[Qemu-devel] [PATCH v2 0/2] target/m68k: add a mechanism to automatically free TCGv

[Laurent Vivier]

    SRC_EA() and gen_extend() can return either a temporary
    TCGv or a memory allocated one. Mark them when they are
    allocated, and free them automatically at end of the
    instruction translation.

    We want to free locally allocated TCGv to avoid
    overflow in sequence like:

      0xc00ae406:  movel %fp@(-132),%fp@(-268)
      0xc00ae40c:  movel %fp@(-128),%fp@(-264)
      0xc00ae412:  movel %fp@(-20),%fp@(-212)
      0xc00ae418:  movel %fp@(-16),%fp@(-208)
      0xc00ae41e:  movel %fp@(-60),%fp@(-220)
      0xc00ae424:  movel %fp@(-56),%fp@(-216)
      0xc00ae42a:  movel %fp@(-124),%fp@(-252)
      0xc00ae430:  movel %fp@(-120),%fp@(-248)
      0xc00ae436:  movel %fp@(-12),%fp@(-260)
      0xc00ae43c:  movel %fp@(-8),%fp@(-256)
      0xc00ae442:  movel %fp@(-52),%fp@(-276)
      0xc00ae448:  movel %fp@(-48),%fp@(-272)
      ...

    That can fill a lot of TCGv entries in a sequence,
    especially since 15fa08f845 ("tcg: Dynamically allocate TCGOps")
    we have no limit to fill the TCGOps cache and we can fill
    the entire TCG variables array and overflow it.

v2: split patch in two (separate the patch to add
    parameter to gen_exten())
    mark to release missed gen_load() in gen_lea_indexed()

Laurent Vivier (2):
  target/m68k: add DisasContext parameter to gen_extend()
  target/m68k: add a mechanism to automatically free TCGv

 target/m68k/translate.c | 102 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 66 insertions(+), 36 deletions(-)

-- 
2.14.3