diff --git a/gcc/fwprop.c b/gcc/fwprop.c
index 7ff5135..67ef93c 100644
--- a/gcc/fwprop.c
+++ b/gcc/fwprop.c
@@ -1101,6 +1101,7 @@ forward_propagate_subreg (df_ref use, rtx
def_insn, rtx def_set)
       src = SET_SRC (def_set);
       if (GET_CODE (src) == SUBREG
 	  && REG_P (SUBREG_REG (src))
+	  && REGNO (SUBREG_REG (src)) >= FIRST_PSEUDO_REGISTER
 	  && GET_MODE (SUBREG_REG (src)) == use_mode
 	  && subreg_lowpart_p (src)
 	  && all_uses_available_at (def_insn, use_insn))
@@ -1119,6 +1120,7 @@ forward_propagate_subreg (df_ref use, rtx
def_insn, rtx def_set)
       if ((GET_CODE (src) == ZERO_EXTEND
 	   || GET_CODE (src) == SIGN_EXTEND)
 	  && REG_P (XEXP (src, 0))
+	  && REGNO (XEXP (src, 0)) >= FIRST_PSEUDO_REGISTER
 	  && GET_MODE (XEXP (src, 0)) == use_mode
 	  && !free_load_extend (src, def_insn)
 	  && all_uses_available_at (def_insn, use_insn))
diff --git a/gcc/testsuite/gcc.target/i386/pr47449.c
b/gcc/testsuite/gcc.target/i386/pr47449.c
new file mode 100644
index 0000000..99ef32f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr47449.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+void bar (void *, void *);
+int
+foo (void *p1, void *p2)
+{
+  int ret1, ret2;
+  __asm ("" : "=D" (ret1), "=S" (ret2));
+  bar (p1, p2);
+  return ret1 + ret2;
+}