[LLVMdev] llvm.powi intrinsic
sabre at nondot.org
Mon Nov 26 20:06:08 PST 2007
On Mon, 26 Nov 2007, Chris Lattner wrote:
>> Do any architectures have an integer power instruction of some sort?
> The purpose of this is to capture this information at a higher level,
> allowing the code generator top (eventually) lower it into an optimal
"allowing the code generator to (eventually) lower it into an optimal"
> sequence of multiplies. for example, powi(x, 9) can be lowered to:
> t = x*x;
> t2 = t*t
> result = t2*t2*x
> The code generator doesn't currently do any smart lowering, if you're
> interested in this, it would be a great place to dive in
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