Almost 7 years ago I detailed 5 major problems in tci[1], of
which three still remain:
* Unaligned accesses to the bytecode stream, which means
that we immediately SIGBUS on any host requiring alignment.
* Non-portable calls to helper functions.
* Full of useless ifdefs and TODOs.
To my mind, this means the code is unmaintained, despite what it
says in MAINTAINERS. Thus tci *should* be simply removed.
However, every time removal is suggested, someone comes out of the
woodwork and says we should keep it, because it's useful for $FOO.
Anyway, if we're not going to remove tci, then we have to fix it.
Previously, I rewrote tci all in one lump. Which was obviously a
mistake, since it meant that the patch was never going to get
reviewed. This time I've done the rewrite in tiny pieces.
Previously, I invented a moderately complex encoding scheme that
allowed any operand to encode a register or an int32_t immediate.
This time the encoding is quite simple: with only 4 exceptions
all operands encoded into 4-bit slots (registers & conditions).
I rely on the new TEMP_CONST optimization to do a decent job of
loading an immediate value into a register once (via movi), and
reusing that across the TB.
There is a disassembler built into tcg/tci.c, replacing the stub
in disas/tci.c, which reuses the same decoding helpers that are
used by the interpreter. So finally -d out_asm is useful.
This is good enough to pass make check check-tcg with all of the
docker cross-compilers enabled. I can boot linux with aarch64,
alpha, and s390x guests.
r~
Based-on: 20210203021550.375058-1-richard.hender...@linaro.org
("[PULL 00/24] tcg patch queue")
[1] https://lists.gnu.org/archive/html/qemu-devel/2014-05/msg02594.html
Richard Henderson (91):
gdbstub: Fix handle_query_xfer_auxv
tcg: Split out tcg_raise_tb_overflow
configure: Fix --enable-tcg-interpreter
tcg: Manage splitwx in tc_ptr_to_region_tree by hand
tcg/tci: Make tci_tb_ptr thread-local
tcg/tci: Inline tci_write_reg32s into the only caller
tcg/tci: Inline tci_write_reg8 into its callers
tcg/tci: Inline tci_write_reg16 into the only caller
tcg/tci: Inline tci_write_reg32 into all callers
tcg/tci: Inline tci_write_reg64 into 64-bit callers
tcg/tci: Merge INDEX_op_ld8u_{i32,i64}
tcg/tci: Merge INDEX_op_ld8s_{i32,i64}
tcg/tci: Merge INDEX_op_ld16u_{i32,i64}
tcg/tci: Merge INDEX_op_ld16s_{i32,i64}
tcg/tci: Merge INDEX_op_{ld_i32,ld32u_i64}
tcg/tci: Merge INDEX_op_st8_{i32,i64}
tcg/tci: Merge INDEX_op_st16_{i32,i64}
tcg/tci: Move stack bounds check to compile-time
tcg/tci: Merge INDEX_op_{st_i32,st32_i64}
tcg/tci: Use g_assert_not_reached
tcg/tci: Remove dead code for TCG_TARGET_HAS_div2_*
tcg/tci: Implement 64-bit division
tcg/tci: Remove TODO as unused
tcg/tci: Restrict TCG_TARGET_NB_REGS to 16
tcg/tci: Fix TCG_REG_R4 misusage
tcg/tci: Use bool in tcg_out_ri*
tcg/tci: Remove TCG_CONST
tcg/tci: Merge identical cases in generation
tcg/tci: Remove tci_read_r8
tcg/tci: Remove tci_read_r8s
tcg/tci: Remove tci_read_r16
tcg/tci: Remove tci_read_r16s
tcg/tci: Remove tci_read_r32s
tcg/tci: Reduce use of tci_read_r64
tcg/tci: Merge basic arithmetic operations
tcg/tci: Merge extension operations
tcg/tci: Remove ifdefs for TCG_TARGET_HAS_ext32[us]_i64
tcg/tci: Merge bswap operations
tcg/tci: Merge mov, not and neg operations
tcg/tci: Rename tci_read_r to tci_read_rval
tcg/tci: Split out tci_args_rrs
tcg/tci: Split out tci_args_rr
tcg/tci: Split out tci_args_rrr
tcg/tci: Split out tci_args_rrrc
tcg/tci: Split out tci_args_l
tcg/tci: Split out tci_args_rrrrrc
tcg/tci: Split out tci_args_rrcl and tci_args_rrrrcl
tcg/tci: Split out tci_args_ri and tci_args_rI
tcg/tci: Reuse tci_args_l for calls.
