On Wed, Dec 3, 2014 at 5:47 AM, H.J. Lu <hjl.to...@gmail.com> wrote: > On Tue, Dec 2, 2014 at 12:01 PM, Uros Bizjak <ubiz...@gmail.com> wrote: >> On Tue, Dec 2, 2014 at 8:40 PM, H.J. Lu <hjl.to...@gmail.com> wrote: >>> On Tue, Dec 2, 2014 at 11:19 AM, Uros Bizjak <ubiz...@gmail.com> wrote: >>>> Hello! >>>> >>>>> Ping. >>>>>> Ping. >>>>>>> Ping. >>>>>>>> Ping. >>>> >>>> It would probably help reviewers if you pointed to actual path >>>> submission [1], which unfortunately contains the explanation in the >>>> patch itself [2], which further explains that this functionality is >>>> currently only supported with gold, patched with [3]. >>>> >>>> [1] https://gcc.gnu.org/ml/gcc-patches/2014-09/msg00645.html >>>> [2] https://gcc.gnu.org/ml/gcc-patches/2014-09/txt2CHtu81P1O.txt >>>> [3] https://sourceware.org/ml/binutils/2014-05/msg00092.html >>>> >>>> After a bit of the above detective work, I think that new gcc option >>>> is not necessary. The configure should detect if new functionality is >>>> supported in the linker, and auto-configure gcc to use it when >>>> appropriate. >>> >>> I think GCC option is needed since one can use -fuse-ld= to >>> change linker. >> >> IMO, nobody will use this highly special x86_64-only option. It would >> be best for gnu-ld to reach feature parity with gold as far as this >> functionality is concerned. In this case, the optimization would be >> auto-configured, and would fire automatically, without any user >> intervention. >> > > Let's do it. I implemented the same feature in bfd linker on both > master and 2.25 branch. >
+bool +i386_binds_local_p (const_tree exp) +{ + /* Globals marked extern are treated as local when linker copy relocations + support is available with -f{pie|PIE}. */ + if (TARGET_64BIT && ix86_copyrelocs && flag_pie + && TREE_CODE (exp) == VAR_DECL + && DECL_EXTERNAL (exp) && !DECL_WEAK (exp)) + return true; + return default_binds_local_p (exp); +} + It returns true with -fPIE and false without -fPIE. It is lying to compiler. Maybe legitimate_pic_address_disp_p is a better place. -- H.J.