From: Taylor Simpson <ltaylorsimpson@gmail.com>
Look for read-after-write instead of overlap of reads and writes
HVX instructions with helpers have pass-by-reference semantics, so
we check for overlaps of reads and writes within the same instruction.
Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
Reviewed-by: Brian Cain <bcain@quicinc.com>
Message-Id: <20240201103340.119081-4-ltaylorsimpson@gmail.com>
Signed-off-by: Brian Cain <bcain@quicinc.com>
---
target/hexagon/gen_analyze_funcs.py | 19 ++++---
target/hexagon/hex_common.py | 45 ++++++++++-----
target/hexagon/translate.c | 58 ++-----------------
target/hexagon/translate.h | 88 +++++++++++++++++++++++------
4 files changed, 115 insertions(+), 95 deletions(-)
diff --git a/target/hexagon/gen_analyze_funcs.py b/target/hexagon/gen_analyze_funcs.py
index 890e6a3a95..81e1d9cfa3 100755
--- a/target/hexagon/gen_analyze_funcs.py
+++ b/target/hexagon/gen_analyze_funcs.py
@@ -43,6 +43,16 @@ def gen_analyze_func(f, tag, regs, imms):
f.write("{\n")
f.write(" Insn *insn G_GNUC_UNUSED = ctx->insn;\n")
+ if (hex_common.is_hvx_insn(tag)):
+ if hex_common.has_hvx_helper(tag):
+ f.write(
+ " const bool G_GNUC_UNUSED insn_has_hvx_helper = true;\n"
+ )
+ f.write(" ctx_start_hvx_insn(ctx);\n")
+ else:
+ f.write(
+ " const bool G_GNUC_UNUSED insn_has_hvx_helper = false;\n"
+ )
## Declare all the registers
for regno, register in enumerate(regs):
@@ -64,15 +74,6 @@ def gen_analyze_func(f, tag, regs, imms):
if reg.is_written():
reg.analyze_write(f, tag, regno)
- has_generated_helper = not hex_common.skip_qemu_helper(
- tag
- ) and not hex_common.is_idef_parser_enabled(tag)
-
- ## Mark HVX instructions with generated helpers
- if (has_generated_helper and
- "A_CVI" in hex_common.attribdict[tag]):
- f.write(" ctx->has_hvx_helper = true;\n")
-
f.write("}\n\n")
diff --git a/target/hexagon/hex_common.py b/target/hexagon/hex_common.py
index 33801e4bd7..9e7f613e3c 100755
--- a/target/hexagon/hex_common.py
+++ b/target/hexagon/hex_common.py
@@ -241,6 +241,16 @@ def is_idef_parser_enabled(tag):
return tag in idef_parser_enabled
+def is_hvx_insn(tag):
+ return "A_CVI" in attribdict[tag]
+
+
+def has_hvx_helper(tag):
+ return (is_hvx_insn(tag) and
+ not skip_qemu_helper(tag) and
+ not is_idef_parser_enabled(tag))
+
+
def imm_name(immlett):
return f"{immlett}iV"
@@ -704,7 +714,8 @@ def analyze_write(self, f, tag, regno):
newv = hvx_newv(tag)
predicated = "true" if is_predicated(tag) else "false"
f.write(code_fmt(f"""\
- ctx_log_vreg_write(ctx, {self.reg_num}, {newv}, {predicated});
+ ctx_log_vreg_write(ctx, {self.reg_num}, {newv}, {predicated},
+ insn_has_hvx_helper);
"""))
class VRegSource(Register, Hvx, OldSource):
@@ -724,7 +735,7 @@ def helper_hvx_desc(self, f):
"""))
def analyze_read(self, f, regno):
f.write(code_fmt(f"""\
- ctx_log_vreg_read(ctx, {self.reg_num});
+ ctx_log_vreg_read(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
class VRegNewSource(Register, Hvx, NewSource):
@@ -741,7 +752,7 @@ def helper_hvx_desc(self, f):
"""))
def analyze_read(self, f, regno):
f.write(code_fmt(f"""\
- ctx_log_vreg_read_new(ctx, {self.reg_num});
+ ctx_log_vreg_read_new(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
class VRegReadWrite(Register, Hvx, ReadWrite):
@@ -767,13 +778,14 @@ def helper_hvx_desc(self, f):
"""))
def analyze_read(self, f, regno):
f.write(code_fmt(f"""\
- ctx_log_vreg_read(ctx, {self.reg_num});
+ ctx_log_vreg_read(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
def analyze_write(self, f, tag, regno):
newv = hvx_newv(tag)
predicated = "true" if is_predicated(tag) else "false"
f.write(code_fmt(f"""\
- ctx_log_vreg_write(ctx, {self.reg_num}, {newv}, {predicated});
+ ctx_log_vreg_write(ctx, {self.reg_num}, {newv}, {predicated},
+ insn_has_hvx_helper);
"""))
class VRegTmp(Register, Hvx, ReadWrite):
@@ -801,13 +813,14 @@ def helper_hvx_desc(self, f):
"""))
def analyze_read(self, f, regno):
f.write(code_fmt(f"""\
- ctx_log_vreg_read(ctx, {self.reg_num});
+ ctx_log_vreg_read(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
def analyze_write(self, f, tag, regno):
newv = hvx_newv(tag)
predicated = "true" if is_predicated(tag) else "false"
f.write(code_fmt(f"""\
- ctx_log_vreg_write(ctx, {self.reg_num}, {newv}, {predicated});
+ ctx_log_vreg_write(ctx, {self.reg_num}, {newv}, {predicated},
+ insn_has_hvx_helper);
"""))
class VRegPairDest(Register, Hvx, Dest):
@@ -832,7 +845,8 @@ def analyze_write(self, f, tag, regno):
newv = hvx_newv(tag)
predicated = "true" if is_predicated(tag) else "false"
f.write(code_fmt(f"""\
- ctx_log_vreg_write_pair(ctx, {self.reg_num}, {newv}, {predicated});
+ ctx_log_vreg_write_pair(ctx, {self.reg_num}, {newv}, {predicated},
+ insn_has_hvx_helper);
"""))
class VRegPairSource(Register, Hvx, OldSource):
@@ -859,7 +873,7 @@ def helper_hvx_desc(self, f):
"""))
def analyze_read(self, f, regno):
f.write(code_fmt(f"""\
- ctx_log_vreg_read_pair(ctx, {self.reg_num});
+ ctx_log_vreg_read_pair(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
class VRegPairReadWrite(Register, Hvx, ReadWrite):
@@ -891,13 +905,14 @@ def helper_hvx_desc(self, f):
"""))
def analyze_read(self, f, regno):
f.write(code_fmt(f"""\
- ctx_log_vreg_read_pair(ctx, {self.reg_num});
+ ctx_log_vreg_read_pair(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
def analyze_write(self, f, tag, regno):
newv = hvx_newv(tag)
predicated = "true" if is_predicated(tag) else "false"
f.write(code_fmt(f"""\
- ctx_log_vreg_write_pair(ctx, {self.reg_num}, {newv}, {predicated});
+ ctx_log_vreg_write_pair(ctx, {self.reg_num}, {newv}, {predicated},
+ insn_has_hvx_helper);
"""))
