diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/tree-predcom.c | 65 |
2 files changed, 52 insertions, 19 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7a1d691d972..aeb3f79e6a5 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-08-12 Bernd Edlinger <bernd.edlinger@hotmail.de> + + PR tree-optimization/71083 + * tree-predcom.c (ref_at_iteration): Use a COMPONENT_REF for the + bitfield access when possible. + 2016-08-12 Patrick Palka <ppalka@gcc.gnu.org> PR middle-end/71654 diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c index 843f68e387b..096365ad9a1 100644 --- a/gcc/tree-predcom.c +++ b/gcc/tree-predcom.c @@ -1365,11 +1365,16 @@ replace_ref_with (gimple *stmt, tree new_tree, bool set, bool in_lhs) /* Returns a memory reference to DR in the ITER-th iteration of the loop it was analyzed in. Append init stmts to STMTS. */ -static tree +static tree ref_at_iteration (data_reference_p dr, int iter, gimple_seq *stmts) { tree off = DR_OFFSET (dr); tree coff = DR_INIT (dr); + tree ref = DR_REF (dr); + enum tree_code ref_code = ERROR_MARK; + tree ref_type = NULL_TREE; + tree ref_op1 = NULL_TREE; + tree ref_op2 = NULL_TREE; if (iter == 0) ; else if (TREE_CODE (DR_STEP (dr)) == INTEGER_CST) @@ -1378,28 +1383,50 @@ ref_at_iteration (data_reference_p dr, int iter, gimple_seq *stmts) else off = size_binop (PLUS_EXPR, off, size_binop (MULT_EXPR, DR_STEP (dr), ssize_int (iter))); - tree addr = fold_build_pointer_plus (DR_BASE_ADDRESS (dr), off); - addr = force_gimple_operand_1 (unshare_expr (addr), stmts, - is_gimple_mem_ref_addr, NULL_TREE); - tree alias_ptr = fold_convert (reference_alias_ptr_type (DR_REF (dr)), coff); - tree type = build_aligned_type (TREE_TYPE (DR_REF (dr)), - get_object_alignment (DR_REF (dr))); /* While data-ref analysis punts on bit offsets it still handles bitfield accesses at byte boundaries. Cope with that. Note that - we cannot simply re-apply the outer COMPONENT_REF because the - byte-granular portion of it is already applied via DR_INIT and - DR_OFFSET, so simply build a BIT_FIELD_REF knowing that the bits + if the bitfield object also starts at a byte-boundary we can simply + replicate the COMPONENT_REF, but we have to subtract the component's + byte-offset from the MEM_REF address first. + Otherwise we simply build a BIT_FIELD_REF knowing that the bits start at offset zero. */ - if (TREE_CODE (DR_REF (dr)) == COMPONENT_REF - && DECL_BIT_FIELD (TREE_OPERAND (DR_REF (dr), 1))) - { - tree field = TREE_OPERAND (DR_REF (dr), 1); - return build3 (BIT_FIELD_REF, TREE_TYPE (DR_REF (dr)), - build2 (MEM_REF, type, addr, alias_ptr), - DECL_SIZE (field), bitsize_zero_node); + if (TREE_CODE (ref) == COMPONENT_REF + && DECL_BIT_FIELD (TREE_OPERAND (ref, 1))) + { + unsigned HOST_WIDE_INT boff; + tree field = TREE_OPERAND (ref, 1); + tree offset = component_ref_field_offset (ref); + ref_type = TREE_TYPE (ref); + boff = tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field)); + /* This can occur in Ada. See the comment in get_bit_range. */ + if (boff % BITS_PER_UNIT != 0 + || !tree_fits_uhwi_p (offset)) + { + ref_code = BIT_FIELD_REF; + ref_op1 = DECL_SIZE (field); + ref_op2 = bitsize_zero_node; + } + else + { + boff >>= LOG2_BITS_PER_UNIT; + boff += tree_to_uhwi (offset); + coff = size_binop (MINUS_EXPR, coff, ssize_int (boff)); + ref_code = COMPONENT_REF; + ref_op1 = field; + ref_op2 = TREE_OPERAND (ref, 2); + ref = TREE_OPERAND (ref, 0); + } } - else - return fold_build2 (MEM_REF, type, addr, alias_ptr); + tree addr = fold_build_pointer_plus (DR_BASE_ADDRESS (dr), off); + addr = force_gimple_operand_1 (unshare_expr (addr), stmts, + is_gimple_mem_ref_addr, NULL_TREE); + tree alias_ptr = fold_convert (reference_alias_ptr_type (ref), coff); + tree type = build_aligned_type (TREE_TYPE (ref), + get_object_alignment (ref)); + ref = build2 (MEM_REF, type, addr, alias_ptr); + if (ref_type) + ref = build3 (ref_code, ref_type, ref, ref_op1, ref_op2); + return ref; } /* Get the initialization expression for the INDEX-th temporary variable |