Add truncf16 and truncf128

Use the generic algorithms to provide implementations for these
routines.

Author: tgross35

crates/compiler-builtins-smoke-test/src/lib.rs

@@ -157,6 +157,8 @@ no_mangle! {
     tgammaf(x: f32) -> f32;
     trunc(x: f64) -> f64;
     truncf(x: f32) -> f32;
+    truncf128(x: f128) -> f128;
+    truncf16(x: f16) -> f16;
     y0(x: f64) -> f64;
     y0f(x: f32) -> f32;
     y1(x: f64) -> f64;

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"],
+        &["fabsf16", "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"],
+        &["fabsf128", "truncf128"],
     ),
     (
         // `(f16, f16) -> f16`

crates/libm-test/benches/random.rs

@@ -117,7 +117,7 @@ libm_macros::for_each_function! {
         exp10 | exp10f | exp2 | exp2f => (true, Some(musl_math_sys::MACRO_FN_NAME)),
 
         // Musl does not provide `f16` and `f128` functions
-        copysignf16 | copysignf128 | fabsf16 | fabsf128 => (false, None),
+        copysignf16 | copysignf128 | fabsf16 | fabsf128 | truncf16 | truncf128  => (false, None),
 
         // By default we never skip (false) and always have a musl function available
         _ => (false, Some(musl_math_sys::MACRO_FN_NAME))

crates/libm-test/src/domain.rs

@@ -199,3 +199,13 @@ impl HasDomain<f16> for crate::op::fabsf16::Routine {
 impl HasDomain<f128> for crate::op::fabsf128::Routine {
     const DOMAIN: Domain<f128> = Domain::<f128>::UNBOUNDED;
 }
+
+#[cfg(f16_enabled)]
+impl HasDomain<f16> for crate::op::truncf16::Routine {
+    const DOMAIN: Domain<f16> = Domain::<f16>::UNBOUNDED;
+}
+
+#[cfg(f128_enabled)]
+impl HasDomain<f128> for crate::op::truncf128::Routine {
+    const DOMAIN: Domain<f128> = Domain::<f128>::UNBOUNDED;
+}

crates/libm-test/src/mpfloat.rs

@@ -141,6 +141,7 @@ libm_macros::for_each_function! {
         lgamma_r, lgammaf_r, modf, modff, nextafter, nextafterf, pow,powf,
         remquo, remquof, scalbn, scalbnf, sincos, sincosf, yn, ynf,
         copysignf16, copysignf128, fabsf16, fabsf128,
+        truncf16, truncf128,
     ],
     fn_extra: match MACRO_FN_NAME {
         // Remap function names that are different between mpfr and libm
@@ -202,11 +203,13 @@ impl_no_round! {
 #[cfg(f16_enabled)]
 impl_no_round! {
     fabsf16 => abs_mut;
+    truncf16 => trunc_mut;
 }
 
 #[cfg(f128_enabled)]
 impl_no_round! {
     fabsf128 => abs_mut;
+    truncf128 => trunc_mut;
 }
 
 /// Some functions are difficult to do in a generic way. Implement them here.

crates/libm-test/tests/compare_built_musl.rs

@@ -48,7 +48,7 @@ where
 libm_macros::for_each_function! {
     callback: musl_rand_tests,
     // Musl does not support `f16` and `f128` on all platforms.
-    skip: [copysignf16, copysignf128, fabsf16, fabsf128],
+    skip: [copysignf16, copysignf128, fabsf16, fabsf128, truncf16, truncf128],
     attributes: [
         #[cfg_attr(x86_no_sse, ignore)] // FIXME(correctness): wrong result on i586
         [exp10, exp10f, exp2, exp2f, rint]
@@ -146,5 +146,7 @@ libm_macros::for_each_function! {
         // Not provided by musl
         fabsf16,
         fabsf128,
+        truncf16,
+        truncf128,
     ],
 }

etc/function-definitions.json

@@ -743,17 +743,33 @@
         "sources": [
             "src/libm_helper.rs",
             "src/math/arch/wasm32.rs",
+            "src/math/generic/trunc.rs",
             "src/math/trunc.rs"
         ],
         "type": "f64"
     },
     "truncf": {
         "sources": [
             "src/math/arch/wasm32.rs",
+            "src/math/generic/trunc.rs",
             "src/math/truncf.rs"
         ],
         "type": "f32"
     },
+    "truncf128": {
+        "sources": [
+            "src/math/generic/trunc.rs",
+            "src/math/truncf128.rs"
+        ],
+        "type": "f128"
+    },
+    "truncf16": {
+        "sources": [
+            "src/math/generic/trunc.rs",
+            "src/math/truncf16.rs"
+        ],
+        "type": "f16"
+    },
     "y0": {
         "sources": [
             "src/libm_helper.rs",

etc/function-list.txt

@@ -111,6 +111,8 @@ tgamma
 tgammaf
 trunc
 truncf
+truncf128
+truncf16
 y0
 y0f
 y1

src/math/mod.rs

@@ -343,19 +343,23 @@ cfg_if! {
     if #[cfg(f16_enabled)] {
         mod copysignf16;
         mod fabsf16;
+        mod truncf16;
 
         pub use self::copysignf16::copysignf16;
         pub use self::fabsf16::fabsf16;
+        pub use self::truncf16::truncf16;
     }
 }
 
 cfg_if! {
     if #[cfg(f128_enabled)] {
         mod copysignf128;
         mod fabsf128;
+        mod truncf128;
 
         pub use self::copysignf128::copysignf128;
         pub use self::fabsf128::fabsf128;
+        pub use self::truncf128::truncf128;
     }
 }
 

src/math/truncf128.rs

@@ -0,0 +1,7 @@
+/// Rounds the number toward 0 to the closest integral value (f128).
+///
+/// This effectively removes the decimal part of the number, leaving the integral part.
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub fn truncf128(x: f128) -> f128 {
+    super::generic::trunc(x)
+}

src/math/truncf16.rs

@@ -0,0 +1,7 @@
+/// Rounds the number toward 0 to the closest integral value (f16).
+///
+/// This effectively removes the decimal part of the number, leaving the integral part.
+#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
+pub fn truncf16(x: f16) -> f16 {
+    super::generic::trunc(x)
+}