diff options
| -rw-r--r-- | gcc/ChangeLog | 14 | ||||
| -rw-r--r-- | gcc/builtins.c | 27 | ||||
| -rw-r--r-- | gcc/expr.c | 73 | ||||
| -rw-r--r-- | gcc/expr.h | 3 |
4 files changed, 87 insertions, 30 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d66b03e..fe14577 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,17 @@ +2019-10-02 Aaron Sawdey <acsawdey@linux.ibm.com> + + * builtins.c (expand_builtin_memory_copy_args): Add might_overlap parm. + (expand_builtin_memcpy): Use might_overlap parm. + (expand_builtin_mempcpy_args): Use might_overlap parm. + (expand_builtin_memmove): Call expand_builtin_memory_copy_args. + (expand_builtin_memory_copy_args): Add might_overlap parm. + * expr.c (emit_block_move_via_cpymem): Rename to + emit_block_move_via_pattern, add might_overlap parm, use cpymem + or movmem optab as appropriate. + (emit_block_move_hints): Add might_overlap parm, do the right + thing for might_overlap==true. + * expr.h (emit_block_move_hints): Update prototype. + 2019-10-02 Eric Botcazou <ebotcazou@adacore.com> * tree-eh.h (unsplit_eh_edges): Declare. diff --git a/gcc/builtins.c b/gcc/builtins.c index 1fd4b88..fa17afd 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -127,7 +127,8 @@ static rtx expand_builtin_memchr (tree, rtx); static rtx expand_builtin_memcpy (tree, rtx); static rtx expand_builtin_memory_copy_args (tree dest, tree src, tree len, rtx target, tree exp, - memop_ret retmode); + memop_ret retmode, + bool might_overlap); static rtx expand_builtin_memmove (tree, rtx); static rtx expand_builtin_mempcpy (tree, rtx); static rtx expand_builtin_mempcpy_args (tree, tree, tree, rtx, tree, memop_ret); @@ -3790,14 +3791,14 @@ expand_builtin_memcpy (tree exp, rtx target) check_memop_access (exp, dest, src, len); return expand_builtin_memory_copy_args (dest, src, len, target, exp, - /*retmode=*/ RETURN_BEGIN); + /*retmode=*/ RETURN_BEGIN, false); } /* Check a call EXP to the memmove built-in for validity. Return NULL_RTX on both success and failure. */ static rtx -expand_builtin_memmove (tree exp, rtx) +expand_builtin_memmove (tree exp, rtx target) { if (!validate_arglist (exp, POINTER_TYPE, POINTER_TYPE, INTEGER_TYPE, VOID_TYPE)) @@ -3809,7 +3810,8 @@ expand_builtin_memmove (tree exp, rtx) check_memop_access (exp, dest, src, len); - return NULL_RTX; + return expand_builtin_memory_copy_args (dest, src, len, target, exp, + /*retmode=*/ RETURN_BEGIN, true); } /* Expand a call EXP to the mempcpy builtin. @@ -3858,7 +3860,8 @@ expand_builtin_mempcpy (tree exp, rtx target) static rtx expand_builtin_memory_copy_args (tree dest, tree src, tree len, - rtx target, tree exp, memop_ret retmode) + rtx target, tree exp, memop_ret retmode, + bool might_overlap) { const char *src_str; unsigned int src_align = get_pointer_alignment (src); @@ -3894,9 +3897,12 @@ expand_builtin_memory_copy_args (tree dest, tree src, tree len, &probable_max_size); src_str = c_getstr (src); - /* If SRC is a string constant and block move would be done - by pieces, we can avoid loading the string from memory - and only stored the computed constants. */ + /* If SRC is a string constant and block move would be done by + pieces, we can avoid loading the string from memory and only + stored the computed constants. This works in the overlap + (memmove) case as well because store_by_pieces just generates a + series of stores of constants from the string constant returned + by c_getstr(). */ if (src_str && CONST_INT_P (len_rtx) && (unsigned HOST_WIDE_INT) INTVAL (len_rtx) <= strlen (src_str) + 1 @@ -3923,13 +3929,14 @@ expand_builtin_memory_copy_args (tree dest, tree src, tree len, method = BLOCK_OP_TAILCALL; bool use_mempcpy_call = (targetm.libc_has_fast_function (BUILT_IN_MEMPCPY) && retmode == RETURN_END + && !might_overlap && target != const0_rtx); if (use_mempcpy_call) method = BLOCK_OP_NO_LIBCALL_RET; dest_addr = emit_block_move_hints (dest_mem, src_mem, len_rtx, method, expected_align, expected_size, min_size, max_size, probable_max_size, - use_mempcpy_call, &is_move_done); + use_mempcpy_call, &is_move_done, might_overlap); /* Bail out when a mempcpy call would be expanded as libcall and when we have a target that provides a fast implementation @@ -3962,7 +3969,7 @@ expand_builtin_mempcpy_args (tree dest, tree src, tree len, rtx target, tree orig_exp, memop_ret retmode) { return expand_builtin_memory_copy_args (dest, src, len, target, orig_exp, - retmode); + retmode, false); } /* Expand into a movstr instruction, if one is available. Return NULL_RTX if @@ -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 @@ -116,7 +116,8 @@ extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods, unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT, bool bail_out_libcall = false, - bool *is_move_done = NULL); + bool *is_move_done = NULL, + bool might_overlap = false); extern rtx emit_block_cmp_hints (rtx, rtx, rtx, tree, rtx, bool, by_pieces_constfn, void *); extern bool emit_storent_insn (rtx to, rtx from); |