CompilerCoursework2/bytecode.txt at master · g2archie/CompilerCoursework2 · GitHub

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Part2: constant variable folding
methodOne();
  	 0: bipush        42
         2: istore_1
         3: bipush        8
         5: istore_2
         6: bipush        8
         8: istore_3
         9: bipush        8
        11: istore        4
        13: bipush        8
        15: istore        5
        17: bipush        8
        19: istore        6
        21: iload_1
        22: sipush        764
        25: iadd
        26: iconst_3
        27: imul
        28: istore        7
        30: iload         7
        32: sipush        1234
        35: iadd
        36: iload_1
        37: isub
        38: ireturn

methodTwo();
 	 0: dconst_0
         1: dstore_1
         2: iconst_1
         3: istore_3
         4: dload_1
         5: iload_3
         6: i2d
         7: dadd
         8: dreturn

methodThree();
  	 0: sipush        12345
         3: istore_1
         4: ldc           #2                  // int 54321
         6: istore_2
         7: iload_1
         8: iload_2
         9: if_icmple     16
        12: iconst_1
        13: goto          17
        16: iconst_0
        17: return

optimized:

methodOne();
 	 0: ldc           #24                 // int 3610
         2: ireturn

methodTwo();
 	 0: ldc2_w        #27                 // double 1.0d
         3: dreturn

methodThree();
	 0: sipush        12345
         3: ldc           #2                  // int 54321
         5: if_icmple     12
         8: iconst_1
         9: goto          13
        12: iconst_0
        13: ireturn


our constant variable folding:
methodOne();
  	 0: bipush        62
         2: istore_1
         3: iload_1
         4: sipush        764
         7: iadd
         8: iconst_3
         9: imul
        10: istore_2
        11: iload_2
        12: sipush        1234
        15: iadd
        16: iload_1
        17: isub
        18: ireturn

methodTwo();
         0: ldc2_w        #2                  // double 0.67d
         3: dstore_1
         4: iconst_1
         5: istore_3
         6: dload_1
         7: iload_3
         8: i2d
         9: dadd
        10: dreturn

methodThree();
	 0: sipush        12345
         3: istore_1
         4: ldc           #4                  // int 54321
         6: istore_2
         7: iload_1
         8: iload_2
         9: if_icmple     16
        12: iconst_1
        13: goto          17
        16: iconst_0
        17: ireturn

methodFour();
  	 0: ldc2_w        #5                  // long 4835783423l
         3: lstore_1
         4: ldc2_w        #7                  // long 400000l
         7: lstore_3
         8: lload_1
         9: lload_3
        10: ladd
        11: lstore        5
        13: lload_1
        14: lload_3
        15: lcmp
        16: ifle          23
        19: iconst_1
        20: goto          24
        23: iconst_0
        24: ireturn

//part2里面的methods和之间的关联
void optimizeMethod(); => safeInstructionDelete
		       => handleStoreInstructions
		       => getLastStaskPush

Number getLastStackPush(); => safeInstructionDelete
			   => binaryOps
			   => convertNumber
			   => stackChangingOp

Number[] binaryOps(); => getLastStackPush
Boolean handleStoreInstuctions();
Number convertNumber();
Boolean stackChangingOp();
Void safeInstructionDelete();


storeInstruction
NOP
ArithmeticInstruction
IINC

Load and store (e.g. aload_0, istore)
Arithmetic and logic (e.g. ladd, fcmpl)
Type conversion (e.g. i2b, d2i)
Object creation and manipulation (new, putfield)
Operand stack management (e.g. swap, dup2)
Control transfer (e.g. ifeq, goto)
Method invocation and return (e.g. invokespecial, areturn)