Re: [PATCH 2/3] Hexagon (target/hexagon) move store size tracking to translation

[Richard Henderson]

On 9/20/22 01:07, Taylor Simpson wrote:
> The store width is needed for packet commit, so it is stored in
> ctx->store_width.  Currently, it is set when a store has a TCG
> override instead of a QEMU helper.  In the QEMU helper case, the
> ctx->store_width is not set, we invoke a helper during packet commit
> that uses the runtime store width.
>
> This patch ensures ctx->store_width is set for all store instructions,
> so performance is improved because packet commit can generate the proper
> TCG store rather than the generic helper.
>
> We do this by
> - Use the attributes from the instructions during translation to
>    set ctx->store_width
> - Remove setting of ctx->store_width from genptr.c
>
> Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
> ---
>   target/hexagon/macros.h    |  8 ++++----
>   target/hexagon/genptr.c    | 36 ++++++++++++------------------------
>   target/hexagon/translate.c | 26 ++++++++++++++++++++++++++
>   3 files changed, 42 insertions(+), 28 deletions(-)
>
> diff --git a/target/hexagon/macros.h b/target/hexagon/macros.h
> index 92eb8bbf05..c8805bdaeb 100644
> --- a/target/hexagon/macros.h
> +++ b/target/hexagon/macros.h
> @@ -156,7 +156,7 @@
>           __builtin_choose_expr(TYPE_TCGV(X), \
>               gen_store1, (void)0))
>   #define MEM_STORE1(VA, DATA, SLOT) \
> -    MEM_STORE1_FUNC(DATA)(cpu_env, VA, DATA, ctx, SLOT)
> +    MEM_STORE1_FUNC(DATA)(cpu_env, VA, DATA, SLOT)
>   
>   #define MEM_STORE2_FUNC(X) \
>       __builtin_choose_expr(TYPE_INT(X), \
> @@ -164,7 +164,7 @@
>           __builtin_choose_expr(TYPE_TCGV(X), \
>               gen_store2, (void)0))
>   #define MEM_STORE2(VA, DATA, SLOT) \
> -    MEM_STORE2_FUNC(DATA)(cpu_env, VA, DATA, ctx, SLOT)
> +    MEM_STORE2_FUNC(DATA)(cpu_env, VA, DATA, SLOT)
>   
>   #define MEM_STORE4_FUNC(X) \
>       __builtin_choose_expr(TYPE_INT(X), \
> @@ -172,7 +172,7 @@
>           __builtin_choose_expr(TYPE_TCGV(X), \
>               gen_store4, (void)0))
>   #define MEM_STORE4(VA, DATA, SLOT) \
> -    MEM_STORE4_FUNC(DATA)(cpu_env, VA, DATA, ctx, SLOT)
> +    MEM_STORE4_FUNC(DATA)(cpu_env, VA, DATA, SLOT)
>   
>   #define MEM_STORE8_FUNC(X) \
>       __builtin_choose_expr(TYPE_INT(X), \
> @@ -180,7 +180,7 @@
>           __builtin_choose_expr(TYPE_TCGV_I64(X), \
>               gen_store8, (void)0))
>   #define MEM_STORE8(VA, DATA, SLOT) \
> -    MEM_STORE8_FUNC(DATA)(cpu_env, VA, DATA, ctx, SLOT)
> +    MEM_STORE8_FUNC(DATA)(cpu_env, VA, DATA, SLOT)
>   #else
>   #define MEM_LOAD1s(VA) ((int8_t)mem_load1(env, slot, VA))
>   #define MEM_LOAD1u(VA) ((uint8_t)mem_load1(env, slot, VA))
> diff --git a/target/hexagon/genptr.c b/target/hexagon/genptr.c
> index 8a334ba07b..806d0974ff 100644
> --- a/target/hexagon/genptr.c
> +++ b/target/hexagon/genptr.c
> @@ -401,62 +401,50 @@ static inline void gen_store32(TCGv vaddr, TCGv src, int 
> width, int slot)
>       tcg_gen_mov_tl(hex_store_val32[slot], src);
>   }
>   
> -static inline void gen_store1(TCGv_env cpu_env, TCGv vaddr, TCGv src,
> -                              DisasContext *ctx, int slot)
> +static inline void gen_store1(TCGv_env cpu_env, TCGv vaddr, TCGv src, int slot)
>   {
>       gen_store32(vaddr, src, 1, slot);
> -    ctx->store_width[slot] = 1;
>   }
>   
> -static inline void gen_store1i(TCGv_env cpu_env, TCGv vaddr, int32_t src,
> -                               DisasContext *ctx, int slot)
> +static inline void gen_store1i(TCGv_env cpu_env, TCGv vaddr, int32_t src, int 
> slot)
>   {
>       TCGv tmp = tcg_constant_tl(src);
> -    gen_store1(cpu_env, vaddr, tmp, ctx, slot);
