On Tue, May 27, 2014 at 3:26 PM, Bernd Schmidt <ber...@codesourcery.com> wrote: > When putting a constant into the constant pool, we make a copy of the tree > in build_constant_desc. This caused me some problems with the ptx backend, > which has a pass to modify the address spaces of all variables and constants > to match the requirements of the backend. It would be nice for it to be able > to find them all by walking the varpool and the gimple of all functions, and > I ran into some testcases where these copies can slip through. > > After a while it occurred to me that the copy is probably a relic of old > obstack times and not necessary anymore. And indeed, in 2.7.2.3 the only > call to it looked like this: > push_obstacks_nochange (); > suspend_momentary (); > p->exp = copy_constant (exp); > pop_obstacks (); > > It seems unlikely that anything in the compiler would want to modify a > constant after it has been put into the constant pool, and even if so, it > should have the responsibility of making the copy itself. So, as an > experiment I've bootstrapped and tested the following patch (x86_64-linux), > and that seemed to work. Ok to apply along with removal of the now unused > copy_constant?
Ok if nobody raises issues within 24h. Thanks, Richard. > > Bernd >
