/c-family

[pf3gnuchains/gcc-fork.git] / gcc / dce.c

diff --git a/gcc/dce.c b/gcc/dce.c
index e6e9836..f63d09e 100644 (file)
--- a/gcc/dce.c
+++ b/gcc/dce.c
@@ -1,5 +1,5 @@
 /* RTL dead code elimination.
-   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -220,6 +220,26 @@ mark_nonreg_stores (rtx body, rtx insn, bool fast)
 }
 
 
+/* Return true if store to MEM, starting OFF bytes from stack pointer,
+   is a call argument store, and clear corresponding bits from SP_BYTES
+   bitmap if it is.  */
+
+static bool
+check_argument_store (rtx mem, HOST_WIDE_INT off, HOST_WIDE_INT min_sp_off,
+                     HOST_WIDE_INT max_sp_off, bitmap sp_bytes)
+{
+  HOST_WIDE_INT byte;
+  for (byte = off; byte < off + GET_MODE_SIZE (GET_MODE (mem)); byte++)
+    {
+      if (byte < min_sp_off
+         || byte >= max_sp_off
+         || !bitmap_clear_bit (sp_bytes, byte - min_sp_off))
+       return false;
+    }
+  return true;
+}
+
+
 /* Try to find all stack stores of CALL_INSN arguments if
    ACCUMULATE_OUTGOING_ARGS.  If all stack stores have been found
    and it is therefore safe to eliminate the call, return true,
@@ -364,7 +384,7 @@ find_call_stack_args (rtx call_insn, bool do_mark, bool fast,
   for (insn = PREV_INSN (call_insn); insn; insn = prev_insn)
     {
       rtx set, mem, addr;
-      HOST_WIDE_INT off, byte;
+      HOST_WIDE_INT off;
 
       if (insn == BB_HEAD (BLOCK_FOR_INSN (call_insn)))
        prev_insn = NULL_RTX;
@@ -374,7 +394,7 @@ find_call_stack_args (rtx call_insn, bool do_mark, bool fast,
       if (CALL_P (insn))
        break;
 
-      if (!INSN_P (insn))
+      if (!NONDEBUG_INSN_P (insn))
        continue;
 
       set = single_set (insn);
@@ -433,17 +453,11 @@ find_call_stack_args (rtx call_insn, bool do_mark, bool fast,
            break;
        }
 
-      if (GET_MODE_SIZE (GET_MODE (mem)) == 0)
+      if (GET_MODE_SIZE (GET_MODE (mem)) == 0
+         || !check_argument_store (mem, off, min_sp_off,
+                                   max_sp_off, sp_bytes))
        break;
 
-      for (byte = off; byte < off + GET_MODE_SIZE (GET_MODE (mem)); byte++)
-       {
-         if (byte < min_sp_off
-             || byte >= max_sp_off
-             || !bitmap_clear_bit (sp_bytes, byte - min_sp_off))
-           break;
-       }
-
       if (!deletable_insn_p (insn, fast, NULL))
        break;