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Step2.1: fibonacchi

20 Sep 01:35
@vsanna vsanna
step2.1
d8902b3
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Step2.1: fibonacchi Latest
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input

class Recursive2 {
    static public void main() {
        fibonacchi(10);
    }

    static int fibonacchi(int n) {
        if(n <= 1) return n;
        return fibonacchi(n-1) + fibonacchi(n-2);
    }
}

output

stack#=0, pc = 259, inst = 10, frame=LFrame{locals=[], operandStack=[Word(0,0,0,0: 0)]}
stack#=0, pc = 261, inst = b8, frame=LFrame{locals=[], operandStack=[Word(0,0,0,a: 10), Word(0,0,0,0: 0)]}
stack#=1, pc = 308, inst = 1a, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,1,8: 264)]}
stack#=1, pc = 309, inst = 4, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,0,a: 10), Word(0,0,1,8: 264)]}
stack#=1, pc = 310, inst = a3, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,0,1: 1), Word(0,0,0,a: 10), Word(0,0,1,8: 264)]}
stack#=1, pc = 315, inst = 1a, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,1,8: 264)]}
stack#=1, pc = 316, inst = 4, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,0,a: 10), Word(0,0,1,8: 264)]}
stack#=1, pc = 317, inst = 64, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,0,1: 1), Word(0,0,0,a: 10), Word(0,0,1,8: 264)]}
stack#=1, pc = 318, inst = b8, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,0,9: 9), Word(0,0,1,8: 264)]}
stack#=2, pc = 308, inst = 1a, frame=LFrame{locals=[Word(0,0,0,9: 9)], operandStack=[Word(0,0,1,41: 321)]}
stack#=2, pc = 309, inst = 4, frame=LFrame{locals=[Word(0,0,0,9: 9)], operandStack=[Word(0,0,0,9: 9), Word(0,0,1,41: 321)]}
stack#=2, pc = 310, inst = a3, frame=LFrame{locals=[Word(0,0,0,9: 9)], operandStack=[Word(0,0,0,1: 1), Word(0,0,0,9: 9), Word(0,0,1,41: 321)]}
stack#=2, pc = 315, inst = 1a, frame=LFrame{locals=[Word(0,0,0,9: 9)], operandStack=[Word(0,0,1,41: 321)]}
stack#=2, pc = 316, inst = 4, frame=LFrame{locals=[Word(0,0,0,9: 9)], operandStack=[Word(0,0,0,9: 9), Word(0,0,1,41: 321)]}
stack#=2, pc = 317, inst = 64, frame=LFrame{locals=[Word(0,0,0,9: 9)], operandStack=[Word(0,0,0,1: 1), Word(0,0,0,9: 9), Word(0,0,1,41: 321)]}
stack#=2, pc = 318, inst = b8, frame=LFrame{locals=[Word(0,0,0,9: 9)], operandStack=[Word(0,0,0,8: 8), Word(0,0,1,41: 321)]}
stack#=3, pc = 308, inst = 1a, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,1,41: 321)]}
stack#=3, pc = 309, inst = 4, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,8: 8), Word(0,0,1,41: 321)]}
stack#=3, pc = 310, inst = a3, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,1: 1), Word(0,0,0,8: 8), Word(0,0,1,41: 321)]}
stack#=3, pc = 315, inst = 1a, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,1,41: 321)]}
stack#=3, pc = 316, inst = 4, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,8: 8), Word(0,0,1,41: 321)]}
stack#=3, pc = 317, inst = 64, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,1: 1), Word(0,0,0,8: 8), Word(0,0,1,41: 321)]}
stack#=3, pc = 318, inst = b8, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,7: 7), Word(0,0,1,41: 321)]}
...
...
stack#=3, pc = 327, inst = 60, frame=LFrame{locals=[Word(0,0,0,6: 6)], operandStack=[Word(0,0,0,3: 3), Word(0,0,0,5: 5), Word(0,0,1,47: 327)]}
stack#=3, pc = 328, inst = ac, frame=LFrame{locals=[Word(0,0,0,6: 6)], operandStack=[Word(0,0,0,8: 8), Word(0,0,1,47: 327)]}
stack#=2, pc = 327, inst = 60, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,8: 8), Word(0,0,0,d: 13), Word(0,0,1,47: 327)]}
stack#=2, pc = 328, inst = ac, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,15: 21), Word(0,0,1,47: 327)]}
stack#=1, pc = 327, inst = 60, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,0,15: 21), Word(0,0,0,22: 34), Word(0,0,1,8: 264)]}
stack#=1, pc = 328, inst = ac, frame=LFrame{locals=[Word(0,0,0,a: 10)], operandStack=[Word(0,0,0,37: 55), Word(0,0,1,8: 264)]}
stack#=0, pc = 264, inst = 57, frame=LFrame{locals=[], operandStack=[Word(0,0,0,37: 55), Word(0,0,0,0: 0)]}
stack#=0, pc = 265, inst = b1, frame=LFrame{locals=[], operandStack=[Word(0,0,0,0: 0)]}
Assets 2
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Step2: Recursive

