[all-commits] [llvm/llvm-project] 2dd17f: [CodeGen] only add nobuiltin to inline builtins if...

[George Burgess IV via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 2dd17ff08165e6118e70f00e22b2c36d2d4e0a9a
      https://github.com/llvm/llvm-project/commit/2dd17ff08165e6118e70f00e22b2c36d2d4e0a9a
  Author: George Burgess IV <george.burgess.iv at gmail.com>
  Date:   2020-04-15 (Wed, 15 Apr 2020)

  Changed paths:
    M clang/lib/CodeGen/CodeGenModule.cpp
    A clang/test/CodeGen/memcpy-no-nobuiltin-if-not-emitted.c

  Log Message:
  -----------
  [CodeGen] only add nobuiltin to inline builtins if we'll emit them

There are some inline builtin definitions that we can't emit
(isTriviallyRecursive & callers go into why). Marking these
nobuiltin is only useful if we actually emit the body, so don't mark
these as such unless we _do_ plan on emitting that.

This suboptimality was encountered in Linux (see some discussion on
D71082, and https://github.com/ClangBuiltLinux/linux/issues/979).

Differential Revision: https://reviews.llvm.org/D78162