[PATCH] i386, rs6000, ia64, s390: Fix C++ ICEs with _Float64x or _Float128 [PR107080]

[PATCH] i386, rs6000, ia64, s390: Fix C++ ICEs with _Float64x or _Float128 [PR107080]

[Jakub Jelinek]

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.

--- 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

Re: [PATCH] i386, rs6000, ia64, s390: Fix C++ ICEs with _Float64x or _Float128 [PR107080]

[Jason Merrill]

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
> 

Re: [PATCH] i386, rs6000, ia64, s390: Fix C++ ICEs with _Float64x or _Float128 [PR107080]

[Segher Boessenkool]

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

Re: [PATCH] i386, rs6000, ia64, s390: Fix C++ ICEs with _Float64x or _Float128 [PR107080]

[Jakub Jelinek]

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

Re: [PATCH] i386, rs6000, ia64, s390: Fix C++ ICEs with _Float64x or _Float128 [PR107080]

[Segher Boessenkool]

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

[PATCH] arm, aarch64, csky: Fix C++ ICEs with _Float16 and __fp16 [PR107080]

[Jakub Jelinek]

On Fri, Sep 30, 2022 at 09:54:49AM -0400, Jason Merrill wrote:
> > 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?

Actually, they already were distinct types that just mangled the same.
So the same issue that had to be solved on i?86, ia64 and rs6000 for
_Float64x vs. long double is a problem on arm and aarch64 with _Float16
vs. __fp16.
The following patch fixes it.

> > 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?

And seems even on csky __fp16 is distinct type from _Float16 (which is a
good thing for consistency, these 3 targets are the only ones that have
__fp16 type), so instead the patch handles it the same as on arm/aarch64,
Dh mangling for __fp16 and DF16_ for _Float16.

Tested with cross-compilers, ok for trunk?

2022-09-30  Jakub Jelinek  <jakub@redhat.com>

	PR c++/107080
	* config/arm/arm.cc (arm_mangle_type): Mangle just __fp16 as Dh
	and _Float16 as DF16_.
	* config/aarch64/aarch64.cc (aarch64_mangle_type): Likewise.
	* config/csky/csky.cc (csky_init_builtins): Fix a comment typo.
	(csky_mangle_type): Mangle __fp16 as Dh and _Float16 as DF16_
	rather than mangling __fp16 as __fp16.

	* g++.target/arm/pr107080.C: New test.
	* g++.target/aarch64/pr107080.C: New test.

--- gcc/config/arm/arm.cc.jj	2022-09-29 18:11:28.746750048 +0200
+++ gcc/config/arm/arm.cc	2022-09-30 19:01:48.774286551 +0200
@@ -30359,6 +30359,8 @@ arm_mangle_type (const_tree type)
   /* Half-precision floating point types.  */
   if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
     {
+      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
+	return NULL;
       if (TYPE_MODE (type) == BFmode)
 	return "u6__bf16";
       else
--- gcc/config/aarch64/aarch64.cc.jj	2022-09-29 18:11:34.806667210 +0200
+++ gcc/config/aarch64/aarch64.cc	2022-09-30 19:02:02.079108171 +0200
@@ -20664,6 +20664,8 @@ aarch64_mangle_type (const_tree type)
   /* Half-precision floating point types.  */
   if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
     {
+      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
+	return NULL;
       if (TYPE_MODE (type) == BFmode)
 	return "u6__bf16";
       else
--- gcc/config/csky/csky.cc.jj	2022-09-08 13:01:19.239779562 +0200
+++ gcc/config/csky/csky.cc	2022-09-30 19:06:09.126794587 +0200
@@ -7300,7 +7300,7 @@ csky_init_cumulative_args (CUMULATIVE_AR
 void
 csky_init_builtins (void)
 {
-  /* Inint fp16.  */
+  /* Init fp16.  */
   static tree csky_floatHF_type_node = make_node (REAL_TYPE);
   TYPE_PRECISION (csky_floatHF_type_node) = GET_MODE_PRECISION (HFmode);
   layout_type (csky_floatHF_type_node);
@@ -7313,10 +7313,10 @@ csky_init_builtins (void)
 static const char *
 csky_mangle_type (const_tree type)
 {
-  if (TYPE_NAME (type) && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
-      && DECL_NAME (TYPE_NAME (type))
-      && !strcmp (IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))), "__fp16"))
-    return "__fp16";
+  if (TREE_CODE (type) == REAL_TYPE
+      && TYPE_PRECISION (type) == 16
+      && TYPE_MAIN_VARIANT (type) != float16_type_node)
+    return "Dh";
 
