Re: [PATCH v2 37/81] tcg/arm: Add full [US]XT[BH] into {s}extract

[Philippe Mathieu-Daudé]

On 7/1/25 09:00, Richard Henderson wrote:
> The armv6 uxt and sxt opcodes have a 2-bit rotate field
> which supports extractions from ofs = {0,8,16,24}.
> Special case ofs = 0, len <= 8 as AND.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   tcg/arm/tcg-target-has.h | 17 +++++++++++++
>   tcg/arm/tcg-target.c.inc | 54 +++++++++++++++++++++++++++++++++++-----
>   2 files changed, 65 insertions(+), 6 deletions(-)
>
> diff --git a/tcg/arm/tcg-target-has.h b/tcg/arm/tcg-target-has.h
> index 316185500d..d6ca35ed1a 100644

Missing:

-- >8 --
@@ -41,8 +41,8 @@ extern bool use_neon_instructions;
 #define TCG_TARGET_HAS_ctz_i32          use_armv7_instructions
 #define TCG_TARGET_HAS_ctpop_i32        0
 #define TCG_TARGET_HAS_deposit_i32      use_armv7_instructions
-#define TCG_TARGET_HAS_extract_i32      use_armv7_instructions
-#define TCG_TARGET_HAS_sextract_i32     use_armv7_instructions
+#define TCG_TARGET_HAS_extract_i32      1
+#define TCG_TARGET_HAS_sextract_i32     1
 #define TCG_TARGET_HAS_extract2_i32     1
 #define TCG_TARGET_HAS_negsetcond_i32   1
 #define TCG_TARGET_HAS_mulu2_i32        1
---

> --- a/tcg/arm/tcg-target-has.h
> +++ b/tcg/arm/tcg-target-has.h
> @@ -82,4 +82,21 @@ extern bool use_neon_instructions;
>   #define TCG_TARGET_HAS_cmpsel_vec       0
>   #define TCG_TARGET_HAS_tst_vec          1
>   
> +static inline bool
> +tcg_target_extract_valid(TCGType type, unsigned ofs, unsigned len)
> +{
> +    if (use_armv7_instructions) {
> +        return true;  /* SBFX or UBFX */
> +    }
> +    switch (len) {
> +    case 8:   /* SXTB or UXTB */
> +    case 16:  /* SXTH or UXTH */
> +        return (ofs % 8) == 0;
> +    }
> +    return false;
> +}
> +
> +#define TCG_TARGET_extract_valid   tcg_target_extract_valid
> +#define TCG_TARGET_sextract_valid  tcg_target_extract_valid
> +
>   #endif