Revert "gimple: allow more folding of memcpy [PR102125]"

This reverts commit 5f6a6c91d7c592cb49f7c519f289777eac09bb74.

diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
index e73bc6a..270a9a2 100644 (file)
--- a/gcc/gimple-fold.cc
+++ b/gcc/gimple-fold.cc
@@ -67,8 +67,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-vector-builder.h"
 #include "tree-ssa-strlen.h"
 #include "varasm.h"
-#include "memmodel.h"
-#include "optabs.h"
 #include "internal-fn.h"
 
 enum strlen_range_kind {
@@ -962,17 +960,14 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
        = build_int_cst (build_pointer_type_for_mode (char_type_node,
                                                      ptr_mode, true), 0);
 
-      /* If we can perform the copy efficiently with first doing all loads and
-        then all stores inline it that way.  Currently efficiently means that
-        we can load all the memory with a single set operation and that the
-        total size is less than MOVE_MAX * MOVE_RATIO.  */
+      /* If we can perform the copy efficiently with first doing all loads
+         and then all stores inline it that way.  Currently efficiently
+        means that we can load all the memory into a single integer
+        register which is what MOVE_MAX gives us.  */
       src_align = get_pointer_alignment (src);
       dest_align = get_pointer_alignment (dest);
       if (tree_fits_uhwi_p (len)
-         && (compare_tree_int
-             (len, (MOVE_MAX
-                    * MOVE_RATIO (optimize_function_for_size_p (cfun))))
-             <= 0)
+         && compare_tree_int (len, MOVE_MAX) <= 0
          /* FIXME: Don't transform copies from strings with known length.
             Until GCC 9 this prevented a case in gcc.dg/strlenopt-8.c
             from being handled, and the case was XFAILed for that reason.
@@ -1006,7 +1001,6 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
              scalar_int_mode mode;
              if (int_mode_for_size (ilen * 8, 0).exists (&mode)
                  && GET_MODE_SIZE (mode) * BITS_PER_UNIT == ilen * 8
-                 && have_insn_for (SET, mode)
                  /* If the destination pointer is not aligned we must be able
                     to emit an unaligned store.  */
                  && (dest_align >= GET_MODE_ALIGNMENT (mode)