   /* Use the default mangling.  */
   return NULL;
--- gcc/testsuite/g++.target/arm/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
+++ gcc/testsuite/g++.target/arm/pr107080.C	2022-09-30 18:58:07.812221153 +0200
@@ -0,0 +1,16 @@
+// PR c++/107080
+// { dg-do compile }
+// { dg-options "-mfp16-format=ieee" }
+
+template <typename T, typename T1> 
+int
+foo (T x, T1 y)
+{
+  return 3;
+}
+
+int
+main ()
+{
+  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
+}
--- gcc/testsuite/g++.target/aarch64/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
+++ gcc/testsuite/g++.target/aarch64/pr107080.C	2022-09-30 18:56:04.805851530 +0200
@@ -0,0 +1,16 @@
+// PR c++/107080
+// { dg-do compile }
+// { dg-options "" }
+
+template <typename T, typename T1> 
+int
+foo (T x, T1 y)
+{
+  return 3;
+}
+
+int
+main ()
+{
+  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
+}


	Jakub

Re: [PATCH] arm, aarch64, csky: Fix C++ ICEs with _Float16 and __fp16 [PR107080]

[Richard Sandiford]

Jakub Jelinek <jakub@redhat.com> writes:
> On Fri, Sep 30, 2022 at 09:54:49AM -0400, Jason Merrill wrote:
>> > 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?
>
> Actually, they already were distinct types that just mangled the same.
> So the same issue that had to be solved on i?86, ia64 and rs6000 for
> _Float64x vs. long double is a problem on arm and aarch64 with _Float16
> vs. __fp16.
> The following patch fixes it.
>
>> > 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?
>
> And seems even on csky __fp16 is distinct type from _Float16 (which is a
> good thing for consistency, these 3 targets are the only ones that have
> __fp16 type), so instead the patch handles it the same as on arm/aarch64,
> Dh mangling for __fp16 and DF16_ for _Float16.
>
> Tested with cross-compilers, ok for trunk?
>
> 2022-09-30  Jakub Jelinek  <jakub@redhat.com>
>
> 	PR c++/107080
> 	* config/arm/arm.cc (arm_mangle_type): Mangle just __fp16 as Dh
> 	and _Float16 as DF16_.
> 	* config/aarch64/aarch64.cc (aarch64_mangle_type): Likewise.
> 	* config/csky/csky.cc (csky_init_builtins): Fix a comment typo.
> 	(csky_mangle_type): Mangle __fp16 as Dh and _Float16 as DF16_
> 	rather than mangling __fp16 as __fp16.
>
> 	* g++.target/arm/pr107080.C: New test.
> 	* g++.target/aarch64/pr107080.C: New test.

OK for the aarch64 part, thanks.  But could you add some scan-assemblers
to the test to check for the mangled names?  I assume they should be:

_Z3fooIDF16_DF16_EiT_T0_
_Z3fooIDF16_DhEiT_T0_

(which is what clang produces).

