diff --git a/gcc/ree.c b/gcc/ree.c
index 67fc9c3..e9ff904 100644
--- a/gcc/ree.c
+++ b/gcc/ree.c
@@ -793,6 +793,14 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state)
       if (state->modified[INSN_UID (cand->insn)].kind != EXT_MODIFIED_NONE)
 	return false;
 
+      enum machine_mode dst_mode = GET_MODE (SET_DEST (PATTERN (cand->insn)));
+      rtx src_reg = get_extended_src_reg (SET_SRC (PATTERN (cand->insn)));
+
+      /* Ensure the number of hard registers of the copy match.  */
+      if (HARD_REGNO_NREGS (REGNO (src_reg), dst_mode)
+	  != HARD_REGNO_NREGS (REGNO (src_reg), GET_MODE (src_reg)))
+	return false;
+
       /* There's only one reaching def.  */
       rtx def_insn = state->defs_list[0];
 
@@ -842,7 +850,7 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, ext_state *state)
       start_sequence ();
       rtx pat = PATTERN (cand->insn);
       rtx new_dst = gen_rtx_REG (GET_MODE (SET_DEST (pat)),
-                                 REGNO (XEXP (SET_SRC (pat), 0)));
+				 REGNO (get_extended_src_reg (SET_SRC (pat))));
       rtx new_src = gen_rtx_REG (GET_MODE (SET_DEST (pat)),
                                  REGNO (SET_DEST (pat)));
       emit_move_insn (new_dst, new_src);