Function bitintr::bmi2::mulx

pub fn mulx<T: MULX>(x: T, y: T, hi: &mut T) -> T

Unsigned multiply without affecting flags.

Unsigned multiplication of x with y storing the high half of the result in p and returning the low half of the result.

Intrinsics (when available BMI2)

MULX: Unsigned Multiply Without Affecting Flags (supports 32/64 bit registers).

Examples

use bitintr::bmi2::mulx;

{ // 8-bit
  let a: u8 = 128;
  let b: u8 = 128;
  let mut hi: u8 = 0;
  let lo: u8 = mulx(a, b, &mut hi);
  // result = 16384 = 0b0100_0000_0000_0000u16
  //                    ^~hi~~~~~ ^~lo~~~~~
  assert_eq!(lo, 0b0000_0000);
  assert_eq!(hi, 0b0100_0000);
}
{ // 16-bit
  let a: u16 = 65_500;
  let b: u16 = 65_500;
  let mut hi: u16 = 0;
  let lo: u16 = mulx(a, b, &mut hi);
  // result = 4290250000 = 0b0b1111_1111_1011_1000_0000_0101_0001_0000u32
  //                           ^~hi~~~~~~~~~~~~~~~ ^~lo~~~~~~~~~~~~~~~
  assert_eq!(lo, 0b0000_0101_0001_0000);
  assert_eq!(hi, 0b1111_1111_1011_1000);
}
{ // 32-bit
  let a: u32 = 4_294_967_200;
  let b: u32 = 2;
  let mut hi: u32 = 0;
  let lo: u32 = mulx(a, b, &mut hi);
  // result = 8589934400
  //        = 0b0b0001_1111_1111_1111_1111_1111_1111_0100_0000u64
  //              ^~hi ^~lo~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  assert_eq!(lo, 0b1111_1111_1111_1111_1111_1111_0100_0000u32);
  assert_eq!(hi, 0b0001u32);
}
{ // 64-bit
  let a: u64 = 9_223_372_036_854_775_800;
  let b: u64 = 100;
  let mut hi: u64 = 0;
  let lo: u64 = mulx(a, b, &mut hi);
  // result = 922337203685477580000
  //        = 0b0b00110001_11111111_11111111_11111111_11111111_11111111_11111111_11111100_11100000u128
  //         ^~hi~~~~~~~~~ ^~lo~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  assert_eq!(lo, 0b11111111_11111111_11111111_11111111_11111111_11111111_11111100_11100000u64);
  assert_eq!(hi, 0b00110001u64);
}