branch instruction

emulate.c

@@ -308,6 +308,26 @@ void dataProcessingInstr(struct ProcessorState *processor, int address)
   }
 }
 
+void branchInstr(struct ProcessorState *processor, uint32_t instruction) 
+{
+  // Check if address is valid
+  verifyAddress(address);
+  uint32_t instr = processor->memory[address];
+
+  //  Check if the instruction should be executed according to its condition codes
+  if(!validCond(getBits(instr, 28, 31), processor)){
+    return;
+  }
+
+  // Calculating offset and sign
+  int32_t offset = getBits(instr, 0, 23);
+  int sign = getBits(offset, 23, 23);
+
+  // Offset shifted and extended and new address (including +8 bytes) loaded to PC
+  processor->registers[14] = (((offset * 4) | 0) | ((sign) ? 0 : 0xFC000000)) + 64;
+  return;
+}
+
 
 // Steps through pipeline calling appropriate instruction method.
 // Sets teminate if instruction is all-0.