class QRegDest(Register, Hvx, Dest):
@@ -920,7 +935,7 @@ def helper_hvx_desc(self, f):
"""))
def analyze_write(self, f, tag, regno):
f.write(code_fmt(f"""\
- ctx_log_qreg_write(ctx, {self.reg_num});
+ ctx_log_qreg_write(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
class QRegSource(Register, Hvx, OldSource):
@@ -941,7 +956,7 @@ def helper_hvx_desc(self, f):
"""))
def analyze_read(self, f, regno):
f.write(code_fmt(f"""\
- ctx_log_qreg_read(ctx, {self.reg_num});
+ ctx_log_qreg_read(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
class QRegReadWrite(Register, Hvx, ReadWrite):
@@ -967,11 +982,11 @@ def helper_hvx_desc(self, f):
"""))
def analyze_read(self, f, regno):
f.write(code_fmt(f"""\
- ctx_log_qreg_read(ctx, {self.reg_num});
+ ctx_log_qreg_read(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
def analyze_write(self, f, tag, regno):
f.write(code_fmt(f"""\
- ctx_log_qreg_write(ctx, {self.reg_num});
+ ctx_log_qreg_write(ctx, {self.reg_num}, insn_has_hvx_helper);
"""))
def init_registers():
diff --git a/target/hexagon/translate.c b/target/hexagon/translate.c
index 8d42ebd91c..0904dc2d38 100644
--- a/target/hexagon/translate.c
+++ b/target/hexagon/translate.c
@@ -380,60 +380,10 @@ static bool need_commit(DisasContext *ctx)
return true;
}
- if (pkt->num_insns == 1) {
- if (pkt->pkt_has_hvx) {
- /*
- * The HVX instructions with generated helpers use
- * pass-by-reference, so they need the read/write overlap
- * check below.
- * The HVX instructions with overrides are OK.
- */
- if (!ctx->has_hvx_helper) {
- return false;
- }
- } else {
- return false;
- }
- }
-
- if (ctx->read_after_write) {
+ if (ctx->read_after_write || ctx->has_hvx_overlap) {
return true;
}
- /* Check for overlap between HVX reads and writes */
- for (int i = 0; i < ctx->vreg_log_idx; i++) {
- int vnum = ctx->vreg_log[i];
- if (test_bit(vnum, ctx->vregs_read)) {
- return true;
- }
- }
- if (!bitmap_empty(ctx->vregs_updated_tmp, NUM_VREGS)) {
- int i = find_first_bit(ctx->vregs_updated_tmp, NUM_VREGS);
- while (i < NUM_VREGS) {
- if (test_bit(i, ctx->vregs_read)) {
- return true;
- }
- i = find_next_bit(ctx->vregs_updated_tmp, NUM_VREGS, i + 1);
- }
- }
- if (!bitmap_empty(ctx->vregs_select, NUM_VREGS)) {
- int i = find_first_bit(ctx->vregs_select, NUM_VREGS);
- while (i < NUM_VREGS) {
- if (test_bit(i, ctx->vregs_read)) {
- return true;
- }
- i = find_next_bit(ctx->vregs_select, NUM_VREGS, i + 1);
- }
- }
-
- /* Check for overlap between HVX predicate reads and writes */
- for (int i = 0; i < ctx->qreg_log_idx; i++) {
- int qnum = ctx->qreg_log[i];
- if (test_bit(qnum, ctx->qregs_read)) {
- return true;
- }
- }
-
return false;
}
@@ -455,8 +405,8 @@ static void mark_implicit_pred_reads(DisasContext *ctx)
static void analyze_packet(DisasContext *ctx)
{
Packet *pkt = ctx->pkt;
