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Hexagon (target/hexagon) Only use branch_taken when packet has multi cof

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When a packet has more than one change-of-flow instruction, only the first
one to branch is considered.  We use the branch_taken variable to keep
track of this.

However, when there is a single cof instruction, we don't need the same
amount of bookkeeping.

We add the pkt_has_multi_cof member to the Packet structure, and pass this
information to the needed functions.

When there is a generated helper function with cof, the generator will
pass this pkt_has_multi_cof as a runtime value.

Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20221108162906.3166-5-tsimpson@quicinc.com>
This commit is contained in:
Taylor Simpson 2022-11-08 08:28:59 -08:00
parent 8e8a85c14e
commit fb67c2bf24
9 changed files with 51 additions and 16 deletions
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15
target/hexagon/decode.c
View File

@ -388,6 +388,7 @@ static void decode_set_insn_attr_fields(Packet *pkt)
uint16_t opcode;
pkt->pkt_has_cof = false;
pkt->pkt_has_multi_cof = false;
pkt->pkt_has_endloop = false;
pkt->pkt_has_dczeroa = false;
@ -412,13 +413,23 @@ static void decode_set_insn_attr_fields(Packet *pkt)
}
}
pkt->pkt_has_cof |= decode_opcode_can_jump(opcode);
if (decode_opcode_can_jump(opcode)) {
if (pkt->pkt_has_cof) {
pkt->pkt_has_multi_cof = true;
}
pkt->pkt_has_cof = true;
}
pkt->insn[i].is_endloop = decode_opcode_ends_loop(opcode);
pkt->pkt_has_endloop |= pkt->insn[i].is_endloop;
pkt->pkt_has_cof |= pkt->pkt_has_endloop;
if (pkt->pkt_has_endloop) {
if (pkt->pkt_has_cof) {
pkt->pkt_has_multi_cof = true;
}
pkt->pkt_has_cof = true;
}
}
}

5
target/hexagon/gen_helper_funcs.py
View File

@ -1,7 +1,7 @@
#!/usr/bin/env python3
##
## Copyright(c) 2019-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
## Copyright(c) 2019-2022 Qualcomm Innovation Center, Inc. All Rights Reserved.
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
@ -238,6 +238,9 @@ def gen_helper_function(f, tag, tagregs, tagimms):
gen_helper_arg_imm(f,immlett)
i += 1
if (hex_common.need_pkt_has_multi_cof(tag)):
f.write(", uint32_t pkt_has_multi_cof")
if hex_common.need_slot(tag):
if i > 0: f.write(", ")
f.write("uint32_t slot")

8
target/hexagon/gen_helper_protos.py
View File

@ -1,7 +1,7 @@
#!/usr/bin/env python3
##
## Copyright(c) 2019-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
## Copyright(c) 2019-2022 Qualcomm Innovation Center, Inc. All Rights Reserved.
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
@ -82,6 +82,7 @@ def gen_helper_prototype(f, tag, tagregs, tagimms):
## Figure out how many arguments the helper will take
if (numscalarresults == 0):
def_helper_size = len(regs)+len(imms)+numscalarreadwrite+1
if hex_common.need_pkt_has_multi_cof(tag): def_helper_size += 1
if hex_common.need_part1(tag): def_helper_size += 1
if hex_common.need_slot(tag): def_helper_size += 1
f.write('DEF_HELPER_%s(%s' % (def_helper_size, tag))
@ -89,6 +90,7 @@ def gen_helper_prototype(f, tag, tagregs, tagimms):
f.write(', void' )
else:
def_helper_size = len(regs)+len(imms)+numscalarreadwrite
if hex_common.need_pkt_has_multi_cof(tag): def_helper_size += 1
if hex_common.need_part1(tag): def_helper_size += 1
if hex_common.need_slot(tag): def_helper_size += 1
f.write('DEF_HELPER_%s(%s' % (def_helper_size, tag))
@ -126,7 +128,9 @@ def gen_helper_prototype(f, tag, tagregs, tagimms):
for immlett,bits,immshift in imms:
f.write(", s32")
## Add the arguments for the instruction slot and part1 (if needed)
## Add the arguments for the instruction pkt_has_multi_cof, slot and
## part1 (if needed)
if hex_common.need_pkt_has_multi_cof(tag): f.write(', i32')
if hex_common.need_slot(tag): f.write(', i32' )
if hex_common.need_part1(tag): f.write(' , i32' )
f.write(')\n')

