[all-commits] [llvm/llvm-project] 6ab320: Remove the unnecessary `is_nothrow_swappable` cond...

[Michael Park via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 6ab3208d779ffb3b32744b0190d7035d4b369173
      https://github.com/llvm/llvm-project/commit/6ab3208d779ffb3b32744b0190d7035d4b369173
  Author: Michael Park <mcypark at gmail.com>
  Date:   2020-07-08 (Wed, 08 Jul 2020)

  Changed paths:
    M libcxx/include/variant

  Log Message:
  -----------
  Remove the unnecessary `is_nothrow_swappable` condition in `swap`.

Thanks to @lewissbaker who pointed out the unnecessary condition in
https://reviews.llvm.org/D81954#inline-756872. Since this codepath does not
make use of `swap` anyway (that codepath is a different branch), we can safely
remove this condition and produce better codegen when all types are nothrow
movable but are potentially-throwing swappable.

See codegen in https://gcc.godbolt.org/z/uDFZjz

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D83274