Re: [PATCH] FR-V: Improve handling of SPR registers

[Kevin Buettner <kevinb at redhat dot com>]

On Oct 30,  5:42pm, Kevin Buettner wrote:

> The patch below depends on some work that Dave Brolley has done on the
> simulator.  I'll commit the change below after Dave commits his patch.

Dave committed his patch earlier today.

My patch had (and still has) the following line:

+#include "opcodes/frv-desc.h"	/* for the H_SPR_... enums */

Andrew pointed out that the file include/gdb/sim-frv.h should
be used to determine the gdb<->sim register numbers.  I've just
added this file and I've added a #include for it in frv-tdep.c.
I've updated frv_register_sim_regno() to use these constants.

opcodes/frv-desc.h is still included in order to calculate particular
SPR numbers.  The H_SPR_ offsets (from opcodes/frv-desc.h) are added
to SIM_FRV_SPR0_REGNUM (from include/gdb/sim-frv.h) to calculate SPR
numbers used for gdb<->sim interactions.  I've noted this fact in the
new header file, include/gdb/sim-frv.h.

It would be possible to add precalculated constants for the SPRs to
include/gdb/sim-frv.h.  However, I don't think this is a good idea
due to the maintenance difficulties associated with keeping this file
in sync with opcodes/frv-desc.h.

Here's what I ended up committing...

	* frv-tdep.c (gdb_assert.h, sim-regno.h, gdb/sim-frv.h)
	(opcodes/frv-desc.h): Include.
	(iacc0h_regnum, iacc0l_regnum): Define.
	(last_spr_regnum, frv_num_regs): Update.
	(new_variant): Don't supply default names for holes in the SPRs.
	Supply names for iacc0h_regnum and iacc0l_regnum.
	(frv_register_type): Use symbolic constants first_fpr_regnum and
	last_fpr_regnum instead of hardcoded constants 64 and 127.  Use
	builtin_type_int instead of builtin_type_int32.
	(frv_register_sim_regno): New function.
	(frv_gdbarch_init): Call set_gdbarch_register_sim_regno().
	* Makefile.in (gdb_sim_frv_h): Define.
	(frv-tdep.o): Update dependencies.

Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.466
diff -u -p -r1.466 Makefile.in
--- Makefile.in	31 Oct 2003 21:13:45 -0000	1.466
+++ Makefile.in	1 Nov 2003 01:37:20 -0000
@@ -590,9 +590,11 @@ demangle_h =    $(INCLUDE_DIR)/demangle.
 obstack_h =     $(INCLUDE_DIR)/obstack.h
 opcode_m68hc11_h = $(INCLUDE_DIR)/opcode/m68hc11.h
 readline_h = 	$(READLINE_SRC)/readline.h
+frv_desc_h =	$(OPCODES_SRC)/frv-desc.h
 sh_opc_h = 	$(OPCODES_SRC)/sh-opc.h
 gdb_sim_arm_h =	$(INCLUDE_DIR)/gdb/sim-arm.h
 gdb_sim_d10v_h = $(INCLUDE_DIR)/gdb/sim-d10v.h
+gdb_sim_frv_h = $(INCLUDE_DIR)/gdb/sim-frv.h
 gdb_sim_sh_h =	$(INCLUDE_DIR)/gdb/sim-sh.h
 splay_tree_h =  $(INCLUDE_DIR)/splay-tree.h
 
@@ -1780,7 +1782,8 @@ frame-unwind.o: frame-unwind.c $(defs_h)
 	$(gdb_assert_h) $(dummy_frame_h)
 frv-tdep.o: frv-tdep.c $(defs_h) $(gdb_string_h) $(inferior_h) $(symfile_h) \
 	$(gdbcore_h) $(arch_utils_h) $(regcache_h) $(frame_h) \
-	$(frame_unwind_h) $(frame_base_h) $(trad_frame_h) $(dis_asm_h)
+	$(frame_unwind_h) $(frame_base_h) $(trad_frame_h) $(dis_asm_h) \
+	$(gdb_assert_h) $(sim_regno_h) $(gdb_sim_frv_h) $(frv_desc_h)
 f-typeprint.o: f-typeprint.c $(defs_h) $(gdb_obstack_h) $(bfd_h) $(symtab_h) \
 	$(gdbtypes_h) $(expression_h) $(value_h) $(gdbcore_h) $(target_h) \
 	$(f_lang_h) $(gdb_string_h)
Index: frv-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/frv-tdep.c,v
retrieving revision 1.57
diff -u -p -r1.57 frv-tdep.c
--- frv-tdep.c	27 Oct 2003 06:30:49 -0000	1.57
+++ frv-tdep.c	1 Nov 2003 01:37:20 -0000
@@ -30,6 +30,10 @@
 #include "frame-base.h"
 #include "trad-frame.h"
 #include "dis-asm.h"
+#include "gdb_assert.h"
+#include "sim-regno.h"
+#include "gdb/sim-frv.h"
+#include "opcodes/frv-desc.h"	/* for the H_SPR_... enums */
 
 extern void _initialize_frv_tdep (void);
 
@@ -45,12 +49,9 @@ static gdbarch_frameless_function_invoca
 static gdbarch_deprecated_push_arguments_ftype frv_push_arguments;
 static gdbarch_deprecated_saved_pc_after_call_ftype frv_saved_pc_after_call;
 
-/* Register numbers.  You can change these as needed, but don't forget
-   to update the simulator accordingly.  */
+/* Register numbers.  The order in which these appear define the
+   remote protocol, so take care in changing them.  */
 enum {
-  /* The total number of registers we know exist.  */
-  frv_num_regs = 147,
-
   /* Register numbers 0 -- 63 are always reserved for general-purpose
      registers.  The chip at hand may have less.  */
   first_gpr_regnum = 0,
@@ -64,10 +65,12 @@ enum {
   first_fpr_regnum = 64,
   last_fpr_regnum = 127,
 
