[v2] target/s390x: Implement DIVIDE TO INTEGER

[PATCH v2 0/4] target/s390x: Implement DIVIDE TO INTEGER

Ilya Leoshkevich posted 4 patches 1 week, 3 days ago

Diff against v1 v3 v4
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git fetch https://github.com/patchew-project/qemu tags/patchew/20260127153736.62730-1-iii@linux.ibm.com

Maintainers: Aurelien Jarno <aurelien@aurel32.net>, Peter Maydell <peter.maydell@linaro.org>, "Alex Bennée" <alex.bennee@linaro.org>, Richard Henderson <richard.henderson@linaro.org>, Ilya Leoshkevich <iii@linux.ibm.com>, David Hildenbrand <david@kernel.org>, Thomas Huth <thuth@redhat.com>

There is a newer version of this series

fpu/softfloat.c                     | 158 ++++++++++++++++++
include/fpu/softfloat.h             |  11 ++
target/s390x/cpu-dump.c             |   1 +
target/s390x/helper.h               |   1 +
target/s390x/tcg/fpu_helper.c       | 118 ++++++++++----
target/s390x/tcg/insn-data.h.inc    |   5 +-
target/s390x/tcg/translate.c        |  26 +++
tests/tcg/s390x/Makefile.target     |   5 +
tests/tcg/s390x/divide-to-integer.c | 242 ++++++++++++++++++++++++++++
9 files changed, 535 insertions(+), 32 deletions(-)
create mode 100644 tests/tcg/s390x/divide-to-integer.c

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[PATCH v2 0/4] target/s390x: Implement DIVIDE TO INTEGER

Posted by Ilya Leoshkevich 1 week, 3 days ago

v1: https://lore.kernel.org/qemu-devel/20260121222116.713325-1-iii@linux.ibm.com/
v1 -> v2: Move the implementatation to fpu/ and rewrite using
          FloatParts (Richard). I can't say I particularly like the way
          it looks, but at least most macros are gone and it survives
          fuzzing.
          Explain why we need -O0 for the test (Alex).
          New patch: s390_get_bfp_rounding_mode().
          Add a few comments with calculation examples to the test.

Hi,

This series implements DIVIDE TO INTEGER instruction, which is
required to run LuaJIT.

Patch 1 is a debugging helper, patch 2 is a small refactoring, patch 3
is the implementation.

Since the instruction is quite complex, I've extensively tested it
using a libFuzzer-based harness [1] that compares emulation with native
execution at ~15k exec/s. The tests (patch 4) use data generated
this way.

Best regards,
Ilya

Ilya Leoshkevich (4):
  target/s390x: Dump Floating-Point-Control Register
  target/s390x: Extract s390_get_bfp_rounding_mode()
  target/s390x: Implement DIVIDE TO INTEGER
  tests/tcg/s390x: Test DIVIDE TO INTEGER

 fpu/softfloat.c                     | 158 ++++++++++++++++++
 include/fpu/softfloat.h             |  11 ++
 target/s390x/cpu-dump.c             |   1 +
 target/s390x/helper.h               |   1 +
 target/s390x/tcg/fpu_helper.c       | 118 ++++++++++----
 target/s390x/tcg/insn-data.h.inc    |   5 +-
 target/s390x/tcg/translate.c        |  26 +++
 tests/tcg/s390x/Makefile.target     |   5 +
 tests/tcg/s390x/divide-to-integer.c | 242 ++++++++++++++++++++++++++++
 9 files changed, 535 insertions(+), 32 deletions(-)
 create mode 100644 tests/tcg/s390x/divide-to-integer.c

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2.52.0