* 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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@64134 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 24 insertions, 0 deletions

diff --git a/gcc/config/m68hc11/m68hc11-protos.h b/gcc/config/m68hc11/m68hc11-protos.h
index dda14692b31..01352b3d87a 100644
--- a/gcc/config/m68hc11/m68hc11-protos.h
+++ b/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));
diff --git a/gcc/config/m68hc11/m68hc11.c b/gcc/config/m68hc11/m68hc11.c
index 9ccac2ee657..ba4407b9f35 100644
--- a/gcc/config/m68hc11/m68hc11.c
+++ b/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;
diff --git a/gcc/config/m68hc11/m68hc11.h b/gcc/config/m68hc11/m68hc11.h
index 3aa6a8eb4f7..95d3f609ae5 100644
--- a/gcc/config/m68hc11/m68hc11.h
+++ b/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.