> +    gen_store1(cpu_env, vaddr, tmp, slot);
>   }
>   
> -static inline void gen_store2(TCGv_env cpu_env, TCGv vaddr, TCGv src,
> -                              DisasContext *ctx, int slot)
> +static inline void gen_store2(TCGv_env cpu_env, TCGv vaddr, TCGv src, int slot)
>   {
>       gen_store32(vaddr, src, 2, slot);
> -    ctx->store_width[slot] = 2;
>   }
>   
> -static inline void gen_store2i(TCGv_env cpu_env, TCGv vaddr, int32_t src,
> -                               DisasContext *ctx, int slot)
> +static inline void gen_store2i(TCGv_env cpu_env, TCGv vaddr, int32_t src, int 
> slot)
>   {
>       TCGv tmp = tcg_constant_tl(src);
> -    gen_store2(cpu_env, vaddr, tmp, ctx, slot);
> +    gen_store2(cpu_env, vaddr, tmp, slot);
>   }
>   
> -static inline void gen_store4(TCGv_env cpu_env, TCGv vaddr, TCGv src,
> -                              DisasContext *ctx, int slot)
> +static inline void gen_store4(TCGv_env cpu_env, TCGv vaddr, TCGv src, int slot)
>   {
>       gen_store32(vaddr, src, 4, slot);
> -    ctx->store_width[slot] = 4;
>   }
>   
> -static inline void gen_store4i(TCGv_env cpu_env, TCGv vaddr, int32_t src,
> -                               DisasContext *ctx, int slot)
> +static inline void gen_store4i(TCGv_env cpu_env, TCGv vaddr, int32_t src, int 
> slot)
>   {
>       TCGv tmp = tcg_constant_tl(src);
> -    gen_store4(cpu_env, vaddr, tmp, ctx, slot);
> +    gen_store4(cpu_env, vaddr, tmp, slot);
>   }
>   
> -static inline void gen_store8(TCGv_env cpu_env, TCGv vaddr, TCGv_i64 src,
> -                              DisasContext *ctx, int slot)
> +static inline void gen_store8(TCGv_env cpu_env, TCGv vaddr, TCGv_i64 src, int 
> slot)
>   {
>       tcg_gen_mov_tl(hex_store_addr[slot], vaddr);
>       tcg_gen_movi_tl(hex_store_width[slot], 8);
>       tcg_gen_mov_i64(hex_store_val64[slot], src);
> -    ctx->store_width[slot] = 8;
>   }
>   
> -static inline void gen_store8i(TCGv_env cpu_env, TCGv vaddr, int64_t src,
> -                               DisasContext *ctx, int slot)
> +static inline void gen_store8i(TCGv_env cpu_env, TCGv vaddr, int64_t src, int 
> slot)
>   {
>       TCGv_i64 tmp = tcg_constant_i64(src);
> -    gen_store8(cpu_env, vaddr, tmp, ctx, slot);
> +    gen_store8(cpu_env, vaddr, tmp, slot);
>   }
>   
>   static TCGv gen_8bitsof(TCGv result, TCGv value)
> diff --git a/target/hexagon/translate.c b/target/hexagon/translate.c
> index 0e8a0772f7..bc02870b9f 100644
> --- a/target/hexagon/translate.c
> +++ b/target/hexagon/translate.c
> @@ -327,6 +327,31 @@ static void mark_implicit_pred_writes(DisasContext *ctx, 
> Insn *insn)
>       mark_implicit_pred_write(ctx, insn, A_IMPLICIT_WRITES_P3, 3);
>   }
>   
> +static void mark_store_width(DisasContext *ctx, Insn *insn)
> +{
> +    uint16_t opcode = insn->opcode;
> +    uint32_t slot = insn->slot;
> +
> +    if (GET_ATTRIB(opcode, A_STORE)) {
> +        if (GET_ATTRIB(opcode, A_MEMSIZE_1B)) {
> +            ctx->store_width[slot] = 1;
> +            return;
> +        }
> +        if (GET_ATTRIB(opcode, A_MEMSIZE_2B)) {
> +            ctx->store_width[slot] = 2;
> +            return;
> +        }
> +        if (GET_ATTRIB(opcode, A_MEMSIZE_4B)) {
> +            ctx->store_width[slot] = 4;
> +            return;
> +        }
> +        if (GET_ATTRIB(opcode, A_MEMSIZE_8B)) {
> +            ctx->store_width[slot] = 8;
> +            return;
> +        }

Hmm.  Perhaps

    int size = 0;
    if (GET_ATTRIB(opcode, A_MEMSIZE_1B)) {
        size |= 1;
    }
    ...
    tcg_debug_assert(is_power_of_2(size));
    ctx->store_width[slot] = size;

just to make sure you get exactly one of the above cases.

Otherwise, LGTM,

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~