Update llvm/clang to trunk r126547.

There are several bugfixes in this update, but the most important one is
to ensure __start_ and __stop_ symbols for linker sets and kernel module
metadata are always emitted in object files:

  http://llvm.org/bugs/show_bug.cgi?id=9292

Before this fix, if you compiled kernel modules with clang, they would
not be properly processed by kldxref, and if they had any dependencies,
the kernel would fail to load those.  Another problem occurred when
attempting to mount a tmpfs filesystem, which would result in 'operation
not supported by device'.

1 files changed, 31 insertions, 0 deletions

diff --git a/contrib/llvm/lib/Target/Sparc/DelaySlotFiller.cpp b/contrib/llvm/lib/Target/Sparc/DelaySlotFiller.cpp
index ee29275..4b12852 100644
--- a/contrib/llvm/lib/Target/Sparc/DelaySlotFiller.cpp
+++ b/contrib/llvm/lib/Target/Sparc/DelaySlotFiller.cpp
@@ -79,6 +79,7 @@ namespace {
     MachineBasicBlock::iterator
     findDelayInstr(MachineBasicBlock &MBB, MachineBasicBlock::iterator slot);
 
+    bool needsUnimp(MachineBasicBlock::iterator I, unsigned &StructSize);
 
   };
   char Filler::ID = 0;
@@ -91,6 +92,7 @@ FunctionPass *llvm::createSparcDelaySlotFillerPass(TargetMachine &tm) {
   return new Filler(tm);
 }
 
+
 /// runOnMachineBasicBlock - Fill in delay slots for the given basic block.
 /// We assume there is only one delay slot per delayed instruction.
 ///
@@ -112,6 +114,13 @@ bool Filler::runOnMachineBasicBlock(MachineBasicBlock &MBB) {
         BuildMI(MBB, ++J, I->getDebugLoc(), TII->get(SP::NOP));
       else
         MBB.splice(++J, &MBB, D);
+      unsigned structSize = 0;
+      if (needsUnimp(I, structSize)) {
+        MachineBasicBlock::iterator J = I;
+        ++J; //skip the delay filler.
+        BuildMI(MBB, ++J, I->getDebugLoc(),
+                TII->get(SP::UNIMP)).addImm(structSize);
+      }
     }
   return Changed;
 }
@@ -287,6 +296,28 @@ bool Filler::isDelayFiller(MachineBasicBlock &MBB,
 {
   if (candidate == MBB.begin())
     return false;
+  if (candidate->getOpcode() == SP::UNIMP)
+    return true;
   const TargetInstrDesc &prevdesc = (--candidate)->getDesc();
   return prevdesc.hasDelaySlot();
 }
+
+bool Filler::needsUnimp(MachineBasicBlock::iterator I, unsigned &StructSize)
+{
+  if (!I->getDesc().isCall())
+    return false;
+
+  unsigned structSizeOpNum = 0;
+  switch (I->getOpcode()) {
+  default: llvm_unreachable("Unknown call opcode.");
+  case SP::CALL: structSizeOpNum = 1; break;
+  case SP::JMPLrr:
+  case SP::JMPLri: structSizeOpNum = 2; break;
+  }
+
+  const MachineOperand &MO = I->getOperand(structSizeOpNum);
+  if (!MO.isImm())
+    return false;
+  StructSize = MO.getImm();
+  return true;
+}