PR tree-optimization/78608 - gimple-ssa-sprintf.c:570:17: runtime error:…

PR tree-optimization/78608 - gimple-ssa-sprintf.c:570:17: runtime error: negation of -9223372036854775808 cannot be represented in type 'long int'

gcc/ChangeLog:
	* gimple-ssa-sprintf.c (tree_digits): Avoid negating TYPE_MIN.

From-SVN: r244511

gcc/ChangeLog

+2017-01-16  Martin Sebor  <msebor@redhat.com>
+
+	PR tree-optimization/78608
+	* gimple-ssa-sprintf.c (tree_digits): Avoid negating TYPE_MIN.
+
 2017-01-16  Jeff Law  <law@redhat.com>
 
 	Revert:

gcc/gimple-ssa-sprintf.c

@@ -577,16 +577,22 @@ tree_digits (tree x, int base, HOST_WIDE_INT prec, bool plus, bool prefix)
       if (tree_fits_shwi_p (x))
 	{
 	  HOST_WIDE_INT i = tree_to_shwi (x);
-	  if (i < 0)
-	    {
-	      absval = -i;
-	      res = 1;
-	    }
-	  else
-	    {
-	      absval = i;
-	      res = plus;
-	    }
+         if (HOST_WIDE_INT_MIN == i)
+           {
+             /* Avoid undefined behavior due to negating a minimum.  */
+             absval = HOST_WIDE_INT_MAX;
+             res = 1;
+           }
+         else if (i < 0)
+	   {
+	     absval = -i;
+	     res = 1;
+	   }
+	 else
+	   {
+	     absval = i;
+	     res = plus;
+	   }
 	}
       else
 	return -1;