re PR other/57324 (Undefined behavior issues found with clang's -fsanitize=undefined)

2013-08-24  Marc Glisse  <marc.glisse@inria.fr>

	PR other/57324
	* hwint.h (HOST_WIDE_INT_UC, HOST_WIDE_INT_1U, HOST_WIDE_INT_M1,
	HOST_WIDE_INT_M1U): New macros.
	* fold-const.c (sign_bit_p, build_range_check, fold_unary_loc,
	fold_binary_loc, fold_ternary_loc): Use the new macros. Use an
	unsigned -1 for lshift.
	* cse.c (cse_insn): Likewise.
	* double-int.c (rshift_double, lshift_double): Likewise.
	* builtins.c (fold_builtin_bitop): Likewise.
	* combine.c (force_to_mode): Likewise.
	* tree.c (integer_pow2p, tree_log2, tree_floor_log2): Likewise.
	* simplify-rtx.c (simplify_const_unary_operation,
	simplify_const_binary_operation): Likewise.
	* tree-stdarg.c (va_list_counter_bump, va_list_ptr_read,
	check_va_list_escapes): Likewise.
	* rtlanal.c (nonzero_bits1): Likewise.
	* expmed.c (expand_smod_pow2): Likewise.
	* tree-ssa-structalias.c (UNKNOWN_OFFSET): Use HOST_WIDE_INT_MIN.

From-SVN: r201953

1 files changed, 13 insertions, 15 deletions

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 6506ae7..1e0e7e5 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -3740,8 +3740,7 @@ sign_bit_p (tree exp, const_tree val)
       hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
       lo = 0;
 
-      mask_hi = ((unsigned HOST_WIDE_INT) -1
-		 >> (HOST_BITS_PER_DOUBLE_INT - width));
+      mask_hi = (HOST_WIDE_INT_M1U >> (HOST_BITS_PER_DOUBLE_INT - width));
       mask_lo = -1;
     }
   else
@@ -3750,8 +3749,7 @@ sign_bit_p (tree exp, const_tree val)
       lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
 
       mask_hi = 0;
-      mask_lo = ((unsigned HOST_WIDE_INT) -1
-		 >> (HOST_BITS_PER_WIDE_INT - width));
+      mask_lo = (HOST_WIDE_INT_M1U >> (HOST_BITS_PER_WIDE_INT - width));
     }
 
   /* We mask off those bits beyond TREE_TYPE (exp) so that we can
@@ -4325,7 +4323,7 @@ build_range_check (location_t loc, tree type, tree exp, int in_p,
       else
 	{
 	  hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
-	  lo = (unsigned HOST_WIDE_INT) -1;
+	  lo = HOST_WIDE_INT_M1U;
 	}
 
       if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
@@ -8096,7 +8094,7 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
 	      unsigned HOST_WIDE_INT cst;
 
 	      cst = tree_low_cst (and1, 1);
-	      cst &= (HOST_WIDE_INT) -1
+	      cst &= HOST_WIDE_INT_M1U
 		     << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
 	      change = (cst == 0);
 #ifdef LOAD_EXTEND_OP
@@ -11277,7 +11275,7 @@ fold_binary_loc (location_t loc,
 	       w <<= 1)
 	    {
 	      unsigned HOST_WIDE_INT mask
-		= (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
+		= HOST_WIDE_INT_M1U >> (HOST_BITS_PER_WIDE_INT - w);
 	      if (((c1.low | c2.low) & mask) == mask
 		  && (c1.low & ~mask) == 0 && c1.high == 0)
 		{
@@ -12297,7 +12295,7 @@ fold_binary_loc (location_t loc,
       /* X / -1 is -X.  */
       if (!TYPE_UNSIGNED (type)
 	  && TREE_CODE (arg1) == INTEGER_CST
-	  && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
+	  && TREE_INT_CST_LOW (arg1) == HOST_WIDE_INT_M1U
 	  && TREE_INT_CST_HIGH (arg1) == -1)
 	return fold_convert_loc (loc, type, negate_expr (arg0));
 
@@ -12380,7 +12378,7 @@ fold_binary_loc (location_t loc,
       /* X % -1 is zero.  */
       if (!TYPE_UNSIGNED (type)
 	  && TREE_CODE (arg1) == INTEGER_CST
-	  && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
+	  && TREE_INT_CST_LOW (arg1) == HOST_WIDE_INT_M1U
 	  && TREE_INT_CST_HIGH (arg1) == -1)
 	return omit_one_operand_loc (loc, type, integer_zero_node, arg0);
 
@@ -13535,7 +13533,7 @@ fold_binary_loc (location_t loc,
 		else
 		  {
 		    max_lo = signed_max_lo;
-		    min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
+		    min_lo = (HOST_WIDE_INT_M1U << (width - 1));
 		    min_hi = -1;
 		  }
 	      }
@@ -13556,7 +13554,7 @@ fold_binary_loc (location_t loc,
 		else
 		  {
 		    max_hi = signed_max_hi;
-		    min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
+		    min_hi = (HOST_WIDE_INT_M1U << (width - 1));
 		  }
 	      }
 
@@ -14175,24 +14173,24 @@ fold_ternary_loc (location_t loc, enum tree_code code, tree type,
 
 	      if (outer_width > HOST_BITS_PER_WIDE_INT)
 		{
-		  mask_hi = ((unsigned HOST_WIDE_INT) -1
+		  mask_hi = (HOST_WIDE_INT_M1U
 			     >> (HOST_BITS_PER_DOUBLE_INT - outer_width));
 		  mask_lo = -1;
 		}
 	      else
 		{
 		  mask_hi = 0;
-		  mask_lo = ((unsigned HOST_WIDE_INT) -1
+		  mask_lo = (HOST_WIDE_INT_M1U
 			     >> (HOST_BITS_PER_WIDE_INT - outer_width));
 		}
 	      if (inner_width > HOST_BITS_PER_WIDE_INT)
 		{
-		  mask_hi &= ~((unsigned HOST_WIDE_INT) -1
+		  mask_hi &= ~(HOST_WIDE_INT_M1U
 			       >> (HOST_BITS_PER_WIDE_INT - inner_width));
 		  mask_lo = 0;
 		}
 	      else
-		mask_lo &= ~((unsigned HOST_WIDE_INT) -1
+		mask_lo &= ~(HOST_WIDE_INT_M1U
 			     >> (HOST_BITS_PER_WIDE_INT - inner_width));
 
 	      if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi