forked from Imagelibrary/binutils-gdb
9204ccd4b1
The CP0 control register set has never been defined, however encodings
for the CFC0 and CTC0 instructions remained available for implementers
up until the MIPS32 ISA declared them invalid and causing the Reserved
Instruction exception[1]. Therefore we handle them for both assembly
and disassembly, however in the latter case the names of CP0 registers
from the regular set are incorrectly printed if named registers are
requested. This is because we do not define separate operand classes
for coprocessor regular and control registers respectively, which means
the disassembler has no way to tell the two cases apart. Consequently
nonsensical disassembly is produced like:
cfc0 v0,c0_random
Later the MIPSr5 ISA reused the encodings for XPA ASE MFHC0 and MTHC0
instructions[2] although it failed to document them in the relevant
opcode table until MIPSr6 only.
Correct the issue then by defining a new register class, OP_REG_CONTROL,
and corresponding operand codes, `g' and `y' for the two positions in
the machine instruction a control register operand can take. Adjust the
test cases affected accordingly.
While at it swap the regular MIPS opcode table "cfc0" and "ctc0" entries
with each other so that they come in the alphabetical order.
References:
[1] "MIPS32 Architecture For Programmers, Volume II: The MIPS32
Instruction Set", MIPS Technologies, Inc., Document Number: MD00086,
Revision 1.00, August 29, 2002, Table A-9 "MIPS32 COP0 Encoding of
rs Field", p. 242
[2] "MIPS Architecture For Programmers, Volume II-A: The MIPS32
Instruction Set", MIPS Technologies, Inc., Document Number: MD00086,
Revision 5.04, December 11, 2013, Section 3.2 "Alphabetical List of
Instructions", pp. 195, 216
include/
* opcode/mips.h: Document `g' and `y' operand codes.
(mips_reg_operand_type): Add OP_REG_CONTROL enumeration
constant.
gas/
* tc-mips.c (convert_reg_type) <OP_REG_CONTROL>: New case.
(macro) <M_TRUNCWS, M_TRUNCWD>: Use the `g' rather than `G'
operand code.
opcodes/
* mips-dis.c (print_reg) <OP_REG_COPRO>: Move control register
handling code over to...
<OP_REG_CONTROL>: ... this new case.
* mips-opc.c (decode_mips_operand) <'g', 'y'>: New cases.
(mips_builtin_opcodes): Update "cfc1", "ctc1", "cttc1", "cttc2",
"cfc0", "ctc0", "cfc2", "ctc2", "cfc3", and "ctc3" entries
replacing the `G' operand code with `g'. Update "cftc1" and
"cftc2" entries replacing the `E' operand code with `y'.
* micromips-opc.c (decode_micromips_operand) <'g'>: New case.
(micromips_opcodes): Update "cfc1", "cfc2", "ctc1", and "ctc2"
entries replacing the `G' operand code with `g'.
binutils/
* testsuite/binutils-all/mips/mips-xpa-virt-1.d: Correct CFC0
operand disassembly.
* testsuite/binutils-all/mips/mips-xpa-virt-3.d: Likewise.
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.