2018-08-19  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR target/86984
	* expr.c (expand_assignment): Assert that bitpos is positive.
	(store_field): Likewise
	(expand_expr_real_1): Make sure that bitpos is positive.
	* config/alpha/alpha.h (CONSTANT_ADDRESS_P): Avoid signed
	integer overflow.

testsuite:
2018-08-19  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	PR target/86984
	* gcc.target/alpha/pr86984.c: New test.

Index: gcc/config/alpha/alpha.h
===================================================================
--- gcc/config/alpha/alpha.h	(revision 263644)
+++ gcc/config/alpha/alpha.h	(working copy)
@@ -678,7 +678,7 @@ enum reg_class {
 
 #define CONSTANT_ADDRESS_P(X)   \
   (CONST_INT_P (X)		\
-   && (unsigned HOST_WIDE_INT) (INTVAL (X) + 0x8000) < 0x10000)
+   && (UINTVAL (X) + 0x8000) < 0x10000)
 
 /* The macros REG_OK_FOR..._P assume that the arg is a REG rtx
    and check its validity for a certain class.
Index: gcc/expr.c
===================================================================
--- gcc/expr.c	(revision 263644)
+++ gcc/expr.c	(working copy)
@@ -5270,6 +5270,7 @@ expand_assignment (tree to, tree from, bool nontem
 		MEM_VOLATILE_P (to_rtx) = 1;
 	    }
 
+	  gcc_assert (known_ge (bitpos, 0));
 	  if (optimize_bitfield_assignment_op (bitsize, bitpos,
 					       bitregion_start, bitregion_end,
 					       mode1, to_rtx, to, from,
@@ -7046,6 +7047,7 @@ store_field (rtx target, poly_int64 bitsize, poly_
 	}
 
       /* Store the value in the bitfield.  */
+      gcc_assert (known_ge (bitpos, 0));
       store_bit_field (target, bitsize, bitpos,
 		       bitregion_start, bitregion_end,
 		       mode, temp, reverse);
@@ -10545,6 +10547,14 @@ expand_expr_real_1 (tree exp, rtx target, machine_
 	mode2
 	  = CONSTANT_P (op0) ? TYPE_MODE (TREE_TYPE (tem)) : GET_MODE (op0);
 
+	/* Make sure bitpos is not negative, it can wreak havoc later.  */
+	if (maybe_lt (bitpos, 0))
+	  {
+	    gcc_assert (offset == NULL_TREE);
+	    offset = size_int (bits_to_bytes_round_down (bitpos));
+	    bitpos = num_trailing_bits (bitpos);
+	  }
+
 	/* If we have either an offset, a BLKmode result, or a reference
 	   outside the underlying object, we must force it to memory.
 	   Such a case can occur in Ada if we have unchecked conversion
@@ -10795,6 +10805,7 @@ expand_expr_real_1 (tree exp, rtx target, machine_
 		&& GET_MODE_CLASS (ext_mode) == MODE_INT)
 	      reversep = TYPE_REVERSE_STORAGE_ORDER (type);
 
