deprecate read/write eflags

Author: gnzlbg

coresimd/x86/eflags.rs

@@ -6,6 +6,8 @@
 #[cfg(target_arch = "x86")]
 #[inline(always)]
 #[stable(feature = "simd_x86", since = "1.27.0")]
+#[rustc_deprecated(since = "1.28.0", reason = "See issue #51810 - use inline assembly instead")]
+#[doc(hidden)]
 pub unsafe fn __readeflags() -> u32 {
     let eflags: u32;
     asm!("pushfd; popl $0" : "=r"(eflags) : : : "volatile");
@@ -18,6 +20,8 @@ pub unsafe fn __readeflags() -> u32 {
 #[cfg(target_arch = "x86_64")]
 #[inline(always)]
 #[stable(feature = "simd_x86", since = "1.27.0")]
+#[rustc_deprecated(since = "1.28.0", reason = "See issue #51810 - use inline assembly instead")]
+#[doc(hidden)]
 pub unsafe fn __readeflags() -> u64 {
     let eflags: u64;
     asm!("pushfq; popq $0" : "=r"(eflags) : : : "volatile");
@@ -29,7 +33,9 @@ pub unsafe fn __readeflags() -> u64 {
 /// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=__writeeflags)
 #[cfg(target_arch = "x86")]
 #[inline(always)]
-#[stable(feature = "simd_x86", since = "1.27.0")]
+#[stable(feature = "simd_x86", since = "1.27.0", reason = "See issue #51810 - use inline assembly instead")]
+#[rustc_deprecated(since = "1.28.0")]
+#[doc(hidden)]
 pub unsafe fn __writeeflags(eflags: u32) {
     asm!("pushl $0; popfd" : : "r"(eflags) : "cc", "flags" : "volatile");
 }
@@ -39,7 +45,9 @@ pub unsafe fn __writeeflags(eflags: u32) {
 /// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=__writeeflags)
 #[cfg(target_arch = "x86_64")]
 #[inline(always)]
-#[stable(feature = "simd_x86", since = "1.27.0")]
+#[stable(feature = "simd_x86", since = "1.27.0", reason = "See issue #51810 - use inline assembly instead")]
+#[rustc_deprecated(since = "1.28.0")]
+#[doc(hidden)]
 pub unsafe fn __writeeflags(eflags: u64) {
     asm!("pushq $0; popfq" : : "r"(eflags) : "cc", "flags" : "volatile");
 }