[PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Michael Meissner]

[PATCH, V3] Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__.

Define the sizes of the PowerPC specific types __float128 and __ibm128 if those
types are enabled.

This patch will define __SIZEOF_IBM128__ and __SIZEOF_FLOAT128__ if their
respective types are created in the compiler.  Currently, this means both of
these will be defined if float128 support is enabled.  But at some point in
the future, __ibm128 could be enabled without enabling float128 support and
__SIZEOF_IBM128__ would be defined.

I have tested this on a little endian power9 system and there were no
regressions.  I did verify by hand that if I compile with -mno-vsx, that
__SIZEOF_IBM128__ is not defined.  Can I check this into the master branch?
Ideally, it should also be backported to GCC 11 and 10.

2022-02-16  Michael Meissner  <meissner@the-meissners.org>

gcc/
	PR target/99708
	* config/rs6000/rs6000-c.cc (rs6000_cpu_cpp_builtins): Define
	__SIZEOF_IBM128__ if the IBM 128-bit long double type is created.
	Define __SIZEOF_FLOAT128__ if we have float128 support.

gcc/testsuite/
	PR target/99708
	* gcc.target/powerpc/pr99708.c: New test.
---
 gcc/config/rs6000/rs6000-c.cc              |  7 ++++++-
 gcc/testsuite/gcc.target/powerpc/pr99708.c | 21 +++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.target/powerpc/pr99708.c

diff --git a/gcc/config/rs6000/rs6000-c.cc b/gcc/config/rs6000/rs6000-c.cc
index 15251efc209..ec4e5c3f53a 100644
--- a/gcc/config/rs6000/rs6000-c.cc
+++ b/gcc/config/rs6000/rs6000-c.cc
@@ -622,8 +622,13 @@ rs6000_cpu_cpp_builtins (cpp_reader *pfile)
     builtin_define ("__RSQRTE__");
   if (TARGET_FRSQRTES)
     builtin_define ("__RSQRTEF__");
+  if (ibm128_float_type_node)
+    builtin_define ("__SIZEOF_IBM128__=16");
   if (TARGET_FLOAT128_TYPE)
-    builtin_define ("__FLOAT128_TYPE__");
+    {
+      builtin_define ("__FLOAT128_TYPE__");
+      builtin_define ("__SIZEOF_FLOAT128__=16");
+    }
 #ifdef TARGET_LIBC_PROVIDES_HWCAP_IN_TCB
   builtin_define ("__BUILTIN_CPU_SUPPORTS__");
 #endif
diff --git a/gcc/testsuite/gcc.target/powerpc/pr99708.c b/gcc/testsuite/gcc.target/powerpc/pr99708.c
new file mode 100644
index 00000000000..d478f7bc4c0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr99708.c
@@ -0,0 +1,21 @@
+/* { dg-do run } */
+/* { require-effective-target ppc_float128_sw } */
+/* { dg-options "-O2 -mvsx -mfloat128" } */
+
+/*
+ * PR target/99708
+ *
+ * Verify that __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__ are properly defined.
+ */
+
+#include <stdlib.h>
+
+int main (void)
+{
+  if (__SIZEOF_FLOAT128__ != sizeof (__float128)
+      || __SIZEOF_IBM128__ != sizeof (__ibm128))
+    abort ();
+
+  return 0;
+}
+
-- 
2.35.1


-- 
Michael Meissner, IBM
PO Box 98, Ayer, Massachusetts, USA, 01432
email: meissner@linux.ibm.com

Re: [PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Segher Boessenkool]

Hi!

On Wed, Feb 16, 2022 at 06:03:53PM -0500, Michael Meissner wrote:
> [PATCH, V3] Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__.
> 
> Define the sizes of the PowerPC specific types __float128 and __ibm128 if those
> types are enabled.
> 
> This patch will define __SIZEOF_IBM128__ and __SIZEOF_FLOAT128__ if their
> respective types are created in the compiler.

