similar to: [LLVMdev] How to reduce the footprint of MDNodes? (About the comment you made at BOF LTO)

On Mon, Nov 11, 2013 at 11:29 PM, Chris Lattner <clattner at apple.com> wrote: > Hi Manman (and llvmdev), > > I filed these two bugs to track the ideas that I was cooking: > > http://llvm.org/bugs/show_bug.cgi?id=17891 > http://llvm.org/bugs/show_bug.cgi?id=17892 > > TL;DR: I'm saying we should go from: > > !14 = metadata !{i32 786445, metadata !1,

On Nov 12, 2013, at 1:28 PM, Chandler Carruth <chandlerc at google.com> wrote: > On Mon, Nov 11, 2013 at 11:29 PM, Chris Lattner <clattner at apple.com> wrote: > Hi Manman (and llvmdev), > > I filed these two bugs to track the ideas that I was cooking: > > http://llvm.org/bugs/show_bug.cgi?id=17891 > http://llvm.org/bugs/show_bug.cgi?id=17892 > > TL;DR:

On Tue, Nov 12, 2013 at 4:14 PM, Chris Lattner <clattner at apple.com> wrote: > I'm moderately opposed to just encoding these in a string format. I think > we can do something substantially better both for space, time, and > readability. Fundamentally, there is no reason for the original metadata > node you describe to not *encode* its operands into a dense bit-packed blob

On Tue, Nov 12, 2013 at 4:19 PM, Chandler Carruth <chandlerc at google.com>wrote: > > On Tue, Nov 12, 2013 at 4:14 PM, Chris Lattner <clattner at apple.com> wrote: > >> I'm moderately opposed to just encoding these in a string format. I think >> we can do something substantially better both for space, time, and >> readability. Fundamentally, there is no

On Tue, Nov 12, 2013 at 4:31 PM, David Blaikie <dblaikie at gmail.com> wrote: > Where would the encoding schema be specified? >>> >> >> Same question applies to a string encoding. We have to define the schema >> somewhere clearly. I'm just lobbying for the textual IR and the APIs to >> both operate directly on N fields, and just make the memory

On Tue, Nov 12, 2013 at 4:38 PM, Chandler Carruth <chandlerc at google.com>wrote: > > On Tue, Nov 12, 2013 at 4:29 PM, Manman Ren <manman.ren at gmail.com> wrote: > >> Hi All, >> >> In LTO, we load in the source modules and link the source modules into a >> destination module. >> Lots of MDNodes are only used by the source modules, for example

On Tue, Nov 12, 2013 at 4:46 PM, Manman Ren <manman.ren at gmail.com> wrote: > > > > On Tue, Nov 12, 2013 at 4:38 PM, Chandler Carruth <chandlerc at google.com>wrote: > >> >> On Tue, Nov 12, 2013 at 4:29 PM, Manman Ren <manman.ren at gmail.com> wrote: >> >>> Hi All, >>> >>> In LTO, we load in the source modules and

Hi All, In LTO, we load in the source modules and link the source modules into a destination module. Lots of MDNodes are only used by the source modules, for example Xalan used 649MB for MDNodes after loading and linking, but the actual destination module only has 393MB of MDNodes. There are 649-393MB (40% of 649MB) not used. MDNodes belong to the Context, deleting modules will not release the

On Tue, Nov 12, 2013 at 4:59 PM, Chandler Carruth <chandlerc at google.com>wrote: > On Tue, Nov 12, 2013 at 4:46 PM, Manman Ren <manman.ren at gmail.com> wrote: > >> >> >> >> On Tue, Nov 12, 2013 at 4:38 PM, Chandler Carruth <chandlerc at google.com>wrote: >> >>> >>> On Tue, Nov 12, 2013 at 4:29 PM, Manman Ren <manman.ren

On Tue, Nov 12, 2013 at 4:29 PM, Manman Ren <manman.ren at gmail.com> wrote: > Hi All, > > In LTO, we load in the source modules and link the source modules into a > destination module. > Lots of MDNodes are only used by the source modules, for example Xalan > used 649MB for MDNodes after loading and linking, but the actual > destination module only has 393MB of

