[backport from gcc-4.8/trunk r190342 <mikpe@it.uu.se>]

gcc/

2012-08-13  Jakub Jelinek  <jakub@redhat.com>

	PR c/53968
	* tree.c (integer_pow2p): Avoid undefined signed overflows.
	* simplify-rtx.c (neg_const_int): Likewise.
	* expr.c (fixup_args_size_notes): Likewise.
	* stor-layout.c (set_min_and_max_values_for_integral_type): Likewise.
	* double-int.c (mul_double_wide_with_sign): Likewise.
	(double_int_mask): Likewise.
	* tree-ssa-loop-ivopts.c (get_address_cost): Likewise.

--- gcc-4.7.1/gcc/double-int.c.~1~	2010-11-30 17:36:19.000000000 +0100
+++ gcc-4.7.1/gcc/double-int.c	2012-09-08 22:31:43.000000000 +0200
@@ -155,7 +155,7 @@ mul_double_with_sign (unsigned HOST_WIDE
 	{
 	  k = i + j;
 	  /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000.  */
-	  carry += arg1[i] * arg2[j];
+	  carry += (unsigned HOST_WIDE_INT) arg1[i] * arg2[j];
 	  /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF.  */
 	  carry += prod[k];
 	  prod[k] = LOWPART (carry);
@@ -616,7 +616,7 @@ double_int_mask (unsigned prec)
   else
     {
       mask.high = 0;
-      mask.low = ((unsigned HOST_WIDE_INT) 2 << (prec - 1)) - 1;
+      mask.low = prec ? ((unsigned HOST_WIDE_INT) 2 << (prec - 1)) - 1 : 0;
     }
 
   return mask;
--- gcc-4.7.1/gcc/expr.c.~1~	2012-06-04 10:43:23.000000000 +0200
+++ gcc-4.7.1/gcc/expr.c	2012-09-08 22:31:43.000000000 +0200
@@ -3804,7 +3804,7 @@ fixup_args_size_notes (rtx prev, rtx las
 
       add_reg_note (insn, REG_ARGS_SIZE, GEN_INT (args_size));
 #ifdef STACK_GROWS_DOWNWARD
-      this_delta = -this_delta;
+      this_delta = -(unsigned HOST_WIDE_INT) this_delta;
 #endif
       args_size -= this_delta;
     }
--- gcc-4.7.1/gcc/simplify-rtx.c.~1~	2012-02-08 14:29:22.000000000 +0100
+++ gcc-4.7.1/gcc/simplify-rtx.c	2012-09-08 22:31:43.000000000 +0200
@@ -67,7 +67,7 @@ static rtx simplify_binary_operation_1 (
 static rtx
 neg_const_int (enum machine_mode mode, const_rtx i)
 {
-  return gen_int_mode (- INTVAL (i), mode);
+  return gen_int_mode (-(unsigned HOST_WIDE_INT) INTVAL (i), mode);
 }
 
 /* Test whether expression, X, is an immediate constant that represents
--- gcc-4.7.1/gcc/stor-layout.c.~1~	2012-06-04 12:19:44.000000000 +0200
+++ gcc-4.7.1/gcc/stor-layout.c	2012-09-08 22:31:43.000000000 +0200
@@ -2525,10 +2525,14 @@ set_min_and_max_values_for_integral_type
 	= build_int_cst_wide (type,
 			      (precision - HOST_BITS_PER_WIDE_INT > 0
 			       ? -1
-			       : ((HOST_WIDE_INT) 1 << (precision - 1)) - 1),
+			       : (HOST_WIDE_INT)
+				 (((unsigned HOST_WIDE_INT) 1
+				   << (precision - 1)) - 1)),
 			      (precision - HOST_BITS_PER_WIDE_INT - 1 > 0
-			       ? (((HOST_WIDE_INT) 1
-				   << (precision - HOST_BITS_PER_WIDE_INT - 1))) - 1
+			       ? (HOST_WIDE_INT)
+				 ((((unsigned HOST_WIDE_INT) 1
+				    << (precision - HOST_BITS_PER_WIDE_INT
+					- 1))) - 1)
 			       : 0));
     }
 
--- gcc-4.7.1/gcc/tree-ssa-loop-ivopts.c.~1~	2012-02-06 14:43:03.000000000 +0100
+++ gcc-4.7.1/gcc/tree-ssa-loop-ivopts.c	2012-09-08 22:31:43.000000000 +0200
@@ -3274,7 +3274,7 @@ get_address_cost (bool symbol_present, b
 
       for (i = width; i >= 0; i--)
 	{
-	  off = -((HOST_WIDE_INT) 1 << i);
+	  off = -((unsigned HOST_WIDE_INT) 1 << i);
 	  XEXP (addr, 1) = gen_int_mode (off, address_mode);
 	  if (memory_address_addr_space_p (mem_mode, addr, as))
 	    break;
@@ -3283,7 +3283,7 @@ get_address_cost (bool symbol_present, b
 
       for (i = width; i >= 0; i--)
 	{
-	  off = ((HOST_WIDE_INT) 1 << i) - 1;
+	  off = ((unsigned HOST_WIDE_INT) 1 << i) - 1;
 	  XEXP (addr, 1) = gen_int_mode (off, address_mode);
 	  if (memory_address_addr_space_p (mem_mode, addr, as))
 	    break;
--- gcc-4.7.1/gcc/tree.c.~1~	2012-06-04 10:43:23.000000000 +0200
+++ gcc-4.7.1/gcc/tree.c	2012-09-08 22:31:43.000000000 +0200
@@ -1795,7 +1795,7 @@ int
 integer_pow2p (const_tree expr)
 {
   int prec;
-  HOST_WIDE_INT high, low;
+  unsigned HOST_WIDE_INT high, low;
 
   STRIP_NOPS (expr);