[cfe-dev] Why does ABI on amd64 require bit extension of function arguments smaller than 32 bits?

[Yuri via cfe-dev]

On 11/04/2016 16:37, Joerg Sonnenberger via cfe-dev wrote:
> The calle is required to do the expansion. The attributes just reflect
> what the content is the registers are supposed to be.


Yes, signext and zeroext require the caller to do the expansion. I am 
asking why it's not the callee who should do the expansion. It seems 
that it would have been more efficient if callee did the expansion.


Yuri