re PR c/39034 (Decimal floating-point math done wrong)

	PR c/39034
	* gcc.dg/dfp/pr39034.c: New test.

Co-Authored-By: Ben Elliston <bje@au.ibm.com>

From-SVN: r143884

gcc/testsuite/ChangeLog

+2009-02-03  Janis Johnson  <janis187@us.ibm.com>
+	    Ben Elliston  <bje@au.ibm.com>
+
+	PR c/39034
+	* gcc.dg/dfp/pr39034.c: New test.
+
 2009-02-02  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	PR testsuite/38263

gcc/testsuite/gcc.dg/dfp/pr39034.c

+/* { dg-do run } */
+/* { dg-options "-std=gnu99 -O" } */
+
+/* DFP TR 24732 == WG14 / N1176, N1312 */
+/* Based on a test from Fred Tydeman.  */
+
+extern void abort (void);
+int failures = 0;
+
+#ifdef DBG
+#include <stdio.h>
+#define FAILURE(MSG) { printf ("line %d: %s\n", __LINE__, MSG); failures++; }
+#else
+#define FAILURE(MSG) failures++;
+#endif
+
+
+/* Test runtime computations.  */
+
+void
+runtime32 (void)
+{
+  volatile float v1 = 28.f, v2 = 3.f, v3 = 9.f, v4 = 31.f, v5 = 3.f, v6 = 10.f;
+  float      b32 = (float)((v1/v2-v3) - (v4/v5-v6));
+  _Decimal32 d32 = (float)((v1/v2-v3) - (v4/v5-v6));
+
+  if (b32)
+    FAILURE ("runtime: b32 should be zero")
+  if (d32)
+    FAILURE ("runtime: d32 should be zero")
+}
+
+void
+runtime64 (void)
+{
+  volatile double v1 = 28., v2 = 3., v3 = 9., v4 = 31., v5 = 3., v6 = 10.;
+  double     b64 = (double)((v1/v2-v3) - (v4/v5-v6));
+  _Decimal64 d64 = (double)((v1/v2-v3) - (v4/v5-v6));
+
+  if (b64)
+    FAILURE ("runtime: b64 should be zero")
+  if (d64)
+    FAILURE ("runtime: d64 should be zero")
+}
+
+void
+runtime128 (void)
+{
+  volatile long double v1 = 28.l, v2 = 3.l, v3 = 9.l,
+                       v4 = 31.l, v5 = 3.l, v6 = 10.l;
+  long double b128 = (long double)((v1/v2-v3) - (v4/v5-v6));
+  _Decimal128 d128 = (long double)((v1/v2-v3) - (v4/v5-v6));
+
+  if (b128)
+    FAILURE ("runtime: b128 should be zero")
+  if (d128)
+    FAILURE ("runtime: d128 should be zero")
+}
+
+/* Test constant folding.  */
+
+void
+fold32 (void)
+{
+  double     d32 = (float)((28.f/3.f-9.f) - (31.f/3.f-10.f));
+  _Decimal32 b32 = (float)((28.f/3.f-9.f) - (31.f/3.f-10.f));
+
+  if (b32)
+    FAILURE ("fold: b32 should be zero")
+  if (d32)
+    FAILURE ("fold: d32 should be zero")
+}
+
+void
+fold64 (void)
+{
+  double     b64 = (double)((28./3.-9.) - (31./3.-10.));
+  _Decimal64 d64 = (double)((28./3.-9.) - (31./3.-10.));
+
+  if (b64)
+    FAILURE ("fold: b64 should be zero")
+  if (d64)
+    FAILURE ("fold: d64 should be zero")
+}
+
+void
+fold128 (void)
+{
+  long double b128 = (long double)((28./3.-9.) - (31./3.-10.));
+  _Decimal128 d128 = (long double)((28./3.-9.) - (31./3.-10.));
+
+  if (b128)
+    FAILURE ("fold: b128 should be zero")
+  if (d128)
+    FAILURE ("fold: d128 should be zero")
+}
+
+int
+main ()
+{
+  runtime32 ();
+  runtime64 ();
+  runtime128 ();
+  fold32 ();
+  fold64 ();
+  fold128 ();
+
+  if (failures != 0)
+    abort ();
+  return 0;
+}