Hide call_used_regs in target-independent code

Now that tests of call_used_regs go through call_used_or_fixed_reg_p,
we can hide call_used_regs from target-independent code.  (It still
needs to be available to targets for the conditional register usage
hooks.)

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* hard-reg-set.h (call_used_regs): Only define if IN_TARGET_CODE.
	(call_used_or_fixed_reg_p): Expand definition of call_used_regs.
	* reginfo.c (call_used_regs): New macro.

From-SVN: r275604

gcc/ChangeLog

 2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* hard-reg-set.h (call_used_regs): Only define if IN_TARGET_CODE.
+	(call_used_or_fixed_reg_p): Expand definition of call_used_regs.
+	* reginfo.c (call_used_regs): New macro.
+
+2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* config/alpha/alpha.c (alpha_compute_frame_layout): Remove redundant
 	fixed_regs test.
 	* config/bpf/bpf.c (bpf_compute_frame_layout, bpf_expand_prologue)

gcc/hard-reg-set.h

@@ -473,8 +473,10 @@ extern struct target_hard_regs *this_target_hard_regs;
   (this_target_hard_regs->x_fixed_reg_set)
 #define fixed_nonglobal_reg_set \
   (this_target_hard_regs->x_fixed_nonglobal_reg_set)
+#ifdef IN_TARGET_CODE
 #define call_used_regs \
   (this_target_hard_regs->x_call_used_regs)
+#endif
 #define call_really_used_regs \
   (this_target_hard_regs->x_call_really_used_regs)
 #define savable_regs \
@@ -517,7 +519,7 @@ extern const char * reg_class_names[];
 inline bool
 call_used_or_fixed_reg_p (unsigned int regno)
 {
-  return fixed_regs[regno] || call_used_regs[regno];
+  return fixed_regs[regno] || this_target_hard_regs->x_call_used_regs[regno];
 }
 
 #endif /* ! GCC_HARD_REG_SET_H */

gcc/reginfo.c

@@ -66,6 +66,9 @@ struct target_hard_regs *this_target_hard_regs = &default_target_hard_regs;
 struct target_regs *this_target_regs = &default_target_regs;
 #endif
 
+#define call_used_regs \
+  (this_target_hard_regs->x_call_used_regs)
+
 /* Data for initializing fixed_regs.  */
 static const char initial_fixed_regs[] = FIXED_REGISTERS;