This makes use of the changes introduced in D134604, in order to
instantiate alias templates witn a final sugared substitution.
This comes at no additional relevant cost.
Since we don't track / unique them in specializations, we wouldn't be
able to resugar them later anyway.
Differential Revision: https://reviews.llvm.org/D136565
This PR reworks HLSL's implicit conversion sequences. Initially I was
seeking to match DXC's behavior more closely, but that was leading to a
pile of special case rules to tie-break ambiguous cases that should
really be left as ambiguous. We've decided that we're going to break
compatibility with DXC here, and we may port this new behavior over to
DXC instead.
This change is a bit closer to C++'s overload resolution rules, but it
does have a bit of nuance around how dimension adjustment conversions
are ranked. Conversion sequence ranks for HLSL are:
* Exact match
* Scalar Widening (i.e. splat)
* Promotion
* Scalar Widening with Promotion
* Conversion
* Scalar Widening with Conversion
* Dimension Reduction (i.e. truncation)
* Dimension Reduction with Promotion
* Dimension Reduction with Conversion
In this implementation I've folded the disambiguation into the
conversion sequence ranks which does add some complexity as compared to
C++, however this avoids needing to add special casing in
`CompareStandardConversionSequences`. I believe the added conversion
rank values provide a simpler approach, but feedback is appreciated.
The HLSL language spec updates are in the PR here:
https://github.com/microsoft/hlsl-specs/pull/261
In HLSL we really want to be using the HLSL vector template and other
built-in sugared spellings for some builtin types. This updates the type
printer to take an option to use HLSL type spellings.
This changes printing vector type names from:
```
T __attribute__((ext_vector_type(N)))
```
To:
```
vector<T, N>
```
This PR brings best practices mentioned to me on other prs and adds them
to the existing builtin tests.
Note to reviewers: I put this up in two commits because the clang-format
changes is making it hard to tell what actually changed.
use the first commit to check for correctness.
There are two issues here. first `ICK_Floating_Integral` were always
defaulting to `CK_FloatingToIntegral` for vectors regardless of
direction of cast. Check was scalar only so added a vec float check to
the conditional.
Second issue was float to int casts were resolving to
ICK_Integral_Promotion when they need to be resolving to
CK_FloatingToIntegral. This was fixed by changing the ordering of
conversion checks.
This fixes#82826
HLSL supports vector truncation and element conversions as part of
standard conversion sequences. The vector truncation conversion is a C++
second conversion in the conversion sequence. If a vector truncation is
in a conversion sequence an element conversion may occur after it before
the standard C++ third conversion.
Vector element conversions can be boolean conversions, floating point or
integral conversions or promotions.
[HLSL Draft
Specification](https://microsoft.github.io/hlsl-specs/specs/hlsl.pdf)
---------
Co-authored-by: Aaron Ballman <aaron@aaronballman.com>