-  /* Register numbers 128 on up are always reserved for special-purpose
-     registers.  */
-  first_spr_regnum = 128,
+  /* The PC register.  */
   pc_regnum = 128,
+
+  /* Register numbers 129 on up are always reserved for special-purpose
+     registers.  */
+  first_spr_regnum = 129,
   psr_regnum = 129,
   ccr_regnum = 130,
   cccr_regnum = 131,
@@ -79,7 +82,12 @@ enum {
   dbar3_regnum = 140,
   lr_regnum = 145,
   lcr_regnum = 146,
-  last_spr_regnum = 146
+  iacc0h_regnum = 147,
+  iacc0l_regnum = 148,
+  last_spr_regnum = 148,
+
+  /* The total number of registers we know exist.  */
+  frv_num_regs = last_spr_regnum + 1
 };
 
 static LONGEST frv_call_dummy_words[] =
@@ -159,13 +167,8 @@ new_variant (void)
   for (r = 0; r < frv_num_regs; r++)
     var->register_names[r] = "";
 
-  /* Do, however, supply default names for the special-purpose
+  /* Do, however, supply default names for the known special-purpose
      registers.  */
-  for (r = first_spr_regnum; r <= last_spr_regnum; ++r)
-    {
-      sprintf (buf, "x%d", r);
-      var->register_names[r] = xstrdup (buf);
-    }
 
   var->register_names[pc_regnum] = "pc";
   var->register_names[lr_regnum] = "lr";
@@ -183,6 +186,10 @@ new_variant (void)
   var->register_names[dbar2_regnum] = "dbar2";
   var->register_names[dbar3_regnum] = "dbar3";
 
+  /* iacc0 (Only found on MB93405.)  */
+  var->register_names[iacc0h_regnum] = "iacc0h";
+  var->register_names[iacc0l_regnum] = "iacc0l";
+
   return var;
 }
 
@@ -236,13 +243,14 @@ frv_register_name (int reg)
   return CURRENT_VARIANT->register_names[reg];
 }
 
+
 static struct type *
 frv_register_type (struct gdbarch *gdbarch, int reg)
 {
-  if (reg >= 64 && reg <= 127)
+  if (reg >= first_fpr_regnum && reg <= last_fpr_regnum)
     return builtin_type_float;
   else
-    return builtin_type_int;
+    return builtin_type_int32;
 }
 
 static int
@@ -251,6 +259,55 @@ frv_register_byte (int reg)
   return (reg * 4);
 }
 
+static int
+frv_register_sim_regno (int reg)
+{
+  static const int spr_map[] =
+    {
+      H_SPR_PSR,		/* psr_regnum */
+      H_SPR_CCR,		/* ccr_regnum */
+      H_SPR_CCCR,		/* cccr_regnum */
+      -1,			/* 132 */
+      -1,			/* 133 */
+      -1,			/* 134 */
+      H_SPR_TBR,		/* tbr_regnum */
+      H_SPR_BRR,		/* brr_regnum */
+      H_SPR_DBAR0,		/* dbar0_regnum */
+      H_SPR_DBAR1,		/* dbar1_regnum */
+      H_SPR_DBAR2,		/* dbar2_regnum */
+      H_SPR_DBAR3,		/* dbar3_regnum */
+      -1,			/* 141 */
+      -1,			/* 142 */
+      -1,			/* 143 */
+      -1,			/* 144 */
+      H_SPR_LR,			/* lr_regnum */
+      H_SPR_LCR,		/* lcr_regnum */
+      H_SPR_IACC0H,		/* iacc0h_regnum */
+      H_SPR_IACC0L		/* iacc0l_regnum */
+    };
+
+  gdb_assert (reg >= 0 && reg < NUM_REGS);
+
+  if (first_gpr_regnum <= reg && reg <= last_gpr_regnum)
+    return reg - first_gpr_regnum + SIM_FRV_GR0_REGNUM;
+  else if (first_fpr_regnum <= reg && reg <= last_fpr_regnum)
+    return reg - first_fpr_regnum + SIM_FRV_FR0_REGNUM;
+  else if (pc_regnum == reg)
+    return SIM_FRV_PC_REGNUM;
+  else if (reg >= first_spr_regnum
+           && reg < first_spr_regnum + sizeof (spr_map) / sizeof (spr_map[0]))
+    {
+      int spr_reg_offset = spr_map[reg - first_spr_regnum];
+
+      if (spr_reg_offset < 0)
+	return SIM_REGNO_DOES_NOT_EXIST;
+      else
+	return SIM_FRV_SPR0_REGNUM + spr_reg_offset;
+    }
+
+  internal_error (__FILE__, __LINE__, "Bad register number %d", reg);
+}
+
 static const unsigned char *
 frv_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenp)
 {
@@ -1138,6 +1195,7 @@ frv_gdbarch_init (struct gdbarch_info in
   set_gdbarch_register_name (gdbarch, frv_register_name);
   set_gdbarch_deprecated_register_byte (gdbarch, frv_register_byte);
   set_gdbarch_register_type (gdbarch, frv_register_type);
+  set_gdbarch_register_sim_regno (gdbarch, frv_register_sim_regno);
 
   set_gdbarch_skip_prologue (gdbarch, frv_skip_prologue);
   set_gdbarch_breakpoint_from_pc (gdbarch, frv_breakpoint_from_pc);