Hi Jason, Sri has addressed the comments you had on FE part. Can you take a look if it is ok? Stage-1 is going to be closed soon, and we hope to get this major feature in 4.8.
thanks, David On Tue, Sep 18, 2012 at 9:29 AM, Sriraman Tallam <tmsri...@google.com> wrote: > Ping. > > On Fri, Aug 24, 2012 at 5:34 PM, Sriraman Tallam <tmsri...@google.com> wrote: >> Hi Jason, >> >> I have created a new patch to use target hooks for all the >> functionality and make the front-end just call the target hooks at the >> appropriate places. This is more like what you suggested in a previous >> mail. In particular, target hooks address the following questions: >> >> * Determine if two function decls with the same signature are versions. >> * Determine the new assembler name of a function version. >> * Generate the dispatcher function for a set of function versions. >> * Compare versions to see if one has a higher priority over the other. >> >> Patch attached and also available for review at: >> >> http://codereview.appspot.com/5752064/ >> >> Hope this is more along the lines of what you had in mind, please let >> me know what you think. >> >> Thanks, >> -Sri. >> >> >> On Mon, Jul 30, 2012 at 12:01 PM, Sriraman Tallam <tmsri...@google.com> >> wrote: >>> On Thu, Jul 19, 2012 at 1:39 PM, Jason Merrill <ja...@redhat.com> wrote: >>>> >>>> On 07/10/2012 03:14 PM, Sriraman Tallam wrote: >>>>> >>>>> I am using the questions you asked previously >>>>> to explain how I solved each of them. When working on this patch, these >>>>> are the exact questions I had and tried to address it. >>>>> >>>>> * Does this attribute affect a function signature? >>>>> >>>>> The function signature should be changed when there is more than one >>>>> definition/declaration of foo distinguished by unique target attributes. >>>> >>>> >[...] >>>> >>>> I agree. I was trying to suggest that these questions are what the front >>>> end needs to care about, not about versioning specifically. If these >>>> questions are turned into target hooks, all of the logic specific to >>>> versioning can be contained in the target. >>>> >>>> My only question intended to be answered by humans is, do people think >>>> moving the versioning logic behind more generic target hooks is worthwhile? >>> >>> I have some comments related >>> >>> For the example below, >>> >>> // Default version. >>> int foo () >>> { >>> ..... >>> } >>> >>> // Version XXX feature supported by Target ABC. >>> int foo __attribute__ ((target ("XXX"))) >>> { >>> .... >>> } >>> >>> How should the second version of foo be treated for targets where >>> feature XXX is not supported? Right now, I am working on having my >>> patch completely ignore such function versions when compiled for >>> targets that do not understand the attribute. I could move this check >>> into a generic target hook so that a function definition that does not >>> make sense for the current target is ignored. >>> >>> Also, currently the patch uses target hooks to do the following: >>> >>> - Find if a particular version can be called directly, rather than go >>> through the dispatcher. >>> - Determine what the dispatcher body should be. >>> - Determining the order in which function versions must be dispatched. >>> >>> I do not have a strong opinion on whether the entire logic should be >>> based on target hooks. >>> >>> Thanks, >>> -Sri. >>> >>>> >>>> >>>> >>>> Jason
