Add sqrtf16 and sqrtf128

Use the generic algorithms to provide implementations for these
routines.

Author: tgross35

crates/libm-macros/src/shared.rs

@@ -9,7 +9,7 @@ const ALL_OPERATIONS_NESTED: &[(FloatTy, Signature, Option<Signature>, &[&str])]
         FloatTy::F16,
         Signature { args: &[Ty::F16], returns: &[Ty::F16] },
         None,
-        &["fabsf16", "truncf16"],
+        &["fabsf16", "sqrtf16", "truncf16"],
     ),
     (
         // `fn(f32) -> f32`
@@ -40,7 +40,7 @@ const ALL_OPERATIONS_NESTED: &[(FloatTy, Signature, Option<Signature>, &[&str])]
         FloatTy::F128,
         Signature { args: &[Ty::F128], returns: &[Ty::F128] },
         None,
-        &["fabsf128", "truncf128"],
+        &["fabsf128", "sqrtf128", "truncf128"],
     ),
     (
         // `(f16, f16) -> f16`

crates/libm-test/benches/icount.rs

@@ -155,6 +155,8 @@ main!(
     icount_bench_sinh_group,
     icount_bench_sinhf_group,
     icount_bench_sqrt_group,
+    icount_bench_sqrtf128_group,
+    icount_bench_sqrtf16_group,
     icount_bench_sqrtf_group,
     icount_bench_tan_group,
     icount_bench_tanf_group,

crates/libm-test/benches/random.rs

@@ -123,6 +123,8 @@ libm_macros::for_each_function! {
         | fabsf16
         | fdimf128
         | fdimf16
+        | sqrtf16
+        | sqrtf128
         | truncf128
         | truncf16 => (false, None),
 

crates/libm-test/tests/compare_built_musl.rs

@@ -87,5 +87,7 @@ libm_macros::for_each_function! {
         fdimf16,
         truncf128,
         truncf16,
+        sqrtf16,
+        sqrtf128,
     ],
 }

crates/util/src/main.rs

@@ -90,6 +90,8 @@ fn do_eval(basis: &str, op: &str, inputs: &[&str]) {
             | fabsf16
             | fdimf128
             | fdimf16
+            | sqrtf128
+            | sqrtf16
             | truncf128
             | truncf16  => None,
             _ => Some(musl_math_sys::MACRO_FN_NAME)

etc/function-definitions.json

@@ -718,6 +718,20 @@
         ],
         "type": "f32"
     },
+    "sqrtf128": {
+        "sources": [
+            "src/math/generic/sqrt.rs",
+            "src/math/sqrtf128.rs"
+        ],
+        "type": "f128"
+    },
+    "sqrtf16": {
+        "sources": [
+            "src/math/generic/sqrt.rs",
+            "src/math/sqrtf16.rs"
+        ],
+        "type": "f16"
+    },
     "tan": {
         "sources": [
             "src/libm_helper.rs",

etc/function-list.txt

@@ -105,6 +105,8 @@ sinh
 sinhf
 sqrt
 sqrtf
+sqrtf128
+sqrtf16
 tan
 tanf
 tanh

src/math/generic/sqrt.rs

@@ -294,6 +294,14 @@ pub trait SqrtHelper: Float {
     const FINAL_ROUNDS: u32;
 }
 
+#[cfg(f16_enabled)]
+impl SqrtHelper for f16 {
+    type ISet1 = u16; // unused
+    type ISet2 = u16; // unused
+
+    const FINAL_ROUNDS: u32 = 2;
+}
+
 impl SqrtHelper for f32 {
     type ISet1 = u32; // unused
     type ISet2 = u32; // unused
@@ -309,6 +317,16 @@ impl SqrtHelper for f64 {
     const FINAL_ROUNDS: u32 = 2;
 }
 
+#[cfg(f128_enabled)]
+impl SqrtHelper for f128 {
+    type ISet1 = u32;
+    type ISet2 = u64;
+
+    const SET1_ROUNDS: u32 = 1;
+    const SET2_ROUNDS: u32 = 2;
+    const FINAL_ROUNDS: u32 = 2;
+}
+
 /// A U0.16 representation of `1/sqrt(x)`.
 ///
 // / The index is a 7-bit number consisting of a single exponent bit and 6 bits of significand.
@@ -355,6 +373,42 @@ mod tests {
         }
     }
 
