diff --git a/library/compiler-builtins/libm/etc/function-definitions.json b/library/compiler-builtins/libm/etc/function-definitions.json index f60a7e5673c9..39b6c97029cb 100644 --- a/library/compiler-builtins/libm/etc/function-definitions.json +++ b/library/compiler-builtins/libm/etc/function-definitions.json @@ -604,6 +604,7 @@ "rint": { "sources": [ "src/libm_helper.rs", + "src/math/arch/aarch64.rs", "src/math/arch/wasm32.rs", "src/math/rint.rs" ], @@ -611,6 +612,7 @@ }, "rintf": { "sources": [ + "src/math/arch/aarch64.rs", "src/math/arch/wasm32.rs", "src/math/rintf.rs" ], diff --git a/library/compiler-builtins/libm/src/math/arch/aarch64.rs b/library/compiler-builtins/libm/src/math/arch/aarch64.rs new file mode 100644 index 000000000000..374ec11bfec3 --- /dev/null +++ b/library/compiler-builtins/libm/src/math/arch/aarch64.rs @@ -0,0 +1,33 @@ +use core::arch::aarch64::{ + float32x2_t, float64x1_t, vdup_n_f32, vdup_n_f64, vget_lane_f32, vget_lane_f64, vrndn_f32, + vrndn_f64, +}; + +pub fn rint(x: f64) -> f64 { + // SAFETY: only requires target_feature=neon, ensured by `cfg_if` in parent module. + let x_vec: float64x1_t = unsafe { vdup_n_f64(x) }; + + // SAFETY: only requires target_feature=neon, ensured by `cfg_if` in parent module. + let result_vec: float64x1_t = unsafe { vrndn_f64(x_vec) }; + + // SAFETY: only requires target_feature=neon, ensured by `cfg_if` in parent module. + let result: f64 = unsafe { vget_lane_f64::<0>(result_vec) }; + + result +} + +pub fn rintf(x: f32) -> f32 { + // There's a scalar form of this instruction (FRINTN) but core::arch doesn't expose it, so we + // have to use the vector form and drop the other lanes afterwards. + + // SAFETY: only requires target_feature=neon, ensured by `cfg_if` in parent module. + let x_vec: float32x2_t = unsafe { vdup_n_f32(x) }; + + // SAFETY: only requires target_feature=neon, ensured by `cfg_if` in parent module. + let result_vec: float32x2_t = unsafe { vrndn_f32(x_vec) }; + + // SAFETY: only requires target_feature=neon, ensured by `cfg_if` in parent module. + let result: f32 = unsafe { vget_lane_f32::<0>(result_vec) }; + + result +} diff --git a/library/compiler-builtins/libm/src/math/arch/mod.rs b/library/compiler-builtins/libm/src/math/arch/mod.rs index 3992419cbaad..091d7650a5ac 100644 --- a/library/compiler-builtins/libm/src/math/arch/mod.rs +++ b/library/compiler-builtins/libm/src/math/arch/mod.rs @@ -17,6 +17,13 @@ cfg_if! { } else if #[cfg(target_feature = "sse2")] { mod i686; pub use i686::{sqrt, sqrtf}; + } else if #[cfg(all( + target_arch = "aarch64", // TODO: also arm64ec? + target_feature = "neon", + target_endian = "little", // see https://github.com/rust-lang/stdarch/issues/1484 + ))] { + mod aarch64; + pub use aarch64::{rint, rintf}; } } diff --git a/library/compiler-builtins/libm/src/math/rint.rs b/library/compiler-builtins/libm/src/math/rint.rs index 50192ffdf03d..c9ea6402ec73 100644 --- a/library/compiler-builtins/libm/src/math/rint.rs +++ b/library/compiler-builtins/libm/src/math/rint.rs @@ -2,7 +2,10 @@ pub fn rint(x: f64) -> f64 { select_implementation! { name: rint, - use_arch: all(target_arch = "wasm32", intrinsics_enabled), + use_arch: any( + all(target_arch = "wasm32", intrinsics_enabled), + all(target_arch = "aarch64", target_feature = "neon", target_endian = "little"), + ), args: x, } diff --git a/library/compiler-builtins/libm/src/math/rintf.rs b/library/compiler-builtins/libm/src/math/rintf.rs index 64968b6be3a3..33b5b3ddebf6 100644 --- a/library/compiler-builtins/libm/src/math/rintf.rs +++ b/library/compiler-builtins/libm/src/math/rintf.rs @@ -2,7 +2,10 @@ pub fn rintf(x: f32) -> f32 { select_implementation! { name: rintf, - use_arch: all(target_arch = "wasm32", intrinsics_enabled), + use_arch: any( + all(target_arch = "wasm32", intrinsics_enabled), + all(target_arch = "aarch64", target_feature = "neon", target_endian = "little"), + ), args: x, }