Richard

> --- gcc/config/arm/arm.cc.jj	2022-09-29 18:11:28.746750048 +0200
> +++ gcc/config/arm/arm.cc	2022-09-30 19:01:48.774286551 +0200
> @@ -30359,6 +30359,8 @@ arm_mangle_type (const_tree type)
>    /* Half-precision floating point types.  */
>    if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
>      {
> +      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
> +	return NULL;
>        if (TYPE_MODE (type) == BFmode)
>  	return "u6__bf16";
>        else
> --- gcc/config/aarch64/aarch64.cc.jj	2022-09-29 18:11:34.806667210 +0200
> +++ gcc/config/aarch64/aarch64.cc	2022-09-30 19:02:02.079108171 +0200
> @@ -20664,6 +20664,8 @@ aarch64_mangle_type (const_tree type)
>    /* Half-precision floating point types.  */
>    if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
>      {
> +      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
> +	return NULL;
>        if (TYPE_MODE (type) == BFmode)
>  	return "u6__bf16";
>        else
> --- gcc/config/csky/csky.cc.jj	2022-09-08 13:01:19.239779562 +0200
> +++ gcc/config/csky/csky.cc	2022-09-30 19:06:09.126794587 +0200
> @@ -7300,7 +7300,7 @@ csky_init_cumulative_args (CUMULATIVE_AR
>  void
>  csky_init_builtins (void)
>  {
> -  /* Inint fp16.  */
> +  /* Init fp16.  */
>    static tree csky_floatHF_type_node = make_node (REAL_TYPE);
>    TYPE_PRECISION (csky_floatHF_type_node) = GET_MODE_PRECISION (HFmode);
>    layout_type (csky_floatHF_type_node);
> @@ -7313,10 +7313,10 @@ csky_init_builtins (void)
>  static const char *
>  csky_mangle_type (const_tree type)
>  {
> -  if (TYPE_NAME (type) && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
> -      && DECL_NAME (TYPE_NAME (type))
> -      && !strcmp (IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))), "__fp16"))
> -    return "__fp16";
> +  if (TREE_CODE (type) == REAL_TYPE
> +      && TYPE_PRECISION (type) == 16
> +      && TYPE_MAIN_VARIANT (type) != float16_type_node)
> +    return "Dh";
>  
>    /* Use the default mangling.  */
>    return NULL;
> --- gcc/testsuite/g++.target/arm/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
> +++ gcc/testsuite/g++.target/arm/pr107080.C	2022-09-30 18:58:07.812221153 +0200
> @@ -0,0 +1,16 @@
> +// PR c++/107080
> +// { dg-do compile }
> +// { dg-options "-mfp16-format=ieee" }
> +
> +template <typename T, typename T1> 
> +int
> +foo (T x, T1 y)
> +{
> +  return 3;
> +}
> +
> +int
> +main ()
> +{
> +  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
> +}
> --- gcc/testsuite/g++.target/aarch64/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
> +++ gcc/testsuite/g++.target/aarch64/pr107080.C	2022-09-30 18:56:04.805851530 +0200
> @@ -0,0 +1,16 @@
> +// PR c++/107080
> +// { dg-do compile }
> +// { dg-options "" }
> +
> +template <typename T, typename T1> 
> +int
> +foo (T x, T1 y)
> +{
> +  return 3;
> +}
> +
> +int
> +main ()
> +{
> +  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
> +}
>
>
> 	Jakub

Re: [PATCH] arm, aarch64, csky: Fix C++ ICEs with _Float16 and __fp16 [PR107080]

[Jakub Jelinek]

On Fri, Sep 30, 2022 at 06:38:39PM +0100, Richard Sandiford wrote:
> OK for the aarch64 part, thanks.  But could you add some scan-assemblers
> to the test to check for the mangled names?  I assume they should be:

Ok, about to commit the aarch64 part, will await review of the rest
afterwards.
> 
> _Z3fooIDF16_DF16_EiT_T0_
> _Z3fooIDF16_DhEiT_T0_
> 
> (which is what clang produces).

Indeed, that is what we now get.  Added.

2022-09-30  Jakub Jelinek  <jakub@redhat.com>

	PR c++/107080
	* config/arm/arm.cc (arm_mangle_type): Mangle just __fp16 as Dh
	and _Float16 as DF16_.
	* config/aarch64/aarch64.cc (aarch64_mangle_type): Likewise.
	* config/csky/csky.cc (csky_init_builtins): Fix a comment typo.
	(csky_mangle_type): Mangle __fp16 as Dh and _Float16 as DF16_
	rather than mangling __fp16 as __fp16.

	* g++.target/arm/pr107080.C: New test.
	* g++.target/aarch64/pr107080.C: New test.

