need -fp-model=strict for icx

git-svn-id: https://scm.gforge.inria.fr/anonscm/svn/mpfr/trunk@14552 280ebfd0-de03-0410-8827-d642c229c3f4

2 files changed, 29 insertions, 0 deletions

diff --git a/INSTALL b/INSTALL
index ec2b72e08..07202826e 100644
--- a/INSTALL
+++ b/INSTALL
@@ -716,3 +716,10 @@ wl="" into wl="-Wl," in the libtool file.
 All tests (make check) should pass (tget_set_d64, tget_set_d128 and
 tset_float128 are skipped, since CompCert does not support _Decimal64,
 _Decimal128 nor _Float128).
+
+e. Using the Intel OneApi compiler
+==================================
+
+When using the Intel OneApi compiler (icx), one should add -fp-model=strict
+to CFLAGS so that the conversion routines from/to native floating-point
+types (float, double, ...) work properly. Otherwise some tests will fail.
diff --git a/tests/tget_flt.c b/tests/tget_flt.c
index 04975c004..b85e74b68 100644
--- a/tests/tget_flt.c
+++ b/tests/tget_flt.c
@@ -21,6 +21,7 @@ https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
 
 #include <float.h>     /* for FLT_MIN */
+#include <math.h>      /* for isnan */
 
 #include "mpfr-test.h"
 #include "ieee_floats.h"
@@ -47,6 +48,25 @@ equal_flt (float f, float g)
     }
 }
 
+/* bug with icx 2021.2.0, when MPFR is not compiled with -fp-model=strict */
+static void
+bug_icx (void)
+{
+  mpfr_t x;
+  float y;
+  mpfr_init2 (x, 24);
+  mpfr_set_flt (x, -0x1p-149f, MPFR_RNDN);
+  mpfr_log (x, x, MPFR_RNDN);
+  y = mpfr_get_flt (x, MPFR_RNDN);
+  if (!isnan (y))
+    {
+      printf ("Error, mpfr_get_flt(NaN) != NaN\n");
+      printf ("got %a\n", y);
+      exit (1);
+    }
+  mpfr_clear (x);
+}
+
 int
 main (void)
 {
@@ -59,6 +79,8 @@ main (void)
 
   tests_start_mpfr ();
 
+  bug_icx ();
+
 #if !defined(MPFR_ERRDIVZERO)
   infp = (float) MPFR_DBL_INFP;
   if (infp * 0.5 != infp)