On 12/10/24 07:23, Richard Henderson wrote:
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> tcg/optimize.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/tcg/optimize.c b/tcg/optimize.c
> index 5f3a824a07..955151f4cf 100644
> --- a/tcg/optimize.c
> +++ b/tcg/optimize.c
> @@ -1716,7 +1716,7 @@ static bool fold_eqv(OptContext *ctx, TCGOp *op)
>
> static bool fold_extract(OptContext *ctx, TCGOp *op)
> {
> - uint64_t z_mask_old, z_mask;
> + uint64_t z_mask_old, z_mask, s_mask, a_mask = -1;
> int pos = op->args[2];
> int len = op->args[3];
>
> @@ -1731,12 +1731,11 @@ static bool fold_extract(OptContext *ctx, TCGOp *op)
> z_mask_old = arg_info(op->args[1])->z_mask;
> z_mask = extract64(z_mask_old, pos, len);
> if (pos == 0) {
> - ctx->a_mask = z_mask_old ^ z_mask;
> + a_mask = z_mask_old ^ z_mask;
> }
> - ctx->z_mask = z_mask;
> - ctx->s_mask = smask_from_zmask(z_mask);
> + s_mask = smask_from_zmask(z_mask);
>
> - return fold_masks(ctx, op);
> + return fold_masks_zsa(ctx, op, z_mask, s_mask, a_mask);
> }
In this case, we could have a fold_masks_za function.
Sometimes, we put special values for one flag, or sometimes we call
smask_from_zmask, or we rely on the implicit behaviour of the
fold_masks_* variant, so this makes it a bit hard to follow.
Either we should go fully explicit (only fold_masks, with the three
masks, and every call site has to mention them), or specialized
functions for every situation we need to support. But a mix in the
middle feels a bit awkward.
>
> static bool fold_extract2(OptContext *ctx, TCGOp *op)
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>