re PR tree-optimization/82549 (ICE at -O1 and above: verify_gimple failed)

	PR tree-optimization/82549
	* fold-const.c (optimize_bit_field_compare, fold_truth_andor_1):
	Formatting fixes.  Instead of calling make_bit_field_ref with negative
	bitpos return 0.

	* gcc.c-torture/compile/pr82549.c: New test.

From-SVN: r253805

1 files changed, 32 insertions, 20 deletions

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index d1e6191..d876074 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -4013,21 +4013,20 @@ optimize_bit_field_compare (location_t loc, enum tree_code code,
 		      size_int (nbitsize - lbitsize - lbitpos));
 
   if (! const_p)
-    /* If not comparing with constant, just rework the comparison
-       and return.  */
-    return fold_build2_loc (loc, code, compare_type,
-			fold_build2_loc (loc, BIT_AND_EXPR, unsigned_type,
-				     make_bit_field_ref (loc, linner, lhs,
-							 unsigned_type,
-							 nbitsize, nbitpos,
-							 1, lreversep),
-				     mask),
-			fold_build2_loc (loc, BIT_AND_EXPR, unsigned_type,
-				     make_bit_field_ref (loc, rinner, rhs,
-							 unsigned_type,
-							 nbitsize, nbitpos,
-							 1, rreversep),
-				     mask));
+    {
+      if (nbitpos < 0)
+	return 0;
+
+      /* If not comparing with constant, just rework the comparison
+	 and return.  */
+      tree t1 = make_bit_field_ref (loc, linner, lhs, unsigned_type,
+				    nbitsize, nbitpos, 1, lreversep);
+      t1 = fold_build2_loc (loc, BIT_AND_EXPR, unsigned_type, t1, mask);
+      tree t2 = make_bit_field_ref (loc, rinner, rhs, unsigned_type,
+				    nbitsize, nbitpos, 1, rreversep);
+      t2 = fold_build2_loc (loc, BIT_AND_EXPR, unsigned_type, t2, mask);
+      return fold_build2_loc (loc, code, compare_type, t1, t2);
+    }
 
   /* Otherwise, we are handling the constant case.  See if the constant is too
      big for the field.  Warn and return a tree for 0 (false) if so.  We do
@@ -4058,6 +4057,9 @@ optimize_bit_field_compare (location_t loc, enum tree_code code,
 	}
     }
 
+  if (nbitpos < 0)
+    return 0;
+
   /* Single-bit compares should always be against zero.  */
   if (lbitsize == 1 && ! integer_zerop (rhs))
     {
@@ -5874,7 +5876,10 @@ fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type,
 	 results.  */
       ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask);
       lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask);
-      if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
+      if (lnbitsize == rnbitsize
+	  && xll_bitpos == xlr_bitpos
+	  && lnbitpos >= 0
+	  && rnbitpos >= 0)
 	{
 	  lhs = make_bit_field_ref (loc, ll_inner, ll_arg,
 				    lntype, lnbitsize, lnbitpos,
@@ -5898,10 +5903,14 @@ fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type,
 	 Note that we still must mask the lhs/rhs expressions.  Furthermore,
 	 the mask must be shifted to account for the shift done by
 	 make_bit_field_ref.  */
-      if ((ll_bitsize + ll_bitpos == rl_bitpos
-	   && lr_bitsize + lr_bitpos == rr_bitpos)
-	  || (ll_bitpos == rl_bitpos + rl_bitsize
-	      && lr_bitpos == rr_bitpos + rr_bitsize))
+      if (((ll_bitsize + ll_bitpos == rl_bitpos
+	    && lr_bitsize + lr_bitpos == rr_bitpos)
+	   || (ll_bitpos == rl_bitpos + rl_bitsize
+	       && lr_bitpos == rr_bitpos + rr_bitsize))
+	  && ll_bitpos >= 0
+	  && rl_bitpos >= 0
+	  && lr_bitpos >= 0
+	  && rr_bitpos >= 0)
 	{
 	  tree type;
 
@@ -5970,6 +5979,9 @@ fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type,
 	}
     }
 
+  if (lnbitpos < 0)
+    return 0;
+
   /* Construct the expression we will return.  First get the component
      reference we will make.  Unless the mask is all ones the width of
      that field, perform the mask operation.  Then compare with the