eflags.rs - source
Description: Source of the Rust file `library/core/src/../../stdarch/crates/core_arch/src/x86/eflags.rs`.

#
core/stdarch/crates/core_arch/src/x86/
eflags.rs

    1//! `i386` intrinsics
    2
    3use crate::arch::asm;
    4
    5/// Reads EFLAGS.
    6///
    7/// [Intel's documentation](https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=__readeflags)
    8#[cfg(target_arch = "x86")]
    9#[inline(always)]
    10#[stable(feature = "simd_x86", since = "1.27.0")]
    11#[deprecated(
    12    since = "1.29.0",
    13    note = "See issue #51810 - use inline assembly instead"
    14)]
    15#[doc(hidden)]
    16pub unsafe fn __readeflags() -> u32 {
    17    let eflags: u32;
    18    asm!("pushfd", "pop {}", out(reg) eflags, options(nomem, att_syntax));
    19    eflags
    20}
    21
    22/// Reads EFLAGS.
    23///
    24/// [Intel's documentation](https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=__readeflags)
    25#[cfg(target_arch = "x86_64")]
    26#[inline(always)]
    27#[stable(feature = "simd_x86", since = "1.27.0")]
    28#[deprecated(
    29    since = "1.29.0",
    30    note = "See issue #51810 - use inline assembly instead"
    31)]
    32#[doc(hidden)]
    33pub unsafe fn __readeflags() -> u64 {
    34    let eflags: u64;
    35    asm!("pushfq", "pop {}", out(reg) eflags, options(nomem, att_syntax));
    36    eflags
    37}
    38
    39/// Write EFLAGS.
    40///
    41/// [Intel's documentation](https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=__writeeflags)
    42#[cfg(target_arch = "x86")]
    43#[inline(always)]
    44#[stable(feature = "simd_x86", since = "1.27.0")]
    45#[deprecated(
    46    since = "1.29.0",
    47    note = "See issue #51810 - use inline assembly instead"
    48)]
    49#[doc(hidden)]
    50pub unsafe fn __writeeflags(eflags: u32) {
    51    asm!("push {}", "popfd", in(reg) eflags, options(nomem, att_syntax));
    52}
    53
    54/// Write EFLAGS.
    55///
    56/// [Intel's documentation](https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=__writeeflags)
    57#[cfg(target_arch = "x86_64")]
    58#[inline(always)]
    59#[stable(feature = "simd_x86", since = "1.27.0")]
    60#[deprecated(
    61    since = "1.29.0",
    62    note = "See issue #51810 - use inline assembly instead"
    63)]
    64#[doc(hidden)]
    65pub unsafe fn __writeeflags(eflags: u64) {
    66    asm!("push {}", "popfq", in(reg) eflags, options(nomem, att_syntax));
    67}
    68
    69#[cfg(test)]
    70mod tests {
    71    use crate::core_arch::x86::*;
    72
    73    #[test]
    74    #[cfg_attr(miri, ignore)] // Uses inline assembly
    75    #[allow(deprecated)]
    76    fn test_readeflags() {
    77        unsafe {
    78            // reads eflags, writes them back, reads them again,
    79            // and compare for equality:
    80            let v = __readeflags();
    81            __writeeflags(v);
    82            let u = __readeflags();
    83            assert_eq!(v, u);
    84        }
    85    }
    86}