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WebAssembly / relaxed-simd

Relax the strict determinism requirements of SIMD operations.
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Fix some tests in `i32x4_relaxed_trunc.wast` #131

Closed alexcrichton closed 1 year ago

alexcrichton commented 1 year ago

This fixes some minor issues I encountered when running these tests. The first is a test for the i32x4.relaxed_trunc_f32x4_s instruction which asserted that 2147483647.0 (INT_MAX) would get translated to INT_MAX through the conversion. This float value, however, is not representable in f32. The two other closest integers that f32 can represent are 2147483648 and 2147483520, so it's not actually possible to exercise a conversion from precisely INT_MAX to INT_MAX. Due to float parsing this meant that the value was getting rounded up to 2147483648 which exceeded INT_MAX which when using cvttpd2dq on x86 would cause INT_MIN to get returning, failing the test. I updated the test to pass something in-bounds (2 in this case) since the other edge cases are already tested.

The other issue fixed in this commit is that many tests asserted that INT_MIN was a possible result but the representation of INT_MIN was missing a 0 in its hexadecimal representation, so zeros were appended.

ngzhian commented 1 year ago

Thanks for the fix! Can you please add a comment to the test regarding INT_MAX not being representable and thus not testable? That is a very useful bit of information to know when looking at the test.

alexcrichton commented 1 year ago

Sure thing!