m68hc11.h (HARD_REGNO_RENAME_OK): Define.

	* config/m68hc11/m68hc11.h (HARD_REGNO_RENAME_OK): Define.
	* config/m68hc11/m68hc11-protos.h (m68hc11_hard_regno_rename_ok):
	Declare.
	* config/m68hc11/m68hc11.c (m68hc11_hard_regno_rename_ok): New function
	for reg rename optimization to avoid using Z and Y registers.

From-SVN: r64134

gcc/ChangeLog

 2003-03-10  Stephane Carrez  <stcarrez@nerim.fr>
 
+	* config/m68hc11/m68hc11.h (HARD_REGNO_RENAME_OK): Define.
+	* config/m68hc11/m68hc11-protos.h (m68hc11_hard_regno_rename_ok):
+	Declare.
+	* config/m68hc11/m68hc11.c (m68hc11_hard_regno_rename_ok): New function
+	for reg rename optimization to avoid using Z and Y registers.
+
+2003-03-10  Stephane Carrez  <stcarrez@nerim.fr>
+
 	* config/m68hc11/m68hc11.md ("*addhi3_68hc12"): Accept any constant
 	when adding to X and Y since leax/leay are fast.
 	("*addhi3"): Accept 'I' constraint when adding to address register.

gcc/config/m68hc11/m68hc11-protos.h

@@ -24,6 +24,7 @@ extern int m68hc11_override_options PARAMS((void));
 extern int m68hc11_optimization_options PARAMS((int,int));
 extern void m68hc11_conditional_register_usage PARAMS((void));
 extern int hard_regno_mode_ok PARAMS((int, enum machine_mode));
+extern int m68hc11_hard_regno_rename_ok PARAMS((int, int));
 
 extern int m68hc11_total_frame_size PARAMS((void));
 extern int m68hc11_initial_frame_pointer_offset PARAMS((void));

gcc/config/m68hc11/m68hc11.c

@@ -394,6 +394,23 @@ hard_regno_mode_ok (regno, mode)
     }
 }
 
+int
+m68hc11_hard_regno_rename_ok (reg1, reg2)
+     int reg1, reg2;
+{
+  /* Don't accept renaming to Z register.  We will replace it to
+     X,Y or D during machine reorg pass.  */
+  if (reg2 == HARD_Z_REGNUM)
+    return 0;
+
+  /* Don't accept renaming D,X to Y register as the code will be bigger.  */
+  if (TARGET_M6811 && reg2 == HARD_Y_REGNUM
+      && (D_REGNO_P (reg1) || X_REGNO_P (reg1)))
+    return 0;
+
+  return 1;
+}
+
 enum reg_class
 preferred_reload_class (operand, class)
      rtx operand;

gcc/config/m68hc11/m68hc11.h

@@ -801,6 +801,12 @@ extern enum reg_class m68hc11_tmp_regs_class;
 
 #define SMALL_REGISTER_CLASSES 1
 
+/* A C expression that is nonzero if hard register number REGNO2 can be
+   considered for use as a rename register for REGNO1 */
+
+#define HARD_REGNO_RENAME_OK(REGNO1,REGNO2) \
+  m68hc11_hard_regno_rename_ok ((REGNO1), (REGNO2))
+
 /* A C expression whose value is nonzero if pseudos that have been
    assigned to registers of class CLASS would likely be spilled
    because registers of CLASS are needed for spill registers.