[LLVMdev] signext on function parameters and return.

[Steve King]

Hello,
For a simple function taking a short and returning a short, clang
generates IR with this function signature:

define signext i16 @foo(i16 signext %x)

Some questions please:

1) For the input parameter and return value, does the target control
whether clang uses signext vs something else?  If so, how does this
target query work?

2) Does the presence of the signext mean it's imperative to sign
extend, or that extension, only if needed, should be signed?

Thanks,
-steve