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[binutils-gdb] opcodes/arc: Move instruction length logic to new function
- From: Andrew Burgess <aburgess at sourceware dot org>
- To: bfd-cvs at sourceware dot org
- Date: 14 Apr 2016 16:18:29 -0000
- Subject: [binutils-gdb] opcodes/arc: Move instruction length logic to new function
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cb040366b36ca624874e036805ca1fca740dae9f
commit cb040366b36ca624874e036805ca1fca740dae9f
Author: Andrew Burgess <andrew.burgess@embecosm.com>
Date: Thu Mar 24 16:54:37 2016 +0000
opcodes/arc: Move instruction length logic to new function
Move the logic that calculates the instruction length out to a new
function. Restructure the code to make it simpler.
opcodes/ChangeLog:
* arc-dis.c (arc_insn_length): New function.
(print_insn_arc): Use arc_insn_length, change insnLen to unsigned.
(find_format): Change insnLen parameter to unsigned.
Diff:
---
opcodes/ChangeLog | 6 ++++++
opcodes/arc-dis.c | 57 ++++++++++++++++++++++++++++++++++++++++++-------------
2 files changed, 50 insertions(+), 13 deletions(-)
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index a426055..7744f67 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,9 @@
+2016-04-14 Andrew Burgess <andrew.burgess@embecosm.com>
+
+ * arc-dis.c (arc_insn_length): New function.
+ (print_insn_arc): Use arc_insn_length, change insnLen to unsigned.
+ (find_format): Change insnLen parameter to unsigned.
+
2016-04-13 Nick Clifton <nickc@redhat.com>
PR target/19937
diff --git a/opcodes/arc-dis.c b/opcodes/arc-dis.c
index eb8bd67..7757ef6 100644
--- a/opcodes/arc-dis.c
+++ b/opcodes/arc-dis.c
@@ -105,7 +105,7 @@ special_flag_p (const char *opname,
/* Find proper format for the given opcode. */
static const struct arc_opcode *
find_format (const struct arc_opcode *arc_table,
- unsigned *insn, int insnLen,
+ unsigned *insn, unsigned int insnLen,
unsigned isa_mask)
{
unsigned int i = 0;
@@ -309,6 +309,37 @@ get_auxreg (const struct arc_opcode *opcode,
}
return NULL;
}
+
+/* Calculate the instruction length for an instruction starting with MSB
+ and LSB, the most and least significant byte. The ISA_MASK is used to
+ filter the instructions considered to only those that are part of the
+ current architecture.
+
+ The instruction lengths are calculated from the ARC_OPCODE table, and
+ cached for later use. */
+
+static unsigned int
+arc_insn_length (bfd_byte msb, struct disassemble_info *info)
+{
+ bfd_byte major_opcode = msb >> 3;
+
+ switch (info->mach)
+ {
+ case bfd_mach_arc_nps400:
+ case bfd_mach_arc_arc700:
+ case bfd_mach_arc_arc600:
+ return (major_opcode > 0xb) ? 2 : 4;
+ break;
+
+ case bfd_mach_arc_arcv2:
+ return (major_opcode > 0x7) ? 2 : 4;
+ break;
+
+ default:
+ abort ();
+ }
+}
+
/* Disassemble ARC instructions. */
static int
@@ -318,7 +349,7 @@ print_insn_arc (bfd_vma memaddr,
bfd_byte buffer[4];
unsigned int lowbyte, highbyte;
int status;
- int insnLen = 0;
+ unsigned int insnLen;
unsigned insn[2] = { 0, 0 };
unsigned isa_mask;
const unsigned char *opidx;
@@ -422,20 +453,19 @@ print_insn_arc (bfd_vma memaddr,
return size;
}
- if ((((buffer[lowbyte] & 0xf8) > 0x38)
- && ((buffer[lowbyte] & 0xf8) != 0x48))
- || ((info->mach == bfd_mach_arc_arcv2)
- && ((buffer[lowbyte] & 0xF8) == 0x48)) /* FIXME! ugly. */
- )
+ insnLen = arc_insn_length (buffer[lowbyte], info);
+ switch (insnLen)
{
- /* This is a short instruction. */
- insnLen = 2;
+ case 2:
insn[0] = (buffer[lowbyte] << 8) | buffer[highbyte];
- }
- else
- {
- insnLen = 4;
+ break;
+ default:
+ /* An unknown instruction is treated as being length 4. This is
+ possibly not the best solution, but matches the behaviour that was
+ in place before the table based instruction length look-up was
+ introduced. */
+ case 4:
/* This is a long instruction: Read the remaning 2 bytes. */
status = (*info->read_memory_func) (memaddr + 2, &buffer[2], 2, info);
if (status != 0)
@@ -444,6 +474,7 @@ print_insn_arc (bfd_vma memaddr,
return -1;
}
insn[0] = ARRANGE_ENDIAN (info, buffer);
+ break;
}
/* Set some defaults for the insn info. */