> Am 25.11.2022 um 11:05 schrieb Jan Hubicka via Gcc-patches > <gcc-patches@gcc.gnu.org>: > > >> >> IPA profile instrumentation tries to clear the pure and const >> flags of functions but that's quite hopeless in particular for >> const since that attribute prevails on the type and thus on each >> call to the function leading to inconsistencies in the IL and >> eventual checking ICEs. There's no good reason to do this and >> it wouldn't fixup any indirect calls so just don't. No other >> instrumentation GCC does bothers about this. > > This was mostly meant to deadl with situation where we auto-detect > function to be const and then partially inline it to a loop. > Then both caller and callee accesses same counters in the memory and if > you move load/stores out of the loop in caller you lose counters and get > inconsistencies at profile read-in time. Don’t we Instrument after partial inlining now? As said, since we have the fntype on the call this doesn’t work anymore for const functions via attributes. Richard > Honza >> >> Bootstrap and regtest pending on x86_64-unknown-linux-gnu, OK? >> >> Thanks, >> Richard. >> >> PR tree-optimization/106912 >> * tree-profile.cc (tree_profiling): Do not clear pure/const >> flags. >> >> * gcc.dg/pr106912.c: New testcase. >> --- >> gcc/testsuite/gcc.dg/pr106912.c | 16 ++++++++++++++++ >> gcc/tree-profile.cc | 3 --- >> 2 files changed, 16 insertions(+), 3 deletions(-) >> create mode 100644 gcc/testsuite/gcc.dg/pr106912.c >> >> diff --git a/gcc/testsuite/gcc.dg/pr106912.c >> b/gcc/testsuite/gcc.dg/pr106912.c >> new file mode 100644 >> index 00000000000..8faa877d8b3 >> --- /dev/null >> +++ b/gcc/testsuite/gcc.dg/pr106912.c >> @@ -0,0 +1,16 @@ >> +/* { dg-do compile } */ >> +/* { dg-options "-O2 -fPIC -ftree-vectorize -fprofile-generate" } */ >> + >> +__attribute__ ((__simd__)) >> +__attribute__ ((__nothrow__ , __leaf__ , __const__)) >> +double foo (double x); >> +void bar(double *f, int n) >> +{ >> + int i; >> + for (i = 0; i < n; i++) >> + f[i] = foo(f[i]); >> +} >> +double foo(double x) >> +{ >> + return x * x / 3.0; >> +} >> diff --git a/gcc/tree-profile.cc b/gcc/tree-profile.cc >> index 2beb49241f2..5491b398870 100644 >> --- a/gcc/tree-profile.cc >> +++ b/gcc/tree-profile.cc >> @@ -814,9 +814,6 @@ tree_profiling (void) >> /* Don't profile functions produced for builtin stuff. */ >> if (DECL_SOURCE_LOCATION (node->decl) == BUILTINS_LOCATION) >> continue; >> - >> - node->set_const_flag (false, false); >> - node->set_pure_flag (false, false); >> } >> >> /* Update call statements and rebuild the cgraph. */ >> -- >> 2.35.3
Re: [PATCH] tree-optimization/106912 - IPA profile and pure/const
Richard Biener via Gcc-patches Fri, 25 Nov 2022 04:05:46 -0800
- [PATCH] tree-optimization/106912 - IPA prof... Richard Biener via Gcc-patches
- Re: [PATCH] tree-optimization/106912 -... Jan Hubicka via Gcc-patches
- Re: [PATCH] tree-optimization/1069... Richard Biener via Gcc-patches
- Re: [PATCH] tree-optimization/... Jan Hubicka via Gcc-patches
- Re: [PATCH] tree-optimizat... Richard Biener via Gcc-patches
- Re: [PATCH] tree-opti... Jan Hubicka via Gcc-patches
- Re: [PATCH] tree-... Richard Biener via Gcc-patches