[gdb/testsuite] Fix gdb.ada/float-bits.exp with -m32

With test-case gdb.ada/float-bits.exp and native we get:
...
(gdb) print 16llf#7FFFF7FF4054A56FA5B99019A5C8#^M
$9 = 5.0e+25^M
(gdb) PASS: gdb.ada/float-bits.exp: print 16llf#7FFFF7FF4054A56FA5B99019A5C8#
...
but with target board unix/-m32 we have instead:
...
(gdb) print 16llf#7FFFF7FF4054A56FA5B99019A5C8#^M
Cannot export value 2596145952482202326224873165792712 as 96-bits \
  unsigned integer (must be between 0 and 79228162514264337593543950335)^M
(gdb) FAIL: gdb.ada/float-bits.exp: print 16llf#7FFFF7FF4054A56FA5B99019A5C8#
...

Fix this by testing whether 16llf is supported by doing ptype long_long_float
which gets us either:
...
type = <16-byte float>^M
...
or:
...
type = <12-byte float>^M
...

Tested on x86_64-linux with native and unix/-m32.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29041

1 files changed, 22 insertions, 5 deletions

diff --git a/gdb/testsuite/gdb.ada/float-bits.exp b/gdb/testsuite/gdb.ada/float-bits.exp
index c98afb5..4ca8dbf 100644
--- a/gdb/testsuite/gdb.ada/float-bits.exp
+++ b/gdb/testsuite/gdb.ada/float-bits.exp
@@ -42,12 +42,29 @@ gdb_test "print val_double := 16lf#bc0d83c94fb6d2ac#" " = -2.0e-19"
 gdb_test "print val_double" " = -2.0e-19" \
     "print val_double after assignment"
 
-gdb_test "print 16llf#7FFFF7FF4054A56FA5B99019A5C8#" " = 5.0e\\+25"
+set 16llf_supported 0
+gdb_test_multiple "ptype long_long_float" "" {
+    -re -wrap "<16-byte float>" {
+	set 16llf_supported 1
+	pass $gdb_test_name
+    }
+    -re -wrap "<\\d+-byte float>" {
+	pass $gdb_test_name
+    }
+}
+
+if { $16llf_supported } {
+    gdb_test "print 16llf#7FFFF7FF4054A56FA5B99019A5C8#" " = 5.0e\\+25"
+}
 gdb_test "print val_long_double" " = 5.0e\\+25"
-gdb_test "print val_long_double := 16llf#7FFFF7FF4054A56FA5B99019A5C8#" \
-    " = 5.0e\\+25"
+if { $16llf_supported } {
+    gdb_test "print val_long_double := 16llf#7FFFF7FF4054A56FA5B99019A5C8#" \
+	" = 5.0e\\+25"
+}
 gdb_test "print val_long_double" " = 5.0e\\+25" \
     "print val_long_double after assignment"
 
-gdb_test "print 16llf#a56fa5b99019a5c800007ffff7ff4054#" \
-    " = <invalid float value>"
+if { $16llf_supported } {
+    gdb_test "print 16llf#a56fa5b99019a5c800007ffff7ff4054#" \
+	" = <invalid float value>"
+}