pr 33870

	pr 33870
	* tree.h (strcut tree_memory_tag): add field unpartitionable.
	remove field in_nested_struct.
	(struct tree_struct_field_tag): add field nesting_level.
	(sft_in_nested_struct): remove.
	(sft_nesting_level): define.
	(sft_unpartitionable_p): define.
	* tree-ssa-alias.c (mem_sym_score): if mp->var is not
	partitionable, return long_max.
	(compute_memory_partitions): do not partition sfts marked
	unpartitionable.
	(create_sft): add argument nesting_level.  set
	sft_nesting_level with it.  update all users.
	(create_overlap_variables_for): show nesting level.
	* tree-dfa.c (dump_subvars_for): likewise.
	(dump_variable): likewise.
	show whether the sft is partitionable or not.
	* tree-flow.h (struct fieldoff): remove field
	in_nested_struct.
	add field nesting_level.
	* tree-ssa-structalias.c (struct variable_info): remove
	field in_nested_struct.
	(push_fields_onto_fieldstack): add argument
	nesting_level.  update all users.
	update documentation.
	update pair->nesting_level with nesting_level.
	make recursive calls with nesting_level + 1.
	(set_uids_in_ptset): if an sft is added to the points-to
	set, mark it as unpartitionable.
	* tree-ssa-operands.c (ref_nesting_level): new.
	(add_vars_for_offset): call it.
	add argument full_ref.  update
	callers.
	if var is inside a nested structure and the nesting level
	of full_ref is lower than the nesting level of var,
	adjust offset by the offset of var.

testsuite/ChangeLog
	
	PR 33870
	* gcc.c-torture/execute/pr33870-1.c: New test.
	* gcc.dg/tree-ssa/alias-16.c: New test.

From-SVN: r130141

1 files changed, 12 insertions, 5 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index decc05d..00b193f 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -2555,10 +2555,10 @@ struct tree_memory_tag GTY(())
   bitmap GTY ((skip)) aliases;
 
   /* True if this tag has global scope.  */
-  unsigned int is_global:1;
+  unsigned int is_global : 1;
 
-  /* True if this SFT is for a field in a nested structure.  */
-  unsigned int in_nested_struct : 1;
+  /* True if this tag should not be grouped into a memory partition.  */
+  unsigned int unpartitionable : 1;
 };
 
 #define MTAG_GLOBAL(NODE) (TREE_MEMORY_TAG_CHECK (NODE)->mtag.is_global)
@@ -2579,6 +2579,11 @@ struct tree_struct_field_tag GTY(())
 
   /* Alias set for a DECL_NONADDRESSABLE_P field.  Otherwise -1.  */
   alias_set_type alias_set;
+
+  /* Nesting level for this subvariable.  This indicates how many
+     structures are wrapping this field.  Fields at the top level have
+     a nesting level of 0.  */
+  unsigned int nesting_level;
 };
 
 #define SFT_PARENT_VAR(NODE) (STRUCT_FIELD_TAG_CHECK (NODE)->sft.parent_var)
@@ -2587,8 +2592,10 @@ struct tree_struct_field_tag GTY(())
 #define SFT_NONADDRESSABLE_P(NODE) \
   (STRUCT_FIELD_TAG_CHECK (NODE)->sft.alias_set != -1)
 #define SFT_ALIAS_SET(NODE) (STRUCT_FIELD_TAG_CHECK (NODE)->sft.alias_set)
-#define SFT_IN_NESTED_STRUCT(NODE) \
-  (STRUCT_FIELD_TAG_CHECK (NODE)->sft.common.in_nested_struct)
+#define SFT_NESTING_LEVEL(NODE) \
+  (STRUCT_FIELD_TAG_CHECK (NODE)->sft.nesting_level)
+#define SFT_UNPARTITIONABLE_P(NODE) \
+  (STRUCT_FIELD_TAG_CHECK (NODE)->sft.common.unpartitionable)
 
 /* Memory Partition Tags (MPTs) group memory symbols under one
    common name for the purposes of placing memory PHI nodes.  */