diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 8c6ed50..7a5d24c 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -22,6 +22,7 @@
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/DwarfWriter.h"
 #include "llvm/Analysis/DebugInfo.h"
+#include "llvm/MC/MCInst.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormattedStream.h"
@@ -1731,11 +1732,23 @@
 /// EmitComments - Pretty-print comments for instructions
 void AsmPrinter::EmitComments(const MachineInstr &MI) const
 {
-  // No comments in MachineInstr yet
+  if (!MI.getDebugLoc().isUnknown()) {
+    DebugLocTuple DLT = MF->getDebugLocTuple(MI.getDebugLoc());
+
+    // Print source line info
+    O.PadToColumn(TAI->getCommentColumn(), 1);
+    O << TAI->getCommentString() << " SrcLine " << DLT.Line << ":" << DLT.Col;
+  }
 }
 
 /// EmitComments - Pretty-print comments for instructions
 void AsmPrinter::EmitComments(const MCInst &MI) const
 {
-  // No comments in MCInst yet
+  if (!MI.getDebugLoc().isUnknown()) {
+    DebugLocTuple DLT = MF->getDebugLocTuple(MI.getDebugLoc());
+
+    // Print source line info
+    O.PadToColumn(TAI->getCommentColumn(), 1);
+    O << TAI->getCommentString() << " SrcLine " << DLT.Line << ":" << DLT.Col;
+  }
 }
diff --git a/test/FrontendC++/2009-07-15-LineNumbers.cpp b/test/FrontendC++/2009-07-15-LineNumbers.cpp
new file mode 100644
index 0000000..c02fe0f
--- /dev/null
+++ b/test/FrontendC++/2009-07-15-LineNumbers.cpp
@@ -0,0 +1,27 @@
+// This is a regression test on debug info to make sure that we can
+// print line numbers in asm.
+// RUN: %llvmgcc -S -O0 -g %s -o - | llvm-as | \
+// RUN:    llc --disable-fp-elim -f -O0 -relocation-model=pic | grep {# SrcLine 25}
+
+#include <stdlib.h>
+
+class DeepStack {
+  int seedVal;
+public:
+  DeepStack(int seed) : seedVal(seed) {}
+
+  int shallowest( int x ) { return shallower(x + 1); }
+  int shallower ( int x ) { return shallow(x + 2); }
+  int shallow   ( int x ) { return deep(x + 3); }
+  int deep      ( int x ) { return deeper(x + 4); }
+  int deeper    ( int x ) { return deepest(x + 6); }
+  int deepest   ( int x ) { return x + 7; }
+
+  int runit() { return shallowest(seedVal); }
+};
+
+int main ( int argc, char** argv) {
+
+  DeepStack DS9( (argc > 1 ? atoi(argv[1]) : 0) );
+  return DS9.runit();
+}