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| author | Richard Biener <rguenther@suse.de> | 2016-06-28 11:55:19 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-06-28 11:55:19 +0000 |
| commit | 7d4cdbd485607cc1d575a42d815a5dec7708aded (patch) | |
| tree | cc5f212f823778695adf1ffc90a0354537fe9967 /gcc | |
| parent | e9ac1f86bf70e0ca794fed6ba3b8fe3026da063e (diff) | |
| download | gcc-7d4cdbd485607cc1d575a42d815a5dec7708aded.zip gcc-7d4cdbd485607cc1d575a42d815a5dec7708aded.tar.gz gcc-7d4cdbd485607cc1d575a42d815a5dec7708aded.tar.bz2 | |
tree-ssa-alias.c (nonoverlapping_component_refs_of_decl_p): Properly handle DECL_BIT_FIELD_REPRESENTATIVE occuring as COMPONENT_REF operand.
2016-06-28 Richard Biener <rguenther@suse.de>
* tree-ssa-alias.c (nonoverlapping_component_refs_of_decl_p):
Properly handle DECL_BIT_FIELD_REPRESENTATIVE occuring as
COMPONENT_REF operand.
(nonoverlapping_component_refs_p): Likewise.
* stor-layout.c (start_bitfield_representative): Mark
DECL_BIT_FIELD_REPRESENTATIVE as DECL_NONADDRESSABLE_P.
From-SVN: r237818
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 9 | ||||
| -rw-r--r-- | gcc/stor-layout.c | 5 | ||||
| -rw-r--r-- | gcc/tree-ssa-alias.c | 28 |
3 files changed, 37 insertions, 5 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 52b3e1c..1ec8955 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2016-06-28 Richard Biener <rguenther@suse.de> + + * tree-ssa-alias.c (nonoverlapping_component_refs_of_decl_p): + Properly handle DECL_BIT_FIELD_REPRESENTATIVE occuring as + COMPONENT_REF operand. + (nonoverlapping_component_refs_p): Likewise. + * stor-layout.c (start_bitfield_representative): Mark + DECL_BIT_FIELD_REPRESENTATIVE as DECL_NONADDRESSABLE_P. + 2016-06-28 Jakub Jelinek <jakub@redhat.com> * Makefile.in: Don't cat ../stage_current if it does not exist. diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c index 40170ef..d66d769 100644 --- a/gcc/stor-layout.c +++ b/gcc/stor-layout.c @@ -1808,6 +1808,11 @@ start_bitfield_representative (tree field) DECL_SIZE_UNIT (repr) = DECL_SIZE_UNIT (field); DECL_PACKED (repr) = DECL_PACKED (field); DECL_CONTEXT (repr) = DECL_CONTEXT (field); + /* There are no indirect accesses to this field. If we introduce + some then they have to use the record alias set. This makes + sure to properly conflict with [indirect] accesses to addressable + fields of the bitfield group. */ + DECL_NONADDRESSABLE_P (repr) = 1; return repr; } diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index b663ddf..70c24b5 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -929,13 +929,20 @@ nonoverlapping_component_refs_of_decl_p (tree ref1, tree ref2) if (type1 != type2 || TREE_CODE (type1) != RECORD_TYPE) goto may_overlap; - /* Different fields of the same record type cannot overlap. - ??? Bitfields can overlap at RTL level so punt on them. */ if (field1 != field2) { component_refs1.release (); component_refs2.release (); - return !(DECL_BIT_FIELD (field1) && DECL_BIT_FIELD (field2)); + /* A field and its representative need to be considered the + same. */ + if (DECL_BIT_FIELD_REPRESENTATIVE (field1) == field2 + || DECL_BIT_FIELD_REPRESENTATIVE (field2) == field1) + return false; + /* Different fields of the same record type cannot overlap. + ??? Bitfields can overlap at RTL level so punt on them. */ + if (DECL_BIT_FIELD (field1) && DECL_BIT_FIELD (field2)) + return false; + return true; } } @@ -1031,9 +1038,20 @@ nonoverlapping_component_refs_p (const_tree x, const_tree y) if (typex == typey) { /* We're left with accessing different fields of a structure, - no possible overlap, unless they are both bitfields. */ + no possible overlap. */ if (fieldx != fieldy) - return !(DECL_BIT_FIELD (fieldx) && DECL_BIT_FIELD (fieldy)); + { + /* A field and its representative need to be considered the + same. */ + if (DECL_BIT_FIELD_REPRESENTATIVE (fieldx) == fieldy + || DECL_BIT_FIELD_REPRESENTATIVE (fieldy) == fieldx) + return false; + /* Different fields of the same record type cannot overlap. + ??? Bitfields can overlap at RTL level so punt on them. */ + if (DECL_BIT_FIELD (fieldx) && DECL_BIT_FIELD (fieldy)) + return false; + return true; + } } if (TYPE_UID (typex) < TYPE_UID (typey)) { |