qemu-aarch64: wrong execution result when executing the code

Host environment

• Operating system: Ubuntu 22.04.4 LTS
• OS/kernel version: Linux vm 6.5.0-26-generic #26~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Mar 12 10:22:43 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
• Architecture: x86_64
• QEMU flavor: qemu-aarch64
• QEMU version: 8.2.1, 8.2.2, 9.0.0-rc0, latest commit 6a4180af
• QEMU command line: qemu-aarch64 -L /usr/aarch64-linux-gnu -E LD_LIBRARY_PATH=/usr/aarch64-linux-gnu/lib foo

Emulated/Virtualized environment

Runs on QEMU user mode

Description of problem

The following aarch64 code results in the wrong execution result 4611686018427387903, which is 0x3fffffffffffffff. (The correct result is -1) The bug seems to be introduced in between v8.1.5 and v8.2.1 since the results are correct in v8.1.5.

// foo.c
#include <stdio.h>
#include <stdint.h>

int64_t callme(size_t _1, size_t _2, int64_t a, int64_t b, int64_t c);

int main() {
    int64_t ret = callme(0, 0, 0, 1, 2);
    printf("%ld\n", ret);
    return 0;
}

// foo.S
.global callme
callme:
  cmp   x2, x3
  cset  x12, lt
  and   w11, w12, #0xff
  cmp   w11, #0x0
  csetm x14, ne
  lsr   x13, x14, x4
  sxtb  x0, w13
  ret

Steps to reproduce

1. Build the code with aarch64-linux-gnu-gcc foo.c foo.S -o foo (aarch64-linux-gnu-gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0)
2. Run the code with qemu-aarch64 -L /usr/aarch64-linux-gnu -E LD_LIBRARY_PATH=/usr/aarch64-linux-gnu/lib foo and see the result

Additional information

• Original discussion is held in this wasmtime issue. Thanks to Alex Crichton for clarifying this bug.