Add missing functions for f16 and f128 by tgross35 · Pull Request #587 · rust-lang/compiler-builtins (original) (raw)

fn zero_widen_mul(self, rhs: Self) -> Self::D {
let product11: u64 = word!(1, self) * word!(1, rhs);
let product12: u64 = word!(1, self) * word!(2, rhs);
let product13: u64 = word!(1, self) * word!(3, rhs);
let product14: u64 = word!(1, self) * word!(4, rhs);
let product21: u64 = word!(2, self) * word!(1, rhs);
let product22: u64 = word!(2, self) * word!(2, rhs);
let product23: u64 = word!(2, self) * word!(3, rhs);
let product24: u64 = word!(2, self) * word!(4, rhs);
let product31: u64 = word!(3, self) * word!(1, rhs);
let product32: u64 = word!(3, self) * word!(2, rhs);
let product33: u64 = word!(3, self) * word!(3, rhs);
let product34: u64 = word!(3, self) * word!(4, rhs);
let product41: u64 = word!(4, self) * word!(1, rhs);
let product42: u64 = word!(4, self) * word!(2, rhs);
let product43: u64 = word!(4, self) * word!(3, rhs);
let product44: u64 = word!(4, self) * word!(4, rhs);
let sum0: u128 = u128::from(product44);
let sum1: u128 = u128::from(product34) + u128::from(product43);
let sum2: u128 = u128::from(product24) + u128::from(product33) + u128::from(product42);
let sum3: u128 = u128::from(product14)
+ u128::from(product23)
+ u128::from(product32)
+ u128::from(product41);
let sum4: u128 = u128::from(product13) + u128::from(product22) + u128::from(product31);
let sum5: u128 = u128::from(product12) + u128::from(product21);
let sum6: u128 = u128::from(product11);
let r0: u128 =
(sum0 & u128::from(WORD_FULL_MASK)) + ((sum1 & u128::from(WORD_LO_MASK)) << 32);
let r1: u128 = (sum0 >> 64)
+ ((sum1 >> 32) & u128::from(WORD_FULL_MASK))
+ (sum2 & u128::from(WORD_FULL_MASK))
+ ((sum3 << 32) & u128::from(WORD_HI_MASK));
let lo = r0.wrapping_add(r1 << 64);
let hi = (r1 >> 64)
+ (sum1 >> 96)
+ (sum2 >> 64)
+ (sum3 >> 32)
+ sum4
+ (sum5 << 32)
+ (sum6 << 64);
u256([
(lo & U128_LO_MASK) as u64,
((lo >> 64) & U128_LO_MASK) as u64,
(hi & U128_LO_MASK) as u64,
((hi >> 64) & U128_LO_MASK) as u64,
])
}