Reducing the number of arguments reduces the overhead of the helper
call
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230405164211.30015-2-tsimpson@quicinc.com>
When there is a conditional change of flow or an endloop instruction, we
preload HEX_REG_PC with ctx->next_PC at gen_start_packet(). Nonetheless,
we still generate TCG code to do this update again at gen_goto_tb() when
the condition for the COF is not met, thus producing redundant
instructions. This can be seen with the following packet:
0x004002e4: 0x5c20d000 { if (!P0) jump:t PC+0 }
Which generates this TCG code:
---- 004002e4
-> mov_i32 pc,$0x4002e8
and_i32 loc9,p0,$0x1
mov_i32 branch_taken,loc9
add_i32 pkt_cnt,pkt_cnt,$0x2
add_i32 insn_cnt,insn_cnt,$0x2
brcond_i32 branch_taken,$0x0,ne,$L1
goto_tb $0x0
mov_i32 pc,$0x4002e4
exit_tb $0x7fb0c36e5200
set_label $L1
goto_tb $0x1
-> mov_i32 pc,$0x4002e8
exit_tb $0x7fb0c36e5201
set_label $L0
exit_tb $0x7fb0c36e5203
Note that even after optimizations, the redundant PC update is still
present:
---- 004002e4
-> mov_i32 pc,$0x4002e8 sync: 0 dead: 0 1 pref=0xffff
mov_i32 branch_taken,$0x1 sync: 0 dead: 0 1 pref=0xffff
add_i32 pkt_cnt,pkt_cnt,$0x2 sync: 0 dead: 0 1 pref=0xffff
add_i32 insn_cnt,insn_cnt,$0x2 sync: 0 dead: 0 1 2 pref=0xffff
goto_tb $0x1
-> mov_i32 pc,$0x4002e8 sync: 0 dead: 0 1 pref=0xffff
exit_tb $0x7fb0c36e5201
set_label $L0
exit_tb $0x7fb0c36e5203
With this patch, the second redundant update is properly discarded.
Note that we need the additional "move_to_pc" flag instead of just
avoiding the update whenever `dest == ctx->next_PC`, as that could
potentially skip updates from a COF with met condition, whose
ctx->branch_dest just happens to be equal to ctx->next_PC.
Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <fc059153c3f0526d97b7f13450c02b276b0908e1.1679519341.git.quic_mathbern@quicinc.com>
The following improvements are made for predicated HVX instructions
During gen_commit_hvx, unconditionally move the "new" value into
the dest
Don't set slot_cancelled
Remove runtime bookkeeping of which registers were updated
Reduce the cases where gen_log_vreg_write[_pair] is called
It's only needed for special operands VxxV and VyV
Remove gen_log_qreg_write
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230307025828.1612809-15-tsimpson@quicinc.com>
We only need to track slot for predicated stores and predicated HVX
instructions.
Add arguments to the probe helper functions to indicate if the slot
is predicated.
Here is a simple example of the differences in the TCG code generated:
IN:
0x00400094: 0xf900c102 { if (P0) R2 = and(R0,R1) }
BEFORE
---- 00400094
mov_i32 slot_cancelled,$0x0
mov_i32 new_r2,r2
and_i32 tmp0,p0,$0x1
brcond_i32 tmp0,$0x0,eq,$L1
and_i32 tmp0,r0,r1
mov_i32 new_r2,tmp0
br $L2
set_label $L1
or_i32 slot_cancelled,slot_cancelled,$0x8
set_label $L2
mov_i32 r2,new_r2
AFTER
---- 00400094
mov_i32 new_r2,r2
and_i32 tmp0,p0,$0x1
brcond_i32 tmp0,$0x0,eq,$L1
and_i32 tmp0,r0,r1
mov_i32 new_r2,tmp0
br $L2
set_label $L1
set_label $L2
mov_i32 r2,new_r2
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230307025828.1612809-14-tsimpson@quicinc.com>
Extend the analyze_<tag> functions for HVX vector and predicate writes
Remove calls to ctx_log_vreg_write[_pair] from gen_tcg_funcs.py
During gen_start_packet, reload the predicated HVX registers into
fugure_VRegs and tmp_VRegs
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230307025828.1612809-8-tsimpson@quicinc.com>
The pkt_has_store_s1 field in CPUHexagonState is only needed in generated
helpers for scalar load instructions. See check_noshuf and mem_load[1248]
in op_helper.c.
