[LLVMdev] Troubling promotion of return value to Integer ...
sabre at nondot.org
Thu Jun 5 23:44:04 PDT 2008
On Jun 5, 2008, at 11:33 PM, Evan Cheng wrote:
> On Jun 4, 2008, at 11:12 AM, Chris Lattner wrote:
>> n Jun 4, 2008, at 10:52 AM, Evan Cheng wrote:
>>> On May 29, 2008, at 10:30 AM, Alireza.Moshtaghi at microchip.com wrote:
>>>> 4) There will be 4 new function attributes:
>>>> sign_ext_from_i8, sign_ext_from_i16
>>>> zero_ext_from_i8, zero_ext_from_i16
>>>> These attributes will be placed on the function CALL node by
>>>> to inform the backend about such promotions and enable optimization
>>>> return value. This should be sufficient for direct and indirect
>>>> (syntax of these attributes to be defined)
>>> Should we go one step further and provide an attribute whose value
>>> the "original type" before the extension?
>> What would that mean? Can you give an example?
> Well, you suggested sext / zext from i8 / i16. Why not from i1 (useful
> for denoting boolean type) or any arbitrary type?
Are you suggesting adding 'sign_ext_from_i1' and 'zero_ext_from_i1'
attributes? I'd be fine with that. It would also solve some existing
code quality issues we have.
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