On Thu, Jun 21, 2018 at 9:37 PM Jeff Law <l...@redhat.com> wrote: > > On 06/21/2018 11:04 AM, Eric Botcazou wrote: > > When code is compiled at -O0, the RTL middle-end makes sure that location > > information is preserved as much as possible by generating NOPs with the > > location information (goto_locus) present on edges in the CFG, if it thinks > > that these edges are the only place where a particular location is > > mentioned. > > > > The attached patch prevents this from happening in a couple of cases: > > 1. if the function has the DECL_IGNORED_P flag set, > > 2. if the NOP is emitted by merge_blocks and the 2nd block is a forwarder > > block whose outgoing edge has no location, because in this case the location > > of the to-be-elided edge is copied onto the aforementioned outgoing edge. > > > > Tested (GCC and GDB) on x86-64/Linux, applied on the mainline. > > > > > > 2018-06-21 Eric Botcazou <ebotca...@adacore.com> > > > > * cfgrtl.c (fixup_reorder_chain): Do not emit NOPs in DECL_IGNORED_P > > functions. > > (rtl_merge_blocks): Likewise. Do not emit a NOP if the location of > > the > > edge can be forwarded. > > (cfg_layout_merge_blocks): Likewise. > Funny Alex and I were just talking about the need to stuff away debug > info on edges for gimple. Attaching it to gimple nops sounds like a > fairly straightforward approach :-)
But wouldn't that create BBs? Sounds like you want DEBUG PHIs... :/ > > jeff
