Message ID | or4jevimcr.fsf@lxoliva.fsfla.org |
---|---|
State | New |
Headers | show |
Series | strub: drop nonaliased parm from build_ref_type_for [PR113394] | expand |
> Am 30.01.2024 um 03:31 schrieb Alexandre Oliva <oliva@adacore.com>: > > > Variant type copies can't have their own alias sets any more, and it's > not like setting them affected the pointed-to objects anyway. > > Regstrapped on x86_64-linux-gnu; also bootstrapped with -fstrub=internal > enabled by default. Ok to install? Ok Richard > for gcc/ChangeLog > > PR debug/113394 > * ipa-strub.cc (build_ref_type_for): Drop nonaliased. Adjust > caller. > > for gcc/testsuite/ChangeLog > > PR debug/113394 > * gcc.dg/strub-internal-pr113394.c: New. > --- > gcc/ipa-strub.cc | 31 ++++-------------------- > gcc/testsuite/gcc.dg/strub-internal-pr113394.c | 6 +++++ > 2 files changed, 11 insertions(+), 26 deletions(-) > create mode 100644 gcc/testsuite/gcc.dg/strub-internal-pr113394.c > > diff --git a/gcc/ipa-strub.cc b/gcc/ipa-strub.cc > index e1b07016b8879..0ee063c9eddc4 100644 > --- a/gcc/ipa-strub.cc > +++ b/gcc/ipa-strub.cc > @@ -2052,36 +2052,17 @@ walk_regimplify_phi (gphi *stmt) > return needs_commit; > } > > -/* Create a reference type to use for PARM when turning it into a reference. > - NONALIASED causes the reference type to gain its own separate alias set, so > - that accessing the indirectly-passed parm won'will not add aliasing > - noise. */ > +/* Create a reference type to use for PARM when turning it into a > + reference. */ > > static tree > -build_ref_type_for (tree parm, bool nonaliased = true) > +build_ref_type_for (tree parm) > { > gcc_checking_assert (TREE_CODE (parm) == PARM_DECL); > > tree ref_type = build_reference_type (TREE_TYPE (parm)); > > - if (!nonaliased) > - return ref_type; > - > - /* Each PARM turned indirect still points to the distinct memory area at the > - wrapper, and the reference in unchanging, so we might qualify it, but... > - const is not really important, since we're only using default defs for the > - reference parm anyway, and not introducing any defs, and restrict seems to > - cause trouble. E.g., libgnat/s-concat3.adb:str_concat_3 has memmoves that, > - if it's wrapped, the memmoves are deleted in dse1. Using a distinct alias > - set seems to not run afoul of this problem, and it hopefully enables the > - compiler to tell the pointers do point to objects that are not otherwise > - aliased. */ > - tree qref_type = build_variant_type_copy (ref_type); > - > - TYPE_ALIAS_SET (qref_type) = new_alias_set (); > - record_alias_subset (TYPE_ALIAS_SET (qref_type), get_alias_set (ref_type)); > - > - return qref_type; > + return ref_type; > } > > /* Add cgraph edges from current_function_decl to callees in SEQ with frequency > @@ -2909,9 +2890,7 @@ pass_ipa_strub::execute (function *) > if with transparent reference, and the wrapper doesn't take any > extra parms that could point into wrapper's parms. So we can > probably drop the TREE_ADDRESSABLE and keep the TRUE. */ > - tree ref_type = build_ref_type_for (nparm, > - true > - || !TREE_ADDRESSABLE (parm)); > + tree ref_type = build_ref_type_for (nparm); > > DECL_ARG_TYPE (nparm) = TREE_TYPE (nparm) = ref_type; > relayout_decl (nparm); > diff --git a/gcc/testsuite/gcc.dg/strub-internal-pr113394.c b/gcc/testsuite/gcc.dg/strub-internal-pr113394.c > new file mode 100644 > index 0000000000000..d21c209cdf699 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/strub-internal-pr113394.c > @@ -0,0 +1,6 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fstrub=internal -g" } */ > + > +/* gcc.c-torture/compile/20020210-1.c */ > +/* PR c/5615 */ > +void f(int a, struct {int b[a];} c) {} /* { dg-warning "anonymous struct" } */ > > > -- > Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/ > Free Software Activist GNU Toolchain Engineer > More tolerance and less prejudice are key for inclusion and diversity > Excluding neuro-others for not behaving ""normal"" is *not* inclusive
diff --git a/gcc/ipa-strub.cc b/gcc/ipa-strub.cc index e1b07016b8879..0ee063c9eddc4 100644 --- a/gcc/ipa-strub.cc +++ b/gcc/ipa-strub.cc @@ -2052,36 +2052,17 @@ walk_regimplify_phi (gphi *stmt) return needs_commit; } -/* Create a reference type to use for PARM when turning it into a reference. - NONALIASED causes the reference type to gain its own separate alias set, so - that accessing the indirectly-passed parm won'will not add aliasing - noise. */ +/* Create a reference type to use for PARM when turning it into a + reference. */ static tree -build_ref_type_for (tree parm, bool nonaliased = true) +build_ref_type_for (tree parm) { gcc_checking_assert (TREE_CODE (parm) == PARM_DECL); tree ref_type = build_reference_type (TREE_TYPE (parm)); - if (!nonaliased) - return ref_type; - - /* Each PARM turned indirect still points to the distinct memory area at the - wrapper, and the reference in unchanging, so we might qualify it, but... - const is not really important, since we're only using default defs for the - reference parm anyway, and not introducing any defs, and restrict seems to - cause trouble. E.g., libgnat/s-concat3.adb:str_concat_3 has memmoves that, - if it's wrapped, the memmoves are deleted in dse1. Using a distinct alias - set seems to not run afoul of this problem, and it hopefully enables the - compiler to tell the pointers do point to objects that are not otherwise - aliased. */ - tree qref_type = build_variant_type_copy (ref_type); - - TYPE_ALIAS_SET (qref_type) = new_alias_set (); - record_alias_subset (TYPE_ALIAS_SET (qref_type), get_alias_set (ref_type)); - - return qref_type; + return ref_type; } /* Add cgraph edges from current_function_decl to callees in SEQ with frequency @@ -2909,9 +2890,7 @@ pass_ipa_strub::execute (function *) if with transparent reference, and the wrapper doesn't take any extra parms that could point into wrapper's parms. So we can probably drop the TREE_ADDRESSABLE and keep the TRUE. */ - tree ref_type = build_ref_type_for (nparm, - true - || !TREE_ADDRESSABLE (parm)); + tree ref_type = build_ref_type_for (nparm); DECL_ARG_TYPE (nparm) = TREE_TYPE (nparm) = ref_type; relayout_decl (nparm); diff --git a/gcc/testsuite/gcc.dg/strub-internal-pr113394.c b/gcc/testsuite/gcc.dg/strub-internal-pr113394.c new file mode 100644 index 0000000000000..d21c209cdf699 --- /dev/null +++ b/gcc/testsuite/gcc.dg/strub-internal-pr113394.c @@ -0,0 +1,6 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrub=internal -g" } */ + +/* gcc.c-torture/compile/20020210-1.c */ +/* PR c/5615 */ +void f(int a, struct {int b[a];} c) {} /* { dg-warning "anonymous struct" } */