re PR debug/80025 (ICE w/ -O2 (-O3, -Ofast) -g -ftracer (infinite recursion in…

re PR debug/80025 (ICE w/ -O2 (-O3, -Ofast) -g -ftracer (infinite recursion in rtx_equal_for_cselib_1))

	PR debug/80025
	* cselib.h (rtx_equal_for_cselib_1): Add depth argument.
	(rtx_equal_for_cselib_p): Pass 0 to it.
	* cselib.c (cselib_hasher::equal): Likewise.
	(rtx_equal_for_cselib_1): Add depth argument.  If depth
	is 128, don't look up VALUE locs and punt.  Increment
	depth in recursive calls when walking VALUE locs.

	* gcc.dg/torture/pr80025.c: New test.

From-SVN: r246606

gcc/ChangeLog

+2017-03-31  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/80025
+	* cselib.h (rtx_equal_for_cselib_1): Add depth argument.
+	(rtx_equal_for_cselib_p): Pass 0 to it.
+	* cselib.c (cselib_hasher::equal): Likewise.
+	(rtx_equal_for_cselib_1): Add depth argument.  If depth
+	is 128, don't look up VALUE locs and punt.  Increment
+	depth in recursive calls when walking VALUE locs.
+
 2017-03-31  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	* gcov.c (md5sum_to_hex): Fix output of MD5 hex bytes.

gcc/cselib.c

@@ -125,7 +125,7 @@ cselib_hasher::equal (const cselib_val *v, const key *x_arg)
   /* We don't guarantee that distinct rtx's have different hash values,
      so we need to do a comparison.  */
   for (l = v->locs; l; l = l->next)
-    if (rtx_equal_for_cselib_1 (l->loc, x, memmode))
+    if (rtx_equal_for_cselib_1 (l->loc, x, memmode, 0))
       {
 	promote_debug_loc (l);
 	return true;
@@ -834,7 +834,7 @@ autoinc_split (rtx x, rtx *off, machine_mode memmode)
    addresses, MEMMODE should be VOIDmode.  */
 
 int
-rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode)
+rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode, int depth)
 {
   enum rtx_code code;
   const char *fmt;
@@ -867,6 +867,9 @@ rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode)
       if (GET_CODE (y) == VALUE)
 	return e == canonical_cselib_val (CSELIB_VAL_PTR (y));
 
+      if (depth == 128)
+	return 0;
+
       for (l = e->locs; l; l = l->next)
 	{
 	  rtx t = l->loc;
@@ -876,7 +879,7 @@ rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode)
 	     list.  */
 	  if (REG_P (t) || MEM_P (t) || GET_CODE (t) == VALUE)
 	    continue;
-	  else if (rtx_equal_for_cselib_1 (t, y, memmode))
+	  else if (rtx_equal_for_cselib_1 (t, y, memmode, depth + 1))
 	    return 1;
 	}
 
@@ -887,13 +890,16 @@ rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode)
       cselib_val *e = canonical_cselib_val (CSELIB_VAL_PTR (y));
       struct elt_loc_list *l;
 
+      if (depth == 128)
+	return 0;
+
       for (l = e->locs; l; l = l->next)
 	{
 	  rtx t = l->loc;
 
 	  if (REG_P (t) || MEM_P (t) || GET_CODE (t) == VALUE)
 	    continue;
-	  else if (rtx_equal_for_cselib_1 (x, t, memmode))
+	  else if (rtx_equal_for_cselib_1 (x, t, memmode, depth + 1))
 	    return 1;
 	}
 
@@ -914,12 +920,12 @@ rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode)
       if (!xoff != !yoff)
 	return 0;
 
-      if (xoff && !rtx_equal_for_cselib_1 (xoff, yoff, memmode))
+      if (xoff && !rtx_equal_for_cselib_1 (xoff, yoff, memmode, depth))
 	return 0;
 
