fix undefined left shift of negative int in math.bitShiftLeft#2044
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sahvx655-wq wants to merge 1 commit into
Open
fix undefined left shift of negative int in math.bitShiftLeft#2044sahvx655-wq wants to merge 1 commit into
sahvx655-wq wants to merge 1 commit into
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Noticed bitShiftLeft shifts a signed int64 directly while bitShiftRight goes through an unsigned bit_cast first. For a negative left operand like math.bitShiftLeft(-1, 1) that signed left shift is undefined behaviour, which ubsan flags as left shift of negative value. Shifting in the unsigned domain the way the right shift already does keeps the same bit pattern result without the UB. Added a couple of negative-operand cases to the runtime tests since they weren't covered before.