re PR middle-end/57748 (ICE when expanding assignment to unaligned zero-sized array)

2013-09-20  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        PR middle-end/57748
        * expr.c (expand_assignment): Remove misalignp code path.

testsuite/

        PR middle-end/57748
        * gcc.dg/torture/pr57748-1.c: New test.
        * gcc.dg/torture/pr57748-2.c: New test.

From-SVN: r202778

gcc/ChangeLog

+2013-09-20  Bernd Edlinger  <bernd.edlinger@hotmail.de>
+
+	PR middle-end/57748
+	* expr.c (expand_assignment): Remove misalignp code path.
+
 2013-09-20  Marek Polacek  <polacek@redhat.com>
 
 	PR sanitizer/58413

gcc/expr.c

@@ -4709,8 +4709,6 @@ expand_assignment (tree to, tree from, bool nontemporal)
       int unsignedp;
       int volatilep = 0;
       tree tem;
-      bool misalignp;
-      rtx mem = NULL_RTX;
 
       push_temp_slots ();
       tem = get_inner_reference (to, &bitsize, &bitpos, &offset, &mode1,
@@ -4720,40 +4718,7 @@ expand_assignment (tree to, tree from, bool nontemporal)
 	  && DECL_BIT_FIELD_TYPE (TREE_OPERAND (to, 1)))
 	get_bit_range (&bitregion_start, &bitregion_end, to, &bitpos, &offset);
 
-      /* If we are going to use store_bit_field and extract_bit_field,
-	 make sure to_rtx will be safe for multiple use.  */
-      mode = TYPE_MODE (TREE_TYPE (tem));
-      if (TREE_CODE (tem) == MEM_REF
-	  && mode != BLKmode
-	  && ((align = get_object_alignment (tem))
-	      < GET_MODE_ALIGNMENT (mode))
-	  && ((icode = optab_handler (movmisalign_optab, mode))
-	      != CODE_FOR_nothing))
-	{
-	  struct expand_operand ops[2];
-
-	  misalignp = true;
-	  to_rtx = gen_reg_rtx (mode);
-	  mem = expand_expr (tem, NULL_RTX, VOIDmode, EXPAND_WRITE);
-
-	  /* If the misaligned store doesn't overwrite all bits, perform
-	     rmw cycle on MEM.  */
-	  if (bitsize != GET_MODE_BITSIZE (mode))
-	    {
-	      create_input_operand (&ops[0], to_rtx, mode);
-	      create_fixed_operand (&ops[1], mem);
-	      /* The movmisalign<mode> pattern cannot fail, else the assignment
-		 would silently be omitted.  */
-	      expand_insn (icode, 2, ops);
-
-	      mem = copy_rtx (mem);
-	    }
-	}
-      else
-	{
-	  misalignp = false;
-	  to_rtx = expand_expr (tem, NULL_RTX, VOIDmode, EXPAND_WRITE);
-	}
+      to_rtx = expand_expr (tem, NULL_RTX, VOIDmode, EXPAND_WRITE);
 
       /* If the bitfield is volatile, we want to access it in the
 	 field's mode, not the computed mode.
@@ -4892,17 +4857,6 @@ expand_assignment (tree to, tree from, bool nontemporal)
 				  get_alias_set (to), nontemporal);
 	}
 
-      if (misalignp)
-	{
-	  struct expand_operand ops[2];
-
-	  create_fixed_operand (&ops[0], mem);
-	  create_input_operand (&ops[1], to_rtx, mode);
-	  /* The movmisalign<mode> pattern cannot fail, else the assignment
-	     would silently be omitted.  */
-	  expand_insn (icode, 2, ops);
-	}
-
       if (result)
 	preserve_temp_slots (result);
       pop_temp_slots ();

gcc/testsuite/ChangeLog

+2013-09-20  Bernd Edlinger  <bernd.edlinger@hotmail.de>
+
+	PR middle-end/57748
+	* gcc.dg/torture/pr57748-1.c: New test.
+	* gcc.dg/torture/pr57748-2.c: New test.
+
 2013-09-20  Marek Polacek  <polacek@redhat.com>
 
 	PR sanitizer/58413

gcc/testsuite/gcc.dg/torture/pr57748-1.c

+/* PR middle-end/57748 */
+/* { dg-do run } */
+/* ICE in expand_assignment:
+   misalignp == true, !MEM_P (to_rtx), offset != 0,
+   => gcc_assert (TREE_CODE (offset) == INTEGER_CST) */
+
+#include <stdlib.h>
+
+extern void abort (void);
+
+typedef long long V
+  __attribute__ ((vector_size (2 * sizeof (long long)), may_alias));
+
+typedef struct S { V a; V b[0]; } P __attribute__((aligned (1)));
+
+struct __attribute__((packed)) T { char c; P s; };
+
+void __attribute__((noinline, noclone))
+check (struct T *t)
+{
+  if (t->s.b[0][0] != 3 || t->s.b[0][1] != 4)
+    abort ();
+}
+
+int __attribute__((noinline, noclone))
+get_i (void)
+{
+  return 0;
+}
+
+void __attribute__((noinline, noclone))
+foo (P *p)
+{
+  V a = { 3, 4 };
+  int i = get_i ();
+  p->b[i] = a;
+}
+
+int
+main ()
+{
+  struct T *t = (struct T *) calloc (128, 1);
+
+  foo (&t->s);
+  check (t);
+
+  free (t);
+  return 0;
+}

gcc/testsuite/gcc.dg/torture/pr57748-2.c

+/* PR middle-end/57748 */
+/* { dg-do run } */
+/* wrong code in expand_assignment:
+   misalignp == true, !MEM_P (to_rtx),
+   offset == 0, bitpos >= GET_MODE_PRECISION,
+   => result = NULL.  */
+
+#include <stdlib.h>
+
+extern void abort (void);
+
+typedef long long V
+  __attribute__ ((vector_size (2 * sizeof (long long)), may_alias));
+
+typedef struct S { V a; V b[0]; } P __attribute__((aligned (1)));
+
+struct __attribute__((packed)) T { char c; P s; };
+
+void __attribute__((noinline, noclone))
+check (struct T *t)
+{
+  if (t->s.b[0][0] != 3 || t->s.b[0][1] != 4)
+    abort ();
+}
+
+void __attribute__((noinline, noclone))
+foo (P *p)
+{
+  V a = { 3, 4 };
+  p->b[0] = a;
+}
+
+int
+main ()
+{
+  struct T *t = (struct T *) calloc (128, 1);
+
+  foo (&t->s);
+  check (t);
+
+  free (t);
+  return 0;
+}