/[NO]SYNCHRONOUS_EXCEPTIONS Controls whether an exception is associated with the instruction that caused it. Specifying /SYNCHRONOUS_EXCEPTIONS slows program execution, so only use it when debugging a specific problem, such as locating the source of an exception. The default, /NOSYNCHRONOUS_EXCEPTIONS, is used where exceptions can be reported imprecisely one or more instructions after the instruction that caused the exception. Specifying /IEEE_MODE=FAST (the default) provides imprecise exception reporting (same as /NOSYNCHRONOUS_EXCEPTIONS). Specifying other /IEEE_MODE keywords provides precise exception reporting (same as /SYNCHRONOUS_EXCEPTIONS).