library/stdarch/crates/core_arch/src/arm/v6.rs

   1 //! ARMv6 intrinsics.
   2 //!
   3 //! The reference is [ARMv6-M Architecture Reference Manual][armv6m].
   4 //!
   5 //! [armv6m]:
   6 //! http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0419c/index.
   7 //! html
   8
   9 #[cfg(test)]
  10 use stdarch_test::assert_instr;
  11
  12 /// Reverse the order of the bytes.
  13 #[inline]
  14 #[cfg_attr(test, assert_instr(rev))]
  15 pub unsafe fn _rev_u16(x: u16) -> u16 {
  16     x.swap_bytes() as u16
  17 }
  18
  19 /// Reverse the order of the bytes.
  20 #[inline]
  21 #[cfg_attr(test, assert_instr(rev))]
  22 pub unsafe fn _rev_u32(x: u32) -> u32 {
  23     x.swap_bytes() as u32
  24 }
  25
  26 #[cfg(test)]
  27 mod tests {
  28     use crate::core_arch::arm::v6;
  29
  30     #[test]
  31     fn _rev_u16() {
  32         unsafe {
  33             assert_eq!(
  34                 v6::_rev_u16(0b0000_0000_1111_1111_u16),
  35                 0b1111_1111_0000_0000_u16
  36             );
  37         }
  38     }
  39
  40     #[test]
  41     fn _rev_u32() {
  42         unsafe {
  43             assert_eq!(
  44                 v6::_rev_u32(0b0000_0000_1111_1111_0000_0000_1111_1111_u32),
  45                 0b1111_1111_0000_0000_1111_1111_0000_0000_u32
  46             );
  47         }
  48     }
  49 }