id = 2089
title = "aarch64: incorrect emulation of sqshrn instruction"
state = "closed"
created_at = "2024-01-10T06:30:57.404Z"
closed_at = "2024-01-27T13:00:19.852Z"
labels = ["accel: TCG", "target: arm", "workflow::Patch available"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/2089"
host-os = "Debian"
host-arch = "x86_64"
qemu-version = "qemu-aarch64 version 8.1.2 (Debian 1:8.1.2+ds-1)"
guest-os = "same as host"
guest-arch = "aarch64"
description = """`sqshrn` instruction test fails with qemu-aarch64, but passes on real aarch64 hardware."""
reproduce = """1. Build [inline_asm_tests](https://cs.android.com/android/platform/superproject/main/+/main:frameworks/libs/binary_translation/tests/inline_asm_tests/) and run with qemu-aarch64
2. Observe two failures

```
[ RUN      ] Arm64InsnTest.SignedSaturatingShiftRightNarrowInt16x1
frameworks/libs/binary_translation/tests/inline_asm_tests/main_arm64.cc:6697: Failure
Expected equality of these values:
  res1
    Which is: 4294967188
  MakeUInt128(0x94U, 0U)
    Which is: 148
[  FAILED  ] Arm64InsnTest.SignedSaturatingShiftRightNarrowInt16x1 (5 ms)
[ RUN      ] Arm64InsnTest.SignedSaturatingRoundingShiftRightNarrowInt16x1
frameworks/libs/binary_translation/tests/inline_asm_tests/main_arm64.cc:6793: Failure
Expected equality of these values:
  res3
    Which is: 4294967168
  MakeUInt128(0x0000000000000080ULL, 0x0000000000000000ULL)
    Which is: 128
[  FAILED  ] Arm64InsnTest.SignedSaturatingRoundingShiftRightNarrowInt16x1 (2 ms)
```"""
additional = """[Direct link to SignedSaturatingShiftRightNarrowInt16x1 test source](https://cs.android.com/android/platform/superproject/main/+/main:frameworks/libs/binary_translation/tests/inline_asm_tests/main_arm64.cc;l=6692;drc=4ee2c3035fa5dc0b7a48b6c6dc498296be071861)"""