Remove use of BITS associated const

These were only introduced in Rust 1.53.0 so they would bump the MSRV unnecessarily.
mrhooray · Nov 4, 2021 · f0e62a3 · f0e62a3
1 parent 4a9a15b
commit f0e62a3
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Showing 7 changed files with 39 additions and 42 deletions.
diff --git a/src/crc128.rs b/src/crc128.rs
@@ -15,9 +15,9 @@ impl Crc<u128> {
 
     const fn init(&self) -> u128 {
         if self.algorithm.refin {
-            self.algorithm.init.reverse_bits() >> (u128::BITS as u8 - self.algorithm.width)
+            self.algorithm.init.reverse_bits() >> (128u8 - self.algorithm.width)
         } else {
-            self.algorithm.init << (u128::BITS as u8 - self.algorithm.width)
+            self.algorithm.init << (128u8 - self.algorithm.width)
         }
     }
 
@@ -35,7 +35,7 @@ impl Crc<u128> {
             }
         } else {
             while i < bytes.len() {
-                let table_index = (crc >> (u128::BITS - 8)) ^ bytes[i] as u128;
+                let table_index = (crc >> 120) ^ bytes[i] as u128;
                 crc = self.table_entry(table_index) ^ (crc << 8);
                 i += 1;
             }
@@ -48,7 +48,7 @@ impl Crc<u128> {
             crc = crc.reverse_bits();
         }
         if !self.algorithm.refout {
-            crc >>= u128::BITS as u8 - self.algorithm.width;
+            crc >>= 128u8 - self.algorithm.width;
         }
         crc ^ self.algorithm.xorout
     }

diff --git a/src/crc16.rs b/src/crc16.rs
@@ -15,9 +15,9 @@ impl Crc<u16> {
 
     const fn init(&self) -> u16 {
         if self.algorithm.refin {
-            self.algorithm.init.reverse_bits() >> (u16::BITS as u8 - self.algorithm.width)
+            self.algorithm.init.reverse_bits() >> (16u8 - self.algorithm.width)
         } else {
-            self.algorithm.init << (u16::BITS as u8 - self.algorithm.width)
+            self.algorithm.init << (16u8 - self.algorithm.width)
         }
     }
 
@@ -35,7 +35,7 @@ impl Crc<u16> {
             }
         } else {
             while i < bytes.len() {
-                let table_index = (crc >> (u16::BITS - 8)) ^ bytes[i] as u16;
+                let table_index = (crc >> 8) ^ bytes[i] as u16;
                 crc = self.table_entry(table_index) ^ (crc << 8);
                 i += 1;
             }
@@ -48,7 +48,7 @@ impl Crc<u16> {
             crc = crc.reverse_bits();
         }
         if !self.algorithm.refout {
-            crc >>= u16::BITS as u8 - self.algorithm.width;
+            crc >>= 16u8 - self.algorithm.width;
         }
         crc ^ self.algorithm.xorout
     }

diff --git a/src/crc32.rs b/src/crc32.rs
@@ -15,9 +15,9 @@ impl Crc<u32> {
 
     const fn init(&self) -> u32 {
         if self.algorithm.refin {
-            self.algorithm.init.reverse_bits() >> (u32::BITS as u8 - self.algorithm.width)
+            self.algorithm.init.reverse_bits() >> (32u8 - self.algorithm.width)
         } else {
-            self.algorithm.init << (u32::BITS as u8 - self.algorithm.width)
+            self.algorithm.init << (32u8 - self.algorithm.width)
         }
     }
 
