diff options
Diffstat (limited to 'gcc/expr.c')
| -rw-r--r-- | gcc/expr.c | 73 |
1 files changed, 54 insertions, 19 deletions
@@ -73,9 +73,10 @@ along with GCC; see the file COPYING3. If not see int cse_not_expected; static bool block_move_libcall_safe_for_call_parm (void); -static bool emit_block_move_via_cpymem (rtx, rtx, rtx, unsigned, unsigned, HOST_WIDE_INT, - unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT, - unsigned HOST_WIDE_INT); +static bool emit_block_move_via_pattern (rtx, rtx, rtx, unsigned, unsigned, + HOST_WIDE_INT, unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT, + unsigned HOST_WIDE_INT, bool); static void emit_block_move_via_loop (rtx, rtx, rtx, unsigned); static void clear_by_pieces (rtx, unsigned HOST_WIDE_INT, unsigned int); static rtx_insn *compress_float_constant (rtx, rtx); @@ -1562,7 +1563,8 @@ emit_block_move_hints (rtx x, rtx y, rtx size, enum block_op_methods method, unsigned HOST_WIDE_INT min_size, unsigned HOST_WIDE_INT max_size, unsigned HOST_WIDE_INT probable_max_size, - bool bail_out_libcall, bool *is_move_done) + bool bail_out_libcall, bool *is_move_done, + bool might_overlap) { int may_use_call; rtx retval = 0; @@ -1622,13 +1624,30 @@ emit_block_move_hints (rtx x, rtx y, rtx size, enum block_op_methods method, set_mem_size (y, const_size); } - if (CONST_INT_P (size) && can_move_by_pieces (INTVAL (size), align)) - move_by_pieces (x, y, INTVAL (size), align, RETURN_BEGIN); - else if (emit_block_move_via_cpymem (x, y, size, align, - expected_align, expected_size, - min_size, max_size, probable_max_size)) + bool pieces_ok = can_move_by_pieces (INTVAL (size), align); + bool pattern_ok = false; + + if (!CONST_INT_P (size) || !pieces_ok || might_overlap) + { + pattern_ok = + emit_block_move_via_pattern (x, y, size, align, + expected_align, expected_size, + min_size, max_size, probable_max_size, + might_overlap); + if (!pattern_ok && might_overlap) + { + /* Do not try any of the other methods below as they are not safe + for overlapping moves. */ + *is_move_done = false; + return retval; + } + } + + if (pattern_ok) ; - else if (may_use_call + else if (CONST_INT_P (size) && pieces_ok) + move_by_pieces (x, y, INTVAL (size), align, RETURN_BEGIN); + else if (may_use_call && !might_overlap && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (x)) && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (y))) { @@ -1645,7 +1664,8 @@ emit_block_move_hints (rtx x, rtx y, rtx size, enum block_op_methods method, retval = emit_block_copy_via_libcall (x, y, size, method == BLOCK_OP_TAILCALL); } - + else if (might_overlap) + *is_move_done = false; else emit_block_move_via_loop (x, y, size, align); @@ -1721,15 +1741,26 @@ block_move_libcall_safe_for_call_parm (void) return true; } -/* A subroutine of emit_block_move. Expand a cpymem pattern; - return true if successful. */ +/* A subroutine of emit_block_move. Expand a cpymem or movmem pattern; + return true if successful. + + X is the destination of the copy or move. + Y is the source of the copy or move. + SIZE is the size of the block to be moved. + + MIGHT_OVERLAP indicates this originated with expansion of a + builtin_memmove() and the source and destination blocks may + overlap. + */ static bool -emit_block_move_via_cpymem (rtx x, rtx y, rtx size, unsigned int align, - unsigned int expected_align, HOST_WIDE_INT expected_size, - unsigned HOST_WIDE_INT min_size, - unsigned HOST_WIDE_INT max_size, - unsigned HOST_WIDE_INT probable_max_size) +emit_block_move_via_pattern (rtx x, rtx y, rtx size, unsigned int align, + unsigned int expected_align, + HOST_WIDE_INT expected_size, + unsigned HOST_WIDE_INT min_size, + unsigned HOST_WIDE_INT max_size, + unsigned HOST_WIDE_INT probable_max_size, + bool might_overlap) { if (expected_align < align) expected_align = align; @@ -1752,7 +1783,11 @@ emit_block_move_via_cpymem (rtx x, rtx y, rtx size, unsigned int align, FOR_EACH_MODE_IN_CLASS (mode_iter, MODE_INT) { scalar_int_mode mode = mode_iter.require (); - enum insn_code code = direct_optab_handler (cpymem_optab, mode); + enum insn_code code; + if (might_overlap) + code = direct_optab_handler (movmem_optab, mode); + else + code = direct_optab_handler (cpymem_optab, mode); if (code != CODE_FOR_nothing /* We don't need MODE to be narrower than BITS_PER_HOST_WIDE_INT |