library/stdarch/crates/std_detect/src/detect/os/windows/aarch64.rs

   1 //! Run-time feature detection for Aarch64 on Windows.
   2
   3 use crate::detect::{cache, Feature};
   4
   5 /// Try to read the features using IsProcessorFeaturePresent.
   6 pub(crate) fn detect_features() -> cache::Initializer {
   7     type DWORD = u32;
   8     type BOOL = i32;
   9
  10     const FALSE: BOOL = 0;
  11     // The following Microsoft documents isn't updated for aarch64.
  12     // https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-isprocessorfeaturepresent
  13     // These are defined in winnt.h of Windows SDK
  14     const PF_ARM_NEON_INSTRUCTIONS_AVAILABLE: u32 = 19;
  15     const PF_ARM_V8_CRYPTO_INSTRUCTIONS_AVAILABLE: u32 = 30;
  16     const PF_ARM_V8_CRC32_INSTRUCTIONS_AVAILABLE: u32 = 31;
  17
  18     extern "system" {
  19         pub fn IsProcessorFeaturePresent(ProcessorFeature: DWORD) -> BOOL;
  20     }
  21
  22     let mut value = cache::Initializer::default();
  23     {
  24         let mut enable_feature = |f, enable| {
  25             if enable {
  26                 value.set(f as u32);
  27             }
  28         };
  29
  30         // Some features such Feature::fp may be supported on current CPU,
  31         // but no way to detect it by OS API.
  32         // Also, we require unsafe block for the extern "system" calls.
  33         unsafe {
  34             enable_feature(
  35                 Feature::asimd,
  36                 IsProcessorFeaturePresent(PF_ARM_NEON_INSTRUCTIONS_AVAILABLE) != FALSE,
  37             );
  38             enable_feature(
  39                 Feature::crc,
  40                 IsProcessorFeaturePresent(PF_ARM_V8_CRC32_INSTRUCTIONS_AVAILABLE) != FALSE,
  41             );
  42             // PF_ARM_V8_CRYPTO_INSTRUCTIONS_AVAILABLE means aes, sha1, sha2 and
  43             // pmull support
  44             enable_feature(
  45                 Feature::aes,
  46                 IsProcessorFeaturePresent(PF_ARM_V8_CRYPTO_INSTRUCTIONS_AVAILABLE) != FALSE,
  47             );
  48             enable_feature(
  49                 Feature::pmull,
  50                 IsProcessorFeaturePresent(PF_ARM_V8_CRYPTO_INSTRUCTIONS_AVAILABLE) != FALSE,
  51             );
  52             enable_feature(
  53                 Feature::sha2,
  54                 IsProcessorFeaturePresent(PF_ARM_V8_CRYPTO_INSTRUCTIONS_AVAILABLE) != FALSE,
  55             );
  56         }
  57     }
  58     value
  59 }