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Diffstat (limited to 'gcc/tree-vect-data-refs.c')
| -rw-r--r-- | gcc/tree-vect-data-refs.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index 29164d1..3d1d7e7 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -779,7 +779,7 @@ vect_compute_data_ref_alignment (struct data_reference *dr) base = ref; while (handled_component_p (base)) base = TREE_OPERAND (base, 0); - unsigned int base_alignment; + unsigned int base_alignment = 0; unsigned HOST_WIDE_INT base_bitpos; get_object_alignment_1 (base, &base_alignment, &base_bitpos); /* As data-ref analysis strips the MEM_REF down to its base operand @@ -788,8 +788,17 @@ vect_compute_data_ref_alignment (struct data_reference *dr) DR_BASE_ADDRESS. */ if (TREE_CODE (base) == MEM_REF) { - base_bitpos -= mem_ref_offset (base).to_short_addr () * BITS_PER_UNIT; - base_bitpos &= (base_alignment - 1); + /* Note all this only works if DR_BASE_ADDRESS is the same as + MEM_REF operand zero, otherwise DR/SCEV analysis might have factored + in other offsets. We need to rework DR to compute the alingment + of DR_BASE_ADDRESS as long as all information is still available. */ + if (operand_equal_p (TREE_OPERAND (base, 0), base_addr, 0)) + { + base_bitpos -= mem_ref_offset (base).to_short_addr () * BITS_PER_UNIT; + base_bitpos &= (base_alignment - 1); + } + else + base_bitpos = BITS_PER_UNIT; } if (base_bitpos != 0) base_alignment = base_bitpos & -base_bitpos; |