| Message ID | 1622481083-25131-1-git-send-email-apinski@marvell.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] Use is_empty_type instead of zero-sized type. | expand |
On Mon, May 31, 2021 at 7:29 PM apinski--- via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > From: Andrew Pinski <apinski@marvell.com> > > Instead of only removing assignments of zero-sized types, > assignments of all empty types should be removed during gimplification. > This moves to use is_empty_type which will be used in other places too. > > OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions. OK. Thanks, Richard. > Thanks, > Andrew Pinski > > gcc/ChangeLog: > > * gimplify.c (zero_sized_field_decl): Delete > (zero_sized_type): Delete > (gimplify_init_ctor_eval): Use is_empty_type instead > of zero_sized_field_decl. > (gimplify_modify_expr): Use is_empty_type instead of > zero_sized_type. > --- > gcc/gimplify.c | 34 +++++++--------------------------- > 1 file changed, 7 insertions(+), 27 deletions(-) > > diff --git a/gcc/gimplify.c b/gcc/gimplify.c > index 3ca29cedad8..39f5b973d18 100644 > --- a/gcc/gimplify.c > +++ b/gcc/gimplify.c > @@ -4644,28 +4644,6 @@ gimplify_init_ctor_eval_range (tree object, tree lower, tree upper, > gimplify_seq_add_stmt (pre_p, gimple_build_label (loop_exit_label)); > } > > -/* Return true if FDECL is accessing a field that is zero sized. */ > - > -static bool > -zero_sized_field_decl (const_tree fdecl) > -{ > - if (TREE_CODE (fdecl) == FIELD_DECL && DECL_SIZE (fdecl) > - && integer_zerop (DECL_SIZE (fdecl))) > - return true; > - return false; > -} > - > -/* Return true if TYPE is zero sized. */ > - > -static bool > -zero_sized_type (const_tree type) > -{ > - if (AGGREGATE_TYPE_P (type) && TYPE_SIZE (type) > - && integer_zerop (TYPE_SIZE (type))) > - return true; > - return false; > -} > - > /* A subroutine of gimplify_init_constructor. Generate individual > MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the > assignments should happen. ELTS is the CONSTRUCTOR_ELTS of the > @@ -4699,11 +4677,13 @@ gimplify_init_ctor_eval (tree object, vec<constructor_elt, va_gc> *elts, > gcc_assert (purpose); > > /* Skip zero-sized fields, unless value has side-effects. This can > - happen with calls to functions returning a zero-sized type, which > + happen with calls to functions returning a empty type, which > we shouldn't discard. As a number of downstream passes don't > - expect sets of zero-sized fields, we rely on the gimplification of > + expect sets of empty type fields, we rely on the gimplification of > the MODIFY_EXPR we make below to drop the assignment statement. */ > - if (! TREE_SIDE_EFFECTS (value) && zero_sized_field_decl (purpose)) > + if (!TREE_SIDE_EFFECTS (value) > + && TREE_CODE (purpose) == FIELD_DECL > + && is_empty_type (TREE_TYPE (purpose))) > continue; > > /* If we have a RANGE_EXPR, we have to build a loop to assign the > @@ -5781,11 +5761,11 @@ gimplify_modify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p, > if (ret != GS_UNHANDLED) > return ret; > > - /* For zero sized types only gimplify the left hand side and right hand > + /* For empty types only gimplify the left hand side and right hand > side as statements and throw away the assignment. Do this after > gimplify_modify_expr_rhs so we handle TARGET_EXPRs of addressable > types properly. */ > - if (zero_sized_type (TREE_TYPE (*from_p)) > + if (is_empty_type (TREE_TYPE (*from_p)) > && !want_value > /* Don't do this for calls that return addressable types, expand_call > relies on those having a lhs. */ > -- > 2.17.1 >
diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 3ca29cedad8..39f5b973d18 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -4644,28 +4644,6 @@ gimplify_init_ctor_eval_range (tree object, tree lower, tree upper, gimplify_seq_add_stmt (pre_p, gimple_build_label (loop_exit_label)); } -/* Return true if FDECL is accessing a field that is zero sized. */ - -static bool -zero_sized_field_decl (const_tree fdecl) -{ - if (TREE_CODE (fdecl) == FIELD_DECL && DECL_SIZE (fdecl) - && integer_zerop (DECL_SIZE (fdecl))) - return true; - return false; -} - -/* Return true if TYPE is zero sized. */ - -static bool -zero_sized_type (const_tree type) -{ - if (AGGREGATE_TYPE_P (type) && TYPE_SIZE (type) - && integer_zerop (TYPE_SIZE (type))) - return true; - return false; -} - /* A subroutine of gimplify_init_constructor. Generate individual MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the assignments should happen. ELTS is the CONSTRUCTOR_ELTS of the @@ -4699,11 +4677,13 @@ gimplify_init_ctor_eval (tree object, vec<constructor_elt, va_gc> *elts, gcc_assert (purpose); /* Skip zero-sized fields, unless value has side-effects. This can - happen with calls to functions returning a zero-sized type, which + happen with calls to functions returning a empty type, which we shouldn't discard. As a number of downstream passes don't - expect sets of zero-sized fields, we rely on the gimplification of + expect sets of empty type fields, we rely on the gimplification of the MODIFY_EXPR we make below to drop the assignment statement. */ - if (! TREE_SIDE_EFFECTS (value) && zero_sized_field_decl (purpose)) + if (!TREE_SIDE_EFFECTS (value) + && TREE_CODE (purpose) == FIELD_DECL + && is_empty_type (TREE_TYPE (purpose))) continue; /* If we have a RANGE_EXPR, we have to build a loop to assign the @@ -5781,11 +5761,11 @@ gimplify_modify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p, if (ret != GS_UNHANDLED) return ret; - /* For zero sized types only gimplify the left hand side and right hand + /* For empty types only gimplify the left hand side and right hand side as statements and throw away the assignment. Do this after gimplify_modify_expr_rhs so we handle TARGET_EXPRs of addressable types properly. */ - if (zero_sized_type (TREE_TYPE (*from_p)) + if (is_empty_type (TREE_TYPE (*from_p)) && !want_value /* Don't do this for calls that return addressable types, expand_call relies on those having a lhs. */
From: Andrew Pinski <apinski@marvell.com> Instead of only removing assignments of zero-sized types, assignments of all empty types should be removed during gimplification. This moves to use is_empty_type which will be used in other places too. OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions. Thanks, Andrew Pinski gcc/ChangeLog: * gimplify.c (zero_sized_field_decl): Delete (zero_sized_type): Delete (gimplify_init_ctor_eval): Use is_empty_type instead of zero_sized_field_decl. (gimplify_modify_expr): Use is_empty_type instead of zero_sized_type. --- gcc/gimplify.c | 34 +++++++--------------------------- 1 file changed, 7 insertions(+), 27 deletions(-)