[Soot-list] A minor difference of the example in "A survivor's Guide to Java Program Analysis with Soot"

[jnuzhjp]

Hi, Soot people. I got touched with Soot framework a week ago, so I  started with the Survivor's Guide of which the version is 1.1. The framework version I downloaded was the latest which was soot-2.3.0.When I came to chapter 3.4 Grimp and tried the Foo example, I found some minor differenece in the outputs after typing the command java soot.Main -f G Foo between  that of the tutorial and that of my practice. Here it comes:
Source code:
public class Foo
{
public static void main(String[] args) 
{
Foo f = new Foo();
int a = 7;
int b = 14;
int x = (f.bar(21) + a) * b;
}
public int bar(int n) {
return n + 42;
}
}
Grimp output in tutorial 1.1:
       public static void main(java.lang.String[]) {
java.lang.String[] r0;
Foo r2;
int i0, i1, i2;
..............................ellipse...............................
Grimp output from my practice using soot-2.3.0:
public static void main(java.lang.String[])
    {
        java.lang.String[] r0;
        Foo r2;
        byte b0, b1;
        int i2;
                ................................ellipse................................

    We can note that the type of  a and b in source code is different from that of the output resulted from practice using soot-2.3.0, the former is int but the latter has changed into byte.
    I don' the know why the int type in this example has narrowed into byte type after transformation, is this one of the strategies of code optimization, would there be any collateral consequences? 
It'll be really appreciated for any answers. Thank you.

Superloafer
2009-09-03 



superloafer
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