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Hexagon (target/hexagon) Clean up pred_written usage

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Only endloop instructions will conditionally write to a predicate.
When there is an endloop instruction, we preload the values into
new_pred_value.

The only place pred_written is needed is when HEX_DEBUG is on.

We remove the last use of check_for_attrib.  However, new uses will be
introduced later in this series, so we mark it with G_GNUC_UNUSED.

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230427230012.3800327-9-tsimpson@quicinc.com>
This commit is contained in:
Taylor Simpson 2023-04-27 15:59:59 -07:00
parent d24f0b2b89
commit 25e1d87d10
2 changed files with 23 additions and 46 deletions
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14
target/hexagon/genptr.c
View File

@ -137,7 +137,9 @@ void gen_log_pred_write(DisasContext *ctx, int pnum, TCGv val)
tcg_gen_and_tl(hex_new_pred_value[pnum],
hex_new_pred_value[pnum], base_val);
}
if (HEX_DEBUG) {
tcg_gen_ori_tl(hex_pred_written, hex_pred_written, 1 << pnum);
}
set_bit(pnum, ctx->pregs_written);
}
@ -826,15 +828,13 @@ static void gen_endloop0(DisasContext *ctx)
/*
* if (lpcfg == 1) {
* hex_new_pred_value[3] = 0xff;
* hex_pred_written |= 1 << 3;
* p3 = 0xff;
* }
*/
TCGLabel *label1 = gen_new_label();
tcg_gen_brcondi_tl(TCG_COND_NE, lpcfg, 1, label1);
{
tcg_gen_movi_tl(hex_new_pred_value[3], 0xff);
tcg_gen_ori_tl(hex_pred_written, hex_pred_written, 1 << 3);
gen_log_pred_write(ctx, 3, tcg_constant_tl(0xff));
}
gen_set_label(label1);
@ -903,14 +903,12 @@ static void gen_endloop01(DisasContext *ctx)
/*
* if (lpcfg == 1) {
* hex_new_pred_value[3] = 0xff;
* hex_pred_written |= 1 << 3;
* p3 = 0xff;
* }
*/
tcg_gen_brcondi_tl(TCG_COND_NE, lpcfg, 1, label1);
{
tcg_gen_movi_tl(hex_new_pred_value[3], 0xff);
tcg_gen_ori_tl(hex_pred_written, hex_pred_written, 1 << 3);
gen_log_pred_write(ctx, 3, tcg_constant_tl(0xff));
}
gen_set_label(label1);

49
target/hexagon/translate.c
View File

@ -239,7 +239,7 @@ static int read_packet_words(CPUHexagonState *env, DisasContext *ctx,
return nwords;
}
static bool check_for_attrib(Packet *pkt, int attrib)
static G_GNUC_UNUSED bool check_for_attrib(Packet *pkt, int attrib)
{
for (int i = 0; i < pkt->num_insns; i++) {
if (GET_ATTRIB(pkt->insn[i].opcode, attrib)) {
@ -262,11 +262,6 @@ static bool need_slot_cancelled(Packet *pkt)
return false;
}
static bool need_pred_written(Packet *pkt)
{
return check_for_attrib(pkt, A_WRITES_PRED_REG);
}
static bool need_next_PC(DisasContext *ctx)
{
Packet *pkt = ctx->pkt;
@ -414,7 +409,7 @@ static void gen_start_packet(DisasContext *ctx)
tcg_gen_movi_tl(hex_gpr[HEX_REG_PC], next_PC);
}
}
if (need_pred_written(pkt)) {
if (HEX_DEBUG) {
tcg_gen_movi_tl(hex_pred_written, 0);
}
@ -428,6 +423,17 @@ static void gen_start_packet(DisasContext *ctx)
}
}
/*
* Preload the predicated pred registers into hex_new_pred_value[pred_num]
* Only endloop instructions conditionally write to pred registers
*/
if (pkt->pkt_has_endloop) {
for (int i = 0; i < ctx->preg_log_idx; i++) {
int pred_num = ctx->preg_log[i];
tcg_gen_mov_tl(hex_new_pred_value[pred_num], hex_pred[pred_num]);
}
}
/* Preload the predicated HVX registers into future_VRegs and tmp_VRegs */
if (!bitmap_empty(ctx->predicated_future_vregs, NUM_VREGS)) {
int i = find_first_bit(ctx->predicated_future_vregs, NUM_VREGS);
@ -535,41 +541,14 @@ static void gen_reg_writes(DisasContext *ctx)
static void gen_pred_writes(DisasContext *ctx)
{
int i;
/* Early exit if the log is empty */
if (!ctx->preg_log_idx) {
return;
}
/*
* Only endloop instructions will conditionally
* write a predicate. If there are no endloop
* instructions, we can use the non-conditional
* write of the predicates.
*/
if (ctx->pkt->pkt_has_endloop) {
TCGv zero = tcg_constant_tl(0);
TCGv pred_written = tcg_temp_new();
for (i = 0; i < ctx->preg_log_idx; i++) {
int pred_num = ctx->preg_log[i];
tcg_gen_andi_tl(pred_written, hex_pred_written, 1 << pred_num);
tcg_gen_movcond_tl(TCG_COND_NE, hex_pred[pred_num],
pred_written, zero,
hex_new_pred_value[pred_num],
hex_pred[pred_num]);
}
} else {
for (i = 0; i < ctx->preg_log_idx; i++) {
for (int i = 0; i < ctx->preg_log_idx; i++) {
int pred_num = ctx->preg_log[i];
tcg_gen_mov_tl(hex_pred[pred_num], hex_new_pred_value[pred_num]);
if (HEX_DEBUG) {
/* Do this so HELPER(debug_commit_end) will know */
tcg_gen_ori_tl(hex_pred_written, hex_pred_written,
1 << pred_num);
}
}
}
}