On Wed, May 22, 2013 at 6:23 PM, Martin Jambor <mjam...@suse.cz> wrote:
> Hi,
>
> I have not intended aggregate jump functions to work with bit-fields
> but apparently forgot to include the test to ignore them. PR 57347
> testcase gives a good example why they need to be avoided. If we ever
> decide to optimize for them too (and not just in IPA land), they
> should be lowered earlier and jump functions can then be built for the
> stores to the representatives.
>
> The following patch disables their generation. It passes bootstrap
> and testing on x8664-linux on trunk, the same for the 4.8 branch is
> currently underway. OK for trunk and for the branch if it passes?
Ok.
Thanks,
Richard.
> Thanks,
>
> Martin
>
>
> 2013-05-21 Martin Jambor <mjam...@suse.cz>
>
> PR middle-end/57347
> * tree.h (contains_bitfld_component_ref_p): Declare.
> * tree-sra.c (contains_bitfld_comp_ref_p): Move...
> * tree.c (contains_bitfld_component_ref_p): ...here. Adjust its
> caller.
> * ipa-prop.c (determine_known_aggregate_parts): Check that LHS does
> not access a bit-field. Assert all final offsets are byte-aligned.
>
> testsuite/
> * gcc.dg/ipa/pr57347.c: New test.
>
> Index: src/gcc/ipa-prop.c
> ===================================================================
> --- src.orig/gcc/ipa-prop.c
> +++ src/gcc/ipa-prop.c
> @@ -1327,7 +1327,9 @@ determine_known_aggregate_parts (gimple
>
> lhs = gimple_assign_lhs (stmt);
> rhs = gimple_assign_rhs1 (stmt);
> - if (!is_gimple_reg_type (rhs))
> + if (!is_gimple_reg_type (rhs)
> + || TREE_CODE (lhs) == BIT_FIELD_REF
> + || contains_bitfld_component_ref_p (lhs))
> break;
>
> lhs_base = get_ref_base_and_extent (lhs, &lhs_offset, &lhs_size,
> @@ -1418,6 +1420,7 @@ determine_known_aggregate_parts (gimple
> {
> struct ipa_agg_jf_item item;
> item.offset = list->offset - arg_offset;
> + gcc_assert ((item.offset % BITS_PER_UNIT) == 0);
> item.value = unshare_expr_without_location (list->constant);
> jfunc->agg.items->quick_push (item);
> }
> Index: src/gcc/testsuite/gcc.dg/ipa/pr57347.c
> ===================================================================
> --- /dev/null
> +++ src/gcc/testsuite/gcc.dg/ipa/pr57347.c
> @@ -0,0 +1,27 @@
> +/* { dg-do run } */
> +/* { dg-options "-O3" } */
> +
> +struct S1 { int f0; int f1 : 10; int f2 : 13; };
> +int i;
> +int *j = &i;
> +
> +static void
> +foo (struct S1 s)
> +{
> + int *p;
> + int l[88];
> + int **pp = &p;
> + *pp = &l[1];
> + l[0] = 1;
> + *j = 1 && s.f2;
> +}
> +
> +int
> +main ()
> +{
> + struct S1 s = { 0, 0, 1 };
> + foo (s);
> + if (i != 1)
> + __builtin_abort ();
> + return 0;
> +}
> Index: src/gcc/tree-sra.c
> ===================================================================
> --- src.orig/gcc/tree-sra.c
> +++ src/gcc/tree-sra.c
> @@ -2998,23 +2998,6 @@ get_repl_default_def_ssa_name (struct ac
> return get_or_create_ssa_default_def (cfun, racc->replacement_decl);
> }
>
> -/* Return true if REF has a COMPONENT_REF with a bit-field field declaration
> - somewhere in it. */
> -
> -static inline bool
> -contains_bitfld_comp_ref_p (const_tree ref)
> -{
> - while (handled_component_p (ref))
> - {
> - if (TREE_CODE (ref) == COMPONENT_REF
> - && DECL_BIT_FIELD (TREE_OPERAND (ref, 1)))
> - return true;
> - ref = TREE_OPERAND (ref, 0);
> - }
> -
> - return false;
> -}
> -
> /* Return true if REF has an VIEW_CONVERT_EXPR or a COMPONENT_REF with a
> bit-field field declaration somewhere in it. */
>
> @@ -3110,7 +3093,7 @@ sra_modify_assign (gimple *stmt, gimple_
> ??? This should move to fold_stmt which we simply should
> call after building a VIEW_CONVERT_EXPR here. */
> if (AGGREGATE_TYPE_P (TREE_TYPE (lhs))
> - && !contains_bitfld_comp_ref_p (lhs))
> + && !contains_bitfld_component_ref_p (lhs))
> {
> lhs = build_ref_for_model (loc, lhs, 0, racc, gsi, false);
> gimple_assign_set_lhs (*stmt, lhs);
> Index: src/gcc/tree.c
> ===================================================================
> --- src.orig/gcc/tree.c
> +++ src/gcc/tree.c
> @@ -11785,4 +11785,21 @@ warn_deprecated_use (tree node, tree att
> }
> }
>
> +/* Return true if REF has a COMPONENT_REF with a bit-field field declaration
> + somewhere in it. */
> +
> +bool
> +contains_bitfld_component_ref_p (const_tree ref)
> +{
> + while (handled_component_p (ref))
> + {
> + if (TREE_CODE (ref) == COMPONENT_REF
> + && DECL_BIT_FIELD (TREE_OPERAND (ref, 1)))
> + return true;
> + ref = TREE_OPERAND (ref, 0);
> + }
> +
> + return false;
> +}
> +
> #include "gt-tree.h"
> Index: src/gcc/tree.h
> ===================================================================
> --- src.orig/gcc/tree.h
> +++ src/gcc/tree.h
> @@ -5974,6 +5974,7 @@ extern tree block_ultimate_origin (const
> extern tree get_binfo_at_offset (tree, HOST_WIDE_INT, tree);
> extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
> HOST_WIDE_INT *, HOST_WIDE_INT *);
> +extern bool contains_bitfld_component_ref_p (const_tree);
>
> /* In tree-nested.c */
> extern tree build_addr (tree, tree);
