On Sun, Jan 10, 2016 at 10:19 PM, Patrick Palka <patr...@parcs.ath.cx> wrote:
> On Mon, Dec 21, 2015 at 6:07 PM, Patrick Palka <patr...@parcs.ath.cx> wrote:
>> We are currently failing to fold equality comparisons involving
>> PTRMEM_CSTs since (I think) r229018 thus making this a GCC 6 regression.
>> This regression shows up in the boost testsuite.
>>
>> Fixed in a straightforward way. OK to commit after bootstrap + regtest?
>>
>> gcc/cp/ChangeLog:
>>
>> * constexpr.c (cxx_eval_binary_expression): Expand
>> the PTRMEM_CST operands of an equality comparison.
>>
>> gcc/testsuite/ChangeLog:
>>
>> * g++.dg/cpp0x/constexpr-ptrmem5.C: New test.
>> ---
>> gcc/cp/constexpr.c | 9 +++++++++
>> gcc/testsuite/g++.dg/cpp0x/constexpr-ptrmem5.C | 14 ++++++++++++++
>> 2 files changed, 23 insertions(+)
>> create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-ptrmem5.C
>>
>> diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
>> index 208f43b..1ad87aa 100644
>> --- a/gcc/cp/constexpr.c
>> +++ b/gcc/cp/constexpr.c
>> @@ -1630,6 +1630,15 @@ cxx_eval_binary_expression (const constexpr_ctx *ctx,
>> tree t,
>> location_t loc = EXPR_LOCATION (t);
>> enum tree_code code = TREE_CODE (t);
>> tree type = TREE_TYPE (t);
>> +
>> + if (code == EQ_EXPR || code == NE_EXPR)
>> + {
>> + if (TREE_CODE (lhs) == PTRMEM_CST && CONSTANT_CLASS_P (rhs))
>> + lhs = cplus_expand_constant (lhs);
>> + if (TREE_CODE (rhs) == PTRMEM_CST && CONSTANT_CLASS_P (lhs))
>> + rhs = cplus_expand_constant (rhs);
>> + }
>> +
>> r = fold_binary_loc (loc, code, type, lhs, rhs);
>> if (r == NULL_TREE)
>> {
>> diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-ptrmem5.C
>> b/gcc/testsuite/g++.dg/cpp0x/constexpr-ptrmem5.C
>> new file mode 100644
>> index 0000000..e28c917
>> --- /dev/null
>> +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-ptrmem5.C
>> @@ -0,0 +1,14 @@
>> +// { dg-do compile { target c++11 } }
>> +
>> +#define SA(x) static_assert ((x), #x)
>> +
>> +struct X { int a, b; };
>> +
>> +void
>> +foo ()
>> +{
>> + SA (&X::a);
>> + SA (&X::a == &X::a);
>> + SA (&X::a != &X::b);
>> + SA ((!&X::b) == 0);
>> +}
>> --
>> 2.7.0.rc0.50.g1470d8f.dirty
>>
>
> Ping.
Ping.
