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On Fri, Apr 14, 2017 at 2:19 PM, Mikulin, Dmitry <dmitry.mikulin at sony.com> wrote: > >>> Is this a run with debug info? i.e. are you passing -g to the per-TU >>> pipeline? I'm inclined to think this is mostly an additive effect >>> adding matchers here and there that don't really hurt small te...

...nPrefix(".cfi"); > that should make all jump table section names begin with ".text.cfi", which I think should be enough to cause the behaviour needed for cross-DSO CFI here (eugenis can probably confirm). > > Peter > > On Tue, May 1, 2018 at 12:59 PM, <dmitry.mikulin at sony.com> wrote: > That seems to do the trick. > I get “symbol ordering file: no such symbol: <blah>” warnings for symbols that didn’t get renamed. > Maybe we'll have a separate order file for CFI builds... > > What about the comment above that line? > > &gt...

On Wed, Apr 18, 2018 at 4:49 PM, <dmitry.mikulin at sony.com> wrote: > Hi Teresa, > > Thanks for the info! > This example is my attempt to reduce FreeBSD kernel to something more > manageable :) > > I will take a look at why globals are not being imported in this case. > What’s the best tool to look into ThinLTO object...

...or CFI, including cross-DSO CFI) still passes. If that breaks check-cfi, we can probably leave the logic in place for cross-DSO CFI only (i.e. module flag named "Cross-DSO CFI" present) and we can figure out a better way to do this later. Peter On Tue, May 1, 2018 at 2:04 PM, <dmitry.mikulin at sony.com> wrote: > Jump table sections already have this prefix: ".text..L.cfi.jumptable.”, > without forcing the name with setSection(). Is that good enough? > > > > On May 1, 2018, at 1:16 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: > > > >...

...ss-DSO CFI) still passes. If that breaks check-cfi, we can probably leave the logic in place for cross-DSO CFI only (i.e. module flag named "Cross-DSO CFI" present) and we can figure out a better way to do this later. > > Peter > > On Tue, May 1, 2018 at 2:04 PM, <dmitry.mikulin at sony.com> wrote: > Jump table sections already have this prefix: ".text..L.cfi.jumptable.”, without forcing the name with setSection(). Is that good enough? > > > > On May 1, 2018, at 1:16 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: > > > > I t...

...>” warnings for symbols that didn’t get renamed. Maybe we'll have a separate order file for CFI builds... What about the comment above that line? > On May 1, 2018, at 11:46 AM, Peter Collingbourne <peter at pcc.me.uk> wrote: > > On Tue, May 1, 2018 at 11:29 AM, <dmitry.mikulin at sony.com> wrote: > It’s not the functions themselves, it’s the jump tables that end up in the same section of the thin-link temporary object. If I have, say, foo and bar and both of them need a jump table entry, both entries will be in the same section of the temp object. The real function...

...e::MachO) F->setSectionPrefix(".cfi"); that should make all jump table section names begin with ".text.cfi", which I think should be enough to cause the behaviour needed for cross-DSO CFI here (eugenis can probably confirm). Peter On Tue, May 1, 2018 at 12:59 PM, <dmitry.mikulin at sony.com> wrote: > That seems to do the trick. > I get “symbol ordering file: no such symbol: <blah>” warnings for symbols > that didn’t get renamed. > Maybe we'll have a separate order file for CFI builds... > > What about the comment above that line? > > &...

...e same page. So not having jump table entries for the functions that don't really need them would be ideal. Thanks. Dmitry. On Apr 18, 2018, at 6:11 PM, Teresa Johnson <tejohnson at google.com<mailto:tejohnson at google.com>> wrote: On Wed, Apr 18, 2018 at 4:49 PM, <dmitry.mikulin at sony.com<mailto:dmitry.mikulin at sony.com>> wrote: Hi Teresa, Thanks for the info! This example is my attempt to reduce FreeBSD kernel to something more manageable :) I will take a look at why globals are not being imported in this case. What’s the best tool to look into ThinLTO obje...

...able, followed by bar. In our case the jump table section is about 80K, so the expectation of foo being on the same page as bar breaks down. > On May 1, 2018, at 11:16 AM, Peter Collingbourne <peter at pcc.me.uk> wrote: > > > > On Tue, May 1, 2018 at 11:10 AM, <dmitry.mikulin at sony.com> wrote: > > > > On Apr 30, 2018, at 6:04 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: > > > > On Mon, Apr 30, 2018 at 1:05 PM, <dmitry.mikulin at sony.com> wrote: > > Replacing direct calls to jump table entries with calls to real...

On Tue, May 1, 2018 at 11:29 AM, <dmitry.mikulin at sony.com> wrote: > It’s not the functions themselves, it’s the jump tables that end up in the > same section of the thin-link temporary object. If I have, say, foo and bar > and both of them need a jump table entry, both entries will be in the same > section of the temp object. T...

