| Message ID | 20170419075647.GF18309@gate.crashing.org |
|---|---|
| State | New |
| Headers | show |
On Wed, Apr 19, 2017 at 02:56:47AM -0500, Segher Boessenkool wrote: > On Tue, Apr 18, 2017 at 11:47:40AM +0200, Jakub Jelinek wrote: > > On Tue, Apr 18, 2017 at 09:30:19AM +0000, Segher Boessenkool wrote: > > > In split_live_ranges_for_shrink_wrap IRA also splits regs that are > > > only used in debug insns, leading to -fcompare-debug failures. > > > > > > Bootstrapped and tested on powerpc64-linux {-m32,-m64}. This happens > > > on at least GCC 5, so not a regression; but it is trivial and obvious, > > > is it okay for trunk anyway? > > > > I think the first question here is if it is beneficial to replace the > > regs in DEBUG_INSNs or not. If it is beneficial, then it of course > > has to be changed such that it never does > > newreg = ira_create_new_reg (dest); > > just because it sees DEBUG_INSN uses, but otherwise it should do what it > > does now. > > > > So one option is e.g. to split that loop into two, one doing analysis, > > i.e. that newreg = ira_create_new_reg (dest);, but not > > validate_change (uin, DF_REF_REAL_LOC (use), newreg, true); > > and this loop would also ignore DEBUG_INSN_P. > > And the other loop, with the same content, just without that newreg = ... > > and with the validate_change, as whole guarded with if (newreg), > > replacing stuff on all insns. > > Like this? Tested as before, etc. Thanks, > > > Segher > > > 2017-04-18 Segher Boessenkool <segher@kernel.crashing.org> > > PR rtl-optimization/80429 > * ira.c (split_live_ranges_for_shrink_wrap): Don't split regs that > are only used in debug insns. Ok, thanks. Jakub
diff --git a/gcc/ira.c b/gcc/ira.c index 7079573..bfb0508 100644 --- a/gcc/ira.c +++ b/gcc/ira.c @@ -4992,25 +4992,40 @@ split_live_ranges_for_shrink_wrap (void) if (!dest || dest == pic_offset_table_rtx) continue; - rtx newreg = NULL_RTX; + bool need_newreg = false; df_ref use, next; for (use = DF_REG_USE_CHAIN (REGNO (dest)); use; use = next) { rtx_insn *uin = DF_REF_INSN (use); next = DF_REF_NEXT_REG (use); + if (DEBUG_INSN_P (uin)) + continue; + basic_block ubb = BLOCK_FOR_INSN (uin); if (ubb == call_dom || dominated_by_p (CDI_DOMINATORS, ubb, call_dom)) { - if (!newreg) - newreg = ira_create_new_reg (dest); - validate_change (uin, DF_REF_REAL_LOC (use), newreg, true); + need_newreg = true; + break; } } - if (newreg) + if (need_newreg) { + rtx newreg = ira_create_new_reg (dest); + + for (use = DF_REG_USE_CHAIN (REGNO (dest)); use; use = next) + { + rtx_insn *uin = DF_REF_INSN (use); + next = DF_REF_NEXT_REG (use); + + basic_block ubb = BLOCK_FOR_INSN (uin); + if (ubb == call_dom + || dominated_by_p (CDI_DOMINATORS, ubb, call_dom)) + validate_change (uin, DF_REF_REAL_LOC (use), newreg, true); + } + rtx_insn *new_move = gen_move_insn (newreg, dest); emit_insn_after (new_move, bb_note (call_dom)); if (dump_file)