lftr and str are inherently unsafe optimiztion. your change might help
a little, but won't make the opts safe. I suggest you run more test to
ensure no regression
Sun
On Wed, Feb 23, 2011 at 2:58 AM, Ye, Mei <mei...@amd.com> wrote:
> For 32-bit targets, when address of data reference crosses the boundary of
> 0x80000000, signed comparisons of address expressions will lead to
> incorrect results.
>
> Additional comments and patches are also available in the bug database.
>
>
>
> My fix is:
>
> 1. In LFTR, force comparison of address expressions to use unsigned type for
>
> 32-bit targets.
>
> 2. Allow results of pointer arithmetic "p + a" and "p - a" (where "p" is a
>
> pointer or an address expression, "a" is neither a pointer nor an address
>
> expression") to be recognized as an address expression.
>
>
>
> Index: be/opt/opt_htable.cxx
>
> ===================================================================
>
> --- be/opt/opt_htable.cxx (revision 3488)
>
> +++ be/opt/opt_htable.cxx (working copy)
>
> @@ -5102,8 +5102,11 @@
>
> if (res0 == ADDRESSABILITY_UNKNOWN)
>
> return ADDRESSABILITY_UNKNOWN;
>
> res1 = Opnd(1)->Check_if_result_is_address(opt_stab);
>
> - if (res1 == ADDRESSABILITY_UNKNOWN)
>
> + if (res1 == ADDRESSABILITY_UNKNOWN) {
>
> + if (res0 == ADDRESSABILITY_IS_ADDRESS)
>
> + return res0;
>
> return ADDRESSABILITY_UNKNOWN;
>
> + }
>
> if (res0 == res1) {
>
> if (res0 == ADDRESSABILITY_IS_ADDRESS)
>
> return ADDRESSABILITY_NOT_ADDRESS;
>
> Index: be/opt/opt_lftr2.cxx
>
> ===================================================================
>
> --- be/opt/opt_lftr2.cxx (revision 3488)
>
> +++ be/opt/opt_lftr2.cxx (working copy)
>
> @@ -1216,11 +1216,18 @@
>
> // adjust operator of new comparison
>
> OPERATOR new_compare_opr = comparison_cr->Opr();
>
> -#ifdef KEY
>
> +#ifdef KEY
>
> MTYPE new_compare_type = tempcr->Dtyp();
>
> // do not change signedness of comparison since that could change
> semantics
>
> new_compare_type = Mtype_TransferSign(comparison_cr->Dsctyp(),
>
>
> new_compare_type);
>
> + if (Is_Target_32bit()
>
> + && (addressable == ADDRESSABILITY_IS_ADDRESS)
>
> + && MTYPE_is_signed(new_compare_type)) {
>
> + // For 32-bit targets, force comparison of address expressions to be
> unsigned.
>
> + new_compare_type =
> Mtype_from_mtype_class_and_size(MTYPE_CLASS_UNSIGNED,
>
> +
> MTYPE_size_min(new_compare_type)/8);
>
> + }
>
> #else
>
> MTYPE new_compare_type = comparison_cr->Dsctyp();
>
> if (addressable == ADDRESSABILITY_IS_ADDRESS &&
>
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