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a2if Conditional Jumps and Control Flow Graphs
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        Compile the following program (file a2if.c) and observe the
        GIMPLE dumps.

        Source file : a2if.c
        Compilation : gcc -c -fdump-tree-gimple a2if.c
        View result : vi -O a2if.c a2if.c.*.gimple
        Clear dumps : rm -f a2if.c.* a2if.o

Program
-------

        #define true  1
        #define false 0
        #define bool  unsigned

        bool LeapYear(unsigned int Year)
        {
            bool Leap;
            if(Year % 4 == 0) {
                if(Year % 100 == 0) {
                    if(Year % 400 == 0) {
                        Leap = true;
                    } else {
                        Leap = false;
                    }
                } else {
                    Leap = true;
                }
            } else {
                Leap = false;
            }
            return Leap;
        }

Questions
---------

        1   How have  if-blocks been translated into  GIMPLE statements?
            Comment  about the  usage of  conditional and  unconditional
            gotos.

        2   Repeat  the above  compilation, but  now asking  for another
            dump that of the pass "cfg".  View this pass and say whether
            this representation  makes it easier to  read and understand
            GIMPLEs. Draw  the control-flow graph of  the program a2if.c
            on a piece of paper by looking at the CFG dump.
            
            Compilation : gcc -c -fdump-tree-cfg a2if.c
            View result : vi -O a2if.c a2if.c.*.cfg
            
***Note***  From here  onwards we  will only look  at passes  from "cfg"
            onwards, each of which uses a CFG-based representation using
            basic blocks.