tcg/tci: Reuse tci_args_l for exit_tb
tcg/tci: Reuse tci_args_l for goto_tb
tcg/tci: Split out tci_args_rrrrrr
tcg/tci: Split out tci_args_rrrr
tcg/tci: Clean up deposit operations
tcg/tci: Reduce qemu_ld/st TCGMemOpIdx operand to 32-bits
tcg/tci: Split out tci_args_{rrm,rrrm,rrrrm}
tcg/tci: Hoist op_size checking into tci_args_*
tcg/tci: Remove tci_disas
tcg/tci: Implement the disassembler properly
tcg: Build ffi data structures for helpers
tcg/tci: Use ffi for calls
tcg/tci: Improve tcg_target_call_clobber_regs
tcg/tci: Move call-return regs to end of tcg_target_reg_alloc_order
tcg/tci: Push opcode emit into each case
tcg/tci: Split out tcg_out_op_rrs
tcg/tci: Split out tcg_out_op_l
tcg/tci: Split out tcg_out_op_p
tcg/tci: Split out tcg_out_op_rr
tcg/tci: Split out tcg_out_op_rrr
tcg/tci: Split out tcg_out_op_rrrc
tcg/tci: Split out tcg_out_op_rrrrrc
tcg/tci: Split out tcg_out_op_rrrbb
tcg/tci: Split out tcg_out_op_rrcl
tcg/tci: Split out tcg_out_op_rrrrrr
tcg/tci: Split out tcg_out_op_rrrr
tcg/tci: Split out tcg_out_op_rrrrcl
tcg/tci: Split out tcg_out_op_{rrm,rrrm,rrrrm}
tcg/tci: Split out tcg_out_op_v
tcg/tci: Split out tcg_out_op_np
tcg/tci: Split out tcg_out_op_r[iI]
tcg/tci: Reserve r13 for a temporary
tcg/tci: Emit setcond before brcond
tcg/tci: Remove tci_write_reg
tcg/tci: Change encoding to uint32_t units
tcg/tci: Implement goto_ptr
tcg/tci: Implement movcond
tcg/tci: Implement andc, orc, eqv, nand, nor
tcg/tci: Implement extract, sextract
tcg/tci: Implement clz, ctz, ctpop
tcg/tci: Implement mulu2, muls2
tcg/tci: Implement add2, sub2
Stefan Weil (2):
tcg/tci: Implement INDEX_op_ld16s_i32
tcg/tci: Implement INDEX_op_ld8s_i64
configure | 5 +-
meson.build | 9 +-
include/exec/exec-all.h | 2 +-
include/exec/helper-ffi.h | 115 ++
include/exec/helper-tcg.h | 24 +-
include/tcg/tcg-opc.h | 6 +-
include/tcg/tcg.h | 1 +
target/hppa/helper.h | 2 +
target/i386/ops_sse_header.h | 6 +
target/m68k/helper.h | 1 +
target/ppc/helper.h | 3 +
tcg/tci/tcg-target-con-set.h | 8 +-
tcg/tci/tcg-target.h | 118 +-
disas/tci.c | 61 -
gdbstub.c | 17 +-
tcg/tcg-common.c | 4 -
tcg/tcg.c | 117 +-
tcg/tci.c | 1695 +++++++++++++-----------
tcg/tci/tcg-target.c.inc | 989 +++++++-------
tcg/tci/README | 20 +-
tests/docker/dockerfiles/fedora.docker | 1 +
21 files changed, 1734 insertions(+), 1470 deletions(-)
create mode 100644 include/exec/helper-ffi.h
delete mode 100644 disas/tci.c
--
2.25.1