       /* Don't recurse if nothing changed.  */
       if (x != xorig || y != yorig)
-	return rtx_equal_for_cselib_1 (x, y, memmode);
+	return rtx_equal_for_cselib_1 (x, y, memmode, depth);
 
       return 0;
     }
@@ -953,7 +959,8 @@ rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode)
     case MEM:
       /* We have to compare any autoinc operations in the addresses
 	 using this MEM's mode.  */
-      return rtx_equal_for_cselib_1 (XEXP (x, 0), XEXP (y, 0), GET_MODE (x));
+      return rtx_equal_for_cselib_1 (XEXP (x, 0), XEXP (y, 0), GET_MODE (x),
+				     depth);
 
     default:
       break;
@@ -988,17 +995,20 @@ rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode)
 	  /* And the corresponding elements must match.  */
 	  for (j = 0; j < XVECLEN (x, i); j++)
 	    if (! rtx_equal_for_cselib_1 (XVECEXP (x, i, j),
-					  XVECEXP (y, i, j), memmode))
+					  XVECEXP (y, i, j), memmode, depth))
 	      return 0;
 	  break;
 
 	case 'e':
 	  if (i == 1
 	      && targetm.commutative_p (x, UNKNOWN)
-	      && rtx_equal_for_cselib_1 (XEXP (x, 1), XEXP (y, 0), memmode)
-	      && rtx_equal_for_cselib_1 (XEXP (x, 0), XEXP (y, 1), memmode))
+	      && rtx_equal_for_cselib_1 (XEXP (x, 1), XEXP (y, 0), memmode,
+					 depth)
+	      && rtx_equal_for_cselib_1 (XEXP (x, 0), XEXP (y, 1), memmode,
+					 depth))
 	    return 1;
-	  if (! rtx_equal_for_cselib_1 (XEXP (x, i), XEXP (y, i), memmode))
+	  if (! rtx_equal_for_cselib_1 (XEXP (x, i), XEXP (y, i), memmode,
+					depth))
 	    return 0;
 	  break;
 

gcc/cselib.h

@@ -82,7 +82,7 @@ extern void cselib_finish (void);
 extern void cselib_process_insn (rtx_insn *);
 extern bool fp_setter_insn (rtx_insn *);
 extern machine_mode cselib_reg_set_mode (const_rtx);
-extern int rtx_equal_for_cselib_1 (rtx, rtx, machine_mode);
+extern int rtx_equal_for_cselib_1 (rtx, rtx, machine_mode, int);
 extern int references_value_p (const_rtx, int);
 extern rtx cselib_expand_value_rtx (rtx, bitmap, int);
 typedef rtx (*cselib_expand_callback)(rtx, bitmap, int, void *);
@@ -134,7 +134,7 @@ rtx_equal_for_cselib_p (rtx x, rtx y)
   if (x == y)
     return 1;
 
-  return rtx_equal_for_cselib_1 (x, y, VOIDmode);
+  return rtx_equal_for_cselib_1 (x, y, VOIDmode, 0);
 }
 
 #endif /* GCC_CSELIB_H */

gcc/testsuite/ChangeLog

+2017-03-31  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/80025
+	* gcc.dg/torture/pr80025.c: New test.
+
 2017-03-30  Matthew Fortune  <matthew.fortune@imgtec.com>
 
 	* gcc.target/mips/pr52125.c: Add -msym32.

gcc/testsuite/gcc.dg/torture/pr80025.c

+/* PR debug/80025 */
+/* { dg-do compile } */
+/* { dg-options "-g -ftracer -w" } */
+
+int a;
+long int b, c;
+
+long int
+foo (void)
+{
+}
+
+void
+bar (int x, short int y, unsigned short int z)
+{
+}
+
+int
+baz (void)
+{
+  a -= b;
+  b = !foo ();
+  bar (b ^= (c ^ 1) ? (c ^ 1) : foo (), (__INTPTR_TYPE__) &bar, a);
+}