Re: [Qemu-devel] [PATCH v8 14/35] RISC-V: Update E order and I extension order

[Alistair Francis]

On Wed, Apr 25, 2018 at 4:53 PM Michael Clark <address@hidden> wrote:

> Section 22.8 Subset Naming Convention of the RISC-V ISA Specification
> defines the canonical order for extensions in the ISA string. It is
> silent on the position of the E extension however E is a substitute
> for I so it must come early in the extension list order. A comment
> is added to state E and I are mutually exclusive, as the E extension
> will be added to the RISC-V port in the future.

> Cc: Sagar Karandikar <address@hidden>
> Cc: Bastian Koppelmann <address@hidden>
> Cc: Palmer Dabbelt <address@hidden>
> Cc: Alistair Francis <address@hidden>
> Signed-off-by: Michael Clark <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Alistair

> ---
>   target/riscv/cpu.c | 2 +-
>   target/riscv/cpu.h | 1 +
>   2 files changed, 2 insertions(+), 1 deletion(-)

> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 5a527fb..4e5a56d 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -26,7 +26,7 @@

>   /* RISC-V CPU definitions */

> -static const char riscv_exts[26] = "IMAFDQECLBJTPVNSUHKORWXYZG";
> +static const char riscv_exts[26] = "IEMAFDQCLBJTPVNSUHKORWXYZG";

>   const char * const riscv_int_regnames[] = {
>     "zero", "ra  ", "sp  ", "gp  ", "tp  ", "t0  ", "t1  ", "t2  ",
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index f3f131b..890cd96 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -71,6 +71,7 @@
>   #define RV(x) ((target_ulong)1 << (x - 'A'))

>   #define RVI RV('I')
> +#define RVE RV('E') /* E and I are mutually exclusive */
>   #define RVM RV('M')
>   #define RVA RV('A')
>   #define RVF RV('F')
> --
> 2.7.0