mbox series

[REVIEW,ONLY,v2,0/1] UNRATIFIED RISC-V: Add 'ZiCondOps' extension (encodings changed!)

Message ID cover.1669687611.git.research_trasio@irq.a4lg.com
Headers
Series UNRATIFIED RISC-V: Add 'ZiCondOps' extension (encodings changed!) |

Message

Tsukasa OI Nov. 29, 2022, 2:06 a.m. UTC 
  *** WAIT FOR SPECIFICATION FREEZE ***
This is an implementation for unratified and not frozen RISC-V extension
and not intended to be merged for now.
The only intent to submit this patchset is to test new instructions for
your (possibly virtual) environment and early review for fast adoption
after ratification.


Just two hours ago, the encodings of "czero.eqz" and "czero.nez"
instructions have changed in the commit 8c5faf4c6d73.

This PATCH v2 reflects this change.


This patchset adds following unratified extension to GNU Binutils:

-   'ZiCondOps' (Integer Conditional Operations)
    version 1.0 in development

which adds 2 instructions ("czero.eqz" and "czero.nez").

This extension makes conditional arithmetic feature much simpler (fewer
instructions when no branches are allowed).  Note that constant timing
guarantee (data-independence / certain side-channel resistance) for this
extension is being discussed and may not be guaranteed.


This is based on the commit 8c5faf4c6d73 of the specification document:
<https://github.com/riscv/riscv-zicondops>




Tsukasa OI (1):
  UNRATIFIED RISC-V: Add 'ZiCondOps' extension

 bfd/elfxx-riscv.c                          |  5 +++++
 gas/testsuite/gas/riscv/zicondops-noarch.d |  3 +++
 gas/testsuite/gas/riscv/zicondops-noarch.l |  3 +++
 gas/testsuite/gas/riscv/zicondops.d        | 11 +++++++++++
 gas/testsuite/gas/riscv/zicondops.s        |  3 +++
 include/opcode/riscv-opc.h                 |  8 ++++++++
 include/opcode/riscv.h                     |  1 +
 opcodes/riscv-opc.c                        |  4 ++++
 8 files changed, 38 insertions(+)
 create mode 100644 gas/testsuite/gas/riscv/zicondops-noarch.d
 create mode 100644 gas/testsuite/gas/riscv/zicondops-noarch.l
 create mode 100644 gas/testsuite/gas/riscv/zicondops.d
 create mode 100644 gas/testsuite/gas/riscv/zicondops.s


base-commit: cb44f89ce977b1ab2d4063f2487950bddfb75bc7

Comments

Tsukasa OI Nov. 29, 2022, 2:40 a.m. UTC | #1 
IMPORTANT NOTE:

I just received an e-mail from Andrew.
Considering his statements...

1.  Actual encodings will change **again** and
2.  The extension name is going to be 'Zicond', not 'Zicondops'.

I'll submit PATCH v3 after both are reflected.

Regards,
Tsukasa

On 2022/11/29 11:06, Tsukasa OI wrote:
> *** WAIT FOR SPECIFICATION FREEZE ***
> This is an implementation for unratified and not frozen RISC-V extension
> and not intended to be merged for now.
> The only intent to submit this patchset is to test new instructions for
> your (possibly virtual) environment and early review for fast adoption
> after ratification.
> 
> 
> Just two hours ago, the encodings of "czero.eqz" and "czero.nez"
> instructions have changed in the commit 8c5faf4c6d73.
> 
> This PATCH v2 reflects this change.
> 
> 
> This patchset adds following unratified extension to GNU Binutils:
> 
> -   'ZiCondOps' (Integer Conditional Operations)
>     version 1.0 in development
> 
> which adds 2 instructions ("czero.eqz" and "czero.nez").
> 
> This extension makes conditional arithmetic feature much simpler (fewer
> instructions when no branches are allowed).  Note that constant timing
> guarantee (data-independence / certain side-channel resistance) for this
> extension is being discussed and may not be guaranteed.
> 
> 
> This is based on the commit 8c5faf4c6d73 of the specification document:
> <https://github.com/riscv/riscv-zicondops>
> 
> 
> 
> 
> Tsukasa OI (1):
>   UNRATIFIED RISC-V: Add 'ZiCondOps' extension
> 
>  bfd/elfxx-riscv.c                          |  5 +++++
>  gas/testsuite/gas/riscv/zicondops-noarch.d |  3 +++
>  gas/testsuite/gas/riscv/zicondops-noarch.l |  3 +++
>  gas/testsuite/gas/riscv/zicondops.d        | 11 +++++++++++
>  gas/testsuite/gas/riscv/zicondops.s        |  3 +++
>  include/opcode/riscv-opc.h                 |  8 ++++++++
>  include/opcode/riscv.h                     |  1 +
>  opcodes/riscv-opc.c                        |  4 ++++
>  8 files changed, 38 insertions(+)
>  create mode 100644 gas/testsuite/gas/riscv/zicondops-noarch.d
>  create mode 100644 gas/testsuite/gas/riscv/zicondops-noarch.l
>  create mode 100644 gas/testsuite/gas/riscv/zicondops.d
>  create mode 100644 gas/testsuite/gas/riscv/zicondops.s
> 
> 
> base-commit: cb44f89ce977b1ab2d4063f2487950bddfb75bc7