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ivica.bogosavljevic authored
Port de369129 Original commit message: In the current implementation of wasm an unrepresentable input of the float32-to-int32 conversion is detected by first truncating the input, then converting the truncated input to int32 and back to float32, and then checking whether the result is the same as the truncated input. This input check does not work on arm and arm64 for an input of (INT32_MAX + 1) because on these platforms the float32-to-int32 conversion results in INT32_MAX if the input is greater than INT32_MAX. When INT32_MAX is converted back to float32, then the result is (INT32_MAX + 1) again because INT32_MAX cannot be represented precisely as float32, and rounding-to-nearest results in (INT32_MAX + 1). Since (INT32_MAX + 1) equals the truncated input value, the input appears to be representable. With the changes in this CL, the result of the float32-to-int32 conversion is incremented by 1 if the original result was INT32_MAX. Thereby the detection of unrepresenable inputs in wasm works. Note that since INT32_MAX cannot be represented precisely in float32, it can also never be a valid result of the float32-to-int32 conversion. BUG=cctest/test-run-wasm/RunWasmCompiled_I32SConvertF32,cctest/test-run-wasm/RunWasmCompiled_I32UConvertF32 Review-Url: https://codereview.chromium.org/2130763002 Cr-Commit-Position: refs/heads/master@{#37586}
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