Move bit manipulation helpers out into their own object

1 files changed, 28 insertions, 49 deletions

diff --git a/src/main/kotlin/cpu/Registers.kt b/src/main/kotlin/cpu/Registers.kt
index 6cf417e..7aa144f 100644
--- a/src/main/kotlin/cpu/Registers.kt
+++ b/src/main/kotlin/cpu/Registers.kt
@@ -1,124 +1,103 @@
 package cpu
 
+import BitManipulation as bm
+
 class Registers {
 
   // General purpose registers
   var B: Int = 0
     set(value) {
-      validateUnsigned8Bit(value)
+      bm.validateUnsigned8Bit(value)
       field = value
     }
   var C: Int = 0
     set(value) {
-      validateUnsigned8Bit(value)
+      bm.validateUnsigned8Bit(value)
       field = value
     }
   var D: Int = 0
     set(value) {
-      validateUnsigned8Bit(value)
+      bm.validateUnsigned8Bit(value)
       field = value
     }
   var E: Int = 0
     set(value) {
-      validateUnsigned8Bit(value)
+      bm.validateUnsigned8Bit(value)
       field = value
     }
   var H: Int = 0
     set(value) {
-      validateUnsigned8Bit(value)
+      bm.validateUnsigned8Bit(value)
       field = value
     }
   var L: Int = 0
     set(value) {
-      validateUnsigned8Bit(value)
+      bm.validateUnsigned8Bit(value)
       field = value
     }
 
   // Special registers
   var A: Int = 0
     set(value) {
-      validateUnsigned8Bit(value)
+      bm.validateUnsigned8Bit(value)
       field = value
     }
   var F: Int = 0
     set(value) {
-      validateUnsigned8Bit(value)
+      bm.validateUnsigned8Bit(value)
       field = value
     }
   var SP: Int = 0
     set(value) {
-      validateUnsigned16Bit(value)
+      bm.validateUnsigned16Bit(value)
       field = value
     }
   var PC: Int = 0
     set(value) {
-      validateUnsigned16Bit(value)
+      bm.validateUnsigned16Bit(value)
       field = value
     }
 
   // 16-Bit accessors
   var AF: Int
     get() {
-      return bytesToWord(A, F)
+      return bm.bytesToWord(A, F)
     }
     set(value) {
-      validateUnsigned16Bit(value)
-      A = getMsb(value)
-      F = getLsb(value)
+      bm.validateUnsigned16Bit(value)
+      A = bm.getMsb(value)
+      F = bm.getLsb(value)
     }
 
   var BC: Int
     get() {
-      return bytesToWord(B, C)
+      return bm.bytesToWord(B, C)
     }
     set(value) {
-      validateUnsigned16Bit(value)
-      B = getMsb(value)
-      C = getLsb(value)
+      bm.validateUnsigned16Bit(value)
+      B = bm.getMsb(value)
+      C = bm.getLsb(value)
     }
 
   var DE: Int
     get() {
-      return bytesToWord(D, E)
+      return bm.bytesToWord(D, E)
     }
     set(value) {
-      validateUnsigned16Bit(value)
-      D = getMsb(value)
-      E = getLsb(value)
+      bm.validateUnsigned16Bit(value)
+      D = bm.getMsb(value)
+      E = bm.getLsb(value)
     }
 
   var HL: Int
     get() {
-      return bytesToWord(H, L)
+      return bm.bytesToWord(H, L)
     }
     set(value) {
-      validateUnsigned16Bit(value)
-      H = getMsb(value)
-      L = getLsb(value)
+      bm.validateUnsigned16Bit(value)
+      H = bm.getMsb(value)
+      L = bm.getLsb(value)
     }
 
-  private fun bytesToWord(msb: Int, lsb: Int): Int {
-    return msb.shl(8) + lsb
-  }
-
-  private fun getMsb(value: Int): Int {
-    return value.shr(8)
-  }
-
-  private fun getLsb(value: Int): Int {
-    return value.and(0xFF)
-  }
-
-  private fun validateUnsigned8Bit(value: Int) {
-    if(value < 0 || value > 255) {
-      throw IllegalArgumentException("Value $value is not an unsigned 8-Bit value")
-    }
-  }
-
-  private fun validateUnsigned16Bit(value: Int) {
-    if(value < 0 || value > 65535) {
-      throw IllegalArgumentException("Value $value is not an unsigned 16-Bit value")
-    }
-  }
 
 }
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