i386, rs6000, ia64, s390: Fix C++ ICEs with _Float64x or _Float128 [PR107080]
Commit Message
Hi!
The following testcase ICEs on x86 as well as ppc64le (the latter
with -mabi=ieeelongdouble), because _Float64x there isn't mangled as
DF64x but e or u9__ieee128 instead.
Those are the mangling that should be used for the non-standard
types with the same mode or for long double, but not for _Float64x.
All the 4 mangle_type targhook implementations start with
type = TYPE_MAIN_VARIANT (type);
so I think it is cleanest to handle it the same in all and return NULL
before the switches on mode or whatever other tests.
s390 doesn't actually have a bug, but while I was there, having
type = TYPE_MAIN_VARIANT (type);
if (TYPE_MAIN_VARIANT (type) == long_double_type_node)
looked useless to me.
Tested on x86_64, i686 and powerpc64le, ok for trunk?
Note, there is one further problem on aarch64/arm, types with HFmode
(_Float16 and __fp16) are there mangled as Dh (which is standard
Itanium mangling:
::= Dh # IEEE 754r half-precision floating point (16 bits)
::= DF <number> _ # ISO/IEC TS 18661 binary floating point type _FloatN (N bits)
so in theory is also ok, but DF16_ is more specific. Should we just
change Dh to DF16_ in those backends, or should __fp16 there be distinct
type from _Float16 where __fp16 would mangle Dh and _Float16 DF16_ ?
And there is csky, which mangles __fp16 (but only if type's name is __fp16,
not _Float16) as __fp16, that looks clearly invalid to me as it isn't
valid in the mangling grammar. So perhaps just nuke csky's mangle_type
and have it mangled as DF16_ by the generic code?
2022-09-29 Jakub Jelinek <jakub@redhat.com>
PR c++/107080
* config/i386/i386.cc (ix86_mangle_type): Always return NULL
for float128_type_node or float64x_type_node, don't check
float128t_type_node later on.
* config/ia64/ia64.cc (ia64_mangle_type): Always return NULL
for float128_type_node or float64x_type_node.
* config/rs6000/rs6000.cc (rs6000_mangle_type): Likewise.
Don't check float128_type_node later on.
* config/s390/s390.cc (s390_mangle_type): Don't use
TYPE_MAIN_VARIANT on type which was set to TYPE_MAIN_VARIANT
a few lines earlier.
* g++.dg/cpp23/ext-floating11.C: New test.
Jakub
Comments
On 9/29/22 06:01, Jakub Jelinek wrote:
> Hi!
>
> The following testcase ICEs on x86 as well as ppc64le (the latter
> with -mabi=ieeelongdouble), because _Float64x there isn't mangled as
> DF64x but e or u9__ieee128 instead.
> Those are the mangling that should be used for the non-standard
> types with the same mode or for long double, but not for _Float64x.
> All the 4 mangle_type targhook implementations start with
> type = TYPE_MAIN_VARIANT (type);
> so I think it is cleanest to handle it the same in all and return NULL
> before the switches on mode or whatever other tests.
> s390 doesn't actually have a bug, but while I was there, having
> type = TYPE_MAIN_VARIANT (type);
> if (TYPE_MAIN_VARIANT (type) == long_double_type_node)
> looked useless to me.
>
> Tested on x86_64, i686 and powerpc64le, ok for trunk?
OK.
> Note, there is one further problem on aarch64/arm, types with HFmode
> (_Float16 and __fp16) are there mangled as Dh (which is standard
> Itanium mangling:
> ::= Dh # IEEE 754r half-precision floating point (16 bits)
> ::= DF <number> _ # ISO/IEC TS 18661 binary floating point type _FloatN (N bits)
> so in theory is also ok, but DF16_ is more specific. Should we just
> change Dh to DF16_ in those backends, or should __fp16 there be distinct
> type from _Float16 where __fp16 would mangle Dh and _Float16 DF16_ ?
You argued for keeping __float128 separate from _Float128, does the same
argument not apply to this case?
> And there is csky, which mangles __fp16 (but only if type's name is __fp16,
> not _Float16) as __fp16, that looks clearly invalid to me as it isn't
> valid in the mangling grammar. So perhaps just nuke csky's mangle_type
> and have it mangled as DF16_ by the generic code?
Sounds good.
