On Wed, Jun 3, 2026 at 4:43 AM Richard Biener <[email protected]> wrote: > > On Wed, Jun 3, 2026 at 4:07 AM Andrew Pinski > <[email protected]> wrote: > > > > EVRP changes some statements into copies but then does > > not do copy prop during its handling. This causes in some > > cases where phiopt could have optimized the phi not to be > > done. So we should move the copy prop pass (sccopy) right > > after evrp instead of after phiopt. > > > > Notes on the testsuite changes: > > dse-points-to.c needs to disable sccopy1 for the same > > reason why it disables all other copyprop passes. > > pr45397.c had an xfail for specifically PR 103221. > > pr81981.c is about a missing warning, in this case moving > > sccopy swaps around which uses is first in the list. > > OK. I guess EVRP copies are more common than tail-recursion > introduced ones.
Yes, that is correct. And the inliner will produce more copies. ccp right after inlining will remove most of those and so will forwprop right before alias pass. Thanks, Andrea > > > Bootstrapped and tested on x86_64-linux-gnu. > > > > PR tree-optimization/103221 > > gcc/ChangeLog: > > > > * passes.def (early_optimizations): Move sccopy > > to after evrp. > > > > gcc/testsuite/ChangeLog: > > > > * gcc.dg/tree-ssa/dse-points-to.c: Disable sccopy1. > > * gcc.dg/tree-ssa/pr45397.c: Remove the xfail. > > * gcc.dg/ubsan/pr81981.c: Swap around which one is xfailed. > > > > Signed-off-by: Andrew Pinski <[email protected]> > > --- > > gcc/passes.def | 2 +- > > gcc/testsuite/gcc.dg/tree-ssa/dse-points-to.c | 2 +- > > gcc/testsuite/gcc.dg/tree-ssa/pr45397.c | 8 +++----- > > gcc/testsuite/gcc.dg/ubsan/pr81981.c | 4 ++-- > > 4 files changed, 7 insertions(+), 9 deletions(-) > > > > diff --git a/gcc/passes.def b/gcc/passes.def > > index cdddb87302f..1fc867fae51 100644 > > --- a/gcc/passes.def > > +++ b/gcc/passes.def > > @@ -94,6 +94,7 @@ along with GCC; see the file COPYING3. If not see > > NEXT_PASS (pass_phiprop); > > NEXT_PASS (pass_fre, true /* may_iterate */); > > NEXT_PASS (pass_early_vrp); > > + NEXT_PASS (pass_sccopy); > > NEXT_PASS (pass_merge_phi); > > NEXT_PASS (pass_dse); > > NEXT_PASS (pass_cd_dce, false /* update_address_taken_p */, true > > /* remove_unused_locals */); > > @@ -104,7 +105,6 @@ along with GCC; see the file COPYING3. If not see > > NEXT_PASS (pass_tail_recursion); > > NEXT_PASS (pass_if_to_switch); > > NEXT_PASS (pass_convert_switch); > > - NEXT_PASS (pass_sccopy); > > NEXT_PASS (pass_profile); > > NEXT_PASS (pass_local_pure_const); > > NEXT_PASS (pass_modref); > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/dse-points-to.c > > b/gcc/testsuite/gcc.dg/tree-ssa/dse-points-to.c > > index 762d6720143..ff84ba8db13 100644 > > --- a/gcc/testsuite/gcc.dg/tree-ssa/dse-points-to.c > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/dse-points-to.c > > @@ -1,5 +1,5 @@ > > /* { dg-do compile } */ > > -/* { dg-options "-O2 -fno-tree-ccp -fno-tree-forwprop -fno-tree-fre > > -fno-tree-vrp -fdump-tree-dse1-details" } */ > > +/* { dg-options "-O2 -fno-tree-ccp -fno-tree-forwprop -fno-tree-fre > > -fno-tree-vrp -fdisable-tree-sccopy1 -fdump-tree-dse1-details" } */ > > > > int > > f () > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr45397.c > > b/gcc/testsuite/gcc.dg/tree-ssa/pr45397.c > > index 8eacb518777..37e57a8996c 100644 > > --- a/gcc/testsuite/gcc.dg/tree-ssa/pr45397.c > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr45397.c > > @@ -18,12 +18,10 @@ int foo_mul (const unsigned char *tmp, int i, int val) > > > > /* All cases should end up using min/max for the saturated operations and > > have no control flow. */ > > -/* EVRP leaves copies in the IL which confuses phiopt1 so we have > > - to rely on phiopt2 instead. */ > > /* { dg-final { scan-tree-dump-not " & 255;" "evrp" } } */ > > -/* { dg-final { scan-tree-dump-times "MAX_EXPR" 3 "phiopt1" { xfail *-*-* > > } } } */ > > -/* { dg-final { scan-tree-dump-times "MIN_EXPR" 3 "phiopt1" { xfail *-*-* > > } } } */ > > -/* { dg-final { scan-tree-dump-not "if " "phiopt1" { xfail *-*-* } } } */ > > +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 3 "phiopt1" } } */ > > +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 3 "phiopt1" } } */ > > +/* { dg-final { scan-tree-dump-not "if " "phiopt1" } } */ > > /* { dg-final { scan-tree-dump-times "MAX_EXPR" 3 "phiopt2" } } */ > > /* { dg-final { scan-tree-dump-times "MIN_EXPR" 3 "phiopt2" } } */ > > /* { dg-final { scan-tree-dump-not "if " "phiopt2" } } */ > > diff --git a/gcc/testsuite/gcc.dg/ubsan/pr81981.c > > b/gcc/testsuite/gcc.dg/ubsan/pr81981.c > > index d201efb3f65..8aac5ae9725 100644 > > --- a/gcc/testsuite/gcc.dg/ubsan/pr81981.c > > +++ b/gcc/testsuite/gcc.dg/ubsan/pr81981.c > > @@ -16,6 +16,6 @@ foo (int i) > > u[0] = i; > > } > > > > - v = u[0]; /* { dg-warning "may be used uninitialized" "" { > > xfail *-*-* } } */ > > - return t[0]; /* { dg-warning "may be used uninitialized" } */ > > + v = u[0]; /* { dg-warning "may be used uninitialized" } */ > > + return t[0]; /* { dg-warning "may be used uninitialized" "" { > > xfail *-*-* } } */ > > } > > -- > > 2.43.0 > >
