Question

Give a MIPS ASM example of how the following C program statement would be handled: num1 = A + arr[4]. Use a diagram (CPU registers, Instruction Register, Instruction Pointer, and System Memory)

Answer 1

The C statement 'num1 = A + arr[4];' can be translated into MIPS assembly language by loading the value from the array into a temporary register, adding it to the value of A from another register, and then storing the result back to the memory address of num1.

Step-by-step explanation:

The C statement num1 = A + arr[4]; can be translated into MIPS assembly language using the following steps. Assume that the base address of the array arr is stored in register $s1 and the value of A is in register $s2. Here is an example of the MIPS assembly code:

• lw $t0, 16($s1) # Load word from array index 4 into register $t0
• add $t1, $s2, $t0 # Add the value in $s2 (A) and $t0 (arr[4]) and store the result in $t1
• sw $t1, 0($s3) # Store the result from $t1 into the memory location assigned to num1 (address in $s3)

The diagram requested is not possible to provide in text format. However, generally, the diagram would include the CPU registers (like $s1, $s2, $s3, $t0, and $t1), the Instruction Register holding the current instruction, the Instruction Pointer (Program Counter) indicating the address of the next instruction, and sections of System Memory showing where the array arr and variable num1 are stored.