(flush_pending_lists): Add new arg, ONLY_WRITE.

(sched_analyze_{1,2,insn}): Add new arg to flush_pending_lists.
(sched_analyze): Always flush pending write list for call, even const.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@11200 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/sched.c b/gcc/sched.c
index a8883e8..f279512 100644 (file)
--- a/gcc/sched.c
+++ b/gcc/sched.c
@@ -313,7 +313,7 @@ static int insn_cost                        PROTO((rtx, rtx, rtx));
 static int priority                    PROTO((rtx));
 static void free_pending_lists         PROTO((void));
 static void add_insn_mem_dependence    PROTO((rtx *, rtx *, rtx, rtx));
-static void flush_pending_lists                PROTO((rtx));
+static void flush_pending_lists                PROTO((rtx, int));
 static void sched_analyze_1            PROTO((rtx, rtx));
 static void sched_analyze_2            PROTO((rtx, rtx));
 static void sched_analyze_insn         PROTO((rtx, rtx, rtx));
@@ -1628,15 +1628,17 @@ add_insn_mem_dependence (insn_list, mem_list, insn, mem)
 }
 \f
 /* Make a dependency between every memory reference on the pending lists
-   and INSN, thus flushing the pending lists.  */
+   and INSN, thus flushing the pending lists.  If ONLY_WRITE, don't flush
+   the read list.  */
 
 static void
-flush_pending_lists (insn)
+flush_pending_lists (insn, only_write)
      rtx insn;
+     int only_write;
 {
   rtx link;
 
-  while (pending_read_insns)
+  while (pending_read_insns && ! only_write)
     {
       add_dependence (insn, XEXP (pending_read_insns, 0), REG_DEP_ANTI);
 
@@ -1765,7 +1767,7 @@ sched_analyze_1 (x, insn)
             seems like a reasonable number.  When compiling GCC with itself,
             this flush occurs 8 times for sparc, and 10 times for m88k using
             the number 32.  */
-         flush_pending_lists (insn);
+         flush_pending_lists (insn, 0);
        }
       else
        {
@@ -1984,7 +1986,7 @@ sched_analyze_2 (x, insn)
              }
            reg_pending_sets_all = 1;
 
-           flush_pending_lists (insn);
+           flush_pending_lists (insn, 0);
          }
 
        /* For all ASM_OPERANDS, we must traverse the vector of input operands.
@@ -2088,7 +2090,7 @@ sched_analyze_insn (x, insn, loop_notes)
        }
       reg_pending_sets_all = 1;
 
-      flush_pending_lists (insn);
+      flush_pending_lists (insn, 0);
 
       link = loop_notes;
       while (XEXP (link, 1))
@@ -2263,15 +2265,11 @@ sched_analyze (head, tail)
          sched_analyze_insn (PATTERN (insn), insn, loop_notes);
          loop_notes = 0;
 
-         /* We don't need to flush memory for a function call which does
-            not involve memory.  */
-         if (! CONST_CALL_P (insn))
-           {
-             /* In the absence of interprocedural alias analysis,
-                we must flush all pending reads and writes, and
-                start new dependencies starting from here.  */
-             flush_pending_lists (insn);
-           }
+         /* In the absence of interprocedural alias analysis, we must flush
+            all pending reads and writes, and start new dependencies starting
+            from here.  But only flush writes for constant calls (which may
+            be passed a pointer to something we haven't written yet).  */
+         flush_pending_lists (insn, CONST_CALL_P (insn));
 
          /* Depend this function call (actually, the user of this
             function call) on all hard register clobberage.  */