Rebased PNaCl localmods in LLVM to 223109

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

Index: lib/CodeGen/AsmPrinter/AsmPrinter.cpp
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 8a327134f273677e7d94343eaec4fb21e14f6da3..719acd50b8503b03ad4d43aa8936bd3d0a160a6b 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -760,9 +760,14 @@ void AsmPrinter::EmitFunctionBody() {
         break;
 
       case TargetOpcode::EH_LABEL:
-      case TargetOpcode::GC_LABEL:
+      case TargetOpcode::GC_LABEL: {
+        // @LOCALMOD-START
+        if (unsigned LabelAlign = GetTargetLabelAlign(&MI))
+          EmitAlignment(LabelAlign);
+        // @LOCALMOD-END
         OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
         break;
+      }
       case TargetOpcode::INLINEASM:
         EmitInlineAsm(&MI);
         break;
@@ -1127,19 +1132,34 @@ void AsmPrinter::EmitJumpTableInfo() {
   if (// In PIC mode, we need to emit the jump table to the same section as the
       // function body itself, otherwise the label differences won't make sense.
       // FIXME: Need a better predicate for this: what about custom entries?
-      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
+      (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
       // We should also do if the section name is NULL or function is declared
       // in discardable section
       // FIXME: this isn't the right predicate, should be based on the MCSection
       // for the function.
-      F->isWeakForLinker()) {
+      // @LOCALMOD-START
+      // the original code is a hack
+      // jumptables usually end up in .rodata
+      // but for functions with weak linkage there is a chance that the are
+      // not needed. So in order to be discard the function AND the jumptable
+      // they keep them both in .text. This fix only works if we never discard
+      // weak functions. This is guaranteed because the bitcode linker already
+      // throws out unused ones.
+      // TODO: Investigate the other case of concern -- PIC code.
+      // Concern is about jumptables being in a different section: can the
+      // rodata and text be too far apart for a RIP-relative offset?
+       F->isWeakForLinker())
+      && !UseReadOnlyJumpTables()) {
     OutStreamer.SwitchSection(
         getObjFileLowering().SectionForGlobal(F, *Mang, TM));
   } else {
     // Otherwise, drop it in the readonly section.
+    // (localmod: pick a readonly section based on the properties of F, which
+    // means a unique readonly section if F gets a unique text section)
     const MCSection *ReadOnlySection =
-        getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
-                                                   /*C=*/nullptr);
+        getObjFileLowering().SectionForGlobal(
+            F, SectionKind::getReadOnly(), *Mang, TM);
+    // @LOCALMOD-END
     OutStreamer.SwitchSection(ReadOnlySection);
     JTInDiffSection = true;
   }
@@ -1161,7 +1181,8 @@ void AsmPrinter::EmitJumpTableInfo() {
     // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
     /// emit a .set directive for each unique entry.
     if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
-        MAI->doesSetDirectiveSuppressesReloc()) {
+        MAI->doesSetDirectiveSuppressesReloc() &&
+        !UseReadOnlyJumpTables()) { // @LOCALMOD
       SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
       const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
       const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
@@ -1242,7 +1263,8 @@ void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
     // If the .set directive avoids relocations, this is emitted as:
     //      .set L4_5_set_123, LBB123 - LJTI1_2
     //      .word L4_5_set_123
-    if (MAI->doesSetDirectiveSuppressesReloc()) {
+    if (MAI->doesSetDirectiveSuppressesReloc() &&
+        !UseReadOnlyJumpTables()) { // @LOCALMOD
       Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
                                       OutContext);
       break;