We add logic in gen_analyze_funcs.py to set need_pkt_has_store_s1 in
DisasContext when it is needed at runtime.
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230307025828.1612809-7-tsimpson@quicinc.com>
We create a new generator that creates an analyze_<tag> function for
each instruction. Currently, these functions record the writes to
R, P, and C registers by calling ctx_log_reg_write[_pair] or
ctx_log_pred_write.
During gen_start_packet, we invoke the analyze_<tag> function for
each instruction in the packet, and we mark the implicit register
and predicate writes.
Doing the analysis up front has several advantages
- We remove calls to ctx_log_* from gen_tcg_funcs.py and genptr.c
- After the analysis is performed, we can initialize hex_new_value
for each of the predicated assignments rather than during TCG
generation for the instructions
- This is a stepping stone for future work where the analysis will
include the set of registers that are read. In cases where
the packet doesn't have an overlap between the registers that are
written and registers that are read, we can avoid the intermediate
step of writing to hex_new_value. Note that other checks will also
be needed (e.g., no instructions can raise an exception).
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230307025828.1612809-6-tsimpson@quicinc.com>
Translators are no longer required to free tcg temporaries.
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Since tcg_temp_new_* is now identical, use those.
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In preparation for returning the number of insns generated
via the same pointer. Adjust only the prototypes so far.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Direct block chaining is documented here
https://qemu.readthedocs.io/en/latest/devel/tcg.html#direct-block-chaining
Hexagon inner loops end with the endloop0 instruction
To go back to the beginning of the loop, this instructions writes to PC
from register SA0 (start address 0). To use direct block chaining, we
have to assign PC with a constant value. So, we specialize the code
generation when the start of the translation block is equal to SA0.
When this is the case, we defer the compare/branch from endloop0 to
gen_end_tb. When this is done, we can assign the start address of the TB
to PC.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20221108162906.3166-12-tsimpson@quicinc.com>
Direct block chaining is documented here
https://qemu.readthedocs.io/en/latest/devel/tcg.html#direct-block-chaining
Recall that Hexagon allows packets with multiple jumps where only the
first one with a true predicate will actually jump. We can use
tcg_gen_goto_tb/tcg_gen_exit_tb when the packet contains a single
PC-relative branch or jump. If not, we use tcg_gen_lookup_and_goto_ptr.
We add the following to DisasContext in order to delay the branching
until the end of packet commit (in gen_end_tb)
branch_cond
The TCGCond condition under which the branch is taken
When branch_cond == TCG_COND_NEVER, there isn't a single
direct branch in this packet.
When branch_cond != TCG_COND_ALWAYS, the value is in
hex_branch_taken
branch_dest
The destination of the branch
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20221108162906.3166-11-tsimpson@quicinc.com>
The imported files don't properly mark all CONDEXEC instructions, so
we add some logic to hex_common.py to add the attribute.
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20221108162906.3166-7-tsimpson@quicinc.com>
Add pc field to Packet structure
For helpers that need PC, pass an extra argument
Remove slot arg from conditional jump helpers
On a trap0, copy pkt->pc into hex_gpr[HEX_REG_PC]
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20221108162906.3166-6-tsimpson@quicinc.com>
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 enables us to reduce the number of parameters to many functions
In particular, the generated functions previously took all 3 as arguments
Not only does this simplify the code, it improves the translation time
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20221108162906.3166-2-tsimpson@quicinc.com>
The store width is needed for packet commit, so it is stored in
ctx->store_width. Currently, it is set when a store has a TCG
override instead of a QEMU helper. In the QEMU helper case, the
ctx->store_width is not set, we invoke a helper during packet commit
that uses the runtime store width.
