Re: [PATCH] tcg: Sanitize shift constants on ppc64le so that shift operations with large constants don't generate invalid instructions.

[Catherine A. Frederick / mptcultist]

Oh dear, it appears that git send-email ate the formatting, hang on.

On Wed, Jun 3, 2020 at 12:47 AM <agrecascino123@gmail.com> wrote:
>
> From: "Catherine A. Frederick" <chocola@animebitch.es>
>
> ---
>  tcg/ppc/tcg-target.inc.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/tcg/ppc/tcg-target.inc.c b/tcg/ppc/tcg-target.inc.c
> index ee1f9227c1..a5450a5e67 100644
> --- a/tcg/ppc/tcg-target.inc.c
> +++ b/tcg/ppc/tcg-target.inc.c
> @@ -790,21 +790,25 @@ static inline void tcg_out_ext32u(TCGContext *s, TCGReg 
> dst, TCGReg src)
>
>  static inline void tcg_out_shli32(TCGContext *s, TCGReg dst, TCGReg src, int 
> c)
>  {
> +    c = ((unsigned)c > 32) ? 32 : c;
>      tcg_out_rlw(s, RLWINM, dst, src, c, 0, 31 - c);
>  }
>
>  static inline void tcg_out_shli64(TCGContext *s, TCGReg dst, TCGReg src, int 
> c)
>  {
> +    c = ((unsigned)c > 64) ? 64 : c;
>      tcg_out_rld(s, RLDICR, dst, src, c, 63 - c);
>  }
>
>  static inline void tcg_out_shri32(TCGContext *s, TCGReg dst, TCGReg src, int 
> c)
>  {
> +    c = ((unsigned)c > 32) ? 32 : c;
>      tcg_out_rlw(s, RLWINM, dst, src, 32 - c, c, 31);
>  }
>
>  static inline void tcg_out_shri64(TCGContext *s, TCGReg dst, TCGReg src, int 
> c)
>  {
> +    c = ((unsigned)c > 64) ? 64 : c;
>      tcg_out_rld(s, RLDICL, dst, src, 64 - c, c);
>  }
>
> --
> 2.26.2
>