5
target/hexagon/gen_tcg_funcs.py
View File

@ -622,6 +622,9 @@ def gen_tcg_func(f, tag, regs, imms):
## Generate the call to the helper
for immlett,bits,immshift in imms:
gen_helper_decl_imm(f,immlett)
if hex_common.need_pkt_has_multi_cof(tag):
f.write(" TCGv pkt_has_multi_cof = ")
f.write("tcg_constant_tl(ctx->pkt->pkt_has_multi_cof);\n")
if hex_common.need_part1(tag):
f.write(" TCGv part1 = tcg_constant_tl(insn->part1);\n")
if hex_common.need_slot(tag):
@ -654,6 +657,8 @@ def gen_tcg_func(f, tag, regs, imms):
for immlett,bits,immshift in imms:
gen_helper_call_imm(f,immlett)
if hex_common.need_pkt_has_multi_cof(tag):
f.write(", pkt_has_multi_cof")
if hex_common.need_slot(tag): f.write(", slot")
if hex_common.need_part1(tag): f.write(", part1" )
f.write(");\n")

3
target/hexagon/hex_common.py
View File

@ -207,6 +207,9 @@ def need_part1(tag):
def need_ea(tag):
return re.compile(r"\bEA\b").search(semdict[tag])
def need_pkt_has_multi_cof(tag):
return 'A_COF' in attribdict[tag]
def skip_qemu_helper(tag):
return tag in overrides.keys()

1
target/hexagon/insn.h
View File

@ -57,6 +57,7 @@ struct Packet {
/* Pre-decodes about COF */
bool pkt_has_cof; /* Has any change-of-flow */
bool pkt_has_multi_cof; /* Has more than one change-of-flow */
bool pkt_has_endloop;
bool pkt_has_dczeroa;

2
target/hexagon/macros.h
View File

@ -407,7 +407,7 @@ static inline TCGv gen_read_ireg(TCGv result, TCGv val, int shift)
#define fCHECK_PCALIGN(A)
#define fWRITE_NPC(A) write_new_pc(env, A)
#define fWRITE_NPC(A) write_new_pc(env, pkt_has_multi_cof != 0, A)
#define fBRANCH(LOC, TYPE) fWRITE_NPC(LOC)
#define fJUMPR(REGNO, TARGET, TYPE) fBRANCH(TARGET, COF_TYPE_JUMPR)

24
target/hexagon/op_helper.c
View File

@ -104,20 +104,26 @@ static void log_store64(CPUHexagonState *env, target_ulong addr,
env->mem_log_stores[slot].data64 = val;
}
static void write_new_pc(CPUHexagonState *env, target_ulong addr)
static void write_new_pc(CPUHexagonState *env, bool pkt_has_multi_cof,
target_ulong addr)
{
HEX_DEBUG_LOG("write_new_pc(0x" TARGET_FMT_lx ")\n", addr);
/*
* If more than one branch is taken in a packet, only the first one
* is actually done.
*/
if (env->branch_taken) {
HEX_DEBUG_LOG("INFO: multiple branches taken in same packet, "
"ignoring the second one\n");
if (pkt_has_multi_cof) {
/*
* If more than one branch is taken in a packet, only the first one
* is actually done.
*/
if (env->branch_taken) {
HEX_DEBUG_LOG("INFO: multiple branches taken in same packet, "
"ignoring the second one\n");
} else {
fCHECK_PCALIGN(addr);
env->next_PC = addr;
env->branch_taken = 1;
}
} else {
fCHECK_PCALIGN(addr);
env->branch_taken = 1;
env->next_PC = addr;
}
}

4
target/hexagon/translate.c
View File

@ -248,7 +248,9 @@ static void gen_start_packet(DisasContext *ctx)
tcg_gen_movi_tl(hex_slot_cancelled, 0);
}
if (pkt->pkt_has_cof) {
tcg_gen_movi_tl(hex_branch_taken, 0);
if (pkt->pkt_has_multi_cof) {
tcg_gen_movi_tl(hex_branch_taken, 0);
}
tcg_gen_movi_tl(hex_next_PC, next_PC);
}
if (need_pred_written(pkt)) {