+    #[test]
+    #[cfg(f16_enabled)]
+    fn sanity_check_f16() {
+        assert_biteq!(sqrt(100.0f16), 10.0);
+        assert_biteq!(sqrt(4.0f16), 2.0);
+    }
+
+    #[test]
+    #[cfg(f16_enabled)]
+    fn spec_tests_f16() {
+        spec_test::<f16>();
+    }
+
+    #[test]
+    #[cfg(f16_enabled)]
+    #[allow(clippy::approx_constant)]
+    fn conformance_tests_f16() {
+        let cases = [
+            (f16::PI, 0x3f17_u16),
+            // 10_000.0, using a hex literal for MSRV hack (Rust < 1.67 checks literal widths as
+            // part of the AST, so the `cfg` is irrelevant here).
+            (f16::from_bits(0x70e2), 0x5640_u16),
+            (f16::from_bits(0x0000000f), 0x13bf_u16),
+            (f16::INFINITY, f16::INFINITY.to_bits()),
+        ];
+
+        for (input, output) in cases {
+            assert_biteq!(
+                sqrt(input),
+                f16::from_bits(output),
+                "input: {input:?} ({:#018x})",
+                input.to_bits()
+            );
+        }
+    }
+
     #[test]
     fn sanity_check_f32() {
         assert_biteq!(sqrt(100.0f32), 10.0);
@@ -416,4 +470,42 @@ mod tests {
             );
         }
     }
+
+    #[test]
+    #[cfg(f128_enabled)]
+    fn sanity_check_f128() {
+        assert_biteq!(sqrt(100.0f128), 10.0);
+        assert_biteq!(sqrt(4.0f128), 2.0);
+    }
+
+    #[test]
+    #[cfg(f128_enabled)]
+    fn spec_tests_f128() {
+        spec_test::<f128>();
+    }
+
+    #[test]
+    #[cfg(f128_enabled)]
+    #[allow(clippy::approx_constant)]
+    fn conformance_tests_f128() {
+        let cases = [
+            (f128::PI, 0x3fffc5bf891b4ef6aa79c3b0520d5db9_u128),
+            // 10_000.0, see `f16` for reasoning.
+            (
+                f128::from_bits(0x400c3880000000000000000000000000),
+                0x40059000000000000000000000000000_u128,
+            ),
+            (f128::from_bits(0x0000000f), 0x1fc9efbdeb14f4ed9b17ae807907e1e9_u128),
+            (f128::INFINITY, f128::INFINITY.to_bits()),
+        ];
+
+        for (input, output) in cases {
+            assert_biteq!(
+                sqrt(input),
+                f128::from_bits(output),
+                "input: {input:?} ({:#018x})",
+                input.to_bits()
+            );
+        }
+    }
 }

src/math/mod.rs

@@ -344,11 +344,13 @@ cfg_if! {
         mod copysignf16;
         mod fabsf16;
         mod fdimf16;
+        mod sqrtf16;
         mod truncf16;
 
         pub use self::copysignf16::copysignf16;
         pub use self::fabsf16::fabsf16;
         pub use self::fdimf16::fdimf16;
+        pub use self::sqrtf16::sqrtf16;
         pub use self::truncf16::truncf16;
     }
 }
@@ -358,11 +360,13 @@ cfg_if! {
         mod copysignf128;
         mod fabsf128;
         mod fdimf128;
+        mod sqrtf128;
         mod truncf128;
 
         pub use self::copysignf128::copysignf128;
         pub use self::fabsf128::fabsf128;
         pub use self::fdimf128::fdimf128;
+        pub use self::sqrtf128::sqrtf128;
         pub use self::truncf128::truncf128;
     }
 }

src/math/sqrtf128.rs

@@ -0,0 +1,5 @@
+/// The square root of `x` (f128).
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub fn sqrtf128(x: f128) -> f128 {
+    return super::generic::sqrt(x);
+}