Re: [PATCH for-9.1] tcg/ppc: Sync tcg_out_test and constraints

[Philippe Mathieu-Daudé]

On 7/8/24 06:08, Richard Henderson wrote:
> Ensure the code structure is the same for matching constraints
> and emitting code, lest we allow constants that cannot be
> trivially tested.
>
> Cc: qemu-stable@nongnu.org
> Fixes: ad788aebbab ("tcg/ppc: Support TCG_COND_TST{EQ,NE}")
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2487
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   tcg/ppc/tcg-target.c.inc | 21 ++++++++++-----------
>   1 file changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/tcg/ppc/tcg-target.c.inc b/tcg/ppc/tcg-target.c.inc
> index 7f3829beeb..3553a47ba9 100644
> --- a/tcg/ppc/tcg-target.c.inc
> +++ b/tcg/ppc/tcg-target.c.inc
> @@ -325,9 +325,11 @@ static bool tcg_target_const_match(int64_t sval, int ct,
>               if ((uval & ~0xffff) == 0 || (uval & ~0xffff0000ull) == 0) {
>                   return 1;
>               }
> -            if (TCG_TARGET_REG_BITS == 32 || type == TCG_TYPE_I32
> -                ? mask_operand(uval, &mb, &me)
> -                : mask64_operand(uval << clz64(uval), &mb, &me)) {
> +            if (uval == (uint32_t)uval && mask_operand(uval, &mb, &me)) {
> +                return 1;
> +            }
> +            if (TCG_TARGET_REG_BITS == 64 &&
> +                mask64_operand(uval << clz64(uval), &mb, &me)) {
>                   return 1;
>               }
>               return 0;
> @@ -1749,8 +1751,6 @@ static void tcg_out_test(TCGContext *s, TCGReg dest, 
> TCGReg arg1, TCGArg arg2,
>   
>       if (type == TCG_TYPE_I32) {
>           arg2 = (uint32_t)arg2;
> -    } else if (arg2 == (uint32_t)arg2) {
> -        type = TCG_TYPE_I32;
>       }
>   
>       if ((arg2 & ~0xffff) == 0) {
> @@ -1761,12 +1761,11 @@ static void tcg_out_test(TCGContext *s, TCGReg dest, 
> TCGReg arg1, TCGArg arg2,
>           tcg_out32(s, ANDIS | SAI(arg1, dest, arg2 >> 16));
>           return;
>       }
> -    if (TCG_TARGET_REG_BITS == 32 || type == TCG_TYPE_I32) {
> -        if (mask_operand(arg2, &mb, &me)) {
> -            tcg_out_rlw_rc(s, RLWINM, dest, arg1, 0, mb, me, rc);
> -            return;
> -        }
> -    } else {
> +    if (arg2 == (uint32_t)arg2 && mask_operand(arg2, &mb, &me)) {
> +        tcg_out_rlw_rc(s, RLWINM, dest, arg1, 0, mb, me, rc);
> +        return;
> +    }
> +    if (TCG_TARGET_REG_BITS == 64) {
>           int sh = clz64(arg2);
>           if (mask64_operand(arg2 << sh, &mb, &me)) {
>               tcg_out_rld_rc(s, RLDICR, dest, arg1, sh, me, rc);

Preferably having someone from PPC also reviewing this,

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>