[all-commits] [llvm/llvm-project] cff0db: [X86] Enable constexpr on POPCNT intrinsics (PR31446)

[Simon Pilgrim via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: cff0db08761f310dfebb5b41b307d2c12bda85fc
      https://github.com/llvm/llvm-project/commit/cff0db08761f310dfebb5b41b307d2c12bda85fc
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2020-08-20 (Thu, 20 Aug 2020)

  Changed paths:
    M clang/docs/ReleaseNotes.rst
    M clang/lib/Headers/popcntintrin.h
    M clang/test/CodeGen/popcnt-builtins.c

  Log Message:
  -----------
  [X86] Enable constexpr on POPCNT intrinsics (PR31446)

This is a first step patch to enable constexpr support and testing to a large number of x86 intrinsics.

All I've done here is provide a DEFAULT_FN_ATTRS_CONSTEXPR variant to our existing DEFAULT_FN_ATTRS tag approach that adds constexpr on c++ builds. The clang cuda headers do something similar.

I've started with POPCNT mainly as its tiny and are wrappers to generic __builtin_* intrinsics which already act as constexpr.

Differential Revision: https://reviews.llvm.org/D86229