riscv: use bits helper for mcounteren

Uses the new `bf_extract` helper for the `mcounteren` register.

Author: rmsyn

riscv/src/register/mcounteren.rs

@@ -1,5 +1,7 @@
 //! mcounteren register
 
+use crate::bits::bf_extract;
+
 /// mcounteren register
 #[derive(Clone, Copy, Debug)]
 pub struct Mcounteren {
@@ -10,26 +12,26 @@ impl Mcounteren {
     /// Supervisor "cycle\[h\]" Enable
     #[inline]
     pub fn cy(&self) -> bool {
-        self.bits & (1 << 0) != 0
+        bf_extract(self.bits, 0, 1) != 0
     }
 
     /// Supervisor "time\[h\]" Enable
     #[inline]
     pub fn tm(&self) -> bool {
-        self.bits & (1 << 1) != 0
+        bf_extract(self.bits, 1, 1) != 0
     }
 
     /// Supervisor "instret\[h\]" Enable
     #[inline]
     pub fn ir(&self) -> bool {
-        self.bits & (1 << 2) != 0
+        bf_extract(self.bits, 2, 1) != 0
     }
 
     /// Supervisor "hpm\[x\]" Enable (bits 3-31)
     #[inline]
     pub fn hpm(&self, index: usize) -> bool {
         assert!((3..32).contains(&index));
-        self.bits & (1 << index) != 0
+        bf_extract(self.bits, index, 1) != 0
     }
 }