re PR tree-optimization/84969 (Wrong code with -ftree-loop-distribute-patterns)

	PR tree-optimization/84969
	* tree-loop-distribution.c (fuse_memset_builtins): Don't reorder
	builtin memset partitions if they set different rhs values.

	gcc/testsuite
	* gcc.dg/tree-ssa/pr84969.c: New test.

From-SVN: r258710

gcc/ChangeLog

+2018-03-21  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/84969
+	* tree-loop-distribution.c (fuse_memset_builtins): Don't reorder
+	builtin memset partitions if they set different rhs values.
+
 2018-03-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/84989

gcc/testsuite/ChangeLog

+2018-03-21  Bin Cheng  <bin.cheng@arm.com>
+
+	PR tree-optimization/84969
+	* gcc.dg/tree-ssa/pr84969.c: New test.
+
 2018-03-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/84989

gcc/testsuite/gcc.dg/tree-ssa/pr84969.c

+/* { dg-do run } */
+/* { dg-options "-O2 -ftree-loop-distribute-patterns" } */
+
+static void
+__attribute__((noipa, noinline))
+foo (char **values, int ndim, char *needquotes, int *dims)
+{
+  int i;
+  int j = 0;
+  int k = 0;
+  char *retval = (char *)__builtin_malloc(1000); 
+  char *p = retval;
+  char *tmp;
+
+  int indx[111];
+
+#define APPENDSTR(str)	(__builtin_strcpy(p, (str)), p += __builtin_strlen(p))
+#define APPENDCHAR(ch)	(*p++ = (ch), *p = '\0')
+
+	APPENDCHAR('{');
+	for (i = 0; i < ndim; i++)
+		indx[i] = 0;
+	do
+	{
+		for (i = j; i < ndim - 1; i++)
+			APPENDCHAR('{');
+
+			APPENDSTR(values[k]);
+		k++;
+
+		for (i = ndim - 1; i >= 0; i--)
+		{
+			indx[i] = (indx[i] + 1) % dims[i];
+			if (indx[i])
+			{
+				APPENDCHAR(',');
+				break;
+			}
+			else
+				APPENDCHAR('}');
+		}
+		j = i;
+	} while (j != -1);
+
+	if (__builtin_strcmp (retval, "{{{0,1},{2,3}}}") != 0)
+	  __builtin_abort ();
+}
+
+int main()
+{
+  char* array[4] = {"0", "1", "2", "3"};
+  char f[] = {0, 0, 0, 0, 0, 0, 0, 0};
+  int dims[] = {1, 2, 2};
+  foo (array, 3, f, dims);
+
+  return 0;
+}

gcc/tree-loop-distribution.c

@@ -2569,6 +2569,7 @@ fuse_memset_builtins (vec<struct partition *> *partitions)
 {
   unsigned i, j;
   struct partition *part1, *part2;
+  tree rhs1, rhs2;
 
   for (i = 0; partitions->iterate (i, &part1);)
     {
@@ -2586,6 +2587,12 @@ fuse_memset_builtins (vec<struct partition *> *partitions)
 	      || !operand_equal_p (part1->builtin->dst_base_base,
 				   part2->builtin->dst_base_base, 0))
 	    break;
+
+	  /* Memset calls setting different values can't be merged.  */
+	  rhs1 = gimple_assign_rhs1 (DR_STMT (part1->builtin->dst_dr));
+	  rhs2 = gimple_assign_rhs1 (DR_STMT (part2->builtin->dst_dr));
+	  if (!operand_equal_p (rhs1, rhs2, 0))
+	    break;
 	}
 
       /* Stable sort is required in order to avoid breaking dependence.  */
@@ -2617,8 +2624,8 @@ fuse_memset_builtins (vec<struct partition *> *partitions)
 	  i++;
 	  continue;
 	}
-      tree rhs1 = gimple_assign_rhs1 (DR_STMT (part1->builtin->dst_dr));
-      tree rhs2 = gimple_assign_rhs1 (DR_STMT (part2->builtin->dst_dr));
+      rhs1 = gimple_assign_rhs1 (DR_STMT (part1->builtin->dst_dr));
+      rhs2 = gimple_assign_rhs1 (DR_STMT (part2->builtin->dst_dr));
       int bytev1 = const_with_all_bytes_same (rhs1);
       int bytev2 = const_with_all_bytes_same (rhs2);
       /* Only merge memset partitions of the same value.  */