> 2022-09-29 Jakub Jelinek <jakub@redhat.com>
>
> PR c++/107080
> * config/i386/i386.cc (ix86_mangle_type): Always return NULL
> for float128_type_node or float64x_type_node, don't check
> float128t_type_node later on.
> * config/ia64/ia64.cc (ia64_mangle_type): Always return NULL
> for float128_type_node or float64x_type_node.
> * config/rs6000/rs6000.cc (rs6000_mangle_type): Likewise.
> Don't check float128_type_node later on.
> * config/s390/s390.cc (s390_mangle_type): Don't use
> TYPE_MAIN_VARIANT on type which was set to TYPE_MAIN_VARIANT
> a few lines earlier.
>
> * g++.dg/cpp23/ext-floating11.C: New test.
>
> --- gcc/config/i386/i386.cc.jj 2022-09-29 09:13:25.713718513 +0200
> +++ gcc/config/i386/i386.cc 2022-09-29 11:29:20.828358152 +0200
> @@ -22725,6 +22725,9 @@ ix86_mangle_type (const_tree type)
> && TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
> return NULL;
>
> + if (type == float128_type_node || type == float64x_type_node)
> + return NULL;
> +
> switch (TYPE_MODE (type))
> {
> case E_BFmode:
> @@ -22735,10 +22738,7 @@ ix86_mangle_type (const_tree type)
> return "DF16_";
> case E_TFmode:
> /* __float128 is "g". */
> - if (type == float128t_type_node)
> - return "g";
> - /* _Float128 should mangle as "DF128_" done in generic code. */
> - return NULL;
> + return "g";
> case E_XFmode:
> /* "long double" or __float80 is "e". */
> return "e";
> --- gcc/config/ia64/ia64.cc.jj 2022-09-27 08:03:26.977984661 +0200
> +++ gcc/config/ia64/ia64.cc 2022-09-29 11:29:44.071037677 +0200
> @@ -11225,6 +11225,9 @@ ia64_mangle_type (const_tree type)
> && TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
> return NULL;
>
> + if (type == float128_type_node || type == float64x_type_node)
> + return NULL;
> +
> /* On HP-UX, "long double" is mangled as "e" so __float128 is
> mangled as "e". */
> if (!TARGET_HPUX && TYPE_MODE (type) == TFmode)
> --- gcc/config/rs6000/rs6000.cc.jj 2022-09-27 08:03:26.999984363 +0200
> +++ gcc/config/rs6000/rs6000.cc 2022-09-29 11:26:10.290985331 +0200
> @@ -20270,13 +20270,12 @@ rs6000_mangle_type (const_tree type)
> if (type == bool_int_type_node) return "U6__booli";
> if (type == bool_long_long_type_node) return "U6__boolx";
>
> + if (type == float128_type_node || type == float64x_type_node)
> + return NULL;
> +
> if (SCALAR_FLOAT_TYPE_P (type) && FLOAT128_IBM_P (TYPE_MODE (type)))
> return "g";
> - if (SCALAR_FLOAT_TYPE_P (type)
> - && FLOAT128_IEEE_P (TYPE_MODE (type))
> - /* _Float128 should mangle as DF128_ (done in generic code)
> - rather than u9__ieee128 (used for __ieee128 and __float128). */
> - && type != float128_type_node)
> + if (SCALAR_FLOAT_TYPE_P (type) && FLOAT128_IEEE_P (TYPE_MODE (type)))
> return "u9__ieee128";
>
> if (type == vector_pair_type_node)
> --- gcc/config/s390/s390.cc.jj 2022-09-26 18:47:26.950349802 +0200
> +++ gcc/config/s390/s390.cc 2022-09-29 11:26:51.180421534 +0200
> @@ -7642,8 +7642,7 @@ s390_mangle_type (const_tree type)
> if (type == s390_builtin_types[BT_BV4SI]) return "U6__booli";
> if (type == s390_builtin_types[BT_BV2DI]) return "U6__booll";
>
> - if (TYPE_MAIN_VARIANT (type) == long_double_type_node
> - && TARGET_LONG_DOUBLE_128)
> + if (type == long_double_type_node && TARGET_LONG_DOUBLE_128)
> return "g";
>
> /* For all other types, use normal C++ mangling. */
> --- gcc/testsuite/g++.dg/cpp23/ext-floating11.C.jj 2022-09-29 11:33:46.331697320 +0200
> +++ gcc/testsuite/g++.dg/cpp23/ext-floating11.C 2022-09-29 11:40:30.610123406 +0200
> @@ -0,0 +1,79 @@
> +// P1467R9 - Extended floating-point types and standard names.
