[opt-remarks] If hotness threshold is set, ignore remarks without hotness

These are blocks that haven't not been executed during training.  For large
projects this could make a significant difference.  For the project, I was
looking at, I got an order of magnitude decrease in the size of the total YAML
files with this and r319235.

Differential Revision: https://reviews.llvm.org/D40678

Re-commit after fixing the failing testcase in rL319576, rL319577 and
rL319578.

llvm-svn: 319581

1 files changed, 3 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/MachineOptimizationRemarkEmitter.cpp b/llvm/lib/CodeGen/MachineOptimizationRemarkEmitter.cpp
index ecc569dab83..91205d2f01e 100644
--- a/llvm/lib/CodeGen/MachineOptimizationRemarkEmitter.cpp
+++ b/llvm/lib/CodeGen/MachineOptimizationRemarkEmitter.cpp
@@ -53,10 +53,9 @@ void MachineOptimizationRemarkEmitter::emit(
 
   LLVMContext &Ctx = MF.getFunction()->getContext();
 
-  // If a diagnostic has a hotness value, then only emit it if its hotness
-  // meets the threshold.
-  if (OptDiag.getHotness() &&
-      *OptDiag.getHotness() < Ctx.getDiagnosticsHotnessThreshold()) {
+  // Only emit it if its hotness meets the threshold.
+  if (OptDiag.getHotness().getValueOr(0) <
+      Ctx.getDiagnosticsHotnessThreshold()) {
     return;
   }