[LLVMdev] Troubling promotion of return value to Integer ...

[Duncan Sands]

Hi Evan,

> If you are using a non-C ABI, then you may not need to do the  
> promotion at all. However, if you do need to do the promotion, you  
> need to know the type of "int".

how does this work for parameters.  Suppose I have an i1 parameter.
The AMD64 ABI says it is passed in one of %rsi, %rdx, %rcx, %r8 and
%r9 registers.  In the case of _Bool (i1) it says that the upper 63
bits will be zero.  How does this work?  I thought i1 would be legalized
to i8 (which is legal, right?).  Due to being marked zext, the upper
7 bits of the i8 will be zero.  But where does it get extended to
an i64 with upper 63 bits zero?

Thanks,

Duncan.