Kuznetsov Artyom lab2 (option 1)

[Kuznetsov-Artyom]

Implemented a plugin that inserts the instruction_start()/insrtuction_end() functions at the beginning and end of the function, respectively.

Example:

// test.cpp
int factorial(int value) {
  return value <= 1 ? 1 : value * factorial(value - 1);
}

; test.ll
define dso_local noundef i32 @_Z9factoriali(i32 noundef %value) {
entry:
  %value.addr = alloca i32, align 4
  store i32 %value, ptr %value.addr, align 4
  %0 = load i32, ptr %value.addr, align 4
  %cmp = icmp sle i32 %0, 1
  br i1 %cmp, label %cond.true, label %cond.false

cond.true:
  br label %cond.end

cond.false:
  %1 = load i32, ptr %value.addr, align 4
  %2 = load i32, ptr %value.addr, align 4
  %sub = sub nsw i32 %2, 1
  %call = call noundef i32 @_Z9factoriali(i32 noundef %sub)
  %mul = mul nsw i32 %1, %call
  br label %cond.end

cond.end:
  %cond = phi i32 [ 1, %cond.true ], [ %mul, %cond.false ]
  ret i32 %cond
}

Result:

; test_opt.ll
define dso_local noundef i32 @_Z9factoriali(i32 noundef %value) {
entry:
  call void @instrument_start()
  %value.addr = alloca i32, align 4
  store i32 %value, ptr %value.addr, align 4
  %0 = load i32, ptr %value.addr, align 4
  %cmp = icmp sle i32 %0, 1
  br i1 %cmp, label %cond.true, label %cond.false

cond.true:
  br label %cond.end

cond.false:
  %1 = load i32, ptr %value.addr, align 4
  %2 = load i32, ptr %value.addr, align 4
  %sub = sub nsw i32 %2, 1
  %call = call noundef i32 @_Z9factoriali(i32 noundef %sub)
  %mul = mul nsw i32 %1, %call
  br label %cond.end

cond.end:
  %cond = phi i32 [ 1, %cond.true ], [ %mul, %cond.false ]
  call void @instrument_end()
  ret i32 %cond
}

[Kuznetsov-Artyom]

Windows crashes for some reason, I'll figure it out tomorrow.

[m-ly4]

Thank you for patient applying remarks)
Very good.