On Tue, Dec 7, 2010 at 3:57 PM, Andrew Pinski <pins...@gmail.com> wrote: > On Tue, Dec 7, 2010 at 3:53 PM, H.J. Lu <hjl.to...@gmail.com> wrote: >> On Tue, Dec 7, 2010 at 3:15 PM, Cary Coutant <ccout...@google.com> wrote: >>>> Here is my proposal. Any comments? >>> >>> We talked about ld -r a while back during the WHOPR project, and the >>> two ways that the linker could work: (1) combine all the .o files and >>> use the plugin to run LTRANS on the IR files, producing a pure, >>> optimized, object file; and (2) combine the non-IR object files as ld >>> -r normally would, and combine that result somehow with the IR from >>> the other files, for later optimization. If I remember correctly, >>> there was support for both modes of operation. The first mode is >>> easily handled with the current design (untested as far as I know -- >>> there are probably bugs, and I'm not sure if we get the symbol >>> visibility correct in those cases). >> >> We considered it. The problem is LTO performs the best when >> generating the final executable/DSO. That is we want the full IR in the >> output of "ld -r". > > What happens when ld -r is the final link? Think loadable linux > kernel modules and some other stuff that abuse elf relocatable > objects? >
"ld -plugin ... -r" will be treated as final link. -- H.J.
