From: Andrew Burgess <andrew.burgess@embecosm.com>
To: binutils@sourceware.org
Cc: Claudiu.Zissulescu@synopsys.com, Cupertino.Miranda@synopsys.com,
noamca@mellanox.com, Andrew Burgess <andrew.burgess@embecosm.com>
Subject: [PATCHv2 1/3] opcodes/arc: Move instruction length logic to new function
Date: Tue, 12 Apr 2016 11:00:00 -0000 [thread overview]
Message-ID: <cb64992909da171def628e036ee5f6cc94e71058.1460458691.git.andrew.burgess@embecosm.com> (raw)
In-Reply-To: <cover.1460458691.git.andrew.burgess@embecosm.com>
In-Reply-To: <cover.1460458691.git.andrew.burgess@embecosm.com>
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.
---
opcodes/ChangeLog | 5 +++++
opcodes/arc-dis.c | 57 ++++++++++++++++++++++++++++++++++++++++++++-----------
2 files changed, 51 insertions(+), 11 deletions(-)
diff --git a/opcodes/arc-dis.c b/opcodes/arc-dis.c
index eb8bd67..458ba47 100644
--- a/opcodes/arc-dis.c
+++ b/opcodes/arc-dis.c
@@ -309,6 +309,41 @@ 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 int
+arc_insn_length (bfd_byte msb, bfd_byte lsb ATTRIBUTE_UNUSED,
+ struct disassemble_info *info)
+{
+ bfd_byte major_opcode = msb >> 3;
+ int len = 0;
+
+ switch (info->mach)
+ {
+ case bfd_mach_arc_nps400:
+ case bfd_mach_arc_arc700:
+ case bfd_mach_arc_arc600:
+ len = (major_opcode > 0xb) ? 2 : 4;
+ break;
+
+ case bfd_mach_arc_arcv2:
+ len = (major_opcode > 0x7) ? 2 : 4;
+ break;
+
+ default:
+ abort ();
+ }
+
+ return len;
+}
+
/* Disassemble ARC instructions. */
static int
@@ -422,20 +457,19 @@ 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], buffer[highbyte], 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 +478,7 @@ print_insn_arc (bfd_vma memaddr,
return -1;
}
insn[0] = ARRANGE_ENDIAN (info, buffer);
+ break;
}
/* Set some defaults for the insn info. */
--
2.5.1
next prev parent reply other threads:[~2016-04-12 11:00 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-12 11:00 [PATCHv2 0/3] ARC: Add another group of nps instructions Andrew Burgess
2016-04-07 11:05 ` [PATCH " Andrew Burgess
2016-04-07 11:05 ` [PATCH 1/3] opcodes/arc: Compute insn lengths in disassembler Andrew Burgess
2016-04-07 11:27 ` Claudiu Zissulescu
2016-04-12 9:27 ` Claudiu Zissulescu
2016-04-07 11:05 ` [PATCH 2/3] bfd/arc: Rename enum entries to avoid conflicts Andrew Burgess
2016-04-07 11:20 ` Claudiu Zissulescu
2016-04-07 11:05 ` [PATCH 3/3] arc/nps400 : New cmem instructions and associated relocation Andrew Burgess
2016-04-11 12:55 ` Cupertino Miranda
2016-04-12 11:00 ` [PATCHv2 " Andrew Burgess
2016-04-13 13:37 ` Nick Clifton
2016-04-12 11:00 ` [PATCHv2 2/3] bfd/arc: Rename enum entries to avoid conflicts Andrew Burgess
2016-04-13 13:34 ` Nick Clifton
2016-04-12 11:00 ` Andrew Burgess [this message]
2016-04-12 12:27 ` [PATCHv2 1/3] opcodes/arc: Move instruction length logic to new function Claudiu Zissulescu
2016-04-13 13:32 ` Nick Clifton
2016-04-13 14:41 ` Andrew Burgess
2016-04-13 15:30 ` Nick Clifton
2016-04-14 12:40 ` Andrew Burgess
2016-04-14 14:45 ` Nick Clifton
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