What is peephole optimization? Explain the following peephole optimization techniques with examples:

• Redundant load/store elimination
• Constant folding
• Strength reduction
• Use of machine idioms

Apply these optimizations to the following assembly code:

MOV R0, a

MOV b, R0

MOV R0, b

ADD R0, R0, #0

MUL R0, R0, #2

MOV R1, #10

ADD R1, R1, #5

MOV R2, #0

ADD R2, R2, R1