> +// { dg-do compile { target c++23 } }
> +// { dg-options "" }
> +
> +#include "ext-floating.h"
> +
> +#ifdef __STRICT_ANSI__
> +#undef __SIZEOF_FLOAT128__
> +#endif
> +
> +extern "C" void abort ();
> +
> +using namespace std;
> +
> +template <typename T, typename U>
> +int
> +foo (T x, U y) noexcept
> +{
> + return 3;
> +}
> +
> +int
> +main ()
> +{
> + if (foo (0.0f, 0.0f) != 3)
> + abort ();
> + if (foo (0.0, 0.0) != 3)
> + abort ();
> + if (foo (0.0L, 0.0L) != 3)
> + abort ();
> +#ifdef __STDCPP_FLOAT16_T__
> + if (foo (0.0f16, 0.0f16) != 3)
> + abort ();
> + if (foo (0.0f, 0.0f16) != 3)
> + abort ();
> +#endif
> +#ifdef __STDCPP_FLOAT32_T__
> + if (foo (0.0f32, 0.0f32) != 3)
> + abort ();
> + if (foo (0.0f, 0.0f32) != 3)
> + abort ();
> +#endif
> +#ifdef __STDCPP_FLOAT64_T__
> + if (foo (0.0f64, 0.0f64) != 3)
> + abort ();
> + if (foo (0.0, 0.0f64) != 3)
> + abort ();
> +#endif
> +#ifdef __STDCPP_FLOAT128_T__
> + if (foo (0.0f128, 0.0f128) != 3)
> + abort ();
> + if (foo (0.0L, 0.0f128) != 3)
> + abort ();
> +#endif
> +#ifdef __STDCPP_BFLOAT16_T__
> + if (foo (0.0bf16, 0.0bf16) != 3)
> + abort ();
> + if (foo (0.0f, 0.0bf16) != 3)
> + abort ();
> +#endif
> +#ifdef __FLT32X_MANT_DIG__
> + if (foo (0.0f32x, 0.0f32x) != 3)
> + abort ();
> + if (foo (0.0, 0.0f32x) != 3)
> + abort ();
> +#endif
> +#ifdef __FLT64X_MANT_DIG__
> + if (foo (0.0f64x, 0.0f64x) != 3)
> + abort ();
> + if (foo (0.0L, 0.0f64x) != 3)
> + abort ();
> +#endif
> +#ifdef __FLT128X_MANT_DIG__
> + if (foo (0.0f128x, 0.0f128x) != 3)
> + abort ();
> + if (foo (0.0L, 0.0f128x) != 3)
> + abort ();
> +#endif
> +}
>
> Jakub
>
Hi!
On Thu, Sep 29, 2022 at 12:01:43PM +0200, Jakub Jelinek via Gcc-patches wrote:
> --- gcc/config/i386/i386.cc.jj 2022-09-29 09:13:25.713718513 +0200
> +++ gcc/config/i386/i386.cc 2022-09-29 11:29:20.828358152 +0200
> @@ -22725,6 +22725,9 @@ ix86_mangle_type (const_tree type)
> && TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
> return NULL;
>
> + if (type == float128_type_node || type == float64x_type_node)
> + return NULL;
Is float128_type_node always IEEE QP, never double-double? I couldn't
find this documented anywhere. If this is not true, this part of the
patch is incorrect.
Segher
On Fri, Sep 30, 2022 at 10:07:59AM -0500, Segher Boessenkool wrote:
> Hi!
>
> On Thu, Sep 29, 2022 at 12:01:43PM +0200, Jakub Jelinek via Gcc-patches wrote:
> > --- gcc/config/i386/i386.cc.jj 2022-09-29 09:13:25.713718513 +0200
> > +++ gcc/config/i386/i386.cc 2022-09-29 11:29:20.828358152 +0200
> > @@ -22725,6 +22725,9 @@ ix86_mangle_type (const_tree type)
> > && TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
> > return NULL;
> >
> > + if (type == float128_type_node || type == float64x_type_node)
> > + return NULL;
>
> Is float128_type_node always IEEE QP, never double-double? I couldn't
> find this documented anywhere. If this is not true, this part of the
> patch is incorrect.
