Sorry, that was sent incorrectly.
Paolo
On Wed, Feb 28, 2024 at 12:06 PM Paolo Bonzini <pbonz...@redhat.com> wrote:
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> tcg/optimize.c | 60 +++++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 52 insertions(+), 8 deletions(-)
>
> diff --git a/tcg/optimize.c b/tcg/optimize.c
> index 3995bc047db..8ea1f287788 100644
> --- a/tcg/optimize.c
> +++ b/tcg/optimize.c
> @@ -1281,6 +1281,43 @@ static bool fold_add2(OptContext *ctx, TCGOp *op)
> return fold_addsub2(ctx, op, true);
> }
>
> +static bool fold_and_to_shifts(OptContext *ctx, uint64_t c, TCGOp *op)
> +{
> + TCGOpcode shl_opc = tcg->type == TCG_TYPE_I32 ? INDEX_op_shl_i32 :
> INDEX_op_shl_i64;
> + TCGOpcode shr_opc = tcg->type == TCG_TYPE_I32 ? INDEX_op_shr_i32 :
> INDEX_op_shr_i64;
> +
> + TCGOpcode first, second;
> + int count;
> + TCGOp *op2;
> +
> + unsigned_c = tcg->type == TCG_TYPE_I32 ? (uint32_t) c : c;
> + if (is_power_of_2(-c) &&
> + !tcg_op_imm_match(op->opc, c)) {
> + /* AND with 11...11000, shift right then left. */
> + count = ctz64(c);
> + first = shr_opc;
> + } else if (is_power_of_2(c + 1) &&
> + !tcg_op_imm_match(INDEX_op_and_i64, c)) {
> + /* AND with 00...00111, shift left then right. */
> + int bits = tcg->type == TCG_TYPE_I32 ? 32 : 64;
> + count = bits - cto64(c);
> + first = shl_opc;
> + } else {
> + return false;
> + }
> +
> +
> + op->opc = first;
> + op->args[2] = arg_new_constant(ctx, count);
> +
> + second = shl_opc ^ shr_opc ^ first;
> + op2 = tcg_op_insert_after(ctx->tcg, op, second, 3);
> + op2->args[0] = op->args[0];
> + op2->args[1] = op->args[0];
> + op2->args[2] = arg_new_constant(ctx, count);
> + return true;
> +}
> +
> static bool fold_and(OptContext *ctx, TCGOp *op)
> {
> uint64_t z1, z2;
> @@ -1294,6 +1331,18 @@ static bool fold_and(OptContext *ctx, TCGOp *op)
>
> z1 = arg_info(op->args[1])->z_mask;
> z2 = arg_info(op->args[2])->z_mask;
> +
> + /*
> + * Known-zeros does not imply known-ones. Therefore unless
> + * arg2 is constant, we can't infer affected bits from it.
> + */
> + if (arg_is_const(op->args[2])) {
> + if (fold_and_to_shifts(ctx, z2, op)) {
> + return true;
> + }
> + ctx->a_mask = z1 & ~z2;
> + }
> +
> ctx->z_mask = z1 & z2;
>
> /*
> @@ -1303,14 +1352,6 @@ static bool fold_and(OptContext *ctx, TCGOp *op)
> ctx->s_mask = arg_info(op->args[1])->s_mask
> & arg_info(op->args[2])->s_mask;
>
> - /*
> - * Known-zeros does not imply known-ones. Therefore unless
> - * arg2 is constant, we can't infer affected bits from it.
> - */
> - if (arg_is_const(op->args[2])) {
> - ctx->a_mask = z1 & ~z2;
> - }
> -
> return fold_masks(ctx, op);
> }
>
> @@ -1333,6 +1374,9 @@ static bool fold_andc(OptContext *ctx, TCGOp *op)
> */
> if (arg_is_const(op->args[2])) {
> uint64_t z2 = ~arg_info(op->args[2])->z_mask;
> + if (fold_and_to_shifts(ctx, z2, op)) {
> + return true;
> + }
> ctx->a_mask = z1 & ~z2;
> z1 &= z2;
> }
> --
> 2.43.2
