[LLVMdev] Fwd: Re: NaNs and Infinities

Javier Martinez javier at jmartinez.org
Tue Apr 20 10:28:29 PDT 2010

I forgot to forward to the rest of the list...

-------- Original Message --------
Subject: Re: [LLVMdev] NaNs and Infinities
Date: Mon, 19 Apr 2010 23:41:43 -0700
From: Javier Martinez <javier at jmartinez.org>
To: lost <lostfreeman at gmail.com>


If it's an immediate you can cast the SDValue to a ConstantFP and use 
the isNaN() or isInfinity() member functions (see below). For non 
immediates you can use bitcasting to convert the float to an integer. If 
bits 0-22 are 0 and bits 23-30 are 1 it's infinity; if bits 0-22 are not 
0 and bits 23-30 are 1 it's NaN. Others can probably give you a answer 
and if not at least you have mine.
ConstantFM *CFP = dyn_cast<ConstantFP>(myValue);
if (CFP != NULL) {
} else {
   // Bitcast to an integer at test bits


On 4/19/2010 3:19 AM, lost wrote:
> Hello!
> How can I test if floating-point value is NaN or positive/negative
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