On Mon, Mar 17, 2025 at 2:14 PM Aleksandar Rakic <aleksandar.ra...@htecgroup.com> wrote: > > From: Robert Suchanek <robert.sucha...@imgtec.com> > > --param early-inlining-insns-cold=NUMBER > --param max-inline-insns-small-and-cold=NUMBER > > Analysis shows that the main difference between -O2 and -Os goes down to > inlining of cold or unlikely functions. The new parameters (defaulted to > 0) mean to disable these limitations with -Os. NUMBER could be set to > something like 4-32 to see the impact. > > The main reason that smaller functions are treated as cold or unlikely > is the function cgraph_maybe_hot_edge_p () always returning FALSE for > -Os.
If you want the code to grow you don't want to use -Os, so it seems odd to add such a parameter. In fact we already have --param max-inline-insns-size which defaults to zero that you could use and that looks to exactly implement your new param? Richard. > > gcc/ > * ipa-inline.cc (want_early_inline_function_p): Check if the > growth is greater than param_early_inlining_insns_cold. > (want_inline_small_function_p): Check if the growth is greater > than param_max_inline_insns_small_and_cold. > * params.opt (early-inlining-insns-cold): New option. > (max-inline-insns-small-and-cold): Likewise. > > Cherry-picked c38d7e548cbb3defb141efb528cb356333e8eb7a > from https://github.com/MIPS/gcc > > Signed-off-by: Robert Suchanek <robert.sucha...@imgtec.com> > Signed-off-by: Faraz Shahbazker <fshahbaz...@wavecomp.com> > Signed-off-by: Aleksandar Rakic <aleksandar.ra...@htecgroup.com> > --- > gcc/ipa-inline.cc | 4 +++- > gcc/params.opt | 8 ++++++++ > 2 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/gcc/ipa-inline.cc b/gcc/ipa-inline.cc > index fe8efa9a157..4d3d0fbc0c3 100644 > --- a/gcc/ipa-inline.cc > +++ b/gcc/ipa-inline.cc > @@ -820,7 +820,8 @@ want_early_inline_function_p (struct cgraph_edge *e) > > if (!want_inline || growth <= param_max_inline_insns_size) > ; > - else if (!e->maybe_hot_p ()) > + else if (!e->maybe_hot_p () > + && growth > param_early_inlining_insns_cold) > { > if (dump_enabled_p ()) > dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt, > @@ -1060,6 +1061,7 @@ want_inline_small_function_p (struct cgraph_edge *e, > bool report) > } > /* If call is cold, do not inline when function body would grow. */ > else if (!e->maybe_hot_p () > + && growth > param_max_inline_insns_small_and_cold > && (growth >= inline_insns_single (e->caller, false, false) > || growth_positive_p (callee, e, growth))) > { > diff --git a/gcc/params.opt b/gcc/params.opt > index 7c572774df2..edb62a221fb 100644 > --- a/gcc/params.opt > +++ b/gcc/params.opt > @@ -130,6 +130,10 @@ Maximum size (in bytes) of objects tracked bytewise by > dead store elimination. > Common Joined UInteger Var(param_early_inlining_insns) Init(6) Optimization > Param > Maximal estimated growth of function body caused by early inlining of single > call. > > +-param=early-inlining-insns-cold= > +Common Joined UInteger Var(param_early_inlining_insns_cold) Init(0) > Optimization Param > +Maximal estimated growth of function body caused by early inlining of cold > call. > + > -param=fsm-scale-path-stmts= > Common Joined UInteger Var(param_fsm_scale_path_stmts) Init(2) > IntegerRange(1, 10) Param Optimization > Scale factor to apply to the number of statements in a threading path > crossing a loop backedge when comparing to max-jump-thread-duplication-stmts. > @@ -573,6 +577,10 @@ The maximum number of instructions when inlining for > size. > Common Joined UInteger Var(param_max_inline_insns_small) Optimization Param > The maximum number of instructions when automatically inlining small > functions. > > +-param=max-inline-insns-small-and-cold= > +Common Joined UInteger Var(param_max_inline_insns_small_and_cold) > Optimization Init(0) Param > +The maximum number of instructions in a small and cold function eligible for > inlining. > + > -param=max-inline-recursive-depth= > Common Joined UInteger Var(param_max_inline_recursive_depth) Optimization > Init(8) Param > The maximum depth of recursive inlining for inline functions. > -- > 2.34.1
