How to pass argument to VC8 linker from .mozconfig

RyanVM · Post by **RyanVM** » August 27th, 2006, 10:32 am

Does anybody know how to pass a flag to the VC8 linker during a compile? On my compiles, I use the /GL flag. Using /GL causes the VC8 linker to assume the /LTCG flag as well, but first it has to restart the linking process on every module. To speed the process up, the /LTCG flag can be sent to the linker in the first place so it doesn't have to start over after realizing that /GL was used with the compiler.

However, --enable-optimize only passes arguments to the compiler and not the linker, meaning the /LTCG flag is completely ignored. I've also tried mk_add_options LDFLAGS="/LTCG", but that apparently only works for unix-based linkers and not VC8.

So, that's where I'm at. Does anybody in here know how to pass the /LTCG argument to the VC8 linker via .mozconfig?

Thanks!

auenf · Post by **auenf** » August 29th, 2006, 2:32 am

http://msdn2.microsoft.com/en-us/library/5y4fae15.aspx

Enf...

RyanVM · Post by **RyanVM** » August 29th, 2006, 8:24 pm

Thanks!

RyanVM · Post by **RyanVM** » August 30th, 2006, 3:57 pm

Doesn't seem to work. If I add "/link /LTCG" to --enable-optimize, make complains about invalid optimizations. If I try creating a LINK environment variable set to /LTCG, that also doesn't work.

I'm beginning to think this is impossible

mahowi · Post by **mahowi** » August 31st, 2006, 8:44 am

Same problem here. It's because /LTCG should be passed to LIB.exe, not LINK.exe. And I couldn't find anything about passing options to LIB.

mahowi · Post by **mahowi** » August 31st, 2006, 9:00 am

You could change line 5449 in configure (line 1275 in configure.in) from

Code: Select all

HOST_AR_FLAGS='-NOLOGO -OUT:"$@"'

to

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HOST_AR_FLAGS='-NOLOGO -LTCG -OUT:"$@"'

RyanVM · Post by **RyanVM** » August 31st, 2006, 5:51 pm

Modifying configure and configure.in didn't seem to work either. For the record, I completely removed my objdir prior to starting the build.

Sephirot · Post by **Sephirot** » September 8th, 2006, 6:06 pm

mahowi wrote:You could change line 5449 in configure (line 1275 in configure.in) from
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HOST_AR_FLAGS='-NOLOGO -OUT:"$@"'
to
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HOST_AR_FLAGS='-NOLOGO -LTCG -OUT:"$@"'

don't forget line 1692 of configure.in (line 6164 in configure)

p.s.

LIB does not use an environment variable.

Running LIB

RyanVM · Post by **RyanVM** » September 9th, 2006, 11:18 am

SUCCESS!!!

Here's a diff (off the trunk) for anybody else who may want to enable LTCG by default.
http://www.ryanvm.net/files/ltcg.diff

RyanVM · Post by **RyanVM** » September 10th, 2006, 6:48 am

One more note, you'll still want to set the LINK environment variable to -LTCG (I do it in my mozset.cmd), as there are a few instances (such as when the actual browser app is being built) when link.exe is still being called. But I have now confirmed that the diff posted above along with the environment variable completely takes care of it

bangbang023 · Post by **bangbang023** » September 10th, 2006, 12:04 pm

How much time does this shave off the build process for you?

auenf · Post by **auenf** » September 11th, 2006, 8:51 pm

hmm, didnt seem to shave any time of for me at all, and i do see some of the /ltcg messages too, just going to try a couple of things...

Enf...

BlueFyre · Post by **BlueFyre** » September 12th, 2006, 3:03 pm

Comparing my build logs and what not, it does not seem to shave any time on average...
It does how ever reduce the build log by 60KB almost... not sure if thats really just /LTCG though

Also I am seeing some of these warnings about /LTCG
Here's a list of files where I am seeing it

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host_cppsetup.obj now.obj w95dllmain.obj prvrsion.obj plvrsion.obj plarena.obj plgetopt.obj plvrsion.obj host_jskwgen.obj jsapi.obj xpt_dump.obj xpt_link.obj xpidl.obj pldhash.obj nsXPComStub.obj host_mar.obj nsZipArchive.obj jsdebug.obj AccessibleMarshal.obj updater.obj CertReader.obj InstallCleanup.obj nsStubNotifier.obj nsinstall.obj nsztool.obj ren8dot3.obj ds32.obj GetShortPathName.obj regxpcom.obj xpcshell.obj maindll.obj StdAfx.obj nsBrowserApp.obj

gorth · Post by **gorth** » September 16th, 2006, 8:27 am

Hello Ryan

Can you post a link to the mozset.cmd file? Thanks.

Sephirot · Post by **Sephirot** » September 17th, 2006, 6:45 am

BlueFyre wrote:Comparing my build logs and what not, it does not seem to shave any time on average...
It does how ever reduce the build log by 60KB almost... not sure if thats really just /LTCG though

Also I am seeing some of these warnings about /LTCG
Here's a list of files where I am seeing it
Code: Select all
host_cppsetup.obj now.obj w95dllmain.obj prvrsion.obj plvrsion.obj plarena.obj plgetopt.obj plvrsion.obj host_jskwgen.obj jsapi.obj xpt_dump.obj xpt_link.obj xpidl.obj pldhash.obj nsXPComStub.obj host_mar.obj nsZipArchive.obj jsdebug.obj AccessibleMarshal.obj updater.obj CertReader.obj InstallCleanup.obj nsStubNotifier.obj nsinstall.obj nsztool.obj ren8dot3.obj ds32.obj GetShortPathName.obj regxpcom.obj xpcshell.obj maindll.obj StdAfx.obj nsBrowserApp.obj

same here ...
for /mozilla/nsprpub/ configure/configure.in need to be modified too.

http://lxr.mozilla.org/mozilla1.8/sourc ... re.in#1469
http://lxr.mozilla.org/mozilla1.8/sourc ... igure#3945