On 11/05/2010 04:30 PM, Eric Blake wrote:
> * tests/test-ceilf2.c (ceilf_reference): Avoid icc's use of DAZ
> [denormals-as-zero] when optimizing without -mieee-fp option.
> * tests/test-floorf2.c (floorf_reference): Likewise.
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
> ---
>
> This fixes failures of icc without -mieee-fp on test-{ceil,floor}f2.c.
> However, it does not fix test-{ceil,floor}f1.c, where my recent testsuite
> improvements flushed out the following compiler quirk:
>
> icc -mieee-fp, as well as icc -O0 (which is also implied by icc -g),
> emit a call to ceilf(); therefore, if -lm has a working
> implementation, then configure detects that it is working, lib/ceil.c
> is never compiled, and the test passes. But icc -O2 (which is the
> default with plain icc) recognizes ceilf and inlines it into assembly
> code that unfortunately turns -0.0f into 0.0. Technically, this is
> not a bug, since POSIX is explicit that compliance of -0.0f is an
> optional feature, if you are not compliant with the <MX> option.
>
> And, since I'm still not sure I want to force -mieee-fp onto all
> gnulib projects, that means I'm still scratching my head for a way
> to either defeat icc's insistence on inlining ceilf, or I'll have
> to tighten m4/ceilf.m4 to detect when icc is being used without full
> IEEE compliance.
That was tougher than I thought. icc is good enough at inlining to
recognize a function pointer that points to a trivial wrapper around
ceilf, and replace even that with the compiler's ceilf replacement. It
took the use of a "non-deterministic" decision between something that is
obviously not ceilf before I got the desired effect. Here's what I'm
squashing in.
diff --git c/ChangeLog w/ChangeLog
index b853aad..e36599e 100644
--- c/ChangeLog
+++ w/ChangeLog
@@ -4,6 +4,9 @@
* tests/test-ceilf2.c (ceilf_reference): Avoid icc's use of DAZ
[denormals-as-zero] when optimizing without -mieee-fp option.
* tests/test-floorf2.c (floorf_reference): Likewise.
+ * tests/test-ceilf1.c (dummy): New function.
+ (main): Use it to outsmart icc's optimization.
+ * tests/test-floorf1.c (dummy, main): Likewise.
tests: require working signbit
* modules/ceilf-tests (Depends-on): Add signbit.
diff --git c/tests/test-ceilf1.c w/tests/test-ceilf1.c
index 4e38247..a77641f 100644
--- c/tests/test-ceilf1.c
+++ w/tests/test-ceilf1.c
@@ -28,40 +28,53 @@ SIGNATURE_CHECK (ceilf, float, (float));
#include "nan.h"
#include "macros.h"
+/* If IEEE compliance was not requested, the ICC compiler inlines its
+ own ceilf assembly that turns -0.0f to 0.0f; but that is a correct
+ result when IEEE is not enforced. To avoid spurious failure, we
+ have to provide this dummy function in order to outsmart ICC's
+ inlining, and call our ceilf through a function pointer. */
