floor: Implement result sign according to IEEE 754.

[gnulib.git] / tests / test-floorf-ieee.c

diff --git a/tests/test-floorf-ieee.c b/tests/test-floorf-ieee.c
index da13848..c4925d2 100644 (file)
--- a/tests/test-floorf-ieee.c
+++ b/tests/test-floorf-ieee.c
@@ -37,9 +37,20 @@ main (int argc, char **argv _GL_UNUSED)
 {
   float (*my_floorf) (float) = argc ? floorf : dummy;
 
+  /* See IEEE 754, section 6.3:
+       "the sign of the result of the round floating-point number to
+        integral value operation is the sign of the operand. These rules
+        shall apply even when operands or results are zero or infinite."  */
+
   /* Zero.  */
   ASSERT (!signbit (my_floorf (0.0f)));
   ASSERT (!!signbit (my_floorf (minus_zerof)) == !!signbit (minus_zerof));
+  /* Positive numbers.  */
+  ASSERT (!signbit (my_floorf (0.3f)));
+  ASSERT (!signbit (my_floorf (0.7f)));
+  /* Negative numbers.  */
+  ASSERT (!!signbit (my_floorf (-0.3f)) == !!signbit (minus_zerof));
+  ASSERT (!!signbit (my_floorf (-0.7f)) == !!signbit (minus_zerof));
 
   return 0;
 }