Fix sparc-sun-solaris2 -O2 -fPIC bootstrap failure with gcse code.

	* loop.c (struct movable): New field move_insn_first.
	(scan_loop): In consec sets code, set it.  Clear it otherwise.
	(move_movables): In consec sets code, use it.  Copy REG_NOTES from
	p to i1 only if i1 does not have REG_NOTES.  Delete obsolete ifdefed
	out code.

From-SVN: r18669

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cedf008479490b5b23b90665c810628e774ed87e..cb9b882c67b30b8fa45049ddd4ff4bd00499e747 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+Wed Mar 18 12:43:20 1998  Jim Wilson  <wilson@cygnus.com>
+
+       * loop.c (struct movable): New field move_insn_first.
+       (scan_loop): In consec sets code, set it.  Clear it otherwise.
+       (move_movables): In consec sets code, use it.  Copy REG_NOTES from
+       p to i1 only if i1 does not have REG_NOTES.  Delete obsolete ifdefed
+       out code.
+
 Wed Mar 18 09:52:56 1998  Richard Henderson  <rth@cygnus.com>
 
        * rtl.c (read_rtx): Fall back on homebrew atoll if HOST_WIDE_INT

diff --git a/gcc/loop.c b/gcc/loop.c
index 89402a547c1a0d2a4d7f6b3ad03c65aa23001502..5e3039f18ff3d5603a31c6500189123063d39efa 100644 (file)
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -262,6 +262,8 @@ struct movable
                                   invariant.  */
   unsigned int move_insn : 1;  /* 1 means that we call emit_move_insn to
                                   load SRC, rather than copying INSN.  */
+  unsigned int move_insn_first:1;/* Same as above, if this is necessary for the
+                                   first insn of a consecutive sets group.  */
   unsigned int is_equiv : 1;   /* 1 means a REG_EQUIV is present on INSN.  */
   enum machine_mode savemode;   /* Nonzero means it is a mode for a low part
                                   that we should avoid changing when clearing
@@ -861,6 +863,7 @@ scan_loop (loop_start, end, nregs, unroll_p)
              m->forces = 0;
              m->partial = 0;
              m->move_insn = move_insn;
+             m->move_insn_first = 0;
              m->is_equiv = (find_reg_note (p, REG_EQUIV, NULL_RTX) != 0);
              m->savemode = VOIDmode;
              m->regno = regno;
@@ -885,6 +888,12 @@ scan_loop (loop_start, end, nregs, unroll_p)
 
              if (m->consec > 0)
                {
+                 /* It is possible for the first instruction to have a
+                    REG_EQUAL note but a non-invariant SET_SRC, so we must
+                    remember the status of the first instruction in case
+                    the last instruction doesn't have a REG_EQUAL note.  */
+                 m->move_insn_first = m->move_insn;
+
                  /* Skip this insn, not checking REG_LIBCALL notes.  */
                  p = next_nonnote_insn (p);
                  /* Skip the consecutive insns, if there are any.  */
@@ -1943,20 +1952,41 @@ move_movables (movables, threshold, insn_count, loop_start, end, nregs)
                            CALL_INSN_FUNCTION_USAGE (i1)
                              = copy_rtx (CALL_INSN_FUNCTION_USAGE (p));
                        }
+                     else if (count == m->consec && m->move_insn_first)
+                       {
+                         /* The SET_SRC might not be invariant, so we must
+                            use the REG_EQUAL note.  */
+                         start_sequence ();
+                         emit_move_insn (m->set_dest, m->set_src);
+                         temp = get_insns ();
+                         end_sequence ();
+
+                         add_label_notes (m->set_src, temp);
+
+                         i1 = emit_insns_before (temp, loop_start);
+                         if (! find_reg_note (i1, REG_EQUAL, NULL_RTX))
+                           REG_NOTES (i1)
+                             = gen_rtx_EXPR_LIST ((m->is_equiv ? REG_EQUIV
+                                                   : REG_EQUAL),
+                                                  m->set_src, REG_NOTES (i1));
+                       }
                      else
                        i1 = emit_insn_before (PATTERN (p), loop_start);
 
-                     REG_NOTES (i1) = REG_NOTES (p);
+                     if (REG_NOTES (i1) == 0)
+                       {
+                         REG_NOTES (i1) = REG_NOTES (p);
 
-                     /* If there is a REG_EQUAL note present whose value is
-                        not loop invariant, then delete it, since it may
-                        cause problems with later optimization passes.
-                        It is possible for cse to create such notes
-                        like this as a result of record_jump_cond.  */
+                         /* If there is a REG_EQUAL note present whose value
+                            is not loop invariant, then delete it, since it
+                            may cause problems with later optimization passes.
+                            It is possible for cse to create such notes
+                            like this as a result of record_jump_cond.  */
                      
-                     if ((temp = find_reg_note (i1, REG_EQUAL, NULL_RTX))
-                         && ! invariant_p (XEXP (temp, 0)))
-                       remove_note (i1, temp);
+                         if ((temp = find_reg_note (i1, REG_EQUAL, NULL_RTX))
+                             && ! invariant_p (XEXP (temp, 0)))
+                           remove_note (i1, temp);
+                       }
 
                      if (new_start == 0)
                        new_start = i1;
@@ -1965,20 +1995,6 @@ move_movables (movables, threshold, insn_count, loop_start, end, nregs)
                        fprintf (loop_dump_stream, " moved to %d",
                                 INSN_UID (i1));
 
-#if 0
-                     /* This isn't needed because REG_NOTES is copied
-                        below and is wrong since P might be a PARALLEL.  */
-                     if (REG_NOTES (i1) == 0
-                         && ! m->partial /* But not if it's a zero-extend clr.  */
-                         && ! m->global /* and not if used outside the loop
-                                           (since it might get set outside).  */
-                         && CONSTANT_P (SET_SRC (PATTERN (p))))
-                       REG_NOTES (i1)
-                         = gen_rtx_EXPR_LIST (REG_EQUAL,
-                                              SET_SRC (PATTERN (p)),
-                                              REG_NOTES (i1));
-#endif
-
                      /* If library call, now fix the REG_NOTES that contain
                         insn pointers, namely REG_LIBCALL on FIRST
                         and REG_RETVAL on I1.  */