+static float
+dummy (float f)
+{
+ return 0;
+}
+
int
-main ()
+main (int argc, char **argv _GL_UNUSED)
{
+ float (*my_ceilf) (float) = argc ? ceilf : dummy;
+
/* Zero. */
- ASSERT (ceilf (0.0f) == 0.0f);
- ASSERT (!signbit (ceilf (0.0f)));
- ASSERT (ceilf (minus_zerof) == 0.0f);
- ASSERT (!!signbit (minus_zerof) == !!signbit (ceilf (minus_zerof)));
+ ASSERT (my_ceilf (0.0f) == 0.0f);
+ ASSERT (!signbit (my_ceilf (0.0f)));
+ ASSERT (my_ceilf (minus_zerof) == 0.0f);
+ ASSERT (!!signbit (minus_zerof) == !!signbit (my_ceilf (minus_zerof)));
/* Positive numbers. */
- ASSERT (ceilf (0.3f) == 1.0f);
- ASSERT (ceilf (0.7f) == 1.0f);
- ASSERT (ceilf (1.0f) == 1.0f);
- ASSERT (ceilf (1.001f) == 2.0f);
- ASSERT (ceilf (1.5f) == 2.0f);
- ASSERT (ceilf (1.999f) == 2.0f);
- ASSERT (ceilf (2.0f) == 2.0f);
- ASSERT (ceilf (65535.99f) == 65536.0f);
- ASSERT (ceilf (65536.0f) == 65536.0f);
- ASSERT (ceilf (2.341e31f) == 2.341e31f);
+ ASSERT (my_ceilf (0.3f) == 1.0f);
+ ASSERT (my_ceilf (0.7f) == 1.0f);
+ ASSERT (my_ceilf (1.0f) == 1.0f);
+ ASSERT (my_ceilf (1.001f) == 2.0f);
+ ASSERT (my_ceilf (1.5f) == 2.0f);
+ ASSERT (my_ceilf (1.999f) == 2.0f);
+ ASSERT (my_ceilf (2.0f) == 2.0f);
+ ASSERT (my_ceilf (65535.99f) == 65536.0f);
+ ASSERT (my_ceilf (65536.0f) == 65536.0f);
+ ASSERT (my_ceilf (2.341e31f) == 2.341e31f);
/* Negative numbers. */
- ASSERT (ceilf (-0.3f) == 0.0f);
- ASSERT (ceilf (-0.7f) == 0.0f);
- ASSERT (ceilf (-1.0f) == -1.0f);
- ASSERT (ceilf (-1.5f) == -1.0f);
- ASSERT (ceilf (-1.999f) == -1.0f);
- ASSERT (ceilf (-2.0f) == -2.0f);
- ASSERT (ceilf (-65535.99f) == -65535.0f);
- ASSERT (ceilf (-65536.0f) == -65536.0f);
- ASSERT (ceilf (-2.341e31f) == -2.341e31f);
+ ASSERT (my_ceilf (-0.3f) == 0.0f);
+ ASSERT (my_ceilf (-0.7f) == 0.0f);
+ ASSERT (my_ceilf (-1.0f) == -1.0f);
+ ASSERT (my_ceilf (-1.5f) == -1.0f);
+ ASSERT (my_ceilf (-1.999f) == -1.0f);
+ ASSERT (my_ceilf (-2.0f) == -2.0f);
+ ASSERT (my_ceilf (-65535.99f) == -65535.0f);
+ ASSERT (my_ceilf (-65536.0f) == -65536.0f);
+ ASSERT (my_ceilf (-2.341e31f) == -2.341e31f);
/* Infinite numbers. */
- ASSERT (ceilf (1.0f / 0.0f) == 1.0f / 0.0f);
- ASSERT (ceilf (-1.0f / 0.0f) == -1.0f / 0.0f);
+ ASSERT (my_ceilf (1.0f / 0.0f) == 1.0f / 0.0f);
+ ASSERT (my_ceilf (-1.0f / 0.0f) == -1.0f / 0.0f);
/* NaNs. */
- ASSERT (isnanf (ceilf (NaNf ())));
+ ASSERT (isnanf (my_ceilf (NaNf ())));
return 0;
}
diff --git c/tests/test-floorf1.c w/tests/test-floorf1.c
index f0f7716..4877c41 100644
--- c/tests/test-floorf1.c
+++ w/tests/test-floorf1.c
@@ -28,40 +28,53 @@ SIGNATURE_CHECK (floorf, float, (float));
#include "nan.h"
#include "macros.h"
+/* If IEEE compliance was not requested, the ICC compiler inlines its
+ own floorf assembly that turns -0.0f to 0.0f; but that is a correct
