(sched_analyze_1...

(sched_analyze_1, sched_analyze_2): Ifdef out code added
for handling psuedo register equivalents that was added Dec 31 1992.

From-SVN: r3290

diff --git a/gcc/sched.c b/gcc/sched.c
index 7df147a..5483fc8 100644 (file)
--- a/gcc/sched.c
+++ b/gcc/sched.c
@@ -1610,6 +1610,16 @@ sched_analyze_1 (x, insn)
            add_dependence (insn, reg_last_sets[regno], REG_DEP_OUTPUT);
          reg_last_sets[regno] = insn;
 
+#if 0
+         /* ??? This code has two serious problems:
+            1) It can cause an infinite loop if regno is mentioned in
+               its reg_known_value.
+            2) It can cause execution time exponential in the size of the
+               input if there are long chains of reg_known_values pointing
+               to other reg_known_values.
+            This code was specifically added to handle fake argument pointers.
+            It may need to be rewritten to just handle that specific case.  */
+
          /* Pseudos that are REG_EQUIV to something may be replaced
             by that during reloading, so we can potentially read
             quantities mentioned in those addresses. */
@@ -1617,6 +1627,7 @@ sched_analyze_1 (x, insn)
            if (reg_known_value[regno] != regno_reg_rtx[regno])
              if (GET_CODE (reg_known_value[regno]) == MEM)
                sched_analyze_2 (XEXP (reg_known_value[regno], 0), insn);
+#endif
 
          /* Don't let it cross a call after scheduling if it doesn't
             already cross one.  */
@@ -1770,11 +1781,22 @@ sched_analyze_2 (x, insn)
            if (reg_last_sets[regno])
              add_dependence (insn, reg_last_sets[regno], 0);
 
+#if 0
+         /* ??? This code has two serious problems:
+            1) It can cause an infinite loop if regno is mentioned in
+               its reg_known_value.
+            2) It can cause execution time exponential in the size of the
+               input if there are long chains of reg_known_values pointing
+               to other reg_known_values.
+            This code was specifically added to handle fake argument pointers.
+            It may need to be rewritten to just handle that specific case.  */
+
            /* Pseudos that are REG_EQUIV to something may be replaced
               by that, so we depend on anything mentioned there too. */
            if (! reload_completed)
              if (reg_known_value[regno] != regno_reg_rtx[regno])
                sched_analyze_2 (reg_known_value[regno], insn);
+#endif
 
            /* If the register does not already cross any calls, then add this
               insn to the sched_before_next_call list so that it will still