Re: [Qemu-devel] [PATCH] Allow microMIPS SWP and SDP to have RD equal to BASE.

[Aurelien Jarno <aurelien@aurel32.net>]

On Sat, Sep 17, 2011 at 05:28:16PM -0700, Eric Johnson wrote:
> The microMIPS SWP and SDP instructions do not modify GPRs.  So their
> behavior is well defined when RD equals BASE.  The MIPS Architecture
> Verification Programs (AVPs) check that they work as expected.  This
> is required for AVPs to pass.
> 
> Signed-off-by: Eric Johnson <ericj@mips.com>
> ---
>  target-mips/translate.c |   10 +++++++++-
>  1 files changed, 9 insertions(+), 1 deletions(-)
> 
> The patch applies to a8467c7a0e8b024a18608ff7db31ca2f2297e641.
> 
> diff --git a/target-mips/translate.c b/target-mips/translate.c
> index d5b1c76..82cf75b 100644
> --- a/target-mips/translate.c
> +++ b/target-mips/translate.c
> @@ -10034,7 +10034,7 @@ static void gen_ldst_pair (DisasContext *ctx, uint32_t opc, int rd,
>      const char *opn = "ldst_pair";
>      TCGv t0, t1;
>  
> -    if (ctx->hflags & MIPS_HFLAG_BMASK || rd == 31 || rd == base) {
> +    if (ctx->hflags & MIPS_HFLAG_BMASK || rd == 31) {
>          generate_exception(ctx, EXCP_RI);
>          return;
>      }
> @@ -10046,6 +10046,10 @@ static void gen_ldst_pair (DisasContext *ctx, uint32_t opc, int rd,
>  
>      switch (opc) {
>      case LWP:
> +        if (rd == base) {
> +            generate_exception(ctx, EXCP_RI);
> +            return;
> +        }
>          save_cpu_state(ctx, 0);
>          op_ld_lw(t1, t0, ctx);
>          gen_store_gpr(t1, rd);
> @@ -10067,6 +10071,10 @@ static void gen_ldst_pair (DisasContext *ctx, uint32_t opc, int rd,
>          break;
>  #ifdef TARGET_MIPS64
>      case LDP:
> +        if (rd == base) {
> +            generate_exception(ctx, EXCP_RI);
> +            return;
> +        }
>          save_cpu_state(ctx, 0);
>          op_ld_ld(t1, t0, ctx);
>          gen_store_gpr(t1, rd);
> 
> 

Thanks, applied.

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net