@@ -35,7 +35,7 @@ impl Crc<u32> {
             }
         } else {
             while i < bytes.len() {
-                let table_index = (crc >> (u32::BITS - 8)) ^ bytes[i] as u32;
+                let table_index = (crc >> 24) ^ bytes[i] as u32;
                 crc = self.table_entry(table_index) ^ (crc << 8);
                 i += 1;
             }
@@ -48,7 +48,7 @@ impl Crc<u32> {
             crc = crc.reverse_bits();
         }
         if !self.algorithm.refout {
-            crc >>= u32::BITS as u8 - self.algorithm.width;
+            crc >>= 32u8 - self.algorithm.width;
         }
         crc ^ self.algorithm.xorout
     }

diff --git a/src/crc64.rs b/src/crc64.rs
@@ -15,9 +15,9 @@ impl Crc<u64> {
 
     const fn init(&self) -> u64 {
         if self.algorithm.refin {
-            self.algorithm.init.reverse_bits() >> (u64::BITS as u8 - self.algorithm.width)
+            self.algorithm.init.reverse_bits() >> (64u8 - self.algorithm.width)
         } else {
-            self.algorithm.init << (u64::BITS as u8 - self.algorithm.width)
+            self.algorithm.init << (64u8 - self.algorithm.width)
         }
     }
 
@@ -35,7 +35,7 @@ impl Crc<u64> {
             }
         } else {
             while i < bytes.len() {
-                let table_index = (crc >> (u64::BITS - 8)) ^ bytes[i] as u64;
+                let table_index = (crc >> 56) ^ bytes[i] as u64;
                 crc = self.table_entry(table_index) ^ (crc << 8);
                 i += 1;
             }
@@ -48,7 +48,7 @@ impl Crc<u64> {
             crc = crc.reverse_bits();
         }
         if !self.algorithm.refout {
-            crc >>= u64::BITS as u8 - self.algorithm.width;
+            crc >>= 64u8 - self.algorithm.width;
         }
         crc ^ self.algorithm.xorout
     }

diff --git a/src/crc8.rs b/src/crc8.rs
@@ -15,9 +15,9 @@ impl Crc<u8> {
 
     const fn init(&self) -> u8 {
         if self.algorithm.refin {
-            self.algorithm.init.reverse_bits() >> (u8::BITS as u8 - self.algorithm.width)
+            self.algorithm.init.reverse_bits() >> (8u8 - self.algorithm.width)
         } else {
-            self.algorithm.init << (u8::BITS as u8 - self.algorithm.width)
+            self.algorithm.init << (8u8 - self.algorithm.width)
         }
     }
 
@@ -41,7 +41,7 @@ impl Crc<u8> {
             crc = crc.reverse_bits();
         }
         if !self.algorithm.refout {
-            crc >>= u8::BITS as u8 - self.algorithm.width;
+            crc >>= 8u8 - self.algorithm.width;
         }
         crc ^ self.algorithm.xorout
     }

diff --git a/src/table.rs b/src/table.rs
@@ -3,9 +3,9 @@ use crate::util::*;
 pub(crate) const fn crc8_table(width: u8, poly: u8, reflect: bool) -> [u8; 256] {
     let poly = if reflect {
         let poly = poly.reverse_bits();
-        poly >> (u8::BITS as u8 - width)
+        poly >> (8u8 - width)
     } else {
-        poly << (u8::BITS as u8 - width)
+        poly << (8u8 - width)
     };
 
     let mut table = [0u8; 256];
@@ -20,9 +20,9 @@ pub(crate) const fn crc8_table(width: u8, poly: u8, reflect: bool) -> [u8; 256]
 pub(crate) const fn crc16_table(width: u8, poly: u16, reflect: bool) -> [u16; 256] {
     let poly = if reflect {
         let poly = poly.reverse_bits();
-        poly >> (u16::BITS as u8 - width)
+        poly >> (16u8 - width)
     } else {
-        poly << (u16::BITS as u8 - width)
+        poly << (16u8 - width)
     };
 
     let mut table = [0u16; 256];
@@ -37,9 +37,9 @@ pub(crate) const fn crc16_table(width: u8, poly: u16, reflect: bool) -> [u16; 25
 pub(crate) const fn crc32_table(width: u8, poly: u32, reflect: bool) -> [u32; 256] {
     let poly = if reflect {
         let poly = poly.reverse_bits();
-        poly >> (u32::BITS as u8 - width)
+        poly >> (32u8 - width)
     } else {
-        poly << (u32::BITS as u8 - width)
+        poly << (32u8 - width)
     };
 
