Commit graph

31 commits

Author SHA1 Message Date
Emilio G. Cota e7a7d8c508
tcg: optimise memory layout of TCGTemp
This brings down the size of the struct from 56 to 32 bytes on 64-bit,
and to 20 bytes on 32-bit. This leads to memory savings:

Before:
$ find . -name 'tcg.o' | xargs size
   text    data     bss     dec     hex filename
  41131   29800      88   71019   1156b ./aarch64-softmmu/tcg/tcg.o
  37969   29416      96   67481   10799 ./x86_64-linux-user/tcg/tcg.o
  39354   28816      96   68266   10aaa ./arm-linux-user/tcg/tcg.o
  40802   29096      88   69986   11162 ./arm-softmmu/tcg/tcg.o
  39417   29672      88   69177   10e39 ./x86_64-softmmu/tcg/tcg.o

After:
$ find . -name 'tcg.o' | xargs size
   text    data     bss     dec     hex filename
  40883   29800      88   70771   11473 ./aarch64-softmmu/tcg/tcg.o
  37473   29416      96   66985   105a9 ./x86_64-linux-user/tcg/tcg.o
  38858   28816      96   67770   108ba ./arm-linux-user/tcg/tcg.o
  40554   29096      88   69738   1106a ./arm-softmmu/tcg/tcg.o
  39169   29672      88   68929   10d41 ./x86_64-softmmu/tcg/tcg.o

Note that using an entire byte for some enums that need less than
that wastes a few bits (noticeable in 32 bits, where we use
20 bytes instead of 16) but avoids extraction code, which overall
is a win--I've tested several variations of the patch, and the appended
is the best performer for OpenSSL's bntest by a very small margin:

Before:
$ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null
[...]
 Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs):

      10538.479833 task-clock (msec)  # 0.999 CPUs utilized  ( +-  0.38% )
               772 context-switches   # 0.073 K/sec          ( +-  2.03% )
                 0 cpu-migrations     # 0.000 K/sec          ( +-100.00% )
             2,207 page-faults        # 0.209 K/sec          ( +-  0.08% )
      10.552871687 seconds time elapsed                      ( +-  0.39% )

After:
$ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null
 Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs):

      10459.968847 task-clock (msec)  # 0.999 CPUs utilized  ( +-  0.30% )
               739 context-switches   # 0.071 K/sec          ( +-  1.71% )
                 0 cpu-migrations     # 0.000 K/sec          ( +- 68.14% )
             2,204 page-faults        # 0.211 K/sec          ( +-  0.10% )
      10.473900411 seconds time elapsed                      ( +-  0.30% )

Backports commit 00c8fa9ffeee7458e5ed62c962faf638156c18da from qemu
2018-02-19 02:03:01 -05:00
Richard Henderson bdf667fd4e
tcg: Check for overflow via highwater mark
We currently pre-compute an worst case code size for any TB, which
works out to be 122kB. Since the average TB size is near 1kB, this
wastes quite a lot of storage.

Instead, check for overflow in between generating code for each opcode.
The overhead of the check isn't measurable and wastage is minimized.

Backports commit b125f9dc7bd68cd4c57189db4da83b0620b28a72 from qemu
2018-02-17 15:24:00 -05:00
Richard Henderson 532877a366
tcg: Remove tcg_gen_code_search_pc
It's no longer used, so tidy up everything reached by it.

Backports commit 04fe64000162c45d8974da9ca4d266f8d0e67eb7 from qemu
2018-02-17 15:24:00 -05:00
Richard Henderson a5ac288135
tcg: Remove gen_intermediate_code_pc
It is no longer used, so tidy up everything reached by it.
This includes the gen_opc_* arrays, the search_pc parameter
and the inline gen_intermediate_code_internal functions.

Backports commit 4e5e1215156662b2b153255c49d4640d82c5568b from qemu
2018-02-17 15:23:59 -05:00
Richard Henderson 66de6cc37c
tcg: Save insn data and use it in cpu_restore_state_from_tb
We can now restore state without retranslation.

Backports commit fca8a500d519a56abeaedf8073167a61d3c6b9c4 from qemu
2018-02-17 15:23:59 -05:00
Richard Henderson 1cbd175736
tcg: Pass data argument to restore_state_to_opc
The gen_opc_* arrays are already redundant with the data stored in
the insn_start arguments. Transition restore_state_to_opc to use
data from the latter.

Backports commit bad729e272387de7dbfa3ec4319036552fc6c107 from qemu
2018-02-17 15:23:58 -05:00
Lioncash b115c5509d
tcg: Add TCG_MAX_INSNS
Adjust all translators to respect it.

