some scripts expect an "unknown operator" for negative alignment

[redianthus]

Hi,

I'm currently adding SIMD support in Owi. I'm using the reference test suite, which contains some test cases where a "unknown operator" error is expected when a module contains v128.load align=-1 (a negative alignment). Is it on purpose? Wouldn't it be better to switch to "alignment must be positive" or something similar?

[rossberg]

That's just the generic error message produced by the lexer when encountering a character sequence that is not recognised as a token (align=n is a single token). It would require a special case in the lexer to produce another message.

[redianthus]

OK, thanks, I understand.

I just found out another case I'm not sure about. In the simd_lane.wast file, there are two tests:

(assert_malformed (module quote "(func (result v128)"
  "(i8x16.shuffle 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 -1"
  "(v128.const i8x16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0)"
  "(v128.const i8x16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15)))") "i8 constant out of range")

And

(assert_malformed (module quote "(func (result i32) (i8x16.extract_lane_s  -1 (v128.const i8x16 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0)))") "unexpected token")

Why in one case the negative lane index is being considered as an "i8 constant out of range" and as an "unexpected token" in the other one?

[redianthus]

And a second one similar:

(assert_malformed (module quote "(func (result v128) "
  "(i8x16.shuffle 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15.0 "
  "(v128.const i8x16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0) "
  "(v128.const i8x16 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15)))") "i8 constant out of range")

Here, 15.0 fails with "i8 constant out of range", whereas here:

(assert_malformed (module quote "(func (result i32) (i8x16.extract_lane_s 1.5 (v128.const i8x16 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0)))") "unexpected token")

The 1.5 fails with "unexpected token".