19 Sep 23:46
@vsanna vsanna
step2
83017bb
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Step2: Recursive

what is attemted

  • Introduced Thread/Frame so that jvm can call other methods(invokeXXX)
  • introduced classparser so that we can manage methods
  • introduced MethodArea so that we can manage classes/methods
  • introduced invokestatic!!
  • make more instructions available
  • add Recursive.java as guest code

output

class Recursive {
    static public void recursiveMain() {
        recursive(10);
    }

    static int recursive(int a) {
        if(a < 1000) {
            return recursive(a + a);
        } else {
            return a;
        }
    }
}

stack#=0, pc = 265, inst = 4, frame=LFrame{locals=[], operandStack=[]}
stack#=0, pc = 266, inst = b8, frame=LFrame{locals=[], operandStack=[Word(0,0,0,1: 1)]}
stack#=1, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,0,1: 1)], operandStack=[]}
stack#=1, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,0,1: 1)], operandStack=[Word(0,0,0,1: 1)]}
stack#=1, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,0,1: 1)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,0,1: 1)]}
stack#=1, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,0,1: 1)], operandStack=[]}
stack#=1, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,0,1: 1)], operandStack=[Word(0,0,0,1: 1)]}
stack#=1, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,0,1: 1)], operandStack=[Word(0,0,0,1: 1), Word(0,0,0,1: 1)]}
stack#=1, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,0,1: 1)], operandStack=[Word(0,0,0,2: 2)]}
stack#=2, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,0,2: 2)], operandStack=[]}
stack#=2, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,0,2: 2)], operandStack=[Word(0,0,0,2: 2)]}
stack#=2, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,0,2: 2)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,0,2: 2)]}
stack#=2, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,0,2: 2)], operandStack=[]}
stack#=2, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,0,2: 2)], operandStack=[Word(0,0,0,2: 2)]}
stack#=2, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,0,2: 2)], operandStack=[Word(0,0,0,2: 2), Word(0,0,0,2: 2)]}
stack#=2, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,0,2: 2)], operandStack=[Word(0,0,0,4: 4)]}
stack#=3, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,0,4: 4)], operandStack=[]}
stack#=3, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,0,4: 4)], operandStack=[Word(0,0,0,4: 4)]}
stack#=3, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,0,4: 4)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,0,4: 4)]}
stack#=3, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,0,4: 4)], operandStack=[]}
stack#=3, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,0,4: 4)], operandStack=[Word(0,0,0,4: 4)]}
stack#=3, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,0,4: 4)], operandStack=[Word(0,0,0,4: 4), Word(0,0,0,4: 4)]}
stack#=3, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,0,4: 4)], operandStack=[Word(0,0,0,8: 8)]}
stack#=4, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[]}
stack#=4, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,8: 8)]}
stack#=4, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,0,8: 8)]}
stack#=4, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[]}
stack#=4, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,8: 8)]}
stack#=4, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,8: 8), Word(0,0,0,8: 8)]}
stack#=4, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,0,8: 8)], operandStack=[Word(0,0,0,10: 16)]}
stack#=5, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,0,10: 16)], operandStack=[]}
stack#=5, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,0,10: 16)], operandStack=[Word(0,0,0,10: 16)]}
stack#=5, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,0,10: 16)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,0,10: 16)]}
stack#=5, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,0,10: 16)], operandStack=[]}
stack#=5, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,0,10: 16)], operandStack=[Word(0,0,0,10: 16)]}
stack#=5, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,0,10: 16)], operandStack=[Word(0,0,0,10: 16), Word(0,0,0,10: 16)]}
stack#=5, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,0,10: 16)], operandStack=[Word(0,0,0,20: 32)]}
stack#=6, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,0,20: 32)], operandStack=[]}
stack#=6, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,0,20: 32)], operandStack=[Word(0,0,0,20: 32)]}
stack#=6, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,0,20: 32)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,0,20: 32)]}
stack#=6, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,0,20: 32)], operandStack=[]}
stack#=6, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,0,20: 32)], operandStack=[Word(0,0,0,20: 32)]}
stack#=6, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,0,20: 32)], operandStack=[Word(0,0,0,20: 32), Word(0,0,0,20: 32)]}
stack#=6, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,0,20: 32)], operandStack=[Word(0,0,0,40: 64)]}
stack#=7, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,0,40: 64)], operandStack=[]}
stack#=7, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,0,40: 64)], operandStack=[Word(0,0,0,40: 64)]}
stack#=7, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,0,40: 64)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,0,40: 64)]}
stack#=7, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,0,40: 64)], operandStack=[]}
stack#=7, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,0,40: 64)], operandStack=[Word(0,0,0,40: 64)]}
stack#=7, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,0,40: 64)], operandStack=[Word(0,0,0,40: 64), Word(0,0,0,40: 64)]}
stack#=7, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,0,40: 64)], operandStack=[Word(0,0,0,80: 128)]}
stack#=8, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,0,80: 128)], operandStack=[]}
stack#=8, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,0,80: 128)], operandStack=[Word(0,0,0,80: 128)]}
stack#=8, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,0,80: 128)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,0,80: 128)]}
stack#=8, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,0,80: 128)], operandStack=[]}
stack#=8, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,0,80: 128)], operandStack=[Word(0,0,0,80: 128)]}
stack#=8, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,0,80: 128)], operandStack=[Word(0,0,0,80: 128), Word(0,0,0,80: 128)]}
stack#=8, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,0,80: 128)], operandStack=[Word(0,0,1,0: 256)]}
stack#=9, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,1,0: 256)], operandStack=[]}
stack#=9, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,1,0: 256)], operandStack=[Word(0,0,1,0: 256)]}
stack#=9, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,1,0: 256)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,1,0: 256)]}
stack#=9, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,1,0: 256)], operandStack=[]}
stack#=9, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,1,0: 256)], operandStack=[Word(0,0,1,0: 256)]}
stack#=9, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,1,0: 256)], operandStack=[Word(0,0,1,0: 256), Word(0,0,1,0: 256)]}
stack#=9, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,1,0: 256)], operandStack=[Word(0,0,2,0: 512)]}
stack#=10, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,2,0: 512)], operandStack=[]}
stack#=10, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,2,0: 512)], operandStack=[Word(0,0,2,0: 512)]}
stack#=10, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,2,0: 512)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,2,0: 512)]}
stack#=10, pc = 320, inst = 1a, frame=LFrame{locals=[Word(0,0,2,0: 512)], operandStack=[]}
stack#=10, pc = 321, inst = 1a, frame=LFrame{locals=[Word(0,0,2,0: 512)], operandStack=[Word(0,0,2,0: 512)]}
stack#=10, pc = 322, inst = 60, frame=LFrame{locals=[Word(0,0,2,0: 512)], operandStack=[Word(0,0,2,0: 512), Word(0,0,2,0: 512)]}
stack#=10, pc = 323, inst = b8, frame=LFrame{locals=[Word(0,0,2,0: 512)], operandStack=[Word(0,0,4,0: 1024)]}
stack#=11, pc = 313, inst = 1a, frame=LFrame{locals=[Word(0,0,4,0: 1024)], operandStack=[]}
stack#=11, pc = 314, inst = 11, frame=LFrame{locals=[Word(0,0,4,0: 1024)], operandStack=[Word(0,0,4,0: 1024)]}
stack#=11, pc = 317, inst = a2, frame=LFrame{locals=[Word(0,0,4,0: 1024)], operandStack=[Word(0,0,3,e8: 1000), Word(0,0,4,0: 1024)]}
stack#=11, pc = 327, inst = 1a, frame=LFrame{locals=[Word(0,0,4,0: 1024)], operandStack=[]}
stack#=11, pc = 328, inst = ac, frame=LFrame{locals=[Word(0,0,4,0: 1024)], operandStack=[Word(0,0,4,0: 1024)]}
Assets 2
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Step1: ForLoop