Backports commit 190ce7fbc79fd0883a6170d7f30da59d366e6830 from qemu
2018-02-17 15:23:58 -05:00
Richard Henderson 2c1ae7a408
target-sparc: Remove gen_opc_jump_pc
Since jump_pc[1] is always npc + 4, we can infer after incrementing
that jump_pc[1] == pc + 4. Because of that, we can encode the branch
destination into a single word, and store that in npc.

Backports commit 6c42444f9a53b6af39d46008cb9f650b11e96cb9 from qemu
2018-02-17 15:23:56 -05:00
Peter Crosthwaite 2b15db6e12
tcg: split tcg_op_defs to -common
tcg_op_defs (and the _max) are both needed by the TCI disassembler. For
multi-arch, tcg.c will be multiple-compiled (arch-obj) with its symbols
hidden from common code. So split the definition off to new file,
tcg-common.c which will remain a regular obj-y for use by both the TCI
disas as well as the multiple tcg.c's.

Backports commit 7d8f787d9d261d6880b69e35ed682241e3f9242f from qemu
2018-02-17 15:23:51 -05:00
Pavel Dovgalyuk 6cdaaf9b1b
softmmu: add helper function to pass through retaddr
This patch introduces several helpers to pass return address
which points to the TB. Correct return address allows correct
restoring of the guest PC and icount. These functions should be used when
helpers embedded into TB invoke memory operations.

Backports commit 282dffc8a4bfe8724548cabb8a26698bde0a6e18 from qemu
2018-02-17 15:23:38 -05:00
Peter Crosthwaite a591219ad6
cpu-defs: Move CPU_TEMP_BUF_NLONGS to tcg
The usages of this define are pure TCG and there is no architecture
specific variation of the value. Localise it to the TCG engine to
remove another architecture agnostic piece from cpu-defs.h.

This follows on from a28177820a868eafda8fab007561cc19f41941f4 where
temp_buf was moved out of the CPU_COMMON obsoleting the need for
the super early definition.

Backports commit 6e0b07306d1793e8402dd218d2e38a7377b5fc27 from qemu
2018-02-17 15:23:15 -05:00
Peter Crosthwaite 3501c34344
tcg: Delete unused cpu_pc_from_tb()
No code uses the cpu_pc_from_tb() function. Delete from tricore and
arm which each provide an unused implementation. Update the comment
in tcg.h to reflect that this is obsoleted by synchronize_from_tb.

Backports commit fee068e4f190a36ef3bda9aa7c802f90434ef8e5 from qemu
2018-02-12 21:14:22 -05:00
Richard Henderson 3f9502dc8b
tcg: Allow extra data to be attached to insn_start
With an eye toward having this data replace the gen_opc_* arrays
that each target collects in order to enable restore_state_from_tb.

Backports commit 9aef40ed1f6e2bd794bbb3ba8c8b773e506334c9 from qemu
2018-02-11 13:03:51 -05:00
Richard Henderson 58e939b91f
tcg: Split trunc_shr_i32 opcode into extr[lh]_i64_i32
Rather than allow arbitrary shift+trunc, only concern ourselves
with low and high parts. This is all that was being used anyway.

Backports commit 609ad70562793937257c89d07bf7c1370b9fc9aa from qemu
2018-02-10 23:00:45 -05:00
Aurelien Jarno 80223e7ad5
tcg: rename trunc_shr_i32 into trunc_shr_i64_i32
The op is sometimes named trunc_shr_i32 and sometimes trunc_shr_i64_i32,
and the name in the README doesn't match the name offered to the
frontends.

Always use the long name to make it clear it is a size changing op.

Backports commit 0632e555fc4d281d69cb08d98d500d96185b041f from qemu
2018-02-10 22:29:30 -05:00
Aurelien Jarno 59909fe549
tcg/optimize: track const/copy status separately
Instead of using an enum which could be either a copy or a const, track
them separately. This will be used in the next patch.

Constants are tracked through a bool. Copies are tracked by initializing
temp's next_copy and prev_copy to itself, allowing to simplify the code
a bit.

Backports commit b41059dd9deec367a4ccd296659f0bc5de2dc705 from qemu
2018-02-10 22:15:43 -05:00
Aurelien Jarno b450b79622
tcg/optimize: optimize temps tracking
The tcg_temp_info structure uses 24 bytes per temp. Now that we emulate
vector registers on most guests, it's not uncommon to have more than 100
used temps. This means we have initialize more than 2kB at least twice
per TB, often more when there is a few goto_tb.

