ldist: Further fixes for -ftrapv [PR94114]

As the testcase shows, arithmetics that for -ftrapv would need multiple
basic blocks can show up not just in nb_bytes expressions where we
are calling rewrite_to_non_trapping_overflow for a while already,
but also in the pointer expression to the start of the region.
While the testcase covers just the first hunk and I've failed to create
a testcase for the latter, it is at least in theory possible too, so I've
adjusted that hunk too.

2020-03-11  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/94114
	* tree-loop-distribution.c (generate_memset_builtin): Call
	rewrite_to_non_trapping_overflow even on mem.
	(generate_memcpy_builtin): Call rewrite_to_non_trapping_overflow even
	on dest and src.

	* gcc.dg/pr94114.c: New test.

gcc/ChangeLog

+2020-03-11  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/94114
+	* tree-loop-distribution.c (generate_memset_builtin): Call
+	rewrite_to_non_trapping_overflow even on mem.
+	(generate_memcpy_builtin): Call rewrite_to_non_trapping_overflow even
+	on dest and src.
+
 2020-03-10  Jeff Law  <law@redhat.com>
 
 	* config/bfin/bfin.md (movsi_insv): Add length attribute.

gcc/testsuite/ChangeLog

+2020-03-11  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/94114
+	* gcc.dg/pr94114.c: New test.
+
 2020-03-10  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/94124 - wrong conversion error with non-viable overload.

gcc/testsuite/gcc.dg/pr94114.c

+/* PR tree-optimization/94114 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-loop-distribute-patterns -ftrapv" } */
+
+void
+foo (int *x, int *y, int *z, long int w)
+{
+  while (y + w > z)
+    {
+      x[w] = 0;
+      --w;
+    }
+}

gcc/tree-loop-distribution.c

@@ -1151,7 +1151,7 @@ generate_memset_builtin (class loop *loop, partition *partition)
   nb_bytes = rewrite_to_non_trapping_overflow (builtin->size);
   nb_bytes = force_gimple_operand_gsi (&gsi, nb_bytes, true, NULL_TREE,
 				       false, GSI_CONTINUE_LINKING);
-  mem = builtin->dst_base;
+  mem = rewrite_to_non_trapping_overflow (builtin->dst_base);
   mem = force_gimple_operand_gsi (&gsi, mem, true, NULL_TREE,
 				  false, GSI_CONTINUE_LINKING);
 
@@ -1205,8 +1205,8 @@ generate_memcpy_builtin (class loop *loop, partition *partition)
   nb_bytes = rewrite_to_non_trapping_overflow (builtin->size);
   nb_bytes = force_gimple_operand_gsi (&gsi, nb_bytes, true, NULL_TREE,
 				       false, GSI_CONTINUE_LINKING);
-  dest = builtin->dst_base;
-  src = builtin->src_base;
+  dest = rewrite_to_non_trapping_overflow (builtin->dst_base);
+  src = rewrite_to_non_trapping_overflow (builtin->src_base);
   if (partition->kind == PKIND_MEMCPY
       || ! ptr_derefs_may_alias_p (dest, src))
     kind = BUILT_IN_MEMCPY;