18 Sep 14:01
@vsanna vsanna
step1
6047046
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Step1: ForLoop

what is attempted

  • modify locals/operandStack so that they accept word(=32bit) instead of byte
  • make more instructions available
  • add ForLoop.java as a guest sample code

output

...
...
pc = 30, inst = ac, locals = [null, Word(2,fa,dc,f8: 49995000), Word(0,0,27,10: 10000)], operandStack = [Word(2,fa,dc,f8: 49995000)]
Assets 2
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Step0: very primitive JVM

18 Sep 11:25
@vsanna vsanna
step0
0388de9
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Step0: very primitive JVM

what to try

  • interpret Code section extracted from a classfile
  • a few instructions
  • no thread, no frame.
  • no method area
  • no heap
  • no classloader

output

> Task :LoveJVM.main()
pc =  8, inst = 10, locals = [0, 0, 0] , operandStack = []
pc = 10, inst = 3b, locals = [0, 0, 0] , operandStack = [10]
pc = 11, inst = 7, locals = [10, 0, 0], operandStack = []
pc = 12, inst = 3c, locals = [10, 0, 0], operandStack = [4]
pc = 13, inst = 1a, locals = [10, 4, 0], operandStack = []
pc = 14, inst = 1b, locals = [10, 4, 0], operandStack = [10]
pc = 15, inst = 60, locals = [10, 4, 0], operandStack = [4, 10]
pc = 16, inst = 3d, locals = [10, 4, 0], operandStack = [14]
pc = 17, inst = 1c, locals = [10, 4, 14], operandStack = []
pc = 18, inst = 5, locals = [10, 4, 14], operandStack = [14]
pc = 19, inst = 6c, locals = [10, 4, 14], operandStack = [2, 14]
pc = 20, inst = 3d, locals = [10, 4, 14], operandStack = [7]
pc = 21, inst = b1, locals = [10, 4, 7], operandStack = [] <--- locals[2](=c) has 7
Assets 2
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