[Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - add MMX/SSE/AVX/AVX512 AVG intrinsics to be used in constexpr

[RKSimon]

The PAVGB/PAVGW intrinsics can all be used in constexpr with suitable handling of the __builtin_ia32_pavg builtins inside VectorExprEvaluator::VisitCallExpr and InterBuiltin.cpp similar to #152540

_mm_avg_pu8
_mm_avg_epu8 _mm256_avg_epu8 _mm512_avg_epu8
_mm_mask_avg_epu8 _mm256_mask_avg_epu8 _mm512_mask_avg_epu8
_mm_maskz_avg_epu8 _mm256_maskz_avg_epu8 _mm512_maskz_avg_epu8

_mm_avg_pu16
_mm_avg_epu16 _mm256_avg_epu16 _mm512_avg_epu16
_mm_mask_avg_epu16 _mm256_mask_avg_epu16 _mm512_mask_avg_epu16
_mm_maskz_avg_epu16 _mm256_maskz_avg_epu16 _mm512_maskz_avg_epu16

These all just need to call APIntOps::avgCeilU - and the builtin types should probably be converted to unsigned.

[llvmbot]

Hi!

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If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: Simon Pilgrim (RKSimon)

The PAVGB/PAVGW intrinsics can all be used in constexpr with suitable handling of the __builtin_ia32_pavg builtins inside VectorExprEvaluator::VisitCallExpr similar to #152540 ``` _mm_avg_pu8 _mm_avg_epu8 _mm256_avg_epu8 _mm512_avg_epu8 _mm_mask_avg_epu8 _mm256_mask_avg_epu8 _mm512_mask_avg_epu8 _mm_maskz_avg_epu8 _mm256_maskz_avg_epu8 _mm512_maskz_avg_epu8

_mm_avg_pu16
_mm_avg_epu16 _mm256_avg_epu16 _mm512_avg_epu16
_mm_mask_avg_epu16 _mm256_mask_avg_epu16 _mm512_mask_avg_epu16
_mm_maskz_avg_epu16 _mm256_maskz_avg_epu16 _mm512_maskz_avg_epu16

These all just need to call APIntOps::avgCeilU - and the builtin types should probably be converted to unsigned.
</details>

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Simon Pilgrim (RKSimon)

The PAVGB/PAVGW intrinsics can all be used in constexpr with suitable handling of the __builtin_ia32_pavg builtins inside VectorExprEvaluator::VisitCallExpr similar to #152540 ``` _mm_avg_pu8 _mm_avg_epu8 _mm256_avg_epu8 _mm512_avg_epu8 _mm_mask_avg_epu8 _mm256_mask_avg_epu8 _mm512_mask_avg_epu8 _mm_maskz_avg_epu8 _mm256_maskz_avg_epu8 _mm512_maskz_avg_epu8

_mm_avg_pu16
_mm_avg_epu16 _mm256_avg_epu16 _mm512_avg_epu16
_mm_mask_avg_epu16 _mm256_mask_avg_epu16 _mm512_mask_avg_epu16
_mm_maskz_avg_epu16 _mm256_maskz_avg_epu16 _mm512_maskz_avg_epu16

These all just need to call APIntOps::avgCeilU - and the builtin types should probably be converted to unsigned.
</details>

[llvmbot]

@llvm/issue-subscribers-backend-x86

Author: Simon Pilgrim (RKSimon)

The PAVGB/PAVGW intrinsics can all be used in constexpr with suitable handling of the __builtin_ia32_pavg builtins inside VectorExprEvaluator::VisitCallExpr similar to #152540 ``` _mm_avg_pu8 _mm_avg_epu8 _mm256_avg_epu8 _mm512_avg_epu8 _mm_mask_avg_epu8 _mm256_mask_avg_epu8 _mm512_mask_avg_epu8 _mm_maskz_avg_epu8 _mm256_maskz_avg_epu8 _mm512_maskz_avg_epu8

_mm_avg_pu16
_mm_avg_epu16 _mm256_avg_epu16 _mm512_avg_epu16
_mm_mask_avg_epu16 _mm256_mask_avg_epu16 _mm512_mask_avg_epu16
_mm_maskz_avg_epu16 _mm256_maskz_avg_epu16 _mm512_maskz_avg_epu16

These all just need to call APIntOps::avgCeilU - and the builtin types should probably be converted to unsigned.
</details>

[donneypr]

Hi! If the PR above doesn't solve the issue I would love to be assigned this task! Thank you.

[RKSimon]

I think @markbhasawut has almost finished work on this - there's still a few open subtasks on #30794 though