On Wed, Aug 9, 2017 at 3:06 PM, Luc Van Oostenryck
<luc.vanoostenryck@xxxxxxxxx> wrote:
>
> I have but I never posted it yet.
> Basically, I have specialized them:
> - TRUNC, ZEXT & SEXT: truncate (may be not neede), zero & sign extend
> for integers
Makes sense.
And yes, I think we could skip TRUNC (casting to a smaller type is one
of those questionable things we do now).
Our IR doesn't really have any well-defined form for upper bits anyway
(ie there's no guarantee that values are zero-extended or
sign-extended to the full register width in the IR), so "TRUNC"
doesn't really have any sane semantics.
> - PTRU & UPTR: conversion pointer from/to unsigned integer (not sure
> it's needed)
So this is a separate thing that doesn't take a size?
So a "int to ptr" conversion on a 64-bit architecture would be a
combination of SEXT.64 and a UPTR?
If so, then yes, I think that's the right thing to do (and then in
basically all cases the PTRU/UPTR just goes away).
Or, like TRUNC, just say that pointers simply *are* the same thing as
an integer of the same size, and PTRU/UPTR just doesn't exist at all.
> - FCVTU & FCVTS: convert float to unsigned/signed integers
> - UCVTF & SCVTF: convert int to float
> - FCVTF: float to float convert (maybe even better/simpler with FTRUNC
> & FEXT ?à)
>
> The main objective being to make things more explicit a avoid to have
> to test the orig-type at each time.
Yes. I think what you describe is the right thing to do. The current
casting is just wrong and nasty, and has too much implicit stuff.
Linus
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