Commit graph

6 commits

Author SHA1 Message Date
Christoph Müllner 36df75a0a9 riscv/disas: Fix disas output of upper immediates
The GNU assembler produces the following output for instructions
with upper immediates:
    00002597                auipc   a1,0x2
    000024b7                lui     s1,0x2
    6409                    lui     s0,0x2 # c.lui

The immediate operands of upper immediates are not shifted.

However, the QEMU disassembler prints them shifted:
    00002597          auipc                   a1,8192
    000024b7          lui                     s1,8192
    6409              lui                     s0,8192 # c.lui

The current implementation extracts the immediate bits and shifts the by 12,
so the internal representation of the immediate is the actual immediate.
However, the immediates are later printed using rv_fmt_rd_imm or
rv_fmt_rd_offset, which don't undo the shift.

Let's fix this by using specific output formats for instructions
with upper immediates, that take care of the shift.

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230711075051.1531007-1-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-07-19 14:30:04 +10:00
Christoph Müllner a47842d166 riscv: Add support for the Zfa extension
This patch introduces the RISC-V Zfa extension, which introduces
additional floating-point instructions:
* fli (load-immediate) with pre-defined immediates
* fminm/fmaxm (like fmin/fmax but with different NaN behaviour)
* fround/froundmx (round to integer)
* fcvtmod.w.d (Modular Convert-to-Integer)
* fmv* to access high bits of float register bigger than XLEN
* Quiet comparison instructions (fleq/fltq)

Zfa defines its instructions in combination with the following extensions:
* single-precision floating-point (F)
* double-precision floating-point (D)
* quad-precision floating-point (Q)
* half-precision floating-point (Zfh)

Since QEMU does not support the RISC-V quad-precision floating-point
ISA extension (Q), this patch does not include the instructions that
depend on this extension. All other instructions are included in this
patch.

The Zfa specification can be found here:
  https://github.com/riscv/riscv-isa-manual/blob/master/src/zfa.tex
The Zfa specifciation is frozen and is in public review since May 3, 2023:
  https://groups.google.com/a/groups.riscv.org/g/isa-dev/c/SED4ntBkabg

The patch also includes a TCG test for the fcvtmod.w.d instruction.
The test cases test for correct results and flag behaviour.
Note, that the Zfa specification requires fcvtmod's flag behaviour
to be identical to a fcvt with the same operands (which is also
tested).

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230710071243.282464-1-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-07-10 22:29:20 +10:00
Christoph Müllner 318df7238b disas/riscv: Add support for XThead* instructions
Support for emulating XThead* instruction has been added recently.
This patch adds support for these instructions to the RISC-V disassembler.

Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230612111034.3955227-9-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-07-10 22:29:14 +10:00
Christoph Müllner fd7c64f6bd disas/riscv: Encapsulate opcode_data into decode
This patch adds a reference to a struct rv_opcode_data object
into struct rv_decode. This further allows to remove all references
to the global variable opcode_data (which is renamed to rvi_opcode_data).

This patch does not introduce any functional change, but prepares
the code for more struct rv_opcode_data objects in the future.

This patch is based on previous work from Liu Zhiwei:
  https://lists.nongnu.org/archive/html/qemu-devel/2022-08/msg03662.html

Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230612111034.3955227-6-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-07-10 22:29:14 +10:00
Christoph Müllner 01b1361f84 disas/riscv: Make rv_op_illegal a shared enum value
The enum value 'rv_op_illegal' does not represent an
instruction, but is a catch-all value in case we have
no match in the decoder. Let's make the value a shared
one, so that other compile units can reuse it.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230612111034.3955227-5-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-07-10 22:29:14 +10:00
Christoph Müllner 5d326db2f9 disas/riscv: Move types/constants to new header file
In order to enable vendor disassembler support, we need to
move types and constants into a header file so that other
compilation units can use them as well.

This patch does not introduce any functional changes.

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230612111034.3955227-4-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2023-07-10 22:29:14 +10:00