On 12/10/24 07:23, Richard Henderson wrote:
> Use of fold_masks should be restricted to those opcodes that
> can reliably make use of it -- those with a single output,
> and from higher-level folders that set up the masks.
> Prepare for conversion of each folder in turn.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> tcg/optimize.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/tcg/optimize.c b/tcg/optimize.c
> index 20c918e83b..1a9e3258e3 100644
> --- a/tcg/optimize.c
> +++ b/tcg/optimize.c
> @@ -1050,6 +1050,11 @@ static bool fold_masks(OptContext *ctx, TCGOp *op)
> uint64_t a_mask = ctx->a_mask;
> uint64_t z_mask = ctx->z_mask;
> uint64_t s_mask = ctx->s_mask;
> + const TCGOpDef *def = &tcg_op_defs[op->opc];
> + TCGTemp *ts;
> +
> + /* Only single-output opcodes are supported here. */
> + tcg_debug_assert(def->nb_oargs == 1);
>
> /*
> * 32-bit ops generate 32-bit results, which for the purpose of
> @@ -1062,8 +1067,6 @@ static bool fold_masks(OptContext *ctx, TCGOp *op)
> a_mask = (int32_t)a_mask;
> z_mask = (int32_t)z_mask;
> s_mask |= MAKE_64BIT_MASK(32, 32);
> - ctx->z_mask = z_mask;
> - ctx->s_mask = s_mask;
> }
>
> if (z_mask == 0) {
> @@ -1072,7 +1075,12 @@ static bool fold_masks(OptContext *ctx, TCGOp *op)
> if (a_mask == 0) {
> return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
> }
> - return false;
> +
> + ts = arg_temp(op->args[0]);
> + reset_ts(ctx, ts);
> + ts_info(ts)->z_mask = z_mask;
> + ts_info(ts)->s_mask = s_mask;
> + return true;
> }
>
> /*
Maybe it would be worth to add a comment stating that a_mask was not
modified, but only clipped to a 32 bit value.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>