[llvm-commits] [llvm] r60366 - /llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

[Duncan Sands]

Hi Bill,

> Use a simple comparison. Overflow on integer negation can only occur when the
> integer is "minint".

to check whether X is "minint", regardless of whether X is constant or not, you
can call ComputeMaskedBits.  If any bit (except for the sign bit) is known to be 1,
then X is not equal to minint.  If the sign bit is known to be 0, then also X is
not equal to minint.

Ciao,

Duncan.