- ctx->has_hvx_helper = false;
ctx->read_after_write = false;
+ ctx->has_hvx_overlap = false;
for (int i = 0; i < pkt->num_insns; i++) {
Insn *insn = &pkt->insn[i];
ctx->insn = insn;
@@ -487,13 +437,13 @@ static void gen_start_packet(DisasContext *ctx)
ctx->future_vregs_idx = 0;
ctx->tmp_vregs_idx = 0;
ctx->vreg_log_idx = 0;
+ bitmap_zero(ctx->vregs_written, NUM_VREGS);
bitmap_zero(ctx->vregs_updated_tmp, NUM_VREGS);
bitmap_zero(ctx->vregs_updated, NUM_VREGS);
bitmap_zero(ctx->vregs_select, NUM_VREGS);
bitmap_zero(ctx->predicated_future_vregs, NUM_VREGS);
bitmap_zero(ctx->predicated_tmp_vregs, NUM_VREGS);
- bitmap_zero(ctx->vregs_read, NUM_VREGS);
- bitmap_zero(ctx->qregs_read, NUM_QREGS);
+ bitmap_zero(ctx->qregs_written, NUM_QREGS);
ctx->qreg_log_idx = 0;
for (i = 0; i < STORES_MAX; i++) {
ctx->store_width[i] = 0;
diff --git a/target/hexagon/translate.h b/target/hexagon/translate.h
index d5e7f49ad8..00cc2bcd63 100644
--- a/target/hexagon/translate.h
+++ b/target/hexagon/translate.h
@@ -50,23 +50,27 @@ typedef struct DisasContext {
int tmp_vregs_num[VECTOR_TEMPS_MAX];
int vreg_log[NUM_VREGS];
int vreg_log_idx;
+ DECLARE_BITMAP(vregs_written, NUM_VREGS);
+ DECLARE_BITMAP(insn_vregs_written, NUM_VREGS);
DECLARE_BITMAP(vregs_updated_tmp, NUM_VREGS);
DECLARE_BITMAP(vregs_updated, NUM_VREGS);
DECLARE_BITMAP(vregs_select, NUM_VREGS);
DECLARE_BITMAP(predicated_future_vregs, NUM_VREGS);
DECLARE_BITMAP(predicated_tmp_vregs, NUM_VREGS);
- DECLARE_BITMAP(vregs_read, NUM_VREGS);
+ DECLARE_BITMAP(insn_vregs_read, NUM_VREGS);
int qreg_log[NUM_QREGS];
int qreg_log_idx;
- DECLARE_BITMAP(qregs_read, NUM_QREGS);
+ DECLARE_BITMAP(qregs_written, NUM_QREGS);
+ DECLARE_BITMAP(insn_qregs_written, NUM_QREGS);
+ DECLARE_BITMAP(insn_qregs_read, NUM_QREGS);
bool pre_commit;
bool need_commit;
TCGCond branch_cond;
target_ulong branch_dest;
bool is_tight_loop;
bool short_circuit;
- bool has_hvx_helper;
bool read_after_write;
+ bool has_hvx_overlap;
TCGv new_value[TOTAL_PER_THREAD_REGS];
TCGv new_pred_value[NUM_PREGS];
TCGv pred_written;
@@ -146,10 +150,25 @@ intptr_t ctx_future_vreg_off(DisasContext *ctx, int regnum,
intptr_t ctx_tmp_vreg_off(DisasContext *ctx, int regnum,
int num, bool alloc_ok);
+static inline void ctx_start_hvx_insn(DisasContext *ctx)
+{
+ bitmap_zero(ctx->insn_vregs_written, NUM_VREGS);
+ bitmap_zero(ctx->insn_vregs_read, NUM_VREGS);
+ bitmap_zero(ctx->insn_qregs_written, NUM_QREGS);
+ bitmap_zero(ctx->insn_qregs_read, NUM_QREGS);
+}
+
static inline void ctx_log_vreg_write(DisasContext *ctx,
int rnum, VRegWriteType type,
- bool is_predicated)
+ bool is_predicated, bool has_helper)
{
+ if (has_helper) {
+ set_bit(rnum, ctx->insn_vregs_written);
+ if (test_bit(rnum, ctx->insn_vregs_read)) {
+ ctx->has_hvx_overlap = true;
+ }
+ }
+ set_bit(rnum, ctx->vregs_written);