+	    gcc_assert (known_ge (bitpos, 0));
 	    op0 = extract_bit_field (op0, bitsize, bitpos, unsignedp,
 				     (modifier == EXPAND_STACK_PARM
 				      ? NULL_RTX : target),
Index: gcc/testsuite/gcc.target/alpha/pr86984.c
===================================================================
--- gcc/testsuite/gcc.target/alpha/pr86984.c	(revision 0)
+++ gcc/testsuite/gcc.target/alpha/pr86984.c	(working copy)
@@ -0,0 +1,96 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wall -Wwrite-strings -Werror -fmerge-all-constants -fno-stack-protector -mieee -fdump-rtl-expand" } */
+
+struct expression {
+  unsigned long int num;
+};
+union YYSTYPE {
+  unsigned long int num;
+  struct expression *exp;
+};
+
+typedef union YYSTYPE YYSTYPE;
+
+struct expression * new_exp_0 (int);
+
+union yyalloc {
+  short yyss_alloc;
+};
+
+static const signed char yypact[] = {
+  -9, -9, -10, -10, -9, 8, 36, -10, 13, -10, -9, -9, -9, -9, -9, -9, -9, -10, 26, 41, 45, 18, -2, 14, -10, -9, 36 };
+static const unsigned char yydefact[] = {
+  0, 0, 12, 11, 0, 0, 2, 10, 0, 1, 0, 0, 0, 0, 0, 0, 0, 13, 0, 4, 5, 6, 7, 8, 9, 0, 3 };
+
+static const signed char yypgoto[3] = "\366\366\377";
+static const signed char yydefgoto[3] = "\377\005\006";
+
+static const unsigned char yytable[] = {
+  7, 1, 2, 8, 3, 4, 15, 16, 9, 18, 19, 20, 21, 22, 23, 24, 10, 11, 12, 13, 14, 15, 16, 16, 26, 14, 15, 16, 17, 10, 11, 12, 13, 14, 15, 16, 0, 0, 25, 10, 11, 12, 13, 14, 15, 16, 12, 13, 14, 15, 16, 13, 14, 15, 16 };
+
+static const signed char yycheck[] = {
+  1, 10, 11, 4, 13, 14, 8, 9, 0, 10, 11, 12, 13, 14, 15, 16, 3, 4, 5, 6, 7, 8, 9, 9, 25, 7, 8, 9, 15, 3, 4, 5, 6, 7, 8, 9, -1, -1, 12, 3, 4, 5, 6, 7, 8, 9, 5, 6, 7, 8, 9, 6, 7, 8, 9 };
+
+static const unsigned char yyr1[] = {
+  0, 16, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18 };
+
+static const unsigned char yyr2[] = {
+  0, 2, 1, 5, 3, 3, 3, 3, 3, 3, 2, 1, 1, 3 };
+
+int __gettextparse (void)
+{
+  int yystate = 0;
+  short yyssa[200];
+  short *yyss = yyss;
+  short *yyssp = yyssa;
+  YYSTYPE yyvsa[200];
+  YYSTYPE *yyvsp = yyvsa;
+  enum { yystacksize = 200 };
+  int yylen = 0;
+  goto yysetstate;
+ yynewstate: yyssp++;
+ yysetstate: *yyssp = yystate;
+
+  if (yyss + yystacksize - 1 <= yyssp)
+    {
+      long unsigned int yysize = yyssp - yyss + 1;
+      {
+	short *yyss1 = yyss;
+	union yyalloc *yyptr = (union yyalloc *) __builtin_malloc ((yystacksize * (sizeof (short) + sizeof (YYSTYPE)) + (sizeof (union yyalloc) - 1)));
+	if (!yyptr) return 0;
+	__builtin_memcpy (&yyptr->yyss_alloc, yyss, yysize * sizeof *(yyss));
+	yyss = &yyptr->yyss_alloc;
+	if (yyss1 != yyssa) __builtin_free (yyss1);
+      }
+      if (yyss + yystacksize - 1 <= yyssp)
+	return 0;
+    }
+
+  int yyn = yypact[yystate];
+  if (yyn == -10)
+    goto yydefault;
+
+  yyn = yytable[yyn];
+  if (yyn <= 0)
+    goto yyreduce;
+
+ yydefault: yyn = yydefact[yystate];
+ yyreduce: yylen = yyr2[yyn];
+
+  YYSTYPE yyval;
+  if (yyn == 12 && (yyval.exp = new_exp_0 (0)) != 0)
+    (yyval.exp)->num = (yyvsp[0].num);
+
+  (yyvsp -= yylen, yyssp -= yylen);
+  yyn = yyr1[yyn];
+  yystate = yypgoto[yyn - 16] + *yyssp;
+  if (0 <= yystate && yystate <= 54 && yycheck[yystate] == *yyssp)
+    yystate = yytable[yystate];
+  else
+    yystate = yydefgoto[yyn - 16];
+
+  goto yynewstate;
+}
+
+/* { dg-final { scan-rtl-dump-not "const_int 230584300921" "expand" } } */
+/* { dg-final { scan-assembler-not "yypgoto\\+230584300921" } } */

