix or base of the internal representation of `f16`.
     #[unstable(feature = "f16", issue = "116909")]
     pub const RADIX: u32 = 2;
@@ -887,8 +884,7 @@ impl f16 {
     /// #![feature(f16)]
     /// # #[cfg(target_has_reliable_f16)] {
     ///
-    /// # // FIXME(f16_f128): enable this once const casting works
-    /// # // assert_ne!((1f16).to_bits(), 1f16 as u128); // to_bits() is not casting!
+    /// assert_ne!((1f16).to_bits(), 1f16 as u16); // to_bits() is not casting!
     /// assert_eq!((12.5f16).to_bits(), 0x4a40);
     /// # }
     /// ```