[PATCH v2 00/29] tcg: bswap improvements

[Richard Henderson]

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.

Changes for v2:
  * Merge tcg_out_rev{16,32,64}, which perhaps solves the issue of
    mnemonics vs actual opcodes, and also preps for Phil suggestion
    of adding additional tcg opcodes for hswap and wswap operations.
  * Improve comments for ppc bswap.
  * Improve README entries.

Patches lacking review/ack:

  03-tcg-aarch64-Merge-tcg_out_rev-16-32-64.patch
  11-tcg-ppc-Support-bswap-flags.patch
  12-tcg-ppc-Use-power10-byte-reverse-instructions.patch
  13-tcg-s390-Support-bswap-flags.patch
  14-tcg-mips-Support-bswap-flags-in-tcg_out_bswap16.patch


r~


Richard Henderson (29):
  tcg: Add flags argument to bswap opcodes
  tcg/i386: Support bswap flags
  tcg/aarch64: Merge tcg_out_rev{16,32,64}
  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/tcg.c                       |  28 +++
 tcg/tci.c                       |   3 +-
 tcg/aarch64/tcg-target.c.inc    | 125 ++++++--------
 tcg/arm/tcg-target.c.inc        | 295 ++++++++++++++------------------
 tcg/i386/tcg-target.c.inc       |  20 ++-
 tcg/mips/tcg-target.c.inc       |  99 +++++------
 tcg/ppc/tcg-target.c.inc        | 230 +++++++++++++++++--------
 tcg/riscv/tcg-target.c.inc      |  64 +++----
 tcg/s390/tcg-target.c.inc       |  34 +++-
 tcg/tci/tcg-target.c.inc        |  23 ++-
 tcg/README                      |  22 ++-
 24 files changed, 702 insertions(+), 526 deletions(-)

-- 
2.25.1