It is always IEEE quad, if there is no IEEE quad support, it is NULL.
The C++ wording is:
"If the implementation supports an extended floating-point type whose
properties are specified by the ISO/IEC/IEEE 60559 floating-point
interchange format binary128, then the typedef-name std::float128_t is
defined in the header <stdfloat> and names such a type, the macro
__STDCPP_FLOAT128_T__ is defined, and the floating-point literal suffixes
f128 and F128 are supported."
and C:
Types designated:
_FloatN
where N is 16, 32, 64, or ≥128 and a multiple of 32; and, types designated
_DecimalN
where N ≥ 32 and a multiple of 32, are collectively called the interchange floating types. Each
interchange floating type has the IEC 60559 interchange format corresponding to its width (N) and
radix (2 for _FloatN, 10 for _DecimalN). Each interchange floating type is not compatible with any
other type."
So, _Float128 and std::float128_t which we use float128_type_node for
must be IEEE binary128, nothing else.
Internally, it is implemented by using targetm.floatn_mode hook to query
which mode if any is the IEEE one with corresponding width.
Jakub
On Fri, Sep 30, 2022 at 05:31:26PM +0200, Jakub Jelinek wrote:
> On Fri, Sep 30, 2022 at 10:07:59AM -0500, Segher Boessenkool wrote:
> > On Thu, Sep 29, 2022 at 12:01:43PM +0200, Jakub Jelinek via Gcc-patches wrote:
> > > --- gcc/config/i386/i386.cc.jj 2022-09-29 09:13:25.713718513 +0200
> > > +++ gcc/config/i386/i386.cc 2022-09-29 11:29:20.828358152 +0200
> > > @@ -22725,6 +22725,9 @@ ix86_mangle_type (const_tree type)
> > > && TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
> > > return NULL;
> > >
> > > + if (type == float128_type_node || type == float64x_type_node)
> > > + return NULL;
> >
> > Is float128_type_node always IEEE QP, never double-double? I couldn't
> > find this documented anywhere. If this is not true, this part of the
> > patch is incorrect.
>
> It is always IEEE quad, if there is no IEEE quad support, it is NULL.
> The C++ wording is:
>
> "If the implementation supports an extended floating-point type whose
> properties are specified by the ISO/IEC/IEEE 60559 floating-point
> interchange format binary128, then the typedef-name std::float128_t is
> defined in the header <stdfloat> and names such a type, the macro
> __STDCPP_FLOAT128_T__ is defined, and the floating-point literal suffixes
> f128 and F128 are supported."
> and C:
> Types designated:
> _FloatN
> where N is 16, 32, 64, or ≥128 and a multiple of 32; and, types designated
> _DecimalN
> where N ≥ 32 and a multiple of 32, are collectively called the interchange floating types. Each
> interchange floating type has the IEC 60559 interchange format corresponding to its width (N) and
> radix (2 for _FloatN, 10 for _DecimalN). Each interchange floating type is not compatible with any
> other type."
>
> So, _Float128 and std::float128_t which we use float128_type_node for
> must be IEEE binary128, nothing else.
Great :-)
> Internally, it is implemented by using targetm.floatn_mode hook to query
> which mode if any is the IEEE one with corresponding width.
