On Tue, Jun 21, 2011 at 5:51 PM, Xinliang David Li <davi...@google.com> wrote: > On Tue, Jun 21, 2011 at 1:42 AM, Richard Guenther > <richard.guent...@gmail.com> wrote: >> On Tue, Jun 21, 2011 at 1:28 AM, Xinliang David Li <davi...@google.com> >> wrote: >>> Good point -- but why does SRA have to be so complicated? If it just >>> do structure expansion and let subsequent phases to clean it up, would >>> it be simpler? Anyway this is off the topic. >> >> Well, it's certainly non-optimal to insert new memory backed variables >> to get rid of memory backed variables ... >> > > Yes, in the current way it is not optimal. > > Before that problem is resolved, is the simple patch ok for trunk? The > non-optimal code issue can be tracked with a different bug.
No, it's not a proper fix. Richard. > Thanks, > > David > >> Richard. >> >>> Thanks, >>> >>> David >>> >>> >>> On Mon, Jun 20, 2011 at 1:47 PM, Richard Guenther >>> <richard.guent...@gmail.com> wrote: >>>> On Mon, Jun 20, 2011 at 6:15 PM, Xinliang David Li <davi...@google.com> >>>> wrote: >>>>> It is used to indicate the fact the var decl needs to have a memory >>>>> home (addressable) -- is there another way to do this? this is to >>>>> avoid the following situation: >>>>> >>>>> 1) after SRA before update SSA, the IR looks like: >>>>> >>>>> MEM[.... &SR_123] = ... >>>>> >>>>> other_var = SR_123; <---- (x) >>>>> >>>>> >>>>> In this case, SR_123 is not of aggregate type, and it is not >>>>> addressable, update_ssa won't assign a VUSE for (x), leading to >>>> >>>> The point is, SRA should never have created the above >>>> >>>> MEM[.... &SR_123] = ... >>>> >>>> Martin, why would it even create new _memory_ backed decls? >>>> >>>> Richard. >>>> >>>>> 2) final IR after SRA: >>>>> >>>>> MEM[..., &SR_123] = .. >>>>> other_var = SR_123_yyy(D); >>>>> >>>>> >>>>> David >>>>> >>>>> On Mon, Jun 20, 2011 at 4:13 AM, Richard Guenther >>>>> <richard.guent...@gmail.com> wrote: >>>>>> On Sat, Jun 18, 2011 at 10:56 AM, Xinliang David Li <davi...@google.com> >>>>>> wrote: >>>>>>> Compiling the test case in the patch with -O2 -m32 without the fix, >>>>>>> the program will abort. The problem is a var decl whose address is >>>>>>> taken is not marked as addressable leading to bad SSA update (missing >>>>>>> VUSE). (the triaging used the the .after and .after_cleanup dump diff >>>>>>> and found the problem). >>>>>>> >>>>>>> the test is on going. Ok after testing? >>>>>> >>>>>> That doesn't make sense. SRA shouldn't generate anything that has >>>>>> its address taken. So, where do we take its address? >>>>>> >>>>>> Richard. >>>>>> >>>>>>> Thanks, >>>>>>> >>>>>>> David >>>>>>> >>>>>> >>>>> >>>> >>> >> >