> gcc/
> 	PR target/99708
> 	* config/rs6000/rs6000-c.cc (rs6000_cpu_cpp_builtins): Define
> 	__SIZEOF_IBM128__ if the IBM 128-bit long double type is created.
> 	Define __SIZEOF_FLOAT128__ if we have float128 support.

> --- a/gcc/config/rs6000/rs6000-c.cc
> +++ b/gcc/config/rs6000/rs6000-c.cc
> @@ -622,8 +622,13 @@ rs6000_cpu_cpp_builtins (cpp_reader *pfile)
>      builtin_define ("__RSQRTE__");
>    if (TARGET_FRSQRTES)
>      builtin_define ("__RSQRTEF__");
> +  if (ibm128_float_type_node)
> +    builtin_define ("__SIZEOF_IBM128__=16");
>    if (TARGET_FLOAT128_TYPE)
> -    builtin_define ("__FLOAT128_TYPE__");
> +    {
> +      builtin_define ("__FLOAT128_TYPE__");
> +      builtin_define ("__SIZEOF_FLOAT128__=16");
> +    }

  if (TARGET_FLOAT128_TYPE)
    builtin_define ("__FLOAT128_TYPE__");

  if (float128_type_node)
    builtin_define ("__SIZEOF_FLOAT128__=16");
  if (ibm128_float_type_node)
    builtin_define ("__SIZEOF_IBM128__=16");

Okay like that.  Thanks!


Segher

Re: [PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Joseph Myers]

The version of this patch applied to GCC 10 branch (commit 
641b407763ecfee5d4ac86d8ffe9eb1eeea5fd10) has broken the glibc build for 
powerpc64le-linux-gnu (it's fine with GCC 11 branch and master, just GCC 
10 branch is broken) 
<https://sourceware.org/pipermail/libc-testresults/2022q1/009444.html>.  
Specifically, the test program links-dso-program.cc built during the glibc 
build no longer builds, with a series of errors in libstdc++ headers such 
as:

/scratch/jmyers/glibc/many10/install/compilers/powerpc64le-linux-gnu/powerpc64le-glibc-linux-gnu/include/c++/10.3.1/type_traits:387:39: error: '__float128' was not declared in this scope
  387 |     struct __is_floating_point_helper<__float128>
      |                                       ^~~~~~~~~~

So it appears that with the GCC 10 version, there is some inconsistency 
between what the compiler defines and what the headers expect.

This file in glibc is built with the following command:

