LLVM assembler Fizz Buzz

fizzbuzz.ll

@.fizz = private unnamed_addr constant [6 x i8] c"fizz \00"
@.buzz = private unnamed_addr constant [6 x i8] c"buzz \00"
@.integer = private unnamed_addr constant [4 x i8] c"%d \00"

@nl = private unnamed_addr constant [2 x i8] c"\0A\00"

declare i32 @printf(i8* noalias nocapture, ...) nounwind

define void @fizzbuzz(i32 %n) {
    %fizz = getelementptr [6 x i8], [6 x i8]* @.fizz, i64 0, i64 0
    %buzz = getelementptr [6 x i8], [6 x i8]* @.buzz, i64 0, i64 0
    %integer = getelementptr [4 x i8], [4 x i8]* @.integer, i64 0, i64 0

    %A = urem i32 %n, 3
    %B = urem i32 %n, 5

    %three = icmp eq i32 %A, 0
    %five = icmp eq i32 %B, 0

    br i1 %three, label %fizz_entry_point, label %buzz_check
    buzz_check:
    br i1 %five, label %buzz_entry_point, label %no_entry_point

    fizz_entry_point: call i32 (i8*, ...) @printf(i8* %fizz)
    br i1 %five, label %buzz_entry_point, label %done

    buzz_entry_point: call i32 (i8*, ...) @printf(i8* %buzz)
    br label %done

    no_entry_point: call i32 (i8*, ...) @printf(i8* %integer, i32 %n) ret void
    done: ret void
}

define i32 @main() {
    header:
        br label %loop

    loop:
        %idx = phi i32 [ 1, %header ], [ %nextidx, %loop ]
        %nextidx = add i32 %idx, 1

        call void @fizzbuzz(i32 %idx)
        %cond = icmp eq i32 %idx, 100
        br i1 %cond, label %end, label %loop

    end:
        %nl = getelementptr [2 x i8], [2 x i8]* @nl, i64 0, i64 0
        call i32 (i8*, ...) @printf(i8* %nl)
        ret i32 0
}