prepare for miri supporting the crc intrinsics

Author: folkertdev

zlib-rs/src/crc32/acle.rs

@@ -50,54 +50,65 @@ unsafe fn remainder(mut c: u32, mut buf: &[u8]) -> u32 {
     c
 }
 
+cfg_select! {
+    miri => {
+        use core::arch::aarch64::{__crc32b, __crc32h, __crc32d, __crc32w};
+    }
+    _ => {
+        use asm::{__crc32b, __crc32h, __crc32d, __crc32w};
+    }
+}
+
 // FIXME the intrinsics below are stable since rust 1.80.0: remove these and use the standard
 // library versions once our MSRV reaches that version.
-
-/// CRC32 single round checksum for bytes (8 bits).
-///
-/// [Arm's documentation](https://developer.arm.com/architectures/instruction-sets/intrinsics/__crc32b)
-#[target_feature(enable = "crc")]
-#[cfg_attr(target_arch = "arm", target_feature(enable = "v8"))]
-unsafe fn __crc32b(mut crc: u32, data: u8) -> u32 {
-    unsafe {
-        core::arch::asm!("crc32b {crc:w}, {crc:w}, {data:w}", crc = inout(reg) crc, data = in(reg) data);
-        crc
+mod asm {
+
+    /// CRC32 single round checksum for bytes (8 bits).
+    ///
+    /// [Arm's documentation](https://developer.arm.com/architectures/instruction-sets/intrinsics/__crc32b)
+    #[target_feature(enable = "crc")]
+    #[cfg_attr(target_arch = "arm", target_feature(enable = "v8"))]
+    unsafe fn __crc32b(mut crc: u32, data: u8) -> u32 {
+        unsafe {
+            core::arch::asm!("crc32b {crc:w}, {crc:w}, {data:w}", crc = inout(reg) crc, data = in(reg) data);
+            crc
+        }
     }
-}
 
-/// CRC32 single round checksum for half words (16 bits).
-///
-/// [Arm's documentation](https://developer.arm.com/architectures/instruction-sets/intrinsics/__crc32h)
-#[target_feature(enable = "crc")]
-#[cfg_attr(target_arch = "arm", target_feature(enable = "v8"))]
-unsafe fn __crc32h(mut crc: u32, data: u16) -> u32 {
-    unsafe {
-        core::arch::asm!("crc32h {crc:w}, {crc:w}, {data:w}", crc = inout(reg) crc, data = in(reg) data);
-        crc
+    /// CRC32 single round checksum for half words (16 bits).
+    ///
+    /// [Arm's documentation](https://developer.arm.com/architectures/instruction-sets/intrinsics/__crc32h)
+    #[target_feature(enable = "crc")]
+    #[cfg_attr(target_arch = "arm", target_feature(enable = "v8"))]
+    unsafe fn __crc32h(mut crc: u32, data: u16) -> u32 {
+        unsafe {
+            core::arch::asm!("crc32h {crc:w}, {crc:w}, {data:w}", crc = inout(reg) crc, data = in(reg) data);
+            crc
+        }
     }
-}
 
-/// CRC32 single round checksum for words (32 bits).
-///
-/// [Arm's documentation](https://developer.arm.com/architectures/instruction-sets/intrinsics/__crc32w)
-#[target_feature(enable = "crc")]
-#[cfg_attr(target_arch = "arm", target_feature(enable = "v8"))]
-pub unsafe fn __crc32w(mut crc: u32, data: u32) -> u32 {
-    unsafe {
-        core::arch::asm!("crc32w {crc:w}, {crc:w}, {data:w}", crc = inout(reg) crc, data = in(reg) data);
-        crc
+    /// CRC32 single round checksum for words (32 bits).
+    ///
+    /// [Arm's documentation](https://developer.arm.com/architectures/instruction-sets/intrinsics/__crc32w)
+    #[target_feature(enable = "crc")]
+    #[cfg_attr(target_arch = "arm", target_feature(enable = "v8"))]
+    pub unsafe fn __crc32w(mut crc: u32, data: u32) -> u32 {
+        unsafe {
+            core::arch::asm!("crc32w {crc:w}, {crc:w}, {data:w}", crc = inout(reg) crc, data = in(reg) data);
+            crc
+        }
     }
-}
 
-/// CRC32 single round checksum for double words (64 bits).
-///
-/// [Arm's documentation](https://developer.arm.com/architectures/instruction-sets/intrinsics/__crc32d)
-#[cfg(target_arch = "aarch64")]
-#[target_feature(enable = "crc")]
-unsafe fn __crc32d(mut crc: u32, data: u64) -> u32 {
-    unsafe {
-        core::arch::asm!("crc32x {crc:w}, {crc:w}, {data:x}", crc = inout(reg) crc, data = in(reg) data);
-        crc
+    /// CRC32 single round checksum for double words (64 bits).
+    ///
+    /// [Arm's documentation](https://developer.arm.com/architectures/instruction-sets/intrinsics/__crc32d)
+    #[cfg(target_arch = "aarch64")]
+    #[target_feature(enable = "crc")]
+    unsafe fn __crc32d(mut crc: u32, data: u64) -> u32 {
+        unsafe {
+            core::arch::asm!("crc32x {crc:w}, {crc:w}, {data:x}", crc = inout(reg) crc, data = in(reg) data);
+            crc
+        }
     }
 }