| //! RDRAND and RDSEED instructions for returning random numbers from an Intel |
| //! on-chip hardware random number generator which has been seeded by an |
| //! on-chip entropy source. |
| #![allow(clippy::module_name_repetitions)] |
| |
| #[allow(improper_ctypes)] |
| extern "unadjusted" { |
| #[link_name = "llvm.x86.rdrand.16"] |
| fn x86_rdrand16_step() -> (u16, i32); |
| #[link_name = "llvm.x86.rdrand.32"] |
| fn x86_rdrand32_step() -> (u32, i32); |
| #[link_name = "llvm.x86.rdseed.16"] |
| fn x86_rdseed16_step() -> (u16, i32); |
| #[link_name = "llvm.x86.rdseed.32"] |
| fn x86_rdseed32_step() -> (u32, i32); |
| } |
| |
| #[cfg(test)] |
| use stdarch_test::assert_instr; |
| |
| /// Read a hardware generated 16-bit random value and store the result in val. |
| /// Returns 1 if a random value was generated, and 0 otherwise. |
| /// |
| /// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_rdrand16_step) |
| #[inline] |
| #[target_feature(enable = "rdrand")] |
| #[cfg_attr(test, assert_instr(rdrand))] |
| #[stable(feature = "simd_x86", since = "1.27.0")] |
| pub unsafe fn _rdrand16_step(val: &mut u16) -> i32 { |
| let (v, flag) = x86_rdrand16_step(); |
| *val = v; |
| flag |
| } |
| |
| /// Read a hardware generated 32-bit random value and store the result in val. |
| /// Returns 1 if a random value was generated, and 0 otherwise. |
| /// |
| /// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_rdrand32_step) |
| #[inline] |
| #[target_feature(enable = "rdrand")] |
| #[cfg_attr(test, assert_instr(rdrand))] |
| #[stable(feature = "simd_x86", since = "1.27.0")] |
| pub unsafe fn _rdrand32_step(val: &mut u32) -> i32 { |
| let (v, flag) = x86_rdrand32_step(); |
| *val = v; |
| flag |
| } |
| |
| /// Read a 16-bit NIST SP800-90B and SP800-90C compliant random value and store |
| /// in val. Return 1 if a random value was generated, and 0 otherwise. |
| /// |
| /// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_rdseed16_step) |
| #[inline] |
| #[target_feature(enable = "rdseed")] |
| #[cfg_attr(test, assert_instr(rdseed))] |
| #[stable(feature = "simd_x86", since = "1.27.0")] |
| pub unsafe fn _rdseed16_step(val: &mut u16) -> i32 { |
| let (v, flag) = x86_rdseed16_step(); |
| *val = v; |
| flag |
| } |
| |
| /// Read a 32-bit NIST SP800-90B and SP800-90C compliant random value and store |
| /// in val. Return 1 if a random value was generated, and 0 otherwise. |
| /// |
| /// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_rdseed32_step) |
| #[inline] |
| #[target_feature(enable = "rdseed")] |
| #[cfg_attr(test, assert_instr(rdseed))] |
| #[stable(feature = "simd_x86", since = "1.27.0")] |
| pub unsafe fn _rdseed32_step(val: &mut u32) -> i32 { |
| let (v, flag) = x86_rdseed32_step(); |
| *val = v; |
| flag |
| } |