* cse.c (cse_set_around_loop): Don't do optimization when

	new pseudos are created.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@19404 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 85d4b24..c95f9d6 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Fri Apr 24 20:55:47 1998  J"orn Rennecke <amylaar@cygnus.co.uk>
+
+       * cse.c (cse_set_around_loop): Don't do optimization when
+       new pseudos are created.
+
 Fri Apr 24 11:00:18 1998  Jeffrey A Law  (law@cygnus.com)
 
        * dbxout.c (dbxout_type_fields): Use HOST_WIDE_INT_PRINT_DEC

diff --git a/gcc/cse.c b/gcc/cse.c
index 19a02ef..ddaf689 100644 (file)
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -8018,9 +8018,24 @@ cse_set_around_loop (x, insn, loop_start)
                    if (cse_check_loop_start_value
                        && validate_change (insn, &SET_SRC (x),
                                            src_elt->exp, 0))
-                     emit_insn_after (gen_move_insn (src_elt->exp,
-                                                     SET_DEST (set)),
-                                      p);
+                     {
+                       /* If this creates new pseudos, this is unsafe,
+                          because the regno of new pseudo is unsuitable
+                          to index into reg_qty when cse_insn processes
+                          the new insn.  Therefore, if a new pseudo was
+                          created, discard this optimization.  */
+                       int nregs = max_reg_num ();
+                       rtx move
+                         = gen_move_insn (src_elt->exp, SET_DEST (set));
+                       if (nregs != max_reg_num ())
+                         {
+                           if (! validate_change (insn, &SET_SRC (x),
+                                                  SET_SRC (set), 0))
+                             abort ();
+                         }
+                       else
+                         emit_insn_after (move, p);
+                     }
                    break;
                  }
            }