commit e36076ee3a2ebc6013372d9b71e6bb09e8612366
author Zequan Wu <zequanwu@google.com> Thu May 21 16:44:30 2020 -0700
committer Zequan Wu <zequanwu@google.com> Thu May 21 17:07:39 2020 -0700
tree a6a0559c263c6549f2e810a0466b4ce45ce2903f
parent 1d64d69ab701d9524ee6871e93a2a2f8195fa798

[clang] Add nomerge function attribute to clang
Differential Revision: https://reviews.llvm.org/D79121

clang/lib/CodeGen/CGCall.cpp

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 6831f82..c324b9f 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -4822,6 +4822,12 @@
         Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
                            llvm::Attribute::StrictFP);
 
+  // Add call-site nomerge attribute if exists.
+  if (InNoMergeAttributedStmt)
+    Attrs =
+      Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
+                         llvm::Attribute::NoMerge);
+
   // Apply some call-site-specific attributes.
   // TODO: work this into building the attribute set.
 

clang/lib/CodeGen/CGStmt.cpp

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index ceecbd4..3559e77 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -25,6 +25,7 @@
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/MDBuilder.h"
+#include "llvm/Support/SaveAndRestore.h"
 
 using namespace clang;
 using namespace CodeGen;
@@ -608,6 +609,13 @@
 }
 
 void CodeGenFunction::EmitAttributedStmt(const AttributedStmt &S) {
+  bool nomerge = false;
+  for (const auto *A : S.getAttrs())
+    if (A->getKind() == attr::NoMerge) {
+      nomerge = true;
+      break;
+    }
+  SaveAndRestore<bool> save_nomerge(InNoMergeAttributedStmt, nomerge);
   EmitStmt(S.getSubStmt(), S.getAttrs());
 }
 

clang/lib/CodeGen/CodeGenFunction.h

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 731317a..2b5871d 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -595,6 +595,9 @@
   /// region.
   bool IsInPreservedAIRegion = false;
 
+  /// True if the current statement has nomerge attribute.
+  bool InNoMergeAttributedStmt = false;
+
   const CodeGen::CGBlockInfo *BlockInfo = nullptr;
   llvm::Value *BlockPointer = nullptr;