Revert "[PATCH v2] In the pipeline, USE or CLOBBER should delay execution if it start...

This reverts commit 85b49ad863965408668627f10b5b1b106053f319.

diff --git a/gcc/haifa-sched.cc b/gcc/haifa-sched.cc
index 47ad09457c78348621d06a831d616da16fb04916..8e8add709b3a79401ef94271127f6095c33b4644 100644 (file)
--- a/gcc/haifa-sched.cc
+++ b/gcc/haifa-sched.cc
@@ -765,23 +765,6 @@ real_insn_for_shadow (rtx_insn *insn)
   return pair->i1;
 }
 
-/* Return TRUE if INSN (a USE or CLOBBER) starts a new live
-    range, FALSE otherwise.  */
-
-static bool
-use_or_clobber_starts_range_p (rtx_insn *insn)
-{
-  gcc_assert (insn);
-
-  if ((GET_CODE (PATTERN (insn)) == CLOBBER
-       || GET_CODE (PATTERN (insn)) == USE)
-      && !sd_lists_empty_p (insn, SD_LIST_FORW)
-      && sd_lists_empty_p (insn, SD_LIST_BACK))
-    return true;
-
-  return false;
-}
-
 /* For a pair P of insns, return the fixed distance in cycles from the first
    insn after which the second must be scheduled.  */
 static int
@@ -6337,39 +6320,11 @@ prune_ready_list (state_t temp_state, bool first_cycle_insn_p,
            }
          else if (recog_memoized (insn) < 0)
            {
-             if (GET_CODE (PATTERN (insn)) == ASM_INPUT
-                 || asm_noperands (PATTERN (insn)) >= 0)
-               {
-                 reason = "asm";
-                 if (!first_cycle_insn_p)
-                   cost = 1;
-               }
-             else if (use_or_clobber_starts_range_p (insn))
-               {
-                 /* If USE or CLOBBER opens an active range, its execution should
-                    be delayed so as to be closer to the relevant instructions and
-                    avoid the generation of some redundant mov instructions.
-                    Otherwise, it should be executed as soon as possible.  */
-                 reason = "unrecog insn";
-                 if (!first_cycle_insn_p)
-                   /* If USE or CLOBBER is not in the first cycle, simply delay it
-                      by one cycle.  */
-                   cost = 1;
-                 else
-                   {
-                     /* If the USE or CLOBBER is in the first cycle and there are no
-                        other non-USE or non-CLOBBER instructions after it, we need
-                        to execute it immediately, otherwise we need to execute the
-                        non-USE or non-CLOBBER instructions first and postpone the
-                        execution of the USE or CLOBBER instructions.  */
-                     int j = i;
-                     while (n > ++j)
-                       if (!use_or_clobber_starts_range_p (ready_element (&ready, j)))
-                         break;
-
-                     cost = (j == n) ? 0 : 1;
-                   }
-               }
+             if (!first_cycle_insn_p
+                 && (GET_CODE (PATTERN (insn)) == ASM_INPUT
+                     || asm_noperands (PATTERN (insn)) >= 0))
+               cost = 1;
+             reason = "asm";
            }
          else if (sched_pressure != SCHED_PRESSURE_NONE)
            {