| Message ID | 1450739227-18825-1-git-send-email-patrick@parcs.ath.cx |
|---|---|
| State | New |
| Headers | show |
On Mon, Dec 21, 2015 at 6:07 PM, Patrick Palka <patrick@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.
On Sun, Jan 10, 2016 at 10:19 PM, Patrick Palka <patrick@parcs.ath.cx> wrote: > On Mon, Dec 21, 2015 at 6:07 PM, Patrick Palka <patrick@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.
On 12/22/2015 12:07 AM, Patrick Palka wrote: > + 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); > + } If both sides are PTRMEM_CST, we should be able to compare them without expanding, using cp_tree_equal. Jason
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); +}