Revert "[PM/CC1] Add -f[no-]split-cold-code CC1 option to toggle splitting"

This broke Chromium's PGO build, it seems because hot-cold-splitting got turned
on unintentionally. See comment on the code review for repro etc.

> This patch adds -f[no-]split-cold-code CC1 options to clang. This allows
> the splitting pass to be toggled on/off. The current method of passing
> `-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose
> correctly (say, with `-O0` or `-Oz`).
>
> To implement the -fsplit-cold-code option, an attribute is applied to
> functions to indicate that they may be considered for splitting. This
> removes some complexity from the old/new PM pipeline builders, and
> behaves as expected when LTO is enabled.
>
> Co-authored by: Saleem Abdulrasool <compnerd@compnerd.org>
> Differential Revision: https://reviews.llvm.org/D57265
> Reviewed By: Aditya Kumar, Vedant Kumar
> Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar

This reverts commit 273c299d5d649a0222fbde03c9a41e41913751b4.

1 files changed, 0 insertions, 11 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 87d64f1..a4c56cc 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1469,17 +1469,6 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
 
   Opts.PassByValueIsNoAlias = Args.hasArg(OPT_fpass_by_value_is_noalias);
 
-  // -f[no-]split-cold-code
-  // This may only be enabled when optimizing, and when small code size
-  // increases are tolerable.
-  Opts.SplitColdCode =
-      (Opts.OptimizationLevel > 0) && (Opts.OptimizeSize != 2) &&
-      Args.hasFlag(OPT_fsplit_cold_code, OPT_fno_split_cold_code, false);
-  if (Arg *A = Args.getLastArg(OPT_fsplit_cold_code))
-    if (!Opts.SplitColdCode)
-      Diags.Report(diag::warn_fe_ignored_opt_split_cold_code)
-          << A->getAsString(Args) << (Opts.OptimizeSize != 2);
-
   return Success;
 }