1 files changed, 38 insertions, 5 deletions

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index fc08384..bbeb026 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -50,6 +50,7 @@
 #include "llvm/Support/Format.h"
 #include "llvm/Support/FormattedStream.h"
 #include <cerrno>
+#include <ctype.h>
 using namespace llvm;
 
 STATISTIC(EmittedInsts, "Number of machine instrs printed");
@@ -917,11 +918,10 @@ void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
   
   if (NumBits == 0) return;   // No need to emit alignment.
   
-  unsigned FillValue = 0;
   if (getCurrentSection()->getKind().isText())
-    FillValue = MAI->getTextAlignFillValue();
-  
-  OutStreamer.EmitValueToAlignment(1 << NumBits, FillValue, 1, 0);
+    OutStreamer.EmitCodeAlignment(1 << NumBits);
+  else
+    OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
 }
 
 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
@@ -1717,7 +1717,7 @@ void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
   }
 
   // Print the main label for the block.
-  if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
+  if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
     if (VerboseAsm) {
       // NOTE: Want this comment at start of line.
       O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
@@ -1764,6 +1764,39 @@ void AsmPrinter::printOffset(int64_t Offset) const {
     O << Offset;
 }
 
+/// isBlockOnlyReachableByFallthough - Return true if the basic block has
+/// exactly one predecessor and the control transfer mechanism between
+/// the predecessor and this block is a fall-through.
+bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) 
+    const {
+  // If this is a landing pad, it isn't a fall through.  If it has no preds,
+  // then nothing falls through to it.
+  if (MBB->isLandingPad() || MBB->pred_empty())
+    return false;
+  
+  // If there isn't exactly one predecessor, it can't be a fall through.
+  MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
+  ++PI2;
+  if (PI2 != MBB->pred_end())
+    return false;
+  
+  // The predecessor has to be immediately before this block.
+  const MachineBasicBlock *Pred = *PI;
+  
+  if (!Pred->isLayoutSuccessor(MBB))
+    return false;
+  
+  // If the block is completely empty, then it definitely does fall through.
+  if (Pred->empty())
+    return true;
+  
+  // Otherwise, check the last instruction.
+  const MachineInstr &LastInst = Pred->back();
+  return !LastInst.getDesc().isBarrier();
+}
+
+
+
 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
   if (!S->usesMetadata())
     return 0;