On Mon, Nov 23, 2015 at 09:48:42PM -0700, Jeff Law wrote: > On 11/23/2015 07:22 PM, Segher Boessenkool wrote: > > > >Here is a test that shows that on at least PowerPC the basic asm is > >identical to the extended asm without clobber (compile with -O2 -S and > >-fno-ipa-icf if you want to have it easier to read). In this case, > >the basic asm is treated as not clobbering memory at the tree level > >already, before expanding to RTL. > And that IMHO, ought to be considered a bug.
I agree. Almost everyone does, as far as I can see. The question is if we want to retain this functionality. No one has depended on this in a long time -- they couldn't, it has been broken since forever -- and there is another mechanism that does reliably give this functionality (extended asm). The first pass that goes wrong for this testcase is fre2, fwiw. Segher
