[LLVMdev] Illegal pointer type
evan.cheng at apple.com
Fri Sep 19 12:12:09 CDT 2008
I am assuming a 16-bit value will be stored in a pair of 8-bit
registers? If so, add pseudo register which represent pairs of 8-bit
registers. Add them to a pseudo register class. This allows you to
mark i16 "legal".
The difficult part is then to figure out how to lower these 16-bit
operations into 8-bit ones. You probably need to custom lower a bunch
of them with target specific code.
On Sep 19, 2008, at 5:01 AM, Sachin.Punyani at microchip.com wrote:
>> -----Original Message-----
>> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-
>> bounces at cs.uiuc.edu]
>> Behalf Of Bill Wendling
>> Sent: Friday, September 19, 2008 4:38 AM
>> On Thu, Sep 18, 2008 at 7:12 AM, <Sachin.Punyani at microchip.com>
>>> What changes would be required in LLVM to support illegal pointer
>> Hi Sachin,
>> The question's a bit broad. And I don't think the answer you want is
>> as simple as "don't run the legalizer" (which probably won't work).
>> you have a more specific question?
> I am trying to ask a broad question. My target has 16 bit pointers but
> register size is 8 bit only. What changes in LLVM would be required to
> support 16 bit pointers on 8 bit registers?
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>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
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