Number of Addresses Machine instruction characteristics • 3 addresses - - - Operand 1, Operand 2, Result a = b + c; May be a forth - next instruction (usually implicit) Not common Needs very long words to hold everything Instruction SUB MPY ADD DIV 9 -11 Y, A, D T, D, E T, T, C Y, Y, T Comment Y←A-B T←D×E T←T+C Y←Y÷T Yonsei University Instruction Set Characteristics and Functions —Implementing the CPU in large part is implementing the machine instruction set • Machine Code is rarely used by humans —Binary numbers / bits —Machine code is usually represented by human • Three address instructions sub y,a,b mul t,d,e add t,t,c div y,y,t • Two address Three address code is a sort of intermediate code that is simple to create and convert to machine code. It can only define an expression with three addresses and one operator. Basically, the three address codes help in determining the sequence in which operations are actioned by the compiler. Pointers for Three Address Code Three, Two, One and Zero Address Instruction :-. (a) Three Address instructions :- In these type of instructions, all operand addresses are explicitly defined. Here the instructions format has three different address fields specifying or memory or processor register operand. Example :- ADD R1,C,B ---> R1 <---M [C] +M [B] i,e the operands at Introduction Section 12.1, 12.2, and 12.3 pp. 406-418 Computer Designer: Machine instruction set provides the functional requirements for the processor Assembly Programmer: Machine instruction set provides the types of supported data, registers, and the capabilities of the ALU Spring 2016 CS430 - Computer Architecture 2 instruction set machine of three-address, two-address, and one-address Question Evaluate the statement below and show how to compile it into MIPS (Million Instructions Per Second) code by using instruction set machine of three-address, two-address, and one-address. F = (X+Y) (VW) Expert Solution Want to see the full answer? The characteristics of Three Address instructions are- They are generated by the compiler for implementing Code Optimization. They use maximum three addresses to represent any statement. They are implemented as a record with the address fields. General Form- In general, Three Address instructions are represented as- a = b op c Here, 1. A computer program instruction that has an address part that contains three addresses, such as the addresses of two operands and the address for the results of the operation specified in the operation part. Note 1: A computer instruction, written as 23 544 496 912 might indicate that the operation, 23, is that of addition, 544 is the address A hypothetical Machine has the following characteristics: 0 3 4 15 . Opcode Address . Instruction Format 0 1 15 Sign Magnitude ; Integer Format Program Counter (PC) = Address of Next Instruction, 12-bits Instruction Register (IR) = Instruction being Executed, 16-bits Accumulator (AC) = Temporary Storage, 16-bits Memory Address Register (MAR View Slot17-18-CH12-InstructionSetAndFunctions-40-slides from CEA 210 at FPT University. + Instruction Sets: Chapter 12 Characteristics and Functions William Stallings, Computer Organization and Number of Addresses • 3 addresses - Operand 1, Operand 2, Result - a = b + c; - May be a forth - next instruction (usually implicit) - Not common - Needs very long words to hold everything M