1 files changed, 57 insertions, 1 deletions
diff --git a/contrib/llvm/lib/Target/Hexagon/HexagonTargetObjectFile.cpp b/contrib/llvm/lib/Target/Hexagon/HexagonTargetObjectFile.cpp
index c9c4f95..ea86c9c 100644
--- a/contrib/llvm/lib/Target/Hexagon/HexagonTargetObjectFile.cpp
+++ b/contrib/llvm/lib/Target/Hexagon/HexagonTargetObjectFile.cpp
@@ -17,6 +17,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/BinaryFormat/ELF.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/GlobalObject.h"
@@ -28,7 +29,6 @@
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
-#include "llvm/Support/ELF.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetMachine.h"
 
@@ -49,6 +49,14 @@ static cl::opt<bool> TraceGVPlacement("trace-gv-placement",
   cl::Hidden, cl::init(false),
   cl::desc("Trace global value placement"));
 
+static cl::opt<bool>
+    EmitJtInText("hexagon-emit-jt-text", cl::Hidden, cl::init(false),
+                 cl::desc("Emit hexagon jump tables in function section"));
+
+static cl::opt<bool>
+    EmitLutInText("hexagon-emit-lut-text", cl::Hidden, cl::init(false),
+                 cl::desc("Emit hexagon lookup tables in function section"));
+
 // TraceGVPlacement controls messages for all builds. For builds with assertions
 // (debug or release), messages are also controlled by the usual debug flags
 // (e.g. -debug and -debug-only=globallayout)
@@ -132,6 +140,13 @@ MCSection *HexagonTargetObjectFile::SelectSectionForGlobal(
          << (Kind.isBSS() ? "kind_bss " : "" )
          << (Kind.isBSSLocal() ? "kind_bss_local " : "" ));
 
+  // If the lookup table is used by more than one function, do not place
+  // it in text section.
+  if (EmitLutInText && GO->getName().startswith("switch.table")) {
+    if (const Function *Fn = getLutUsedFunction(GO))
+      return selectSectionForLookupTable(GO, TM, Fn);
+  }
+
   if (isGlobalInSmallSection(GO, TM))
     return selectSmallSectionForGlobal(GO, Kind, TM);
 
@@ -256,6 +271,11 @@ unsigned HexagonTargetObjectFile::getSmallDataSize() const {
   return SmallDataThreshold;
 }
 
+bool HexagonTargetObjectFile::shouldPutJumpTableInFunctionSection(
+    bool UsesLabelDifference, const Function &F) const {
+  return EmitJtInText;
+}
+
 /// Descends any type down to "elementary" components,
 /// discovering the smallest addressable one.
 /// If zero is returned, declaration will not be modified.
@@ -393,3 +413,39 @@ MCSection *HexagonTargetObjectFile::selectSmallSectionForGlobal(
   // Otherwise, we work the same as ELF.
   return TargetLoweringObjectFileELF::SelectSectionForGlobal(GO, Kind, TM);
 }
+
+// Return the function that uses the lookup table. If there are more
+// than one live function that uses this look table, bail out and place
+// the lookup table in default section.
+const Function *
+HexagonTargetObjectFile::getLutUsedFunction(const GlobalObject *GO) const {
+  const Function *ReturnFn = nullptr;
+  for (auto U : GO->users()) {
+    // validate each instance of user to be a live function.
+    auto *I = dyn_cast<Instruction>(U);
+    if (!I)
+      continue;
+    auto *Bb = I->getParent();
+    if (!Bb)
+      continue;
+    auto *UserFn = Bb->getParent();
+    if (!ReturnFn)
+      ReturnFn = UserFn;
+    else if (ReturnFn != UserFn)
+      return nullptr;
+  }
+  return ReturnFn;
+}
+
+MCSection *HexagonTargetObjectFile::selectSectionForLookupTable(
+    const GlobalObject *GO, const TargetMachine &TM, const Function *Fn) const {
+
+  SectionKind Kind = SectionKind::getText();
+  // If the function has explicit section, place the lookup table in this
+  // explicit section.
+  if (Fn->hasSection())
+    return getExplicitSectionGlobal(Fn, Kind, TM);
+
+  const auto *FuncObj = dyn_cast<GlobalObject>(Fn);
+  return SelectSectionForGlobal(FuncObj, Kind, TM);
+}