[LLVMdev] How doesn't llvm generate IR for logical negate operation

[Bruce Hoult]

LLVM doesn't have a "logical neg" (or "not") operator. That's a C thing. Do
a compare against 0 to create an i1 result, then zero extend the i1 to the
size of integer result you want.


On Sat, Apr 11, 2015 at 12:07 PM, zhi chen <zchenhn at gmail.com> wrote:

> How can I generate LLVM IR for both logical NEG (!)? For example, if I
> have Int32Ty a,
>
> For the bitwise NEG(~):
>
> c = ~a ;
>
> I can use the following API from LLVM:
>
> BinaryOperator *neg = BinaryOperator::CreateNeg(nbits, "bitwiseNEG", insertBefore);
>
> How, if I want to generate logical NEG:
>
> c = !a;
>
> what should I do for this?
>
> Thanks
>
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