[PATCH 2/3] PowerPC: require IBM long double for pr70117.

[Michael Meissner <meissner@linux.ibm.com>]

PowerPC: require IBM long double for pr70117.

Since the test is explicitly checking for IBM extended double, do not try to
run it when long double is IEEE 128-bit.

I have tested this patch and the first patch in the series on a little endian
power9 system with 3 compilers that have the 3 different long double types
configured.  I verified that this test is listed as unsupported if long double
is not IBM 128-bit, and it passes if long double is IBM 128-bit.

Can I check this patch into the master branch?  After an appropriate soak-in
time, can I back port this patch to the previous open GCC trees?

gcc/testsuite/
2020-11-21  Michael Meissner  <meissner@linux.ibm.com>

	PR target/70117
	* gcc.target/powerpc/pr70117.c: Only run the test if long double
	uses the IBM extended double format.
---
 gcc/testsuite/gcc.target/powerpc/pr70117.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/gcc/testsuite/gcc.target/powerpc/pr70117.c b/gcc/testsuite/gcc.target/powerpc/pr70117.c
index 3bbd2c595e0..2077d15afd4 100644
--- a/gcc/testsuite/gcc.target/powerpc/pr70117.c
+++ b/gcc/testsuite/gcc.target/powerpc/pr70117.c
@@ -1,26 +1,12 @@
-/* { dg-do run { target { powerpc*-*-linux* powerpc*-*-darwin* powerpc*-*-aix* rs6000-*-* } } } */
-/* { dg-options "-std=c99 -mlong-double-128 -O2" } */
+/* { dg-require-effective-target ppc_long_double_ibm } */
+/* { dg-options "-std=c99 -O2" } */
 
 #include <float.h>
 
-#if defined(__LONG_DOUBLE_IEEE128__)
-/* If long double is IEEE 128-bit, we need to use the __ibm128 type instead of
-   long double.  We can't use __ibm128 on systems that don't support IEEE
-   128-bit floating point, because the type is not enabled on those
-   systems.  */
-#define LDOUBLE __ibm128
-
-#elif defined(__LONG_DOUBLE_IBM128__)
-#define LDOUBLE long double
-
-#else
-#error "long double must be either IBM 128-bit or IEEE 128-bit"
-#endif
-
 union gl_long_double_union
 {
   struct { double hi; double lo; } dd;
-  LDOUBLE ld;
+  long double ld;
 };
 
 /* This is gnulib's LDBL_MAX which, being 107 bits in precision, is
@@ -36,7 +22,7 @@ volatile double dnan = 0.0/0.0;
 int
 main (void)
 {
-  LDOUBLE ld;
+  long double ld;
 
   ld = gl_LDBL_MAX.ld;
   if (__builtin_isinf (ld))
-- 
2.22.0


-- 
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meissner@linux.ibm.com, phone: +1 (978) 899-4797