[amdgcn] Unfix registers for frame pointer

Allow the registers used for the frame pointer to be used for other purposes
if the frame pointer is not being used.

2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* config/gcn/gcn.h (FIXED_REGISTERS): Unfix frame pointer.
	(CALL_USED_REGISTERS): Make frame pointer callee-saved.

From-SVN: r278306

gcc/ChangeLog

 2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>
 
+	* config/gcn/gcn.h (FIXED_REGISTERS): Unfix frame pointer.
+	(CALL_USED_REGISTERS): Make frame pointer callee-saved.
+
+2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>
+
 	* config/gcn/gcn.c (MAX_NORMAL_SGPR_COUNT, MAX_NORMAL_VGPR_COUNT): New.
 	(gcn_conditional_register_usage): Use constants in place of hard-coded
 	values.

gcc/config/gcn/gcn.h

@@ -162,7 +162,7 @@
     /* Scalars.  */				    \
     1, 1, 0, 0, 1, 1, 0, 0, 1, 1,		    \
 /*		fp    sp    lr.  */		    \
-    1, 1, 0, 0, 1, 1, 1, 1, 0, 0,		    \
+    1, 1, 0, 0, 0, 0, 1, 1, 0, 0,		    \
 /*  exec_save, cc_save */			    \
     1, 1, 1, 1, 0, 0, 0, 0, 0, 0,		    \
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0,		    \
@@ -203,7 +203,7 @@
 #define CALL_USED_REGISTERS {			    \
     /* Scalars.  */				    \
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 		    \
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 		    \
+    1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 		    \
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 		    \
     1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 		    \
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 		    \