This has been on my to-do list for several years, and I've
finally spent a rainy weekend doing something about it.
The current tcg bswap opcode is fairly strict: for swaps smaller
than the TCGv size, it requires zero-extended input and provides
zero-extended output.
This has meant that various tcg/ backends have their own handling
of bswap when it comes to memory, to minimize overhead for stores
(which do not care about zero-extended output) or for signed loads
(which would rather not sign-extend after zero-extending).
Solve this by adding some operation flags to the tcg bswap opcode:
TCG_BSWAP_IZ -- Input is Zero extended
TCG_BSWAP_OZ -- Output is Zero extended
TCG_BSWAP_OS -- Output is Sign extended
For instance, bswap before store would not set any of these flags,
allowing unextended input and producing unextended output.
The patch set can be broken into sections:
* patches 1 - 16 implement the functionality in the backend,
but do not provide the interface to use it,
* patch 17 enables the interface,
* patches 18 - 25 use the new interface in the front ends
* patches 26 - 28 remove some tcg backend complexity,
leaving the bswap handling to the middle-end.
r~
Richard Henderson (28):
tcg: Add flags argument to bswap opcodes
tcg/i386: Support bswap flags
tcg/aarch64: Support bswap flags
tcg/arm: Support bswap flags
tcg/ppc: Split out tcg_out_ext{8,16,32}s
tcg/ppc: Split out tcg_out_sari{32,64}
tcg/ppc: Split out tcg_out_bswap16
tcg/ppc: Split out tcg_out_bswap32
tcg/ppc: Split out tcg_out_bswap64
tcg/ppc: Support bswap flags
tcg/ppc: Use power10 byte-reverse instructions
tcg/s390: Support bswap flags
tcg/mips: Support bswap flags in tcg_out_bswap16
tcg/mips: Support bswap flags in tcg_out_bswap32
tcg/tci: Support bswap flags
tcg: Handle new bswap flags during optimize
tcg: Add flags argument to tcg_gen_bswap16_*, tcg_gen_bswap32_i64
tcg: Make use of bswap flags in tcg_gen_qemu_ld_*
tcg: Make use of bswap flags in tcg_gen_qemu_st_*
target/arm: Improve REV32
target/arm: Improve vector REV
target/arm: Improve REVSH
target/i386: Improve bswap translation
target/sh4: Improve swap.b translation
target/mips: Fix gen_mxu_s32ldd_s32lddr
tcg/arm: Unset TCG_TARGET_HAS_MEMORY_BSWAP
tcg/aarch64: Unset TCG_TARGET_HAS_MEMORY_BSWAP
tcg/riscv: Remove MO_BSWAP handling
include/tcg/tcg-op.h | 8 +-
include/tcg/tcg-opc.h | 10 +-
include/tcg/tcg.h | 12 ++
tcg/aarch64/tcg-target.h | 2 +-
tcg/arm/tcg-target.h | 2 +-
target/arm/translate-a64.c | 21 +--
target/arm/translate.c | 4 +-
target/i386/tcg/translate.c | 14 +-
target/mips/tcg/mxu_translate.c | 6 +-
target/s390x/translate.c | 4 +-
target/sh4/translate.c | 3 +-
tcg/optimize.c | 56 ++++++-
tcg/tcg-op.c | 143 +++++++++++------
tcg/tci.c | 3 +-
tcg/aarch64/tcg-target.c.inc | 99 +++++-------
tcg/arm/tcg-target.c.inc | 272 ++++++++++++--------------------
tcg/i386/tcg-target.c.inc | 20 ++-
tcg/mips/tcg-target.c.inc | 99 ++++++------
tcg/ppc/tcg-target.c.inc | 199 ++++++++++++++---------
tcg/riscv/tcg-target.c.inc | 64 ++++----
tcg/s390/tcg-target.c.inc | 34 +++-
tcg/tci/tcg-target.c.inc | 23 ++-
tcg/README | 18 ++-
23 files changed, 607 insertions(+), 509 deletions(-)
--
2.25.1
