re PR rtl-optimization/68376 (wrong code at -O1 and above on x86_64-linux-gnu)

	PR rtl-optimization/68376
	PR rtl-optimization/68670
	* ifcvt.c (noce_try_abs): For one_cmpl allow < 0, >= 0
	or > -1 conditions regardless of negate, and disallow
	all other conditions.

	* gcc.c-torture/execute/pr68376-2.c (f5, f6, f7, f8): New
	tests.
	(main): Call them.
	* gcc.dg/pr68670-1.c: New test.
	* gcc.dg/pr68670-2.c: New test.

From-SVN: r231526

gcc/ChangeLog

+2015-12-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/68376
+	PR rtl-optimization/68670
+	* ifcvt.c (noce_try_abs): For one_cmpl allow < 0, >= 0
+	or > -1 conditions regardless of negate, and disallow
+	all other conditions.
+
 2015-12-10  Ilya Enkovich  <enkovich.gnu@gmail.com>
 
 	* tree-chkp.c (chkp_call_returns_bounds_p): Return true

gcc/ifcvt.c

@@ -2601,45 +2601,22 @@ noce_try_abs (struct noce_if_info *if_info)
      Note that these rtx constants are known to be CONST_INT, and
      therefore imply integer comparisons.
      The one_cmpl case is more complicated, as we want to handle
-     only x < 0 ? ~x : x or x >= 0 ? ~x : x but not
-     x <= 0 ? ~x : x or x > 0 ? ~x : x, as the latter two
-     have different result for x == 0.  */
+     only x < 0 ? ~x : x or x >= 0 ? x : ~x to one_cmpl_abs (x)
+     and x < 0 ? x : ~x or x >= 0 ? ~x : x to ~one_cmpl_abs (x),
+     but not other cases (x > -1 is equivalent of x >= 0).  */
   if (c == constm1_rtx && GET_CODE (cond) == GT)
-    {
-      if (one_cmpl && negate)
-	return FALSE;
-    }
+    ;
   else if (c == const1_rtx && GET_CODE (cond) == LT)
     {
-      if (one_cmpl && !negate)
+      if (one_cmpl)
 	return FALSE;
     }
   else if (c == CONST0_RTX (GET_MODE (b)))
     {
-      if (one_cmpl)
-	switch (GET_CODE (cond))
-	  {
-	  case GT:
-	    if (!negate)
-	      return FALSE;
-	    break;
-	  case GE:
-	    /* >= 0 is the same case as above > -1.  */
-	    if (negate)
-	      return FALSE;
-	    break;
-	  case LT:
-	    if (negate)
-	      return FALSE;
-	    break;
-	  case LE:
-	    /* <= 0 is the same case as above < 1.  */
-	    if (!negate)
-	      return FALSE;
-	    break;
-	  default:
-	    return FALSE;
-	  }
+      if (one_cmpl
+	  && GET_CODE (cond) != GE
+	  && GET_CODE (cond) != LT)
+	return FALSE;
     }
   else
     return FALSE;

gcc/testsuite/ChangeLog

+2015-12-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/68376
+	PR rtl-optimization/68670
+	* gcc.c-torture/execute/pr68376-2.c (f5, f6, f7, f8): New
+	tests.
+	(main): Call them.
+	* gcc.dg/pr68670-1.c: New test.
+	* gcc.dg/pr68670-2.c: New test.
+
 2015-12-10  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/68348

gcc/testsuite/gcc.c-torture/execute/pr68376-2.c

@@ -26,6 +26,30 @@ f4 (int x)
   return x <= 0 ? x : ~x;
 }
 
+__attribute__((noinline, noclone)) int
+f5 (int x)
+{
+  return x >= 0 ? ~x : x;
+}
+
+__attribute__((noinline, noclone)) int
+f6 (int x)
+{
+  return x >= 0 ? x : ~x;
+}
+
+__attribute__((noinline, noclone)) int
+f7 (int x)
+{
+  return x > 0 ? ~x : x;
+}
+
+__attribute__((noinline, noclone)) int
+f8 (int x)
+{
+  return x > 0 ? x : ~x;
+}
+
 int
 main ()
 {
@@ -37,5 +61,13 @@ main ()
     abort ();
   if (f4 (5) != -6 || f4 (-5) != -5 || f4 (0) != 0)
     abort ();
+  if (f5 (5) != -6 || f5 (-5) != -5 || f5 (0) != -1)
+    abort ();
+  if (f6 (5) != 5 || f6 (-5) != 4 || f6 (0) != 0)
+    abort ();
+  if (f7 (5) != -6 || f7 (-5) != -5 || f7 (0) != 0)
+    abort ();
+  if (f8 (5) != 5 || f8 (-5) != 4 || f8 (0) != -1)
+    abort ();
   return 0;
 }

gcc/testsuite/gcc.dg/pr68670-1.c

+/* PR rtl-optimization/68670 */
+/* { dg-do run } */
+/* { dg-options "-O2 -ftracer" } */
+
+#include "../gcc.c-torture/execute/pr68376-1.c"

gcc/testsuite/gcc.dg/pr68670-2.c

+/* PR rtl-optimization/68670 */
+/* { dg-do run } */
+/* { dg-options "-O2 -ftracer" } */
+
+#include "../gcc.c-torture/execute/pr68376-2.c"