PowerPC: Update long double IEEE 128-bit tests.

will schmidt will_schmidt@vnet.ibm.com
Tue Oct 27 15:07:17 GMT 2020


On Thu, 2020-10-22 at 18:07 -0400, Michael Meissner via Gcc-patches wrote:
> PowerPC: Update long double IEEE 128-bit tests.
> 
> I have split all of these patches into separate patches to hopefully get them
> into the tree.
> 
> This patch fixes 3 tests in the testsuite that fail if long double is set
> to IEEE 128-bit.
> 
> I have tested this patch with bootstrap builds on a little endian power9 system
> running Linux.  With the other patches, I have built two full bootstrap builds
> using this patch and the patches after this patch.  One build used the current
> default for long double (IBM extended double) and the other build switched the
> default to IEEE 128-bit.  I used the Advance Toolchain AT 14.0 compiler as the
> library used by this compiler.  There are no regressions between the tests.
> There are 3 fortran benchmarks (ieee/large_2.f90, default_format_2.f90, and
> default_format_denormal_2.f90) that now pass.
> 
> Can I install this into the trunk?
> 
> We have gotten some requests to back port these changes to GCC 10.x.  At the
> moment, I am not planning to do the back port, but I may need to in the future.
> 
> gcc/testsuite/
> 2020-10-22  Michael Meissner  <meissner@linux.ibm.com>
> 
> 	* c-c++-common/dfp/convert-bfp-11.c: If long double is IEEE
> 	128-bit, skip the test.
> 	* gcc.dg/nextafter-2.c: On PowerPC, if long double is IEEE
> 	128-bit, include math.h to get the built-in mapped correctly.
> 	* gcc.target/powerpc/pr70117.c: Add support for long double being
> 	IEEE 128-bit.
> ---
>  gcc/testsuite/c-c++-common/dfp/convert-bfp-11.c |  7 +++++++
>  gcc/testsuite/gcc.dg/nextafter-2.c              | 10 ++++++++++
>  gcc/testsuite/gcc.target/powerpc/pr70117.c      |  6 ++++--
>  3 files changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/gcc/testsuite/c-c++-common/dfp/convert-bfp-11.c b/gcc/testsuite/c-c++-common/dfp/convert-bfp-11.c
> index 95c433d2c24..6ee0c1c6ae9 100644
> --- a/gcc/testsuite/c-c++-common/dfp/convert-bfp-11.c
> +++ b/gcc/testsuite/c-c++-common/dfp/convert-bfp-11.c
> @@ -5,6 +5,7 @@
>     Don't force 128-bit long doubles because runtime support depends
>     on glibc.  */
> 
> +#include <float.h>
>  #include "convert.h"
> 
>  volatile _Decimal32 sd;
> @@ -39,6 +40,12 @@ main ()
>    if (sizeof (long double) != 16)
>      return 0;
> 
> +  /* This test is written to test IBM extended double, which is a pair of
> +     doubles.  If long double can hold a larger value than a double can, such
> +     as when long double is IEEE 128-bit, just exit immediately.  */
> +  if (LDBL_MAX_10_EXP > DBL_MAX_10_EXP)
> +    return 0;
> +
>    convert_101 ();
>    convert_102 ();
> 
> diff --git a/gcc/testsuite/gcc.dg/nextafter-2.c b/gcc/testsuite/gcc.dg/nextafter-2.c
> index e51ae94be0c..64e9e3c485f 100644
> --- a/gcc/testsuite/gcc.dg/nextafter-2.c
> +++ b/gcc/testsuite/gcc.dg/nextafter-2.c
> @@ -13,4 +13,14 @@
>  #  define NO_LONG_DOUBLE 1
>  # endif
>  #endif
> +
> +#if defined(_ARCH_PPC) && defined(__LONG_DOUBLE_IEEE128__)
> +/* On PowerPC systems, long double uses either the IBM long double format, or
> +   IEEE 128-bit format.  The compiler switches the long double built-in
> +   function names and glibc switches the names when math.h is included.
> +   Because this test is run with -fno-builtin, include math.h so that the
> +   appropriate nextafter functions are called.  */


Great comment. :-)


> +#include <math.h>
> +#endif
> +
>  #include "nextafter-1.c"
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr70117.c b/gcc/testsuite/gcc.target/powerpc/pr70117.c
> index 3bbd2c595e0..928efe39c7b 100644
> --- a/gcc/testsuite/gcc.target/powerpc/pr70117.c
> +++ b/gcc/testsuite/gcc.target/powerpc/pr70117.c
> @@ -9,9 +9,11 @@
>     128-bit floating point, because the type is not enabled on those
>     systems.  */
>  #define LDOUBLE __ibm128
> +#define IBM128_MAX ((__ibm128) 1.79769313486231580793728971405301199e+308L)
> 
>  #elif defined(__LONG_DOUBLE_IBM128__)
>  #define LDOUBLE long double
> +#define IBM128_MAX LDBL_MAX
> 
>  #else
>  #error "long double must be either IBM 128-bit or IEEE 128-bit"
> @@ -75,10 +77,10 @@ main (void)
>    if (__builtin_isnormal (ld))
>      __builtin_abort ();
> 
> -  ld = LDBL_MAX;
> +  ld = IBM128_MAX;
>    if (!__builtin_isnormal (ld))
>      __builtin_abort ();
> -  ld = -LDBL_MAX;
> +  ld = -IBM128_MAX;
>    if (!__builtin_isnormal (ld))
>      __builtin_abort ();
> 

ok

lgtm, 
thanks
-Will

> -- 
> 2.22.0
> 
> 



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