     let mut table = [0u32; 256];
@@ -54,9 +54,9 @@ pub(crate) const fn crc32_table(width: u8, poly: u32, reflect: bool) -> [u32; 25
 pub(crate) const fn crc64_table(width: u8, poly: u64, reflect: bool) -> [u64; 256] {
     let poly = if reflect {
         let poly = poly.reverse_bits();
-        poly >> (u64::BITS as u8 - width)
+        poly >> (64u8 - width)
     } else {
-        poly << (u64::BITS as u8 - width)
+        poly << (64u8 - width)
     };
 
     let mut table = [0u64; 256];
@@ -71,9 +71,9 @@ pub(crate) const fn crc64_table(width: u8, poly: u64, reflect: bool) -> [u64; 25
 pub(crate) const fn crc128_table(width: u8, poly: u128, reflect: bool) -> [u128; 256] {
     let poly = if reflect {
         let poly = poly.reverse_bits();
-        poly >> (u128::BITS as u8 - width)
+        poly >> (128u8 - width)
     } else {
-        poly << (u128::BITS as u8 - width)
+        poly << (128u8 - width)
     };
 
     let mut table = [0u128; 256];

diff --git a/src/util.rs b/src/util.rs
@@ -1,16 +1,13 @@
 pub(crate) const fn crc8(poly: u8, reflect: bool, mut value: u8) -> u8 {
+    let mut i = 0;
     if reflect {
-        let mut i = 0;
         while i < 8 {
             value = (value >> 1) ^ ((value & 1) * poly);
             i += 1;
         }
     } else {
-        value <<= u8::BITS - 8;
-
-        let mut i = 0;
         while i < 8 {
-            value = (value << 1) ^ (((value >> (u8::BITS - 1)) & 1) * poly);
+            value = (value << 1) ^ (((value >> 7) & 1) * poly);
             i += 1;
         }
     }
@@ -25,11 +22,11 @@ pub(crate) const fn crc16(poly: u16, reflect: bool, mut value: u16) -> u16 {
             i += 1;
         }
     } else {
-        value <<= u16::BITS - 8;
+        value <<= 8;
 
         let mut i = 0;
         while i < 8 {
-            value = (value << 1) ^ (((value >> (u16::BITS - 1)) & 1) * poly);
+            value = (value << 1) ^ (((value >> 15) & 1) * poly);
             i += 1;
         }
     }
@@ -44,11 +41,11 @@ pub(crate) const fn crc32(poly: u32, reflect: bool, mut value: u32) -> u32 {
             i += 1;
         }
     } else {
-        value <<= u32::BITS - 8;
+        value <<= 24;
 
         let mut i = 0;
         while i < 8 {
-            value = (value << 1) ^ (((value >> (u32::BITS - 1)) & 1) * poly);
+            value = (value << 1) ^ (((value >> 31) & 1) * poly);
             i += 1;
         }
     }
@@ -63,11 +60,11 @@ pub(crate) const fn crc64(poly: u64, reflect: bool, mut value: u64) -> u64 {
             i += 1;
         }
     } else {
-        value <<= u64::BITS - 8;
+        value <<= 56;
 
         let mut i = 0;
         while i < 8 {
-            value = (value << 1) ^ (((value >> (u64::BITS - 1)) & 1) * poly);
+            value = (value << 1) ^ (((value >> 63) & 1) * poly);
             i += 1;
         }
     }
@@ -82,11 +79,11 @@ pub(crate) const fn crc128(poly: u128, reflect: bool, mut value: u128) -> u128 {
             i += 1;
         }
     } else {
-        value <<= u128::BITS - 8;
+        value <<= 120;
 
         let mut i = 0;
         while i < 8 {
-            value = (value << 1) ^ (((value >> (u128::BITS - 1)) & 1) * poly);
+            value = (value << 1) ^ (((value >> 127) & 1) * poly);
             i += 1;
         }
     }