Be more careful about the order we put stuff onto the worklist. This allow us to

collapse this:
bool %le(int %A, int %B) {
        %c1 = setgt int %A, %B
        %tmp = select bool %c1, int 1, int 0
        %c2 = setlt int %A, %B
        %result = select bool %c2, int -1, int %tmp
        %c3 = setle int %result, 0
        ret bool %c3
}

into:

bool %le(int %A, int %B) {
        %c3 = setle int %A, %B          ; <bool> [#uses=1]
        ret bool %c3
}

which is handy, because the Java FE makes these sequences all over the place.

This is tested as: test/Regression/Transforms/InstCombine/JavaCompare.ll

llvm-svn: 14086