This patch ensures ctx->store_width is set for all store instructions,
so performance is improved because packet commit can generate the proper
TCG store rather than the generic helper.
We do this by
- Use the attributes from the instructions during translation to
set ctx->store_width
- Remove setting of ctx->store_width from genptr.c
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220920080746.26791-3-tsimpson@quicinc.com>
We have found cases where pkt_has_store_s[01] is set incorrectly.
This leads to generating an unnecessary store that is left over
from a previous packet.
Add an attribute to determine if an instruction is a scalar store
The attribute is attached to the fSTORE macro (hex_common.py)
Update the logic in decode.c that sets pkt_has_store_s[01]
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220920080746.26791-4-tsimpson@quicinc.com>
Pass these along to translator_loop -- pc may be used instead
of tb->pc, and host_pc is currently unused. Adjust all targets
at one time.
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We have fetched and locked the logfile in translator_loop.
Pass the filepointer down to the disas_log hook so that it
need not be fetched and locked again.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-13-richard.henderson@linaro.org>
This code appears to be trying to make sure there is a logfile.
But that's already true -- the logfile will either be set by -D,
or will be stderr. In either case, not appropriate here.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-3-richard.henderson@linaro.org>
Change SET_USR_FIELD to write to hex_new_value[HEX_REG_USR] instead
of hex_gpr[HEX_REG_USR].
Then, we need code to mark the instructions that can set implicitly
set USR
- Macros added to hex_common.py
- A_FPOP added in translate.c
Test case added in tests/tcg/hexagon/overflow.c
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Change additional tcg_const_tl to tcg_constant_tl
Note that gen_pred_cancal had slot_mask initialized with tcg_const_tl.
However, it is not constant throughout, so we initialize it with
tcg_temp_new and replace the first use with the constant value.
Inspired-by: Richard Henderson <richard.henderson@linaro.org>
Inspired-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
GDB single-stepping is now handled generically.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Replace uses of tcg_const_* with the allocate and free close together.
Inspired-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211003004750.3608983-3-f4bug@amsat.org>
When a packet has 2 stores, either both commit or neither commit.
At the beginning of gen_commit_packet, we check for multiple stores.
If there are multiple stores, call a helper that will probe each of
them before proceeding with the commit.
Note that we don't call the probe helper for packets with only one
store. Therefore, we call process_store_log before anything else
involved in committing the packet.
We also fix a typo in the comment in process_store_log.
Test case added in tests/tcg/hexagon/hex_sigsegv.c
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <1633036599-7637-1-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
[rth: Split out of a larger patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The hook is now unused, with breakpoints checked outside translation.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1622589584-22571-5-git-send-email-tsimpson@quicinc.com>
Change #if HEX_DEBUG to if (HEX_DEBUG) so the debug code doesn't bit rot
Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-17-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-8-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Multiple writes to the same preg are and'ed together. Rather than
generating a runtime check, we can determine at TCG generation time
if the predicate has previously been written in the packet.
Test added to tests/tcg/hexagon/misc.c
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-7-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
When exiting a TB, generate all the code before returning from
hexagon_tr_translate_packet so that nothing needs to be done in
hexagon_tr_tb_stop.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-6-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Remove hexagon_env_get_cpu and replace with env_archcpu
Replace CPU(hexagon_env_get_cpu(env)) with env_cpu(env)
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-5-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-4-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Change cpu_ldl_code to translator_ldl.
Don't end the TB after every packet when HEX_DEBUG is on.
Make gen_check_store_width a simple call.
Reported-by: Richard Henderson <<richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <1615783984-25918-1-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Read the instruction memory
Create a packet data structure
Generate TCG code for the start of the packet
Invoke the generate function for each instruction
Generate TCG code for the end of the packet
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <1612763186-18161-30-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
