On December 6, 2019 5:46:25 PM GMT+01:00, Erick Ochoa <erick.oc...@theobroma-systems.com> wrote: > > >On 2019-12-06 5:50 a.m., Richard Biener wrote: >> On Wed, Dec 4, 2019 at 6:03 PM Erick Ochoa >> <erick.oc...@theobroma-systems.com> wrote: >>> >>> >>> >>> On 2019-12-04 7:52 a.m., Richard Biener wrote: >>>> On Tue, Dec 3, 2019 at 11:51 PM Erick Ochoa >>>> <erick.oc...@theobroma-systems.com> wrote: >>>>> >>>>> Hi, >>>>> >>>>> I am trying to use the function: >`cgraph_node::get_untransformed_body` during >>>>> the wpa stage of a SIMPLE_IPA_PASS transformation. While the >execute function >>>> >>>> I think SIMPLE_IPA_PASSes have no "WPA" stage but run at LTRANS >time >>>> (WPA transform stage). So you might simply see that not all bodies >are >>>> available in your LTRANS unit? >>>> >>> >>> This makes a lot of sense, and it is indeed documented in the GCC >internals >>> manual: >>> >>> A small inter-procedural pass (SIMPLE_IPA_PASS) is a pass that >does >>> everything at once and thus it can not be executed during WPA in >WHOPR >>> mode. It defines only the Execute stage and during this stage it >>> accesses and modifies the function bodies. Such passes are useful >for >>> optimization at LGEN or LTRANS time and are used, for example, to >>> implement early optimization before writing object files. >>> >>> I got confused because the dump_file for my pass includes the >substring 'wpa'. >>> Should I file a bug to change the name of the dumpfile to something >more like >>> `ltrans*`? >> >> Well, you probably placed your pass in the IPA pipeline rather than >the >> all_late_ipa_passes one? In principle IPA passes _can_ pull in >bodies >> during WPA >> analysis, that just will be very costly> >>> Thanks for your help! > >I am a bit confused. >Can you please clarify: > >> I think SIMPLE_IPA_PASSes have no "WPA" stage but run at LTRANS time >> (WPA transform stage). > >I did have a SIMPLE_IPA_PASS and the dump file contained "wpa" in it. > >> Well, you probably placed your pass in the IPA pipeline rather than >the >> all_late_ipa_passes one? > >I did place my pass in the IPA pipeline rather than the >all_late_ipa_passes >one. > >Are SIMPLE_IPA_PASSes normally used in the all_late_ipa_passes which >means they are normally scheduled to run at LTRANS time? However, if >I place my SIMPLE_IPA_PASS during the IPA pipeline, then my >SIMPLE_IPA_PASS >will execute at "WPA" stage?
Yes. >> In principle IPA passes _can_ pull in bodies >> during WPA > >So, if SIMPLE_IPA_PASSes are placed in the IPA pipeline, is there a >reason why `cgraph_node::get_untransformed_body` would crash? That I have no idea. Richard. >Thanks again! > >>> >>>>> is running, I need to access the body of a function in order to >iterate over >>>>> the gimple instructions in the first basic block. I have found >that the >>>>> majority of the cgraph_node will return successfully. However, >there are some >>>>> functions which consistently produce a segmentation fault >following this >>>>> stacktrace: >>>>> >>>>> ``` >>>>> 0xbc2adb crash_signal >>>>> /home/eochoa/code/gcc/gcc/toplev.c:328 >>>>> 0xa54858 lto_get_decl_name_mapping(lto_file_decl_data*, char >const*) >>>>> /home/eochoa/code/gcc/gcc/lto-section-in.c:367 >>>>> 0x7030e7 cgraph_node::get_untransformed_body() >>>>> /home/eochoa/code/gcc/gcc/cgraph.c:3516 >>>>> 0x150613f get_bb1_callees >>>>> /home/eochoa/code/gcc/gcc/ipa-initcall-cp.c:737 >>>>> 0x150613f reach_nodes_via_bb1_dfs >>>>> ``` >>>>> >>>>> Is there a way for `cgraph_node::get_untransformed_body` to >succeed >>>>> consistently? (I.e. are there some preconditions that I need to >make sure are >>>>> in place before calling cgraph_node::get_untransformed_body? >>>>> >>>>> I am using gcc version 10.0.0 20191127 (experimental) >>>>> >>>>> Thanks
