loop.c (record_giv): Avoid simplifying MULT to ASHIFT.

        * loop.c (record_giv): Avoid simplifying MULT to ASHIFT.
        (express_from_1): Wrap lines.
        * rtlanal.c (commutative_operand_precedence): Rename from
        operand_preference; export.
        * rtl.h: Declare it.
        * simplify-rtx.c (simplify_gen_binary): Tidy +/- const_int handling.
        (simplify_binary_operation): Invoke simplify_plus_minus on
        (CONST (PLUS ...)) as well.
        (struct simplify_plus_minus_op_data): New.
        (simplify_plus_minus_op_data_cmp): New.
        (simplify_plus_minus): Use them.  Avoid infinite recursion with
        simplify_binary_operation wrt CONST.

From-SVN: r45473

gcc/ChangeLog

+2001-09-07  Richard Henderson  <rth@redhat.com>
+
+	* loop.c (record_giv): Avoid simplifying MULT to ASHIFT.
+	(express_from_1): Wrap lines.
+	* rtlanal.c (commutative_operand_precedence): Rename from
+	operand_preference; export.
+	* rtl.h: Declare it.
+	* simplify-rtx.c (simplify_gen_binary): Tidy +/- const_int handling.
+	(simplify_binary_operation): Invoke simplify_plus_minus on
+	(CONST (PLUS ...)) as well.
+	(struct simplify_plus_minus_op_data): New.
+	(simplify_plus_minus_op_data_cmp): New.
+	(simplify_plus_minus): Use them.  Avoid infinite recursion with
+	simplify_binary_operation wrt CONST.
+
 Fri Sep  7 11:52:30 2001   Kazu Hirata  <kazu@hxi.com>
 
 	* h8300-protos.h (general_operand_dst_push): Remove.

gcc/loop.c

@@ -4922,9 +4922,12 @@ record_giv (loop, v, insn, src_reg, dest_reg, mult_val, add_val, ext_val,
   rtx set = single_set (insn);
   rtx temp;
 
-  /* Attempt to prove constantness of the values.  */
+  /* Attempt to prove constantness of the values.  Don't let simplity_rtx
+     undo the MULT canonicalization that we performed earlier.  */
   temp = simplify_rtx (add_val);
-  if (temp)
+  if (temp
+      && ! (GET_CODE (add_val) == MULT
+	    && GET_CODE (temp) == ASHIFT))
     add_val = temp;
 
   v->insn = insn;
@@ -6371,7 +6374,10 @@ express_from_1 (a, b, mult)
     }
   else if (CONSTANT_P (a))
     {
-      return simplify_gen_binary (MINUS, GET_MODE (b) != VOIDmode ? GET_MODE (b) : GET_MODE (a), b, a);
+      enum machine_mode mode_a = GET_MODE (a);
+      enum machine_mode mode_b = GET_MODE (b);
+      enum machine_mode mode = mode_b == VOIDmode ? mode_a : mode_b;
+      return simplify_gen_binary (MINUS, mode, b, a);
     }
   else if (GET_CODE (b) == PLUS)
     {

gcc/rtl.h

@@ -1374,6 +1374,7 @@ extern int reg_used_between_p		PARAMS ((rtx, rtx, rtx));
 extern int reg_referenced_between_p	PARAMS ((rtx, rtx, rtx));
 extern int reg_set_between_p		PARAMS ((rtx, rtx, rtx));
 extern int regs_set_between_p		PARAMS ((rtx, rtx, rtx));
+extern int commutative_operand_precedence PARAMS ((rtx));
 extern int swap_commutative_operands_p	PARAMS ((rtx, rtx));
 extern int modified_between_p		PARAMS ((rtx, rtx, rtx));
 extern int no_labels_between_p		PARAMS ((rtx, rtx));

gcc/rtlanal.c

@@ -30,7 +30,6 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 static void set_of_1		PARAMS ((rtx, rtx, void *));
 static void insn_dependent_p_1	PARAMS ((rtx, rtx, void *));
 static int computed_jump_p_1	PARAMS ((rtx));
-static int operand_preference	PARAMS ((rtx));
 static void parms_set 		PARAMS ((rtx, rtx, void *));
 
 /* Bit flags that specify the machine subtype we are compiling for.
@@ -2558,8 +2557,8 @@ regno_use_in (regno, x)
    We use negative values to indicate a preference for the first operand
    and positive values for the second operand.  */
 
-static int
-operand_preference (op)
+int
+commutative_operand_precedence (op)
      rtx op;
 {
   /* Constants always come the second operand.  Prefer "nice" constants.  */
@@ -2597,7 +2596,8 @@ int
 swap_commutative_operands_p (x, y)
      rtx x, y;
 {
-  return operand_preference (x) < operand_preference (y);
+  return (commutative_operand_precedence (x)
+	  < commutative_operand_precedence (y));
 }
 
 /* Return 1 if X is an autoincrement side effect and the register is