powerpc64le-glibc-linux-gnu-g++ links-dso-program.cc -c 
-I/scratch/jmyers/glibc/many10/build/glibcs/powerpc64le-linux-gnu/glibc/  
-g -O2 -Wall -Wwrite-strings -Wundef -Werror -fmerge-all-constants 
-frounding-math -fno-stack-protector -fno-common -mabi=ieeelongdouble 
-Wno-psabi -mno-gnu-attribute -mlong-double-128  -fpie -mno-float128      
-I../include 
-I/scratch/jmyers/glibc/many10/build/glibcs/powerpc64le-linux-gnu/glibc/support  
-I/scratch/jmyers/glibc/many10/build/glibcs/powerpc64le-linux-gnu/glibc  
-I../sysdeps/unix/sysv/linux/powerpc/powerpc64/le/fpu  
-I../sysdeps/unix/sysv/linux/powerpc/powerpc64/fpu  
-I../sysdeps/unix/sysv/linux/powerpc/powerpc64/le  
-I../sysdeps/unix/sysv/linux/powerpc/powerpc64  
-I../sysdeps/unix/sysv/linux/wordsize-64  
-I../sysdeps/unix/sysv/linux/powerpc  -I../sysdeps/powerpc/nptl  
-I../sysdeps/unix/sysv/linux/include -I../sysdeps/unix/sysv/linux  
-I../sysdeps/nptl  -I../sysdeps/pthread  -I../sysdeps/gnu  
-I../sysdeps/unix/inet  -I../sysdeps/unix/sysv  -I../sysdeps/unix/powerpc  
-I../sysdeps/unix  -I../sysdeps/posix  
-I../sysdeps/powerpc/powerpc64/le/power8/fpu/multiarch  
-I../sysdeps/powerpc/powerpc64/le/power7/fpu/multiarch  
-I../sysdeps/powerpc/powerpc64/le/fpu/multiarch  
-I../sysdeps/powerpc/powerpc64/le/power8/fpu  
-I../sysdeps/powerpc/powerpc64/le/power7/fpu  
-I../sysdeps/powerpc/powerpc64/le/fpu  -I../sysdeps/powerpc/powerpc64/fpu  
-I../sysdeps/powerpc/powerpc64/le/power8/multiarch  
-I../sysdeps/powerpc/powerpc64/le/power7/multiarch  
-I../sysdeps/powerpc/powerpc64/le/multiarch  
-I../sysdeps/powerpc/powerpc64/multiarch  
-I../sysdeps/powerpc/powerpc64/le/power8  
-I../sysdeps/powerpc/powerpc64/power8  
-I../sysdeps/powerpc/powerpc64/le/power7  
-I../sysdeps/powerpc/powerpc64/power7  
-I../sysdeps/powerpc/powerpc64/power6  
-I../sysdeps/powerpc/powerpc64/power4  -I../sysdeps/powerpc/power4  
-I../sysdeps/powerpc/powerpc64/le  -I../sysdeps/powerpc/powerpc64  
-I../sysdeps/wordsize-64  -I../sysdeps/powerpc/fpu  -I../sysdeps/powerpc  
-I../sysdeps/ieee754/ldbl-128ibm-compat  
-I../sysdeps/ieee754/ldbl-128ibm/include -I../sysdeps/ieee754/ldbl-128ibm  
-I../sysdeps/ieee754/ldbl-opt  -I../sysdeps/ieee754/dbl-64  
-I../sysdeps/ieee754/flt-32  -I../sysdeps/ieee754/float128  
-I../sysdeps/ieee754  -I../sysdeps/generic  -I.. -I../libio -I.   
-D_LIBC_REENTRANT -include 
/scratch/jmyers/glibc/many10/build/glibcs/powerpc64le-linux-gnu/glibc/libc-modules.h 
-DMODULE_NAME=nonlib -include ../include/libc-symbols.h  -DPIC     
-DTOP_NAMESPACE=glibc -o 
/scratch/jmyers/glibc/many10/build/glibcs/powerpc64le-linux-gnu/glibc/support/links-dso-program.o 
-MD -MP -MF 
/scratch/jmyers/glibc/many10/build/glibcs/powerpc64le-linux-gnu/glibc/support/links-dso-program.o.dt 
-MT 
/scratch/jmyers/glibc/many10/build/glibcs/powerpc64le-linux-gnu/glibc/support/links-dso-program.o

-- 
Joseph S. Myers
joseph@codesourcery.com

Re: [PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Segher Boessenkool]

On Fri, Mar 11, 2022 at 08:42:27PM +0000, Joseph Myers wrote:
> The version of this patch applied to GCC 10 branch (commit 
> 641b407763ecfee5d4ac86d8ffe9eb1eeea5fd10) has broken the glibc build for 
> powerpc64le-linux-gnu (it's fine with GCC 11 branch and master, just GCC 
> 10 branch is broken) 

Mike, please revert it then?


Segher

Re: [PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Jakub Jelinek]

On Fri, Mar 11, 2022 at 02:51:23PM -0600, Segher Boessenkool wrote:
> On Fri, Mar 11, 2022 at 08:42:27PM +0000, Joseph Myers wrote:
> > The version of this patch applied to GCC 10 branch (commit 
> > 641b407763ecfee5d4ac86d8ffe9eb1eeea5fd10) has broken the glibc build for 
> > powerpc64le-linux-gnu (it's fine with GCC 11 branch and master, just GCC 
> > 10 branch is broken) 
> 
> Mike, please revert it then?

Preferably also the GCC 11 commit, because otherwise it needs backports
of the follow-up changes too.

