Make macros for R/I-type operations and use them to implement basically every single one i think

src/decode.rs

@@ -85,15 +85,10 @@ impl Instruction {
         imm_20 | imm_10_1 | imm_11 | imm_19_12
     }
 
-    // The following are AFAIK only used for shift by immediate operations
-
+    /// Technically part of immediate. Only used to determine shift type for immediate shifts afaik
+    /// 32bit ones use funct7 in this way
     #[inline]
     pub fn funct6(self) -> u8 {
         (self.0 >> 26 & 0x3f) as u8
     }
-
-    #[inline]
-    pub fn imm_shamt(self) -> usize {
-        (self.0 >> 20 & 0x3f) as usize
-    }
 }