--- gcc/config/arm/arm.cc.jj	2022-09-29 18:11:28.746750048 +0200
+++ gcc/config/arm/arm.cc	2022-09-30 19:01:48.774286551 +0200
@@ -30359,6 +30359,8 @@ arm_mangle_type (const_tree type)
   /* Half-precision floating point types.  */
   if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
     {
+      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
+	return NULL;
       if (TYPE_MODE (type) == BFmode)
 	return "u6__bf16";
       else
--- gcc/config/aarch64/aarch64.cc.jj	2022-09-29 18:11:34.806667210 +0200
+++ gcc/config/aarch64/aarch64.cc	2022-09-30 19:02:02.079108171 +0200
@@ -20664,6 +20664,8 @@ aarch64_mangle_type (const_tree type)
   /* Half-precision floating point types.  */
   if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
     {
+      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
+	return NULL;
       if (TYPE_MODE (type) == BFmode)
 	return "u6__bf16";
       else
--- gcc/config/csky/csky.cc.jj	2022-09-08 13:01:19.239779562 +0200
+++ gcc/config/csky/csky.cc	2022-09-30 19:06:09.126794587 +0200
@@ -7300,7 +7300,7 @@ csky_init_cumulative_args (CUMULATIVE_AR
 void
 csky_init_builtins (void)
 {
-  /* Inint fp16.  */
+  /* Init fp16.  */
   static tree csky_floatHF_type_node = make_node (REAL_TYPE);
   TYPE_PRECISION (csky_floatHF_type_node) = GET_MODE_PRECISION (HFmode);
   layout_type (csky_floatHF_type_node);
@@ -7313,10 +7313,10 @@ csky_init_builtins (void)
 static const char *
 csky_mangle_type (const_tree type)
 {
-  if (TYPE_NAME (type) && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
-      && DECL_NAME (TYPE_NAME (type))
-      && !strcmp (IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))), "__fp16"))
-    return "__fp16";
+  if (TREE_CODE (type) == REAL_TYPE
+      && TYPE_PRECISION (type) == 16
+      && TYPE_MAIN_VARIANT (type) != float16_type_node)
+    return "Dh";
 
   /* Use the default mangling.  */
   return NULL;
--- gcc/testsuite/g++.target/arm/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
+++ gcc/testsuite/g++.target/arm/pr107080.C	2022-09-30 18:58:07.812221153 +0200
@@ -0,0 +1,19 @@
+// PR c++/107080
+// { dg-do compile }
+// { dg-options "-mfp16-format=ieee" }
+
+template <typename T, typename T1> 
+int
+foo (T x, T1 y)
+{
+  return 3;
+}
+
+int
+main ()
+{
+  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
+}
+
+// { dg-final { scan-assembler "_Z3fooIDF16_DF16_EiT_T0_" } }
+// { dg-final { scan-assembler "_Z3fooIDF16_DhEiT_T0_" } }
--- gcc/testsuite/g++.target/aarch64/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
+++ gcc/testsuite/g++.target/aarch64/pr107080.C	2022-09-30 19:45:08.657342253 +0200
@@ -0,0 +1,19 @@
+// PR c++/107080
+// { dg-do compile }
+// { dg-options "" }
+
+template <typename T, typename T1> 
+int
+foo (T x, T1 y)
+{
+  return 3;
+}
+
+int
+main ()
+{
+  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
+}
+
+// { dg-final { scan-assembler "_Z3fooIDF16_DF16_EiT_T0_" } }
+// { dg-final { scan-assembler "_Z3fooIDF16_DhEiT_T0_" } }

	Jakub

Re: [PATCH] arm, aarch64, csky: Fix C++ ICEs with _Float16 and __fp16 [PR107080]

[Jason Merrill]

On 9/30/22 13:13, Jakub Jelinek wrote:
> On Fri, Sep 30, 2022 at 09:54:49AM -0400, Jason Merrill wrote:
>>> 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?
> 
> Actually, they already were distinct types that just mangled the same.
> So the same issue that had to be solved on i?86, ia64 and rs6000 for
> _Float64x vs. long double is a problem on arm and aarch64 with _Float16
> vs. __fp16.
> The following patch fixes it.
> 
>>> 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?
> 
> And seems even on csky __fp16 is distinct type from _Float16 (which is a
> good thing for consistency, these 3 targets are the only ones that have
> __fp16 type), so instead the patch handles it the same as on arm/aarch64,
> Dh mangling for __fp16 and DF16_ for _Float16.
> 
> Tested with cross-compilers, ok for trunk?

