Use profile info to set function section prefix to group hot/cold functions.
Summary:
The original implementation is in r261607, which was reverted in r269726 to accomendate the ProfileSummaryInfo analysis pass. The new implementation:
1. add a new metadata for function section prefix
2. query against ProfileSummaryInfo in CGP to set the correct section prefix for each function
3. output the section prefix set by CGP
Reviewers: davidxl, eraman
Subscribers: vsk, llvm-commits
Differential Revision: https://reviews.llvm.org/D24989
llvm-svn: 284533
diff --git a/llvm/lib/IR/MDBuilder.cpp b/llvm/lib/IR/MDBuilder.cpp
index a5a4cd0..f4bfd59 100644
--- a/llvm/lib/IR/MDBuilder.cpp
+++ b/llvm/lib/IR/MDBuilder.cpp
@@ -63,6 +63,12 @@
createConstant(ConstantInt::get(Int64Ty, Count))});
}
+MDNode *MDBuilder::createFunctionSectionPrefix(StringRef Prefix) {
+ return MDNode::get(Context,
+ {createString("function_section_prefix"),
+ createString(Prefix)});
+}
+
MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) {
assert(Lo.getBitWidth() == Hi.getBitWidth() && "Mismatched bitwidths!");
