From b2ca651002d586077c9e531a7c05d8fa7a915773 Mon Sep 17 00:00:00 2001 From: rguenth Date: Mon, 14 Apr 2014 11:49:42 +0000 Subject: [PATCH] 2014-04-14 Richard Biener Marc Glisse PR c/60819 c-family/ * c-common.c (convert_vector_to_pointer_for_subscript): Properly apply may-alias the scalar pointer type when applicable. * gcc.target/i386/vec-may_alias.c: New testcase. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@209365 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/c-family/ChangeLog | 7 +++++++ gcc/c-family/c-common.c | 15 ++++++++++++++- gcc/testsuite/ChangeLog | 6 ++++++ gcc/testsuite/gcc.target/i386/vec-may_alias.c | 25 +++++++++++++++++++++++++ 4 files changed, 52 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.target/i386/vec-may_alias.c diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index f510bcc66e3..206b47b1369 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,10 @@ +2014-04-14 Richard Biener + Marc Glisse + + PR c/60819 + * c-common.c (convert_vector_to_pointer_for_subscript): Properly + apply may-alias the scalar pointer type when applicable. + 2014-04-12 Igor Zamyatin PR middle-end/60467 diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 1d56bc02ec8..c0e247b2707 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -11784,8 +11784,21 @@ convert_vector_to_pointer_for_subscript (location_t loc, c_common_mark_addressable_vec (*vecp); type = build_qualified_type (TREE_TYPE (type), TYPE_QUALS (type)); - type = build_pointer_type (type); type1 = build_pointer_type (TREE_TYPE (*vecp)); + bool ref_all = TYPE_REF_CAN_ALIAS_ALL (type1); + if (!ref_all + && !DECL_P (*vecp)) + { + /* If the original vector isn't declared may_alias and it + isn't a bare vector look if the subscripting would + alias the vector we subscript, and if not, force ref-all. */ + alias_set_type vecset = get_alias_set (*vecp); + alias_set_type sset = get_alias_set (type); + if (!alias_sets_must_conflict_p (sset, vecset) + && !alias_set_subset_of (sset, vecset)) + ref_all = true; + } + type = build_pointer_type_for_mode (type, ptr_mode, ref_all); *vecp = build1 (ADDR_EXPR, type1, *vecp); *vecp = convert (type, *vecp); } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index e944a0e2d98..36655885d10 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2014-04-14 Richard Biener + Marc Glisse + + PR c/60819 + * gcc.target/i386/vec-may_alias.c: New testcase. + 2014-04-14 Rainer Orth * lib/target-supports.exp diff --git a/gcc/testsuite/gcc.target/i386/vec-may_alias.c b/gcc/testsuite/gcc.target/i386/vec-may_alias.c new file mode 100644 index 00000000000..e970497454f --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/vec-may_alias.c @@ -0,0 +1,25 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -w -Wno-abi" } */ + +typedef int v2si __attribute__ ((vector_size (8))); +typedef short v4hi __attribute__ ((vector_size (8))); +typedef short v4hia __attribute__ ((vector_size (8), may_alias)); + +__attribute__ ((noinline, noclone)) +int f (v2si A, int N) +{ return ((v4hia)A)[N]; } + +__attribute__ ((noinline, noclone)) +int g (v2si A, int N) +{ return ((v4hi)A)[N]; } + +int main() +{ + v2si x = { 0, 0 }, y = { 1, 1 }; + if (f (x, 0) || f (x, 1) || f (x, 2) || f (x, 3)) + __builtin_abort (); + if (g (y, 0) != 1 || g (y, 1) || g (y, 2) != 1 || g (y, 3)) + __builtin_abort (); + return 0; +} + -- 2.11.4.GIT