Avoid terminating early in LRA, unless -fchecking (PR57676)

gcc/
	PR rtl-optimization/57676
	* lra-assigns.c (lra_assign): Guard test for maximum iterations
	with flag_checking.

gcc/testsuite/
	PR rtl-optimization/57676
	* gcc.dg/torture/pr57676.c: New test.

From-SVN: r233967

gcc/ChangeLog

+2016-03-04  Bernd Schmidt  <bschmidt@redhat.com>
+
+	PR rtl-optimization/57676
+	* lra-assigns.c (lra_assign): Guard test for maximum iterations
+	with flag_checking.
+
 2016-03-04  Ilya Enkovich  <enkovich.gnu@gmail.com>
 
 	* tree-vect-patterns.c (search_type_for_mask): Handle
 	comparison of booleans.
 
-
 2016-03-04  Jakub Jelinek  <jakub@redhat.com>
 
 	* doc/extend.texi (__builtin_alloca, __builtin_alloca_with_align):

gcc/lra-assigns.c

@@ -1620,7 +1620,12 @@ lra_assign (void)
   timevar_pop (TV_LRA_ASSIGN);
   if (former_reload_pseudo_spill_p)
     lra_assignment_iter_after_spill++;
-  if (lra_assignment_iter_after_spill > LRA_MAX_ASSIGNMENT_ITERATION_NUMBER)
+  /* This is conditional on flag_checking because valid code can take
+     more than this maximum number of iteration, but at the same time
+     the test can uncover errors in machine descriptions.  */
+  if (flag_checking
+      && (lra_assignment_iter_after_spill
+	  > LRA_MAX_ASSIGNMENT_ITERATION_NUMBER))
     internal_error
       ("Maximum number of LRA assignment passes is achieved (%d)\n",
        LRA_MAX_ASSIGNMENT_ITERATION_NUMBER);

gcc/testsuite/ChangeLog

+2016-03-04  Bernd Schmidt  <bschmidt@redhat.com>
+
+	PR rtl-optimization/57676
+	* gcc.dg/torture/pr57676.c: New test.
+
 2016-03-04  Ilya Enkovich  <enkovich.gnu@gmail.com>
 
 	* gcc.dg/pr70026.c: New test.

gcc/testsuite/gcc.dg/torture/pr57676.c

+/* Verify that LRA does not abort prematurely in a release build of the
+   compiler.  */
+/* { dg-do compile } */
+/* { dg-options "-fno-checking -w -funroll-loops" } */
+
+int a, b, c;
+
+void f(p1)
+{
+    for(;;)
+    {
+        if(p1 ? : (c /= 0))
+        {
+            int d;
+
+            for(; d; d++)
+            {
+                for(b = 0; b < 4; b++)
+                    p1 /= p1;
+lbl:
+                while(a);
+            }
+        }
+
+        if((c &= 1))
+            goto lbl;
+    }
+}