| Message ID | CAO2gOZXsLsQhyd2Kiw9hXhzKqUpVqjPvfThY=JAmrwci2uW3Sg@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
Can callgraph node count be fixed up properly instead of doing individual fixups like this? David On Fri, Jan 17, 2014 at 2:38 PM, Dehao Chen <dehao@google.com> wrote: > In AutoFDO, sometime edge count might be propagated to be too large > due to bad debug info. In this cases, we need to make sure the count > scale is no larger than 100% otherwise it'll make real hot code cold. > > Bootstrapped and passed regression test. Performance test on-going. > > OK for google-4_8 if performance test is ok? > > Thanks, > Dehao > > Index: gcc/tree-inline.c > =================================================================== > --- gcc/tree-inline.c (revision 206721) > +++ gcc/tree-inline.c (working copy) > @@ -2262,6 +2262,9 @@ copy_cfg_body (copy_body_data * id, gcov_type coun > else > count_scale = REG_BR_PROB_BASE; > > + if (flag_auto_profile && count_scale > REG_BR_PROB_BASE) > + count_scale = REG_BR_PROB_BASE; > + > /* Register specific tree functions. */ > gimple_register_cfg_hooks (); > > Index: gcc/cgraphclones.c > =================================================================== > --- gcc/cgraphclones.c (revision 206721) > +++ gcc/cgraphclones.c (working copy) > @@ -216,7 +216,10 @@ cgraph_clone_node (struct cgraph_node *n, tree dec > count, we will not update the original callee because it may > mistakenly mark some hot function as cold. */ > if (flag_auto_profile && count >= n->count) > - update_original = false; > + { > + update_original = false; > + new_node->count = n->count; > + } > if (update_original) > { > n->count -= count;
Unfortunately, copy_cfg_body is actually using basic block count instead of cgraph edge count. Thus even fixing up the call graph does not solve the problem. The 2nd chunk of the patch (cgraphclones.c) is actually not necessary. We only need the first part (tree-inline.c). Thanks, Dehao On Fri, Jan 17, 2014 at 3:12 PM, Xinliang David Li <davidxl@google.com> wrote: > Can callgraph node count be fixed up properly instead of doing > individual fixups like this? > > David > > On Fri, Jan 17, 2014 at 2:38 PM, Dehao Chen <dehao@google.com> wrote: >> In AutoFDO, sometime edge count might be propagated to be too large >> due to bad debug info. In this cases, we need to make sure the count >> scale is no larger than 100% otherwise it'll make real hot code cold. >> >> Bootstrapped and passed regression test. Performance test on-going. >> >> OK for google-4_8 if performance test is ok? >> >> Thanks, >> Dehao >> >> Index: gcc/tree-inline.c >> =================================================================== >> --- gcc/tree-inline.c (revision 206721) >> +++ gcc/tree-inline.c (working copy) >> @@ -2262,6 +2262,9 @@ copy_cfg_body (copy_body_data * id, gcov_type coun >> else >> count_scale = REG_BR_PROB_BASE; >> >> + if (flag_auto_profile && count_scale > REG_BR_PROB_BASE) >> + count_scale = REG_BR_PROB_BASE; >> + >> /* Register specific tree functions. */ >> gimple_register_cfg_hooks (); >> >> Index: gcc/cgraphclones.c >> =================================================================== >> --- gcc/cgraphclones.c (revision 206721) >> +++ gcc/cgraphclones.c (working copy) >> @@ -216,7 +216,10 @@ cgraph_clone_node (struct cgraph_node *n, tree dec >> count, we will not update the original callee because it may >> mistakenly mark some hot function as cold. */ >> if (flag_auto_profile && count >= n->count) >> - update_original = false; >> + { >> + update_original = false; >> + new_node->count = n->count; >> + } >> if (update_original) >> { >> n->count -= count;
ok. David On Wed, Jan 22, 2014 at 3:23 PM, Dehao Chen <dehao@google.com> wrote: > Unfortunately, copy_cfg_body is actually using basic block count > instead of cgraph edge count. Thus even fixing up the call graph does > not solve the problem. The 2nd chunk of the patch (cgraphclones.c) is > actually not necessary. We only need the first part (tree-inline.c). > > Thanks, > Dehao > > On Fri, Jan 17, 2014 at 3:12 PM, Xinliang David Li <davidxl@google.com> wrote: >> Can callgraph node count be fixed up properly instead of doing >> individual fixups like this? >> >> David >> >> On Fri, Jan 17, 2014 at 2:38 PM, Dehao Chen <dehao@google.com> wrote: >>> In AutoFDO, sometime edge count might be propagated to be too large >>> due to bad debug info. In this cases, we need to make sure the count >>> scale is no larger than 100% otherwise it'll make real hot code cold. >>> >>> Bootstrapped and passed regression test. Performance test on-going. >>> >>> OK for google-4_8 if performance test is ok? >>> >>> Thanks, >>> Dehao >>> >>> Index: gcc/tree-inline.c >>> =================================================================== >>> --- gcc/tree-inline.c (revision 206721) >>> +++ gcc/tree-inline.c (working copy) >>> @@ -2262,6 +2262,9 @@ copy_cfg_body (copy_body_data * id, gcov_type coun >>> else >>> count_scale = REG_BR_PROB_BASE; >>> >>> + if (flag_auto_profile && count_scale > REG_BR_PROB_BASE) >>> + count_scale = REG_BR_PROB_BASE; >>> + >>> /* Register specific tree functions. */ >>> gimple_register_cfg_hooks (); >>> >>> Index: gcc/cgraphclones.c >>> =================================================================== >>> --- gcc/cgraphclones.c (revision 206721) >>> +++ gcc/cgraphclones.c (working copy) >>> @@ -216,7 +216,10 @@ cgraph_clone_node (struct cgraph_node *n, tree dec >>> count, we will not update the original callee because it may >>> mistakenly mark some hot function as cold. */ >>> if (flag_auto_profile && count >= n->count) >>> - update_original = false; >>> + { >>> + update_original = false; >>> + new_node->count = n->count; >>> + } >>> if (update_original) >>> { >>> n->count -= count;
Index: gcc/tree-inline.c =================================================================== --- gcc/tree-inline.c (revision 206721) +++ gcc/tree-inline.c (working copy) @@ -2262,6 +2262,9 @@ copy_cfg_body (copy_body_data * id, gcov_type coun else count_scale = REG_BR_PROB_BASE; + if (flag_auto_profile && count_scale > REG_BR_PROB_BASE) + count_scale = REG_BR_PROB_BASE; + /* Register specific tree functions. */ gimple_register_cfg_hooks (); Index: gcc/cgraphclones.c =================================================================== --- gcc/cgraphclones.c (revision 206721) +++ gcc/cgraphclones.c (working copy) @@ -216,7 +216,10 @@ cgraph_clone_node (struct cgraph_node *n, tree dec count, we will not update the original callee because it may mistakenly mark some hot function as cold. */ if (flag_auto_profile && count >= n->count) - update_original = false; + { + update_original = false; + new_node->count = n->count; + } if (update_original) { n->count -= count;