+ result when IEEE is not enforced. To avoid spurious failure, we
+ have to provide this dummy function in order to outsmart ICC's
+ inlining, and call our floorf through a function pointer. */
+static float
+dummy (float f)
+{
+ return 0;
+}
+
int
-main ()
+main (int argc, char **argv _GL_UNUSED)
{
+ float (*my_floorf) (float) = argc ? floorf : dummy;
+
/* Zero. */
- ASSERT (floorf (0.0f) == 0.0f);
- ASSERT (!signbit (floorf (0.0f)));
- ASSERT (floorf (minus_zerof) == 0.0f);
- ASSERT (!!signbit (minus_zerof) == !!signbit (floorf (minus_zerof)));
+ ASSERT (my_floorf (0.0f) == 0.0f);
+ ASSERT (!signbit (my_floorf (0.0f)));
+ ASSERT (my_floorf (minus_zerof) == 0.0f);
+ ASSERT (!!signbit (minus_zerof) == !!signbit (my_floorf (minus_zerof)));
/* Positive numbers. */
- ASSERT (floorf (0.3f) == 0.0f);
- ASSERT (floorf (0.7f) == 0.0f);
- ASSERT (floorf (1.0f) == 1.0f);
- ASSERT (floorf (1.5f) == 1.0f);
- ASSERT (floorf (1.999f) == 1.0f);
- ASSERT (floorf (2.0f) == 2.0f);
- ASSERT (floorf (65535.99f) == 65535.0f);
- ASSERT (floorf (65536.0f) == 65536.0f);
- ASSERT (floorf (2.341e31f) == 2.341e31f);
+ ASSERT (my_floorf (0.3f) == 0.0f);
+ ASSERT (my_floorf (0.7f) == 0.0f);
+ ASSERT (my_floorf (1.0f) == 1.0f);
+ ASSERT (my_floorf (1.5f) == 1.0f);
+ ASSERT (my_floorf (1.999f) == 1.0f);
+ ASSERT (my_floorf (2.0f) == 2.0f);
+ ASSERT (my_floorf (65535.99f) == 65535.0f);
+ ASSERT (my_floorf (65536.0f) == 65536.0f);
+ ASSERT (my_floorf (2.341e31f) == 2.341e31f);
/* Negative numbers. */
- ASSERT (floorf (-0.3f) == -1.0f);
- ASSERT (floorf (-0.7f) == -1.0f);
- ASSERT (floorf (-1.0f) == -1.0f);
- ASSERT (floorf (-1.001f) == -2.0f);
- ASSERT (floorf (-1.5f) == -2.0f);
- ASSERT (floorf (-1.999f) == -2.0f);
- ASSERT (floorf (-2.0f) == -2.0f);
- ASSERT (floorf (-65535.99f) == -65536.0f);
- ASSERT (floorf (-65536.0f) == -65536.0f);
- ASSERT (floorf (-2.341e31f) == -2.341e31f);
+ ASSERT (my_floorf (-0.3f) == -1.0f);
+ ASSERT (my_floorf (-0.7f) == -1.0f);
+ ASSERT (my_floorf (-1.0f) == -1.0f);
+ ASSERT (my_floorf (-1.001f) == -2.0f);
+ ASSERT (my_floorf (-1.5f) == -2.0f);
+ ASSERT (my_floorf (-1.999f) == -2.0f);
+ ASSERT (my_floorf (-2.0f) == -2.0f);
+ ASSERT (my_floorf (-65535.99f) == -65536.0f);
+ ASSERT (my_floorf (-65536.0f) == -65536.0f);
+ ASSERT (my_floorf (-2.341e31f) == -2.341e31f);
/* Infinite numbers. */
- ASSERT (floorf (1.0f / 0.0f) == 1.0f / 0.0f);
- ASSERT (floorf (-1.0f / 0.0f) == -1.0f / 0.0f);
+ ASSERT (my_floorf (1.0f / 0.0f) == 1.0f / 0.0f);
+ ASSERT (my_floorf (-1.0f / 0.0f) == -1.0f / 0.0f);
/* NaNs. */
- ASSERT (isnanf (floorf (NaNf ())));
+ ASSERT (isnanf (my_floorf (NaNf ())));
return 0;
}
--
Eric Blake ebl...@redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org
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