re PR rtl-optimization/7702 (gcc-3.2 optimization problem on a DEC alpha under OSF1)

        PR optimization/7702
        * reload1.c (reload_cse_simplify_set): Honor
        CANNOT_CHANGE_MODE_CLASS.

From-SVN: r62921

gcc/ChangeLog

+2003-02-14  Falk Hueffner  <falk.hueffner@student.uni-tuebingen.de>
+
+	PR optimization/7702
+	* reload1.c (reload_cse_simplify_set): Honor
+	CANNOT_CHANGE_MODE_CLASS.
+
 2003-02-14  Alexandre Oliva  <aoliva@redhat.com>
 
 	* config/mn10300/mn10300.c (mn10300_wide_const_load_uses_clr): New
@@ -22,23 +28,23 @@
 
 2003-02-13  Adam Nemet  <anemet@lnxw.com>
 
-        PR opt/2391 
-        * combine.c: Fix spelling in comment.
-        (cached_nonzero_bits): New function.
-        (cached_num_sign_bit_copies): New function.
+	PR opt/2391 
+	* combine.c: Fix spelling in comment.
+	(cached_nonzero_bits): New function.
+	(cached_num_sign_bit_copies): New function.
 	(nonzero_bits_with_known): New macro.
 	(num_sign_bit_copies_with_known): New macro.
-        (nonzero_bits1): Rename from nonzero_bits.  Add three new
+	(nonzero_bits1): Rename from nonzero_bits.  Add three new
 	arguments.  Change calls from nonzero_bits to
 	nonzero_bits_with_known.
-        (num_sign_bit_copies1): Rename from num_sign_bit_copies.  Add
+	(num_sign_bit_copies1): Rename from num_sign_bit_copies.  Add
 	three new arguments.  Change calls from num_sign_bit_copies to
 	num_sign_bit_copies_with_known.
-        (nonzero_bits): New macro.
-        (num_sign_bit_copies): New macro.
-        (update_table_tick): Don't traverse identical subexpression more
+	(nonzero_bits): New macro.
+	(num_sign_bit_copies): New macro.
+	(update_table_tick): Don't traverse identical subexpression more
 	than once.
-        (get_last_value_validate): Likewise.
+	(get_last_value_validate): Likewise.
 
 2003-02-13  Zack Weinberg  <zack@codesourcery.com>
 

gcc/reload1.c

@@ -8282,7 +8282,13 @@ reload_cse_simplify_set (set, insn)
 	{
 #ifdef LOAD_EXTEND_OP
 	  if (GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) < BITS_PER_WORD
-	      && extend_op != NIL)
+	      && extend_op != NIL
+#ifdef CANNOT_CHANGE_MODE_CLASS
+	      && !CANNOT_CHANGE_MODE_CLASS (GET_MODE (SET_DEST (set)),
+					    word_mode,
+					    REGNO_REG_CLASS (REGNO (SET_DEST (set))))
+#endif
+	      )
 	    {
 	      rtx wide_dest = gen_rtx_REG (word_mode, REGNO (SET_DEST (set)));
 	      ORIGINAL_REGNO (wide_dest) = ORIGINAL_REGNO (SET_DEST (set));