if (type != EXT_TMP) {
if (!test_bit(rnum, ctx->vregs_updated)) {
ctx->vreg_log[ctx->vreg_log_idx] = rnum;
@@ -175,42 +194,77 @@ static inline void ctx_log_vreg_write(DisasContext *ctx,
static inline void ctx_log_vreg_write_pair(DisasContext *ctx,
int rnum, VRegWriteType type,
- bool is_predicated)
+ bool is_predicated, bool has_helper)
{
- ctx_log_vreg_write(ctx, rnum ^ 0, type, is_predicated);
- ctx_log_vreg_write(ctx, rnum ^ 1, type, is_predicated);
+ ctx_log_vreg_write(ctx, rnum ^ 0, type, is_predicated, has_helper);
+ ctx_log_vreg_write(ctx, rnum ^ 1, type, is_predicated, has_helper);
}
-static inline void ctx_log_vreg_read(DisasContext *ctx, int rnum)
+static inline void ctx_log_vreg_read(DisasContext *ctx, int rnum,
+ bool has_helper)
{
- set_bit(rnum, ctx->vregs_read);
+ if (has_helper) {
+ set_bit(rnum, ctx->insn_vregs_read);
+ if (test_bit(rnum, ctx->insn_vregs_written)) {
+ ctx->has_hvx_overlap = true;
+ }
+ }
+ if (test_bit(rnum, ctx->vregs_written)) {
+ ctx->read_after_write = true;
+ }
}
-static inline void ctx_log_vreg_read_new(DisasContext *ctx, int rnum)
+static inline void ctx_log_vreg_read_new(DisasContext *ctx, int rnum,
+ bool has_helper)
{
g_assert(is_gather_store_insn(ctx) ||
test_bit(rnum, ctx->vregs_updated) ||
test_bit(rnum, ctx->vregs_select) ||
test_bit(rnum, ctx->vregs_updated_tmp));
- set_bit(rnum, ctx->vregs_read);
+ if (has_helper) {
+ set_bit(rnum, ctx->insn_vregs_read);
+ if (test_bit(rnum, ctx->insn_vregs_written)) {
+ ctx->has_hvx_overlap = true;
+ }
+ }
+ if (is_gather_store_insn(ctx)) {
+ ctx->read_after_write = true;
+ }
}
-static inline void ctx_log_vreg_read_pair(DisasContext *ctx, int rnum)
+static inline void ctx_log_vreg_read_pair(DisasContext *ctx, int rnum,
+ bool has_helper)
{
- ctx_log_vreg_read(ctx, rnum ^ 0);
- ctx_log_vreg_read(ctx, rnum ^ 1);
+ ctx_log_vreg_read(ctx, rnum ^ 0, has_helper);
+ ctx_log_vreg_read(ctx, rnum ^ 1, has_helper);
}
static inline void ctx_log_qreg_write(DisasContext *ctx,
- int rnum)
+ int rnum, bool has_helper)
{
+ if (has_helper) {
+ set_bit(rnum, ctx->insn_qregs_written);
+ if (test_bit(rnum, ctx->insn_qregs_read)) {
+ ctx->has_hvx_overlap = true;
+ }
+ }
+ set_bit(rnum, ctx->qregs_written);
ctx->qreg_log[ctx->qreg_log_idx] = rnum;
ctx->qreg_log_idx++;
}
-static inline void ctx_log_qreg_read(DisasContext *ctx, int qnum)
+static inline void ctx_log_qreg_read(DisasContext *ctx,
+ int qnum, bool has_helper)
{
- set_bit(qnum, ctx->qregs_read);
+ if (has_helper) {
+ set_bit(qnum, ctx->insn_qregs_read);
+ if (test_bit(qnum, ctx->insn_qregs_written)) {
+ ctx->has_hvx_overlap = true;
+ }
+ }
+ if (test_bit(qnum, ctx->qregs_written)) {
+ ctx->read_after_write = true;
+ }
}
extern TCGv hex_gpr[TOTAL_PER_THREAD_REGS];
--
2.25.1
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