1 files changed, 49 insertions, 0 deletions
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index 5d9df2cc089..d951d98ae7a 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -1443,6 +1443,55 @@ note_stores (const_rtx x, void (*fun) (rtx, const_rtx, void *), void *data)
       note_stores (XVECEXP (x, 0, i), fun, data);
 }
 
+/* Call FUN on each register or MEM that is stored into or clobbered by X.
+   (X would be the pattern of an insn).  DATA is an arbitrary pointer,
+   ignored by note_stores, but passed to FUN.
+   FUN may alter parts of the RTL.
+
+   FUN receives three arguments:
+   1. the REG, MEM, CC0 or PC being stored in or clobbered,
+   2. the SET or CLOBBER rtx that does the store,
+   3. the pointer DATA provided to note_stores.
+
+  If the item being stored in or clobbered is a SUBREG of a hard register,
+  the SUBREG will be passed.  */
+
+void
+walk_stores (rtx x, void (*fun) (rtx, rtx, void *), void *data)
+{
+  int i;
+
+  if (GET_CODE (x) == COND_EXEC)
+    x = COND_EXEC_CODE (x);
+
+  if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
+    {
+      rtx dest = SET_DEST (x);
+
+      while ((GET_CODE (dest) == SUBREG
+	      && (!REG_P (SUBREG_REG (dest))
+		  || REGNO (SUBREG_REG (dest)) >= FIRST_PSEUDO_REGISTER))
+	     || GET_CODE (dest) == ZERO_EXTRACT
+	     || GET_CODE (dest) == STRICT_LOW_PART)
+	dest = XEXP (dest, 0);
+
+      /* If we have a PARALLEL, SET_DEST is a list of EXPR_LIST expressions,
+	 each of whose first operand is a register.  */
+      if (GET_CODE (dest) == PARALLEL)
+	{
+	  for (i = XVECLEN (dest, 0) - 1; i >= 0; i--)
+	    if (XEXP (XVECEXP (dest, 0, i), 0) != 0)
+	      (*fun) (XEXP (XVECEXP (dest, 0, i), 0), x, data);
+	}
+      else
+	(*fun) (dest, x, data);
+    }
+
+  else if (GET_CODE (x) == PARALLEL)
+    for (i = XVECLEN (x, 0) - 1; i >= 0; i--)
+      walk_stores (XVECEXP (x, 0, i), fun, data);
+}
+
 /* Like notes_stores, but call FUN for each expression that is being
    referenced in PBODY, a pointer to the PATTERN of an insn.  We only call
    FUN for each expression, not any interior subexpressions.  FUN receives a