Instead used a TCGTempSet bit array to track which temps are in used in
the current basic block. This means there are only around 16 bytes to
initialize.

This improves the boot time of a MIPS guest on an x86-64 host by around
7% and moves out tcg_optimize from the the top of the profiler list.

Backports commit 1208d7dd5fddc1fbd98de800d17429b4e5578848 from qemu
2018-02-10 21:51:46 -05:00
Richard Henderson 336833c11e
tcg: Add MO_ALIGN, MO_UNALN
These modifiers control, on a per-memory-op basis, whether
unaligned memory accesses are allowed. The default setting
reflects the target's definition of ALIGNED_ONLY.

Backports commit dfb36305626636e2e07e0c5acd3a002a5419399e from qemu
2018-02-10 20:18:53 -05:00
Richard Henderson ac713c7034
tcg: Push merged memop+mmu_idx parameter to softmmu routines
The extra information is not yet used but it is now available.
This requires minor changes through all of the tcg backends.

Backports commit 3972ef6f830d65e9bacbd31257abedc055fd6dc8 from qemu
2018-02-10 20:03:22 -05:00
Richard Henderson 6234d07489
tcg: Merge memop and mmu_idx parameters to qemu_ld/st
At the tcg opcode level, not at the tcg-op.h generator level.
This requires minor changes through all of the tcg backends,
but none of the cpu translators.

Backports commit 59227d5d45bb3c31dc2118011691c35b3c00879c from qemu
2018-02-10 19:01:49 -05:00
Richard Henderson 6bd102ba86
tcg: Use tcg_malloc to allocate TCGLabel
Pre-allocating 512 of them per TB is a waste.

Backports commit 51e3972c41598adc91fe3f4767057f5198dcc15c from qemu
2018-02-09 14:48:20 -05:00
Richard Henderson 232632e76c
tcg: Change translator-side labels to a pointer
This is improved type checking for the translators -- it's no longer
possible to accidentally swap arguments to the branch functions.

Note that the code generating backends still manipulate labels as int.

With notable exceptions, the scope of the change is just a few lines
for each target, so it's not worth building extra machinery to do this
change in per-target increments.

Backports commit 42a268c241183877192c376d03bd9b6d527407c7 from qemu
2018-02-09 14:17:56 -05:00
Richard Henderson 4fcaabf38c
tcg: Remove opcodes instead of noping them out
With the linked list scheme we need not leave nops in the stream
that we need to process later.

Backports commit 0c627cdca20155753a536c51385abb73941a59a0 from qemu
2018-02-09 13:03:58 -05:00
Lioncash 0273e6ae18
tcg: Put opcodes in a linked list
The previous setup required ops and args to be completely sequential,
and was error prone when it came to both iteration and optimization.
2018-02-09 12:54:05 -05:00
Richard Henderson a41b9acc0c
tcg: Introduce tcg_op_buf_count and tcg_op_buf_full
The method by which we count the number of ops emitted
is going to change. Abstract that away into some inlines.

Backports commit fe700adb3db5b028b504423b946d4ee5200a8f2f from qemu.
2018-02-09 09:31:17 -05:00
Richard Henderson 500c546444
tcg: Move some opcode generation functions out of line
Some of these functions are really quite large.  We have a number of
things that ought to be circularly dependent, but we duplicated code
to break that chain for the inlines.

This saved 25% of the code size of one of the translators I examined.
2018-02-09 08:10:00 -05:00
Richard Henderson cb7b19ad26
tcg: Change ts->mem_reg to ts->mem_base
Chain the temporaries together via pointers intstead of indices.
The mem_reg value is now mem_base->reg.  This will be important later.

This does require that the frame pointer have a global temporary
allocated for it.  This is simple bar the existing reserved_regs check.

Backports commit b3a62939561e07bc34493444fa926b6137cba4e8 from qemu
2018-02-08 13:04:48 -05:00
Richard Henderson 6b4b493dae
tcg: Change tcg_global_mem_new_* to take a TCGv_ptr
Thus, use cpu_env as the parameter, not TCG_AREG0 directly.
Update all uses in the translators.

Backports commit e1ccc05444676b92c63708096e36582be27fbee1 from qemu
2018-02-08 12:33:33 -05:00
xorstream 1aeaf5c40d This code should now build the x86_x64-softmmu part 2. 2017-01-19 22:50:28 +11:00
farmdve 2304bbfc96 Remove more instances of tcg_register_jit 2016-01-07 16:39:41 +02:00
Nguyen Anh Quynh 344d016104 import 2015-08-21 15:04:50 +08:00