OK.

> 2022-09-30  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR c++/107080
> 	* config/arm/arm.cc (arm_mangle_type): Mangle just __fp16 as Dh
> 	and _Float16 as DF16_.
> 	* config/aarch64/aarch64.cc (aarch64_mangle_type): Likewise.
> 	* config/csky/csky.cc (csky_init_builtins): Fix a comment typo.
> 	(csky_mangle_type): Mangle __fp16 as Dh and _Float16 as DF16_
> 	rather than mangling __fp16 as __fp16.
> 
> 	* g++.target/arm/pr107080.C: New test.
> 	* g++.target/aarch64/pr107080.C: New test.
> 
> --- gcc/config/arm/arm.cc.jj	2022-09-29 18:11:28.746750048 +0200
> +++ gcc/config/arm/arm.cc	2022-09-30 19:01:48.774286551 +0200
> @@ -30359,6 +30359,8 @@ arm_mangle_type (const_tree type)
>     /* Half-precision floating point types.  */
>     if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
>       {
> +      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
> +	return NULL;
>         if (TYPE_MODE (type) == BFmode)
>   	return "u6__bf16";
>         else
> --- gcc/config/aarch64/aarch64.cc.jj	2022-09-29 18:11:34.806667210 +0200
> +++ gcc/config/aarch64/aarch64.cc	2022-09-30 19:02:02.079108171 +0200
> @@ -20664,6 +20664,8 @@ aarch64_mangle_type (const_tree type)
>     /* Half-precision floating point types.  */
>     if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
>       {
> +      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
> +	return NULL;
>         if (TYPE_MODE (type) == BFmode)
>   	return "u6__bf16";
>         else
> --- gcc/config/csky/csky.cc.jj	2022-09-08 13:01:19.239779562 +0200
> +++ gcc/config/csky/csky.cc	2022-09-30 19:06:09.126794587 +0200
> @@ -7300,7 +7300,7 @@ csky_init_cumulative_args (CUMULATIVE_AR
>   void
>   csky_init_builtins (void)
>   {
> -  /* Inint fp16.  */
> +  /* Init fp16.  */
>     static tree csky_floatHF_type_node = make_node (REAL_TYPE);
>     TYPE_PRECISION (csky_floatHF_type_node) = GET_MODE_PRECISION (HFmode);
>     layout_type (csky_floatHF_type_node);
> @@ -7313,10 +7313,10 @@ csky_init_builtins (void)
>   static const char *
>   csky_mangle_type (const_tree type)
>   {
> -  if (TYPE_NAME (type) && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
> -      && DECL_NAME (TYPE_NAME (type))
> -      && !strcmp (IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))), "__fp16"))
> -    return "__fp16";
> +  if (TREE_CODE (type) == REAL_TYPE
> +      && TYPE_PRECISION (type) == 16
> +      && TYPE_MAIN_VARIANT (type) != float16_type_node)
> +    return "Dh";
>   
>     /* Use the default mangling.  */
>     return NULL;
> --- gcc/testsuite/g++.target/arm/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
> +++ gcc/testsuite/g++.target/arm/pr107080.C	2022-09-30 18:58:07.812221153 +0200
> @@ -0,0 +1,16 @@
> +// PR c++/107080
> +// { dg-do compile }
> +// { dg-options "-mfp16-format=ieee" }
> +
> +template <typename T, typename T1>
> +int
> +foo (T x, T1 y)
> +{
> +  return 3;
> +}
> +
> +int
> +main ()
> +{
> +  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
> +}
> --- gcc/testsuite/g++.target/aarch64/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
> +++ gcc/testsuite/g++.target/aarch64/pr107080.C	2022-09-30 18:56:04.805851530 +0200
> @@ -0,0 +1,16 @@
> +// PR c++/107080
> +// { dg-do compile }
> +// { dg-options "" }
> +
> +template <typename T, typename T1>
> +int
> +foo (T x, T1 y)
> +{
> +  return 3;
> +}
> +
> +int
> +main ()
> +{
> +  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
> +}
> 
> 
> 	Jakub
>