On Mon, Mar 28, 2011 at 5:47 PM, Richard Sandiford
<richard.sandif...@linaro.org> wrote:
> This patch fixes a case where expand_builtin_memset_args was creating
> a zero- rather than sign-extended character-sized CONST_INT. The problem
> showed up on s390, where a character was being passed as (const_int 171)
> rather than (const_int -85).
>
> Tested on x86_64-linux-gnu. Andreas also confirms that it fixes
> the s390 failure. OK to install?
Ok.
Thanks,
Richard.
> Richard
>
>
> gcc/
> * builtins.c (expand_builtin_memset_args): Use gen_int_mode
> instead of GEN_INT.
>
> Index: gcc/builtins.c
> ===================================================================
> --- gcc/builtins.c 2011-03-24 15:13:39.000000000 +0000
> +++ gcc/builtins.c 2011-03-28 13:56:31.000000000 +0100
> @@ -3935,6 +3935,7 @@ expand_builtin_memset_args (tree dest, t
> {
> tree fndecl, fn;
> enum built_in_function fcode;
> + enum machine_mode val_mode;
> char c;
> unsigned int dest_align;
> rtx dest_mem, dest_addr, len_rtx;
> @@ -3969,14 +3970,14 @@ expand_builtin_memset_args (tree dest, t
>
> len_rtx = expand_normal (len);
> dest_mem = get_memory_rtx (dest, len);
> + val_mode = TYPE_MODE (unsigned_char_type_node);
>
> if (TREE_CODE (val) != INTEGER_CST)
> {
> rtx val_rtx;
>
> val_rtx = expand_normal (val);
> - val_rtx = convert_to_mode (TYPE_MODE (unsigned_char_type_node),
> - val_rtx, 0);
> + val_rtx = convert_to_mode (val_mode, val_rtx, 0);
>
> /* Assume that we can memset by pieces if we can store
> * the coefficients by pieces (in the required modes).
> @@ -3987,8 +3988,7 @@ expand_builtin_memset_args (tree dest, t
> builtin_memset_read_str, &c, dest_align,
> true))
> {
> - val_rtx = force_reg (TYPE_MODE (unsigned_char_type_node),
> - val_rtx);
> + val_rtx = force_reg (val_mode, val_rtx);
> store_by_pieces (dest_mem, tree_low_cst (len, 1),
> builtin_memset_gen_str, val_rtx, dest_align,
> true, 0);
> @@ -4014,7 +4014,8 @@ expand_builtin_memset_args (tree dest, t
> true))
> store_by_pieces (dest_mem, tree_low_cst (len, 1),
> builtin_memset_read_str, &c, dest_align, true, 0);
> - else if (!set_storage_via_setmem (dest_mem, len_rtx, GEN_INT (c),
> + else if (!set_storage_via_setmem (dest_mem, len_rtx,
> + gen_int_mode (c, val_mode),
> dest_align, expected_align,
> expected_size))
> goto do_libcall;
>