	Jakub

Re: [PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Segher Boessenkool]

On Fri, Mar 11, 2022 at 09:57:50PM +0100, Jakub Jelinek wrote:
> On Fri, Mar 11, 2022 at 02:51:23PM -0600, Segher Boessenkool wrote:
> > On Fri, Mar 11, 2022 at 08:42:27PM +0000, Joseph Myers wrote:
> > > The version of this patch applied to GCC 10 branch (commit 
> > > 641b407763ecfee5d4ac86d8ffe9eb1eeea5fd10) has broken the glibc build for 
> > > powerpc64le-linux-gnu (it's fine with GCC 11 branch and master, just GCC 
> > > 10 branch is broken) 
> > 
> > Mike, please revert it then?
> 
> Preferably also the GCC 11 commit, because otherwise it needs backports
> of the follow-up changes too.

Good point.  Yes please.


Segher

Re: [PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Michael Meissner]

On Fri, Mar 11, 2022 at 02:51:23PM -0600, Segher Boessenkool wrote:
> On Fri, Mar 11, 2022 at 08:42:27PM +0000, Joseph Myers wrote:
> > The version of this patch applied to GCC 10 branch (commit 
> > 641b407763ecfee5d4ac86d8ffe9eb1eeea5fd10) has broken the glibc build for 
> > powerpc64le-linux-gnu (it's fine with GCC 11 branch and master, just GCC 
> > 10 branch is broken) 
> 
> Mike, please revert it then?

Ok, I will revert both the GCC 11 and GCC 10 backport once I make sure the fix
builds.  Sorry about that.  Obviously, we will want to backport whatever we do
shortly to the older branches.

-- 
Michael Meissner, IBM
PO Box 98, Ayer, Massachusetts, USA, 01432
email: meissner@linux.ibm.com

Re: [PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Michael Meissner]

On Fri, Mar 11, 2022 at 03:07:39PM -0600, Segher Boessenkool wrote:
> On Fri, Mar 11, 2022 at 09:57:50PM +0100, Jakub Jelinek wrote:
> > On Fri, Mar 11, 2022 at 02:51:23PM -0600, Segher Boessenkool wrote:
> > > On Fri, Mar 11, 2022 at 08:42:27PM +0000, Joseph Myers wrote:
> > > > The version of this patch applied to GCC 10 branch (commit 
> > > > 641b407763ecfee5d4ac86d8ffe9eb1eeea5fd10) has broken the glibc build for 
> > > > powerpc64le-linux-gnu (it's fine with GCC 11 branch and master, just GCC 
> > > > 10 branch is broken) 
> > > 
> > > Mike, please revert it then?
> > 
> > Preferably also the GCC 11 commit, because otherwise it needs backports
> > of the follow-up changes too.
> 
> Good point.  Yes please.

Both GCC 10 and GCC 11 reverted.

-- 
Michael Meissner, IBM
PO Box 98, Ayer, Massachusetts, USA, 01432
email: meissner@linux.ibm.com

Re: [PATCH, V3] PR target/99708- Define __SIZEOF_FLOAT128__ and __SIZEOF_IBM128__

[Segher Boessenkool]

On Fri, Mar 11, 2022 at 05:51:05PM -0500, Michael Meissner wrote:
> On Fri, Mar 11, 2022 at 02:51:23PM -0600, Segher Boessenkool wrote:
> > On Fri, Mar 11, 2022 at 08:42:27PM +0000, Joseph Myers wrote:
> > > The version of this patch applied to GCC 10 branch (commit 
> > > 641b407763ecfee5d4ac86d8ffe9eb1eeea5fd10) has broken the glibc build for 
> > > powerpc64le-linux-gnu (it's fine with GCC 11 branch and master, just GCC 
> > > 10 branch is broken) 
> > 
> > Mike, please revert it then?
> 
> Ok, I will revert both the GCC 11 and GCC 10 backport once I make sure the fix
> builds.  Sorry about that.  Obviously, we will want to backport whatever we do
> shortly to the older branches.

Yes, except the "shortly".  Experience shows that we need more thorough
testing for this, which means we need to wait longer, so that other
projects have time to do their testing.  Rushing things only causes more
problems :-/


Segher