Created attachment 464819 [details] testcase for reproduce Attached testcase prints different result depending on whether BaselineJIT is enabled/disabled. I'm not sure this case is a bug. Can you please check it out? - Tested version: WebKit-7615.1.18.8 (commit hash: b0db89e8f5e9d65a74fac732b3a90dc444ed3a42) - Steps to reproduce: - with JIT: `jsc --validateOptions=true --thresholdForJITSoon=10 --thresholdForJITAfterWarmUp=10 --thresholdForOptimizeAfterWarmUp=100 --thresholdForOptimizeAfterLongWarmUp=100 --thresholdForOptimizeSoon=100 --thresholdForFTLOptimizeAfterWarmUp=1000 --thresholdForFTLOptimizeSoon=1000 --validateBCE=true --forceWeakRandomSeed=true --forcedWeakRandomSeed=1 poc.js` - without BaselineJIT: `jsc --validateOptions=true --thresholdForJITSoon=10 --thresholdForJITAfterWarmUp=10 --thresholdForOptimizeAfterWarmUp=100 --thresholdForOptimizeAfterLongWarmUp=100 --thresholdForOptimizeSoon=100 --thresholdForFTLOptimizeAfterWarmUp=1000 --thresholdForFTLOptimizeSoon=1000 --validateBCE=true --forceWeakRandomSeed=true --forcedWeakRandomSeed=1 --useBaselineJIT=false poc.js` - Actual results: - with JIT: - prints "-1" 15 times - without JIT: - prints "-1" 16 times (or ) ** changing N in `while (v1 < N) { ...` to 1, produces stdout randomly like: - with JIT: "-1\n-1\nException: ReferenceError: Can't find variable: v0\nglobal code@" or "-1" - without BaselineJIT: "-1"
<rdar://problem/105102438>
There's no bug here. The test itself has variable behavior. It spawns a thread that prints more output. However, that thread is in a race against the main thread that will terminate the process. Depending on where the main thread terminates the process, the other thread may or may not have gotten in a few more prints. Hence, the code is behaving correctly. The test is just bad.