On Tue, Nov 12, 2013 at 6:07 PM, Manman Ren <manman.ren at gmail.com> wrote: > Hi Chandler, > > I don't quite get why you think sharing is not buying us anything... > It reduces the memory footprint of the source modules (there is sharing > among the source modules) and the number of MDNodes created for the > destination module (we do not need to re-create the MDNodes

On Thu, Jun 20, 2013 at 5:25 PM, Manman Ren <mren at apple.com> wrote: > > On Jun 20, 2013, at 5:18 PM, David Blaikie <dblaikie at gmail.com> wrote: > > On Thu, Jun 20, 2013 at 5:13 PM, Manman Ren <mren at apple.com> wrote: > > > On Jun 20, 2013, at 4:52 PM, David Blaikie wrote: > > On Thu, Jun 20, 2013 at 4:45 PM, Manman Ren <mren at apple.com>

More details please :] What do you mean by "name the metadata"? Are you referring to the name field of the MDNode? Thanks, Manman On Jun 21, 2013, at 7:19 AM, David Blaikie wrote: > > On Jun 21, 2013 1:19 AM, "Jeremy Lakeman" <Jeremy.Lakeman at gmail.com> wrote: > > > > Wouldn't it be simpler to name the metadata based on the hash of the content?

Wouldn't it be simpler to name the metadata based on the hash of the content? Then you could use a normal reference to that metadata without needing to create a new type or teach the rest of llvm how to use it... On Fri, Jun 21, 2013 at 3:22 PM, Manman Ren <mren at apple.com> wrote: > > A summary of options for issue #3: > 3> To actually access the MDNode referenced via

On Fri, Jun 21, 2013 at 11:50 AM, Manman Ren <mren at apple.com> wrote: > > On Jun 21, 2013, at 11:35 AM, Eric Christopher wrote: > >> On Thu, Jun 20, 2013 at 10:52 PM, Manman Ren <mren at apple.com> wrote: >>> >>> A summary of options for issue #3: >>> 3> To actually access the MDNode referenced via the hash value, we need to perform a

On Thu, Jun 20, 2013 at 5:13 PM, Manman Ren <mren at apple.com> wrote: > > On Jun 20, 2013, at 4:52 PM, David Blaikie wrote: > >> On Thu, Jun 20, 2013 at 4:45 PM, Manman Ren <mren at apple.com> wrote: >>> >>> On Jun 20, 2013, at 3:55 PM, Manman Ren <mren at apple.com> wrote: >>> >>> >>> On Jun 20, 2013, at 2:58 PM, Eric

A summary of options for issue #3: 3> To actually access the MDNode referenced via the hash value, we need to perform a lookup from the hash value to find the corresponding MDNode. The questions are where to store this map and how to keep it up-to-date when a MDNode is replaced. --------------------- Option a) a map in DwarfDebug, AsmWriter and DIBuilder, modify access functions in DI classes

On Thu, Jun 20, 2013 at 4:45 PM, Manman Ren <mren at apple.com> wrote: > > On Jun 20, 2013, at 3:55 PM, Manman Ren <mren at apple.com> wrote: > > > On Jun 20, 2013, at 2:58 PM, Eric Christopher wrote: > > Hi Manman, > > On Thu, Jun 20, 2013 at 2:51 PM, Manman Ren <mren at apple.com> wrote: > > > The intent of this proposal is to speedup

On Jun 21, 2013, at 11:56 AM, Eric Christopher wrote: > On Fri, Jun 21, 2013 at 11:50 AM, Manman Ren <mren at apple.com> wrote: >> >> On Jun 21, 2013, at 11:35 AM, Eric Christopher wrote: >> >>> On Thu, Jun 20, 2013 at 10:52 PM, Manman Ren <mren at apple.com> wrote: >>>> >>>> A summary of options for issue #3: >>>>

The intent of this proposal is to speedup compilation of "-flto -g" for c++ programs. This is based on discussions with Adrian, David and Eric. --------------------------- Problem: A single class can be used in multiple source files and the DI (Debug Info) class is included in multiple bc files. The duplication of class definitions causes blow-up in # of MDNodes, # of DIEs, leading to