Hi, Thank you for reviewing v1!
Changes in v2: Removed the target hook and added a new optab for cfcmov. Lingling Kong (2): [APX CFCMOV] Support APX CFCMOV in if_convert pass [APX CFCMOV] Support APX CFCMOV in backend gcc/config/i386/i386-expand.cc | 63 +++++ gcc/config/i386/i386-opts.h | 4 +- gcc/config/i386/i386.cc | 16 +- gcc/config/i386/i386.h | 1 + gcc/config/i386/i386.md | 53 +++- gcc/config/i386/i386.opt | 3 + gcc/config/i386/predicates.md | 7 + gcc/ifcvt.cc | 246 ++++++++++++++++++- gcc/optabs.def | 1 + gcc/testsuite/gcc.target/i386/apx-cfcmov-1.c | 73 ++++++ gcc/testsuite/gcc.target/i386/apx-cfcmov-2.c | 40 +++ 11 files changed, 494 insertions(+), 13 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/apx-cfcmov-1.c create mode 100644 gcc/testsuite/gcc.target/i386/apx-cfcmov-2.c -- > -----Original Message----- > From: Hongtao Liu <crazy...@gmail.com> > Sent: Monday, June 17, 2024 11:05 AM > To: Jeff Law <jeffreya...@gmail.com> > Cc: Alexander Monakov <amona...@ispras.ru>; Kong, Lingling > <lingling.k...@intel.com>; gcc-patches@gcc.gnu.org; Liu, Hongtao > <hongtao....@intel.com>; Uros Bizjak <ubiz...@gmail.com> > Subject: Re: [PATCH 0/3] [APX CFCMOV] Support APX CFCMOV > > On Sat, Jun 15, 2024 at 1:22 AM Jeff Law <jeffreya...@gmail.com> wrote: > > > > > > > > On 6/14/24 11:10 AM, Alexander Monakov wrote: > > > > > > On Fri, 14 Jun 2024, Kong, Lingling wrote: > > > > > >> APX CFCMOV[1] feature implements conditionally faulting which means > > >> that all memory faults are suppressed when the condition code > > >> evaluates to false and load or store a memory operand. Now we could load > or store a memory operand may trap or fault for conditional move. > > >> > > >> In middle-end, now we don't support a conditional move if we knew > > >> that a load from A or B could trap or fault. > > > > > > Predicated loads&stores on Itanium don't trap either. They are > > > modeled via COND_EXEC on RTL. The late if-conversion pass (the > > > instance that runs after > > > reload) is capable of introducing them. > > > > > >> To enable CFCMOV, we add a target HOOK > > >> TARGET_HAVE_CONDITIONAL_MOVE_MEM_NOTRAP > > >> in if-conversion pass to allow convert to cmov. > > > > > > Considering the above, is the new hook really necessary? Can you > > > model the new instructions via (cond_exec () (set ...)) instead of (set > (if_then_else ...)) ? > > Note that turning on cond_exec will turn off some of the cmove support. > Yes, cfcmov looks more like a cmov than a cond_exec. > > > > But the general suggesting of trying to avoid a hook for this is a > > good one. In fact, my first reaction to this thread was "do we really > > need a hook for this". > Maybe a new optab, .i.e cfmovmodecc, and it differs from movcc for Conditional > Fault? > > > > jeff > > > > -- > BR, > Hongtao