tree.h says just
/* Names for individual types (code should normally iterate over all
such types; these are only for back-end use, or in contexts such as
*.def where iteration is not possible). */
and there is nothing whatsoever in doc/. Looking at the current
implementation never shows intent :-(
Segher
@@ -22725,6 +22725,9 @@ ix86_mangle_type (const_tree type)
&& TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
return NULL;
+ if (type == float128_type_node || type == float64x_type_node)
+ return NULL;
+
switch (TYPE_MODE (type))
{
case E_BFmode:
@@ -22735,10 +22738,7 @@ ix86_mangle_type (const_tree type)
return "DF16_";
case E_TFmode:
/* __float128 is "g". */
- if (type == float128t_type_node)
- return "g";
- /* _Float128 should mangle as "DF128_" done in generic code. */
- return NULL;
+ return "g";
case E_XFmode:
/* "long double" or __float80 is "e". */
return "e";
@@ -11225,6 +11225,9 @@ ia64_mangle_type (const_tree type)
&& TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
return NULL;
+ if (type == float128_type_node || type == float64x_type_node)
+ return NULL;
+
/* On HP-UX, "long double" is mangled as "e" so __float128 is
mangled as "e". */
if (!TARGET_HPUX && TYPE_MODE (type) == TFmode)
@@ -20270,13 +20270,12 @@ rs6000_mangle_type (const_tree type)
if (type == bool_int_type_node) return "U6__booli";
if (type == bool_long_long_type_node) return "U6__boolx";
+ if (type == float128_type_node || type == float64x_type_node)
+ return NULL;
+
if (SCALAR_FLOAT_TYPE_P (type) && FLOAT128_IBM_P (TYPE_MODE (type)))
return "g";
- if (SCALAR_FLOAT_TYPE_P (type)
- && FLOAT128_IEEE_P (TYPE_MODE (type))
- /* _Float128 should mangle as DF128_ (done in generic code)
- rather than u9__ieee128 (used for __ieee128 and __float128). */
- && type != float128_type_node)
+ if (SCALAR_FLOAT_TYPE_P (type) && FLOAT128_IEEE_P (TYPE_MODE (type)))
return "u9__ieee128";
if (type == vector_pair_type_node)
@@ -7642,8 +7642,7 @@ s390_mangle_type (const_tree type)
if (type == s390_builtin_types[BT_BV4SI]) return "U6__booli";
if (type == s390_builtin_types[BT_BV2DI]) return "U6__booll";
- if (TYPE_MAIN_VARIANT (type) == long_double_type_node
- && TARGET_LONG_DOUBLE_128)
+ if (type == long_double_type_node && TARGET_LONG_DOUBLE_128)
return "g";
/* For all other types, use normal C++ mangling. */
@@ -0,0 +1,79 @@
+// P1467R9 - Extended floating-point types and standard names.
+// { dg-do compile { target c++23 } }
+// { dg-options "" }
+
+#include "ext-floating.h"
+
+#ifdef __STRICT_ANSI__
+#undef __SIZEOF_FLOAT128__
+#endif
+
+extern "C" void abort ();
+
+using namespace std;
+
+template <typename T, typename U>
+int
+foo (T x, U y) noexcept
+{
+ return 3;
+}
+
+int
+main ()
+{
+ if (foo (0.0f, 0.0f) != 3)
+ abort ();
+ if (foo (0.0, 0.0) != 3)
+ abort ();
+ if (foo (0.0L, 0.0L) != 3)
+ abort ();
+#ifdef __STDCPP_FLOAT16_T__
+ if (foo (0.0f16, 0.0f16) != 3)
+ abort ();
+ if (foo (0.0f, 0.0f16) != 3)
+ abort ();
+#endif
+#ifdef __STDCPP_FLOAT32_T__
+ if (foo (0.0f32, 0.0f32) != 3)
+ abort ();
+ if (foo (0.0f, 0.0f32) != 3)
+ abort ();
+#endif
+#ifdef __STDCPP_FLOAT64_T__
+ if (foo (0.0f64, 0.0f64) != 3)
+ abort ();
+ if (foo (0.0, 0.0f64) != 3)
+ abort ();
+#endif
+#ifdef __STDCPP_FLOAT128_T__
+ if (foo (0.0f128, 0.0f128) != 3)
+ abort ();
+ if (foo (0.0L, 0.0f128) != 3)
+ abort ();
+#endif
+#ifdef __STDCPP_BFLOAT16_T__
+ if (foo (0.0bf16, 0.0bf16) != 3)
+ abort ();
+ if (foo (0.0f, 0.0bf16) != 3)
+ abort ();
+#endif
+#ifdef __FLT32X_MANT_DIG__
+ if (foo (0.0f32x, 0.0f32x) != 3)
+ abort ();
+ if (foo (0.0, 0.0f32x) != 3)
+ abort ();
+#endif
+#ifdef __FLT64X_MANT_DIG__
+ if (foo (0.0f64x, 0.0f64x) != 3)
+ abort ();
+ if (foo (0.0L, 0.0f64x) != 3)
+ abort ();
+#endif
+#ifdef __FLT128X_MANT_DIG__
+ if (foo (0.0f128x, 0.0f128x) != 3)
+ abort ();
+ if (foo (0.0L, 0.0f128x) != 3)
+ abort ();
+#endif
+}