Compiler failure on ARM64 Windows

[targos]

Compiler failure on ARM64 Windows

[lemire]

The issue has been fixed in 5.2.4. I suspect it is a bug in Visual Studio, but we have a workaround.

[lemire]

Note that we do have Visual Studio ARM tests in CI: https://github.com/simdutf/simdutf/blob/master/.github/workflows/vs17-arm-ci.yml

[lemire]

It says that it fails on the last line:

  constexpr static uint8_t source_table[64] = {
      'A', 'Q', 'g', 'w', 'B', 'R', 'h', 'x', 'C', 'S', 'i', 'y', 'D',
      'T', 'j', 'z', 'E', 'U', 'k', '0', 'F', 'V', 'l', '1', 'G', 'W',
      'm', '2', 'H', 'X', 'n', '3', 'I', 'Y', 'o', '4', 'J', 'Z', 'p',
      '5', 'K', 'a', 'q', '6', 'L', 'b', 'r', '7', 'M', 'c', 's', '8',
      'N', 'd', 't', '9', 'O', 'e', 'u', '+', 'P', 'f', 'v', '/',
  };
  constexpr static uint8_t source_table_url[64] = {
      'A', 'Q', 'g', 'w', 'B', 'R', 'h', 'x', 'C', 'S', 'i', 'y', 'D',
      'T', 'j', 'z', 'E', 'U', 'k', '0', 'F', 'V', 'l', '1', 'G', 'W',
      'm', '2', 'H', 'X', 'n', '3', 'I', 'Y', 'o', '4', 'J', 'Z', 'p',
      '5', 'K', 'a', 'q', '6', 'L', 'b', 'r', '7', 'M', 'c', 's', '8',
      'N', 'd', 't', '9', 'O', 'e', 'u', '-', 'P', 'f', 'v', '_',
  };
  const uint8x16_t v3f = vdupq_n_u8(0x3f);
  const uint8x16x4_t table =
      vld4q_u8((options & base64_url) ? source_table_url : source_table);

The function signature for vld4q_u8 is vld4q_u8(uint8_t const * ptr). So this looks correct to me...

https://developer.arm.com/architectures/instruction-sets/intrinsics/vld4q_u8

Let me spin up my ARM-based Windows box.

[lemire]

Issue verified.

Puzzling. I don't understand.

[lemire]

The next release will contain a fix.

[targos]

Thanks for the quick fix

[lemire]

@targos I bought a Windows-based ARM machine specifically for this purpose. It is kind of nice and it is interesting to be able to run Windows on ARM.

(Note: I also like x64, I like all processors equally.)