On Mon, Jun 18, 2012 at 11:18 AM, Richard Sandiford
<rdsandif...@googlemail.com> wrote:
> The result of expand_expr_addr_expr_1 is eventually converted to tmode,
> and any variable offset is likewise applied in tmode, so tmode also seems
> like the natural mode for applying constant offsets. This patch makes sure
> that the operand is converted to tmode first, just like we do for
> variable offsets. It fixes a case where the new plus_constant
> assert triggers.
>
> Tested on x86_64-linux-gnu. Also tested by HJ on x32 (thanks).
> OK to install?
Ok.
Thanks,
Richard.
> Richard
>
>
> gcc/
> PR middle-end/53698
> * expr.c (expand_expr_addr_expr_1): Convert to tmode before
> performing an addition.
>
> gcc/testsuite/
> PR middle-end/53698
> * gcc.target/i386/pr53698.c: New test.
>
> Index: gcc/expr.c
> ===================================================================
> --- gcc/expr.c 2012-06-06 10:09:21.000000000 +0100
> +++ gcc/expr.c 2012-06-18 09:35:35.361926943 +0100
> @@ -7631,6 +7631,7 @@ expand_expr_addr_expr_1 (tree exp, rtx t
> of such an object. */
> gcc_assert ((bitpos % BITS_PER_UNIT) == 0);
>
> + result = convert_memory_address_addr_space (tmode, result, as);
> result = plus_constant (tmode, result, bitpos / BITS_PER_UNIT);
> if (modifier < EXPAND_SUM)
> result = force_operand (result, target);
> Index: gcc/testsuite/gcc.target/i386/pr53698.c
> ===================================================================
> --- /dev/null 2012-05-16 15:38:36.131804707 +0100
> +++ gcc/testsuite/gcc.target/i386/pr53698.c 2012-06-18 09:36:01.033855874
> +0100
> @@ -0,0 +1,16 @@
> +/* { dg-do compile { target { ! { ia32 } } } } */
> +/* { dg-options "-O -mx32 -maddress-mode=long -fno-tree-dominator-opts" } */
> +
> +extern char foo[];
> +
> +void
> +test2 (void)
> +{
> + int s;
> + for (s = 0;; ++s)
> + {
> + if (foo[s] != s)
> + __builtin_abort ();
> + foo[s] = s;
> + }
> +}
