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git.proxmox.com Git - rustc.git/blob - library/stdarch/crates/core_arch/src/x86_64/rdrand.rs
1 //! RDRAND and RDSEED instructions for returning random numbers from an Intel
2 //! on-chip hardware random number generator which has been seeded by an
3 //! on-chip entropy source.
5 #![allow(clippy::module_name_repetitions)]
7 #[allow(improper_ctypes)]
9 #[link_name = "llvm.x86.rdrand.64"]
10 fn x86_rdrand64_step() -> (u64, i32);
11 #[link_name = "llvm.x86.rdseed.64"]
12 fn x86_rdseed64_step() -> (u64, i32);
16 use stdarch_test
::assert_instr
;
18 /// Read a hardware generated 64-bit random value and store the result in val.
19 /// Returns 1 if a random value was generated, and 0 otherwise.
21 /// [Intel's documentation](https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=_rdrand64_step)
23 #[target_feature(enable = "rdrand")]
24 #[cfg_attr(test, assert_instr(rdrand))]
25 #[stable(feature = "simd_x86", since = "1.27.0")]
26 pub unsafe fn _rdrand64_step(val
: &mut u64) -> i32 {
27 let (v
, flag
) = x86_rdrand64_step();
32 /// Read a 64-bit NIST SP800-90B and SP800-90C compliant random value and store
33 /// in val. Return 1 if a random value was generated, and 0 otherwise.
35 /// [Intel's documentation](https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=_rdseed64_step)
37 #[target_feature(enable = "rdseed")]
38 #[cfg_attr(test, assert_instr(rdseed))]
39 #[stable(feature = "simd_x86", since = "1.27.0")]
40 pub unsafe fn _rdseed64_step(val
: &mut u64) -> i32 {
41 let (v
, flag
) = x86_rdseed64_step();