[PATCH v8 4/7] RISC-V: Print highest address on the disassembler

[Tsukasa OI <research_trasio@irq.a4lg.com>]

This patch makes possible to print the highest address (0xffffffff on RV32,
0xffffffff_ffffffff on RV64).  This is particularly useful if the highest
address space is used for I/O registers and corresponding symbols
are defined.

gas/ChangeLog:

	* testsuite/gas/riscv/dis-addr-topaddr.s: New test for the top
	address printing.
	* testsuite/gas/riscv/dis-addr-topaddr-32.d: Likewise.
	* testsuite/gas/riscv/dis-addr-topaddr-64.d: Likewise.

opcodes/ChangeLog:

	* riscv-dis.c (struct riscv_private_data): Add `to_print_addr' to
	enable printing the highest address.
	(maybe_print_address): Utilize `to_print_addr'.
	(riscv_disassemble_insn): Likewise.
---
 gas/testsuite/gas/riscv/dis-addr-topaddr-32.d | 11 +++++++++++
 gas/testsuite/gas/riscv/dis-addr-topaddr-64.d | 11 +++++++++++
 gas/testsuite/gas/riscv/dis-addr-topaddr.s    | 10 ++++++++++
 opcodes/riscv-dis.c                           |  9 ++++++---
 4 files changed, 38 insertions(+), 3 deletions(-)
 create mode 100644 gas/testsuite/gas/riscv/dis-addr-topaddr-32.d
 create mode 100644 gas/testsuite/gas/riscv/dis-addr-topaddr-64.d
 create mode 100644 gas/testsuite/gas/riscv/dis-addr-topaddr.s

diff --git a/gas/testsuite/gas/riscv/dis-addr-topaddr-32.d b/gas/testsuite/gas/riscv/dis-addr-topaddr-32.d
new file mode 100644
index 00000000000..87854cd58e6
--- /dev/null
+++ b/gas/testsuite/gas/riscv/dis-addr-topaddr-32.d
@@ -0,0 +1,11 @@
+#as: -march=rv32ic
+#source: dis-addr-topaddr.s
+#objdump: -d
+
+.*:     file format elf32-(little|big)riscv
+
+
+Disassembly of section .text:
+
+0+000 <target>:
+[ 	]+[0-9a-f]+:[ 	]+fff00283[ 	]+lb[   	]+t0,-1\(zero\) # ffffffff <addr_top>
diff --git a/gas/testsuite/gas/riscv/dis-addr-topaddr-64.d b/gas/testsuite/gas/riscv/dis-addr-topaddr-64.d
new file mode 100644
index 00000000000..38f67efdcaf
--- /dev/null
+++ b/gas/testsuite/gas/riscv/dis-addr-topaddr-64.d
@@ -0,0 +1,11 @@
+#as: -march=rv64ic -defsym rv64=1
+#source: dis-addr-topaddr.s
+#objdump: -d
+
+.*:     file format elf64-(little|big)riscv
+
+
+Disassembly of section .text:
+
+0+000 <target>:
+[ 	]+[0-9a-f]+:[ 	]+fff00283[ 	]+lb[   	]+t0,-1\(zero\) # ffffffffffffffff <addr_top>
diff --git a/gas/testsuite/gas/riscv/dis-addr-topaddr.s b/gas/testsuite/gas/riscv/dis-addr-topaddr.s
new file mode 100644
index 00000000000..b66587f448d
--- /dev/null
+++ b/gas/testsuite/gas/riscv/dis-addr-topaddr.s
@@ -0,0 +1,10 @@
+.ifdef rv64
+topbase = 0xffffffff00000000
+.else
+topbase = 0
+.endif
+
+.set addr_top, topbase + 0xffffffff  # -1
+
+target:
+	lb	t0, -1(zero)
diff --git a/opcodes/riscv-dis.c b/opcodes/riscv-dis.c
index b3ca680e506..7532c72187d 100644
--- a/opcodes/riscv-dis.c
+++ b/opcodes/riscv-dis.c
@@ -52,6 +52,7 @@ struct riscv_private_data
   bfd_vma gp;
   bfd_vma print_addr;
   bfd_vma hi_addr[OP_MASK_RD + 1];
+  bool to_print_addr;
 };
 
 /* Used for mapping symbols.  */
@@ -183,6 +184,7 @@ maybe_print_address (struct riscv_private_data *pd, int base_reg, int offset,
     pd->print_addr = offset;
   else
     return;  /* Don't print the address.  */
+  pd->to_print_addr = true;
 
   /* Sign-extend a 32-bit value to a 64-bit value.  */
   if (wide)
@@ -602,9 +604,10 @@ riscv_disassemble_insn (bfd_vma memaddr, insn_t word, disassemble_info *info)
 
       pd = info->private_data = xcalloc (1, sizeof (struct riscv_private_data));
       pd->gp = -1;
-      pd->print_addr = -1;
+      pd->print_addr = 0;
       for (i = 0; i < (int)ARRAY_SIZE (pd->hi_addr); i++)
 	pd->hi_addr[i] = -1;
+      pd->to_print_addr = false;
 
       for (i = 0; i < info->symtab_size; i++)
 	if (strcmp (bfd_asymbol_name (info->symtab[i]), RISCV_GP_SYMBOL) == 0)
@@ -668,13 +671,13 @@ riscv_disassemble_insn (bfd_vma memaddr, insn_t word, disassemble_info *info)
 	  print_insn_args (op->args, word, memaddr, info);
 
 	  /* Try to disassemble multi-instruction addressing sequences.  */
-	  if (pd->print_addr != (bfd_vma)-1)
+	  if (pd->to_print_addr)
 	    {
 	      info->target = pd->print_addr;
 	      (*info->fprintf_styled_func)
 		(info->stream, dis_style_comment_start, " # ");
 	      (*info->print_address_func) (info->target, info);
-	      pd->print_addr = -1;
+	      pd->to_print_addr = false;
 	    }
 
 	  /* Finish filling out insn_info fields.  */
-- 
2.34.1