Hi Claudiu, On Fri, Nov 17, 2017 at 03:05:23PM +0000, Claudiu Zissulescu wrote: > I've found a potential issue when performing CFG operations for hardware > loops. > > When a port is using hardware loops (like ARC) makes use of reorg_loops to > find and analyze loops that end in loop_end instructions. The very same > function can be set to reorder the cfg such that the loop end occurs after > the loop start. This task is performed by reoder_loops function which at its > turn calls cfg_layout_finalize -> fixup_reoreder_chain -> > force_nonfallthru_and_redirect (cfgrtl.c:1476). > However, the latter is splitting a call and its corresponding > CALL_ARG_LOCATION note, leading to an assert in dwarf2out_var_location() at > dwarf2out.c:26391. Thus, I've made a hack which patches the > force_nonfallthru_and_redirect() function to avoid splitting calls and their > note: > > diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c > index ae46908..38a739c 100644 > --- a/gcc/cfgrtl.c > +++ b/gcc/cfgrtl.c > @@ -1626,6 +1626,9 @@ force_nonfallthru_and_redirect (edge e, basic_block > target, rtx jump_label) > else > new_head = BB_END (e->src); > new_head = NEXT_INSN (new_head); > + if (new_head && NOTE_P (new_head) > + && NOTE_KIND (new_head) == NOTE_INSN_CALL_ARG_LOCATION) > + new_head = NEXT_INSN (new_head); > > jump_block = create_basic_block (new_head, NULL, e->src); > jump_block->count = count; > > I do not know if this is the way forward and I would like to have your input > on this subject.
This looks correct. The same issue is handled similarly elsewhere, too. Please send the patch to gcc-patches! (Add a comment though?) Thanks, Segher
