stabilize_reference question

[Per Bothner]

> g++.old-deja/g++.mike/p9506.C might be a testcase.

This is it:

char * volatile p;
void foo() {
  --p = 0;
}

The generated code (with -O) is:

foo__Fv:
.LLFB1:
        !#PROLOGUE# 0
        !#PROLOGUE# 1
        sethi   %hi(p), %g3
        ld      [%g3+%lo(p)], %g2
        add     %g2, -1, %g2
        st      %g2, [%g3+%lo(p)]
        st      %g0, [%g3+%lo(p)]
        retl
        nop

It is the same with my patch, with the original version that you
replaced, and Cygnus 98r2.  However, the testcase does not seem
to call stabilize_reference with a COMPOUND_EXPR.

> check PR 9506 to see if it was done around:

The PR was submitted Apr 22. 1996.  It does discuss volatile
and the comma operator.  It is not very conclusive.

	--Per Bothner
Cygnus Solutions     bothner@cygnus.com     http://www.cygnus.com/~bothner