| Message ID | patch-18131-tamar@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | middle-end: thread through existing LCSSA variable for alternative exits too [PR113237] | expand |
On 1/7/24 18:29, Tamar Christina wrote: > gcc/ChangeLog: > > PR tree-optimization/113237 > * tree-vect-loop-manip.cc (slpeel_tree_duplicate_loop_to_edge_cfg): Use > existing LCSSA variable for exit when all exits are early break. Might that be the same error as I got here when building with bootstrap-lto and bootstrap-O3: https://gcc.gnu.org/pipermail/gcc-testresults/2024-January/804807.html ?
No, that error is fixed by some earlier patches sent early last week that are awaiting review :)
On Sun, 7 Jan 2024, Tamar Christina wrote: > Hi All, > > Builing on top of the previous patch, similar to when we have a single exit if > we have a case where all exits are considered early exits and there are existing > non virtual phi then in order to maintain LCSSA we have to use the existing PHI > variables. We can't simply clear them and just rebuild them because the order > of the PHIs in the main exit must match the original exit for when we add the > skip_epilog guard. > > But the infrastructure is already in place to maintain them, we just have to use > the right value. > > Bootstrapped Regtested on aarch64-none-linux-gnu, x86_64-pc-linux-gnu > and no issues normally and with with --enable-checking=release --enable-lto > --with-build-config=bootstrap-O3 --enable-checking=yes,rtl,extra. > > Ok for master? OK Richard. > Thanks, > Tamar > > gcc/ChangeLog: > > PR tree-optimization/113237 > * tree-vect-loop-manip.cc (slpeel_tree_duplicate_loop_to_edge_cfg): Use > existing LCSSA variable for exit when all exits are early break. > > gcc/testsuite/ChangeLog: > > PR tree-optimization/113237 > * gcc.dg/vect/vect-early-break_98-pr113237.c: New test. > > --- inline copy of patch -- > diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c > new file mode 100644 > index 0000000000000000000000000000000000000000..e6d150b571f753e9eb3859f06f62b371817494a3 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c > @@ -0,0 +1,20 @@ > +/* { dg-do compile } */ > +/* { dg-add-options vect_early_break } */ > +/* { dg-require-effective-target vect_early_break } */ > +/* { dg-require-effective-target vect_int } */ > + > +long Perl_pp_split_limit; > +int Perl_block_gimme(); > +int Perl_pp_split() { > + char strend; > + long iters; > + int gimme = Perl_block_gimme(); > + while (--Perl_pp_split_limit) { > + if (gimme) > + iters++; > + if (strend) > + break; > + } > + if (iters) > + return 0; > +} > diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc > index 7fd6566341b4893a1e209d1f8ff65d6d180f1190..77649b84f45b9e5dacec2809e0c854c8fcc17ce1 100644 > --- a/gcc/tree-vect-loop-manip.cc > +++ b/gcc/tree-vect-loop-manip.cc > @@ -1700,7 +1700,12 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop, edge loop_exit, > if (peeled_iters && !virtual_operand_p (new_arg)) > { > tree tmp_arg = gimple_phi_result (from_phi); > - if (!new_phi_args.get (tmp_arg)) > + /* Similar to the single exit case, If we have an existing > + LCSSA variable thread through the original value otherwise > + skip it and directly use the final value. */ > + if (tree *res = new_phi_args.get (tmp_arg)) > + new_arg = *res; > + else > new_arg = tmp_arg; > } > > > > > >
--- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c @@ -0,0 +1,20 @@ +/* { dg-do compile } */ +/* { dg-add-options vect_early_break } */ +/* { dg-require-effective-target vect_early_break } */ +/* { dg-require-effective-target vect_int } */ + +long Perl_pp_split_limit; +int Perl_block_gimme(); +int Perl_pp_split() { + char strend; + long iters; + int gimme = Perl_block_gimme(); + while (--Perl_pp_split_limit) { + if (gimme) + iters++; + if (strend) + break; + } + if (iters) + return 0; +} diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc index 7fd6566341b4893a1e209d1f8ff65d6d180f1190..77649b84f45b9e5dacec2809e0c854c8fcc17ce1 100644 --- a/gcc/tree-vect-loop-manip.cc +++ b/gcc/tree-vect-loop-manip.cc @@ -1700,7 +1700,12 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop, edge loop_exit, if (peeled_iters && !virtual_operand_p (new_arg)) { tree tmp_arg = gimple_phi_result (from_phi); - if (!new_phi_args.get (tmp_arg)) + /* Similar to the single exit case, If we have an existing + LCSSA variable thread through the original value otherwise + skip it and directly use the final value. */ + if (tree *res = new_phi_args.get (tmp_arg)) + new_arg = *res; + else new_arg = tmp_arg; }
Hi All, Builing on top of the previous patch, similar to when we have a single exit if we have a case where all exits are considered early exits and there are existing non virtual phi then in order to maintain LCSSA we have to use the existing PHI variables. We can't simply clear them and just rebuild them because the order of the PHIs in the main exit must match the original exit for when we add the skip_epilog guard. But the infrastructure is already in place to maintain them, we just have to use the right value. Bootstrapped Regtested on aarch64-none-linux-gnu, x86_64-pc-linux-gnu and no issues normally and with with --enable-checking=release --enable-lto --with-build-config=bootstrap-O3 --enable-checking=yes,rtl,extra. Ok for master? Thanks, Tamar gcc/ChangeLog: PR tree-optimization/113237 * tree-vect-loop-manip.cc (slpeel_tree_duplicate_loop_to_edge_cfg): Use existing LCSSA variable for exit when all exits are early break. gcc/testsuite/ChangeLog: PR tree-optimization/113237 * gcc.dg/vect/vect-early-break_98-pr113237.c: New test. --- inline copy of patch -- diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c new file mode 100644 index 0000000000000000000000000000000000000000..e6d150b571f753e9eb3859f06f62b371817494a3 -- diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c new file mode 100644 index 0000000000000000000000000000000000000000..e6d150b571f753e9eb3859f06f62b371817494a3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_98-pr113237.c @@ -0,0 +1,20 @@ +/* { dg-do compile } */ +/* { dg-add-options vect_early_break } */ +/* { dg-require-effective-target vect_early_break } */ +/* { dg-require-effective-target vect_int } */ + +long Perl_pp_split_limit; +int Perl_block_gimme(); +int Perl_pp_split() { + char strend; + long iters; + int gimme = Perl_block_gimme(); + while (--Perl_pp_split_limit) { + if (gimme) + iters++; + if (strend) + break; + } + if (iters) + return 0; +} diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc index 7fd6566341b4893a1e209d1f8ff65d6d180f1190..77649b84f45b9e5dacec2809e0c854c8fcc17ce1 100644 --- a/gcc/tree-vect-loop-manip.cc +++ b/gcc/tree-vect-loop-manip.cc @@ -1700,7 +1700,12 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop, edge loop_exit, if (peeled_iters && !virtual_operand_p (new_arg)) { tree tmp_arg = gimple_phi_result (from_phi); - if (!new_phi_args.get (tmp_arg)) + /* Similar to the single exit case, If we have an existing + LCSSA variable thread through the original value otherwise + skip it and directly use the final value. */ + if (tree *res = new_phi_args.get (tmp_arg)) + new_arg = *res; + else new_arg = tmp_arg; }