| use core::f32; |
| |
| #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] |
| pub fn truncf(x: f32) -> f32 { |
| // On wasm32 we know that LLVM's intrinsic will compile to an optimized |
| // `f32.trunc` native instruction, so we can leverage this for both code size |
| // and speed. |
| llvm_intrinsically_optimized! { |
| #[cfg(target_arch = "wasm32")] { |
| return unsafe { ::core::intrinsics::truncf32(x) } |
| } |
| } |
| let x1p120 = f32::from_bits(0x7b800000); // 0x1p120f === 2 ^ 120 |
| |
| let mut i: u32 = x.to_bits(); |
| let mut e: i32 = (i >> 23 & 0xff) as i32 - 0x7f + 9; |
| let m: u32; |
| |
| if e >= 23 + 9 { |
| return x; |
| } |
| if e < 9 { |
| e = 1; |
| } |
| m = -1i32 as u32 >> e; |
| if (i & m) == 0 { |
| return x; |
| } |
| force_eval!(x + x1p120); |
| i &= !m; |
| f32::from_bits(i) |
| } |
| |
| // PowerPC tests are failing on LLVM 13: https://github.com/rust-lang/rust/issues/88520 |
| #[cfg(not(target_arch = "powerpc64"))] |
| #[cfg(test)] |
| mod tests { |
| #[test] |
| fn sanity_check() { |
| assert_eq!(super::truncf(1.1), 1.0); |
| } |
| } |