.... So not having jump table entries for the functions > that don't really need them would be ideal. > > Thanks. > Dmitry. > > > On Apr 18, 2018, at 6:11 PM, Teresa Johnson <tejohnson at google.com> wrote: > > > > On Wed, Apr 18, 2018 at 4:49 PM, <dmitry.mikulin at sony.com> wrote: > >> Hi Teresa, >> >> Thanks for the info! >> This example is my attempt to reduce FreeBSD kernel to something more >> manageable :) >> >> I will take a look at why globals are not being imported in this case. >> What’s the b...

...e same page. So not having jump table entries for the functions that don't really need them would be ideal. Thanks. Dmitry. On Apr 18, 2018, at 6:11 PM, Teresa Johnson <tejohnson at google.com<mailto:tejohnson at google.com>> wrote: On Wed, Apr 18, 2018 at 4:49 PM, <dmitry.mikulin at sony.com<mailto:dmitry.mikulin at sony.com>> wrote: Hi Teresa, Thanks for the info! This example is my attempt to reduce FreeBSD kernel to something more manageable :) I will take a look at why globals are not being imported in this case. What’s the best tool to look into ThinLTO obje...

> On Apr 13, 2017, at 7:43 PM, Davide Italiano <davide at freebsd.org> wrote: > > On Thu, Apr 13, 2017 at 5:18 PM, Mikulin, Dmitry > <dmitry.mikulin at sony.com> wrote: >> I’m taking a first look at InstCombine performance. I picked up the caching patch and ran a few experiments on one of our larger C++ apps. The size of the *.0.2.internalize.bc no-debug IR is ~ 30M. Here are my observations so far. >...

> On Apr 30, 2018, at 6:04 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: > > On Mon, Apr 30, 2018 at 1:05 PM, <dmitry.mikulin at sony.com> wrote: > Replacing direct calls to jump table entries with calls to real targets recovers most of the performance loss in my benchmark. Dealing with link order files is a bit cumbersome though: I can’t keep both, say “foo” and “foo.cfi” next to each other in link order, because i...

On Tue, May 1, 2018 at 11:10 AM, <dmitry.mikulin at sony.com> wrote: > > > > On Apr 30, 2018, at 6:04 PM, Peter Collingbourne <peter at pcc.me.uk> > wrote: > > > > On Mon, Apr 30, 2018 at 1:05 PM, <dmitry.mikulin at sony.com> wrote: > > Replacing direct calls to jump table entries with calls to re...

...s is part of a more complex example where it is not possible to do this? Also note that with r327254 we started importing global variables. Do you know why we don't import in your case? I wonder if it has to do with it being CFI inserted code? Teresa On Tue, Apr 17, 2018 at 9:17 AM <dmitry.mikulin at sony.com> wrote: > I watched Teresa’s talk on ThinLTO from last year’s CppCon, and it > sounded like adding global variable information to the summaries was in the > works, or at least in planning. Can someone (Teresa?) please share the > current status? If it’s part of future p...

...http://llvm-cs.pcc.me.uk/lib/Transforms/IPO/LowerTypeTests.cpp#1620 >> Renaming: http://llvm-cs.pcc.me.uk/lib/Transforms/IPO/LowerTypeTests.cpp#1642 >> Do you have an example of what you are seeing? >> >> Peter >> >> On Thu, Apr 26, 2018 at 4:54 PM, <dmitry.mikulin at sony.com> wrote: >> Hi Peter, >> >> We could probably tolerate a certain amount of unused jump table entries. However, I just realized that all non-inline imported calls end up going through a jump table entry. Is that correct? Initially I thought you meant calls promoted f...

...s is part of a more complex example where it is not possible to do this? Also note that with r327254 we started importing global variables. Do you know why we don't import in your case? I wonder if it has to do with it being CFI inserted code? Teresa On Tue, Apr 17, 2018 at 9:17 AM <dmitry.mikulin at sony.com<mailto:dmitry.mikulin at sony.com>> wrote: I watched Teresa’s talk on ThinLTO from last year’s CppCon, and it sounded like adding global variable information to the summaries was in the works, or at least in planning. Can someone (Teresa?) please share the current status? If i...

...: http://llvm-cs.pcc.me.uk/lib/Transforms/IPO/LowerTypeTests.cpp#1620 >> Renaming: http://llvm-cs.pcc.me.uk/lib/Transforms/IPO/LowerTypeTests.cpp#1642 >> Do you have an example of what you are seeing? >> >> Peter >> >> On Thu, Apr 26, 2018 at 4:54 PM, <dmitry.mikulin at sony.com> wrote: >> Hi Peter, >> >> We could probably tolerate a certain amount of unused jump table entries. However, I just realized that all non-inline imported calls end up going through a jump table entry. Is that correct? Initially I thought you meant calls promoted fr...

...irect function reference instead of just direct calls. Also, I believe the logic for replaceDirectCalls() should be more restrictive, currently it will also rewrite calls where the function use is as a function pointer argument instead of the call target. On Mon, Apr 30, 2018 at 1:05 PM <dmitry.mikulin at sony.com> wrote: > Replacing direct calls to jump table entries with calls to real targets > recovers most of the performance loss in my benchmark. Dealing with link > order files is a bit cumbersome though: I can’t keep both, say “foo” and > “foo.cfi” next to each other in link...