Re: [PATCH 04/21] Hexagon (target/hexagon) Add overrides for allocframe/deallocframe

[Richard Henderson <richard.henderson@linaro.org>]

On 4/26/23 01:41, Taylor Simpson wrote:
> +#ifndef CONFIG_HEXAGON_IDEF_PARSER
> +/* frame = ((LR << 32) | FP) ^ (FRAMEKEY << 32)) */
> +static void gen_frame_scramble(TCGv_i64 result)
> +{
> +    TCGv_i64 framekey = tcg_temp_new_i64();
> +    tcg_gen_extu_i32_i64(framekey, hex_gpr[HEX_REG_FRAMEKEY]);
> +    tcg_gen_shli_i64(framekey, framekey, 32);
> +    tcg_gen_concat_i32_i64(result, hex_gpr[HEX_REG_FP], hex_gpr[HEX_REG_LR]);
> +    tcg_gen_xor_i64(result, result, framekey);
> +}
> +#endif

Better as

     tmp = tcg_temp_new_i32();
     tcg_gen_xor_i32(tmp, hex_gpr[HEX_REG_LR], hex_gpr[HEX_REG_FRAMEKEY]);
     tcg_gen_concat_i32_i64(result, hex_gpr[HEX_REG_FRAMEKEY], tmp);

> +#ifndef CONFIG_HEXAGON_IDEF_PARSER
> +/* Stack overflow check */
> +static void gen_framecheck(TCGv EA, int framesize)
> +{
> +    /* Not modelled in linux-user mode */
> +    /* Placeholder for system mode */
> +}

g_assert_not_reached();

> +    TCGv_i64 frame = tcg_temp_new_i64();
> +    tcg_gen_addi_tl(r30, r29, -8);
> +    gen_frame_scramble(frame);

Perhaps better as

     TCGv_i64 frame = gen_frame_scramble();

with the allocation inside the subroutine.

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


r~