Former-commit-id: 02816d9454359849c9f9cc12b0e0e31d9ce208cd

src/interfaces/irdb/STARS_IRDB_Op.cpp

@@ -308,17 +308,19 @@ void STARS_IRDB_op_t::SetSIB(char value)
 	operand.mem.hasSIB=true;
 
 	// update the base register.  Odd casting to avoid compiler error bcause base is a STARS_RegNo
-	(*(int*)&operand.mem.base)&=0x7;
+	(*(int*)&operand.mem.base)&=~0x7;
 	(*(int*)&operand.mem.base)|=(value&0x7);
 
 	// Set scale.  Odd casting to avoid compiler error bcause base is a STARS_RegNo
-	(*(int*)&operand.mem.index)&=(0x7<<3);
+	(*(int*)&operand.mem.index)&=~(0x7<<3);
 	(*(int*)&operand.mem.index)|=(value>>3)&0x7;
 
 	// set scale
 	operand.mem.scale= (STARS_RegNo)((value>>6)&0x3);
 	if(operand.mem.index==STARS_x86_R_sp)
 		operand.mem.scale=(STARS_RegNo)0;
+
+	assert(value==GetSIB());
 }
 
 void STARS_IRDB_op_t::Dump()