math/test: Allow user to set control element of input vector

argf and argd have been designed such that non-special input is
tested, optionally followed by a vector with one special lane. To be
able to test that vector functions have correct behaviour w.r.t. fenv
exceptions, we need to be able to choose a different value for the
last lane, as using 1 leads to false negatives when testing a function
for which 1 is a special value. We add an option, -c, for the user to
provide a different control value.

1 files changed, 12 insertions, 2 deletions

diff --git a/math/test/ulp.c b/math/test/ulp.c
index 24185a2..e011ae3 100644
--- a/math/test/ulp.c
+++ b/math/test/ulp.c
@@ -223,8 +223,9 @@ static int secondcall;
 #if __aarch64__ && WANT_VMATH
 typedef __f32x4_t v_float;
 typedef __f64x2_t v_double;
-static const float fv[2] = {1.0f, -INFINITY};
-static const double dv[2] = {1.0, -INFINITY};
+/* First element of fv and dv may be changed by -c argument.  */
+static float fv[2] = {1.0f, -INFINITY};
+static double dv[2] = {1.0, -INFINITY};
 static inline v_float argf(float x) { return (v_float){x,x,x,fv[secondcall]}; }
 static inline v_double argd(double x) { return (v_double){x,dv[secondcall]}; }
 #if WANT_SVE_MATH
@@ -633,6 +634,9 @@ usage (void)
   puts ("-q: quiet.");
   puts ("-m: use mpfr even if faster method is available.");
   puts ("-f: disable fenv testing (rounding modes and exceptions).");
+  puts ("-c: neutral 'control value' to test behaviour when one lane can affect another. \n"
+	"    This should be different from tested input in other lanes, and non-special \n"
+	"    (i.e. should not trigger fenv exceptions). Default is 1.");
   puts ("Supported func:");
   for (const struct fun *f = fun; f->name; f++)
     printf ("\t%s\n", f->name);
@@ -800,6 +804,12 @@ main (int argc, char *argv[])
 	      conf.rc = argv[0][0];
 	    }
 	  break;
+	case 'c':
+	  argc--;
+	  argv++;
+	  fv[0] = strtof(argv[0], 0);
+	  dv[0] = strtod(argv[0], 0);
+	  break;
 	default:
 	  usage ();
 	}