On December 27, 2016 11:17:00 PM GMT+01:00, Andreas Tobler <andreast-l...@fgznet.ch> wrote: >On 16.09.16 13:30, Richard Biener wrote: >> On Thu, 15 Sep 2016, Richard Biener wrote: >> >>> >>> This addresses sth I needed to address with the early LTO debug >patches >>> (you might now figure I'm piecemail merging stuff from that patch). >>> >>> When the cgraph code optimizes out a global we call the >late_global_decl >>> debug hook to eventually add a DW_AT_const_value to its DIE (we >don't >>> really expect a location as that will be invalid after optimizing >out >>> and will be pruned). >>> >>> With the early LTO debug patches I have introduced a >early_dwarf_finished >>> flag (mainly for consistency checking) and I figured I can use that >to >>> detect the call to the late hook during the early phase and provide >>> the following cleaned up variant of avoiding to create locations >that >>> require later pruning (which doesn't work with emitting the early >DIEs). >>> >>> Bootstrapped on x86_64-unknown-linux-gnu, testing in progress. >>> >>> I verified it does the correct thing for a unit like >>> >>> static const int i = 2; >>> >>> (but ISTR we do have at least one testcase in the testsuite as >well). >>> >>> Will commit if testing finishes successfully. >> >> Ok, so it showed issues when merging that back to early-LTO-debug. >> Turns out in LTO we never call early_finish and thus >early_dwarf_finished >> was never set. Also dwarf2out_late_global_decl itself is a better >> place to constrain generating locations. >> >> The following variant is in very late stage of testing. >> >> Bootstrapped on x86_64-unknown-linux-gnu, testing in progress. >> LTO bootstrap on x86_64-unknown-linux-gnu in stage3. LTO bootstrap >> with early-LTO-debug in stage3, bootstraped with early-LTO-debug, >> testing in progress. > >Any chance to backport this commit (r240228) to 6.x? >It fixes a bootstrap comparison issue on aarch64-*-freebsd*. >The aarch64-*-freebsd* port is not yet merged to 6.x and 5.4.x due to >the bootstrap comparison failure I faced.
Did you analyze the bootstrap miscompare? I suspect the patch merely papers over the problem. Was that regular bootstrap (with or without compare-debug)? Richard. >I did a bootstrap with a backport of this revision to 6.x on >amd64-*-freebsd* and I did not see any issues. > >TIA, >Andreas > >> 2016-09-16 Richard Biener <rguent...@suse.de> >> >> * dwarf2out.c (early_dwarf_finished): New global. >> (set_early_dwarf::set_early_dwarf): Assert early_dwarf_finished >> is false. >> (dwarf2out_early_finish): Set early_dwarf_finished at the end, >> if called from LTO exit early. >> (dwarf2out_late_global_decl): When being during the early >> debug phase do not add locations but only const value attributes. >> Adjust the way we generate early DIEs for LTO. >> >> lto/ >> * lto.c (lto_main): Invoke early_finish debug hook.
