Inliner uses a smaller inline threshold for callees with cold attribute.

Added command line option inlinecold-threshold to set threshold for inlining
functions with cold attribute. Listen to the cold attribute when it would
decrease the inline threshold.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200886 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp
index dc710d1415..8647f39a90 100644
--- a/lib/Transforms/IPO/Inliner.cpp
+++ b/lib/Transforms/IPO/Inliner.cpp
@@ -50,6 +50,10 @@ static cl::opt<int>
 HintThreshold("inlinehint-threshold", cl::Hidden, cl::init(325),
               cl::desc("Threshold for inlining functions with inline hint"));
 
+static cl::opt<int>
+ColdThreshold("inlinecold-threshold", cl::Hidden, cl::init(75),
+              cl::desc("Threshold for inlining functions with cold attribute"));
+
 // Threshold to use when optsize is specified (and there is no -inline-limit).
 const int OptSizeThreshold = 75;
 
@@ -277,6 +281,13 @@ unsigned Inliner::getInlineThreshold(CallSite CS) const {
                                                Attribute::MinSize))
     thres = HintThreshold;
 
+  // Listen to the cold attribute when it would decrease the threshold.
+  bool ColdCallee = Callee && !Callee->isDeclaration() &&
+    Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                         Attribute::Cold);
+  if (ColdCallee && ColdThreshold < thres)
+    thres = ColdThreshold;
+
   return thres;
 }