From b8b2b0094a9047a1ad476d96f0d20d4b56fca625 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 19 Jul 2011 11:24:28 +0200 Subject: [PATCH] re PR tree-optimization/49768 (C99 style union initializations does not work as expected with optimizations) PR tree-optimization/49768 * gimple-fold.c (fold_nonarray_ctor_reference): Return NULL if offset is smaller than bitoffset, but offset+size is bigger than bitoffset. * gcc.c-torture/execute/pr49768.c: New test. From-SVN: r176437 --- gcc/ChangeLog | 7 +++++++ gcc/gimple-fold.c | 14 +++++++++----- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.c-torture/execute/pr49768.c | 12 ++++++++++++ 4 files changed, 33 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr49768.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 62293beeaa1..d46d52d2138 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2011-07-19 Jakub Jelinek + + PR tree-optimization/49768 + * gimple-fold.c (fold_nonarray_ctor_reference): Return NULL + if offset is smaller than bitoffset, but offset+size is bigger + than bitoffset. + 2011-07-19 Ira Rosen PR tree-optimization/49771 diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index bf00a0f0460..d1c5c89546f 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -3231,7 +3231,7 @@ fold_nonarray_ctor_reference (tree type, tree ctor, double_int bitoffset; double_int byte_offset_cst = tree_to_double_int (byte_offset); double_int bits_per_unit_cst = uhwi_to_double_int (BITS_PER_UNIT); - double_int bitoffset_end; + double_int bitoffset_end, access_end; /* Variable sized objects in static constructors makes no sense, but field_size can be NULL for flexible array members. */ @@ -3252,14 +3252,16 @@ fold_nonarray_ctor_reference (tree type, tree ctor, else bitoffset_end = double_int_zero; - /* Is OFFSET in the range (BITOFFSET, BITOFFSET_END)? */ - if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) >= 0 + access_end = double_int_add (uhwi_to_double_int (offset), + uhwi_to_double_int (size)); + + /* Is there any overlap between [OFFSET, OFFSET+SIZE) and + [BITOFFSET, BITOFFSET_END)? */ + if (double_int_cmp (access_end, bitoffset, 0) > 0 && (field_size == NULL_TREE || double_int_cmp (uhwi_to_double_int (offset), bitoffset_end, 0) < 0)) { - double_int access_end = double_int_add (uhwi_to_double_int (offset), - uhwi_to_double_int (size)); double_int inner_offset = double_int_sub (uhwi_to_double_int (offset), bitoffset); /* We do have overlap. Now see if field is large enough to @@ -3267,6 +3269,8 @@ fold_nonarray_ctor_reference (tree type, tree ctor, fields. */ if (double_int_cmp (access_end, bitoffset_end, 0) > 0) return NULL_TREE; + if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) < 0) + return NULL_TREE; return fold_ctor_reference (type, cval, double_int_to_uhwi (inner_offset), size); } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ffc6f0baa73..07c283dcc0c 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2011-07-19 Jakub Jelinek + + PR tree-optimization/49768 + * gcc.c-torture/execute/pr49768.c: New test. + 2011-07-19 Ira Rosen PR tree-optimization/49771 diff --git a/gcc/testsuite/gcc.c-torture/execute/pr49768.c b/gcc/testsuite/gcc.c-torture/execute/pr49768.c new file mode 100644 index 00000000000..85bc9d2a06f --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr49768.c @@ -0,0 +1,12 @@ +/* PR tree-optimization/49768 */ + +extern void abort (void); + +int +main () +{ + static struct { unsigned int : 1; unsigned int s : 1; } s = { .s = 1 }; + if (s.s != 1) + abort (); + return 0; +} -- 2.30.2