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Diffstat (limited to 'gcc/testsuite/gcc.c-torture/execute/991228-1.c')
-rw-r--r--gcc/testsuite/gcc.c-torture/execute/991228-1.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.c-torture/execute/991228-1.c b/gcc/testsuite/gcc.c-torture/execute/991228-1.c
new file mode 100644
index 000000000..c6fe78e7d
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/991228-1.c
@@ -0,0 +1,25 @@
+__extension__ union { double d; int i[2]; } u = { d: -0.25 };
+
+/* This assumes the endianness of words in a long long is the same as
+ that for doubles, which doesn't hold for a few platforms, but we
+ can probably special case them here, as appropriate. */
+long long endianness_test = 1;
+#define MSW (*(int*)&endianness_test)
+
+int
+signbit(double x)
+{
+ __extension__ union { double d; int i[2]; } u = { d: x };
+ return u.i[MSW] < 0;
+}
+
+int main(void)
+{
+ if (2*sizeof(int) != sizeof(double) || u.i[MSW] >= 0)
+ exit(0);
+
+ if (!signbit(-0.25))
+ abort();
+
+ exit(0);
+}