| Message ID | 2601473.BddDVKsqQX@fomalhaut |
|---|---|
| State | New |
| Headers | show |
| Series | Reduce DF computation at -O0 | expand |
On Thu, Oct 6, 2022 at 7:27 PM Eric Botcazou via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > Hi, > > even at -O0 there may be a fair amount of DF computation performed when > compiling large units and part of it appears to be useless. > > Bootstrapped/regtested on x86-64/Linux, OK for the mainline? OK. > > 2022-10-06 Eric Botcazou <ebotcazou@adacore.com> > > * function.cc (thread_prologue_and_epilogue_insns): Update only entry > and exit blocks when not optimizing. Remove dead statement. > > -- > Eric Botcazou
diff --git a/gcc/function.cc b/gcc/function.cc index 5498a712c4a..6474a663b30 100644 --- a/gcc/function.cc +++ b/gcc/function.cc @@ -6249,10 +6249,15 @@ thread_prologue_and_epilogue_insns (void) } } - /* Threading the prologue and epilogue changes the artificial refs - in the entry and exit blocks. */ - epilogue_completed = 1; - df_update_entry_exit_and_calls (); + /* Threading the prologue and epilogue changes the artificial refs in the + entry and exit blocks, and may invalidate DF info for tail calls. */ + if (optimize) + df_update_entry_exit_and_calls (); + else + { + df_update_entry_block_defs (); + df_update_exit_block_uses (); + } } /* Reposition the prologue-end and epilogue-begin notes after