Mark jump tables in code sections with DataRegion directives.

Even out-of-line jump tables can be in the code section, so mark them
as data-regions for those targets which support the directives.

rdar://12362871&12362974

llvm-svn: 164571

2 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index d6d45104098..9453a80061b 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1082,6 +1082,11 @@ void AsmPrinter::EmitJumpTableInfo() {
 
   EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
 
+  // Jump tables in code sections are marked with a data_region directive
+  // where that's supported.
+  if (!JTInDiffSection)
+    OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
+
   for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
     const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
 
@@ -1122,6 +1127,8 @@ void AsmPrinter::EmitJumpTableInfo() {
     for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
       EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
   }
+  if (!JTInDiffSection)
+    OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
 }
 
 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
index b0acd7d5a10..16488eb7ae7 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
@@ -34,6 +34,10 @@ AsmWriterFlavor("x86-asm-syntax", cl::init(ATT),
              clEnumValN(Intel, "intel", "Emit Intel-style assembly"),
              clEnumValEnd));
 
+static cl::opt<bool>
+MarkedJTDataRegions("mark-data-regions", cl::init(false),
+  cl::desc("Mark code section jump table data regions."),
+  cl::Hidden);
 
 void X86MCAsmInfoDarwin::anchor() { }
 
@@ -59,6 +63,7 @@ X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
 
   SupportsDebugInformation = true;
   DwarfUsesInlineInfoSection = true;
+  UseDataRegionDirectives = MarkedJTDataRegions;
 
   // Exceptions handling
   ExceptionsType = ExceptionHandling::DwarfCFI;