Doubt with GVNPRE


I have a program as:

int main(int argc, char **argv)
        int a,b,k,l;
        if (argc > 1) {
        } else {
        return 0;

Now i run the following on it:

    llvm-gcc -O1 -emit-llvm -c -o 1.bc 1.c
    llvm-dis 1.bc -o 1.ll
    opt -gvnpre 1.bc -o 1p.bc // I believe this line writes the code to 1p.bc after applying gvnpre to 1.bc
    llvm-dis 1p.bc -o 1p.ll

Now 1.ll is as :

GVNPRE is unmaintained, slow, and has been removed from trunk.