[BZ #22142] powerpc: Fix the carry bit on mpn_[add|sub]_n on POWER7

Fix the ifdef clause that was being used in the opposite way, setting
a wrong value of the carry bit.

This is also correcting 2 memory accesses that were mistakenly referring
to r0 while they were supposed to mean the immediate value 0.

	[BZ #22142]
	* stdio-common/tst-printf.c (fp_test): Add tests for DBL_MAX and
	-DBL_MAX.
	(do_test): Likewise.
	* stdio-common/tst-printf.sh: Likewise.
	* sysdeps/powerpc/powerpc64/power7/add_n.S: Invert the initial
	ifdef clause in order to set the carry bit right.  Replace r0 by
	0 without changing the behavior.

1 files changed, 4 insertions, 0 deletions

diff --git a/stdio-common/tst-printf.c b/stdio-common/tst-printf.c
index b6d62a5a2f..162effaf63 100644
--- a/stdio-common/tst-printf.c
+++ b/stdio-common/tst-printf.c
@@ -136,6 +136,8 @@ fp_test (void)
   }
   printf("%10s\n", (char *) NULL);
   printf("%-10s\n", (char *) NULL);
+  printf("%.8f\n", DBL_MAX);
+  printf("%.8f\n", -DBL_MAX);
 }
 
 static int
@@ -181,6 +183,8 @@ I am ready for my first lesson today.";
   printf("null string:\t\"%s\"\n", (char *)NULL);
   printf("limited string:\t\"%.22s\"\n", longstr);
 
+  printf("a-style max:\t\"%a\"\n", DBL_MAX);
+  printf("a-style -max:\t\"%a\"\n", -DBL_MAX);
   printf("e-style >= 1:\t\"%e\"\n", 12.34);
   printf("e-style >= .1:\t\"%e\"\n", 0.1234);
   printf("e-style < .1:\t\"%e\"\n", 0.001234);