Revert r124611 - "Keep track of incoming argument's location while emitting LiveIns."

In other words, do not keep track of argument's location.  The debugger (gdb) is not prepared to see line table entries for arguments. For the debugger, "second" line table entry marks beginning of function body.
This requires some coordination with debugger to get this working. 
 - The debugger needs to be aware of prolog_end attribute attached with line table entries.
 - The compiler needs to accurately mark prolog_end in line table entries (at -O0 and at -O1+)

llvm-svn: 126155

1 files changed, 1 insertions, 10 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 62ebc81ef86..ae63f2e657f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -851,17 +851,8 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
       PrepareEHLandingPad();
 
     // Lower any arguments needed in this block if this is the entry block.
-    if (LLVMBB == &Fn.getEntryBlock()) {
-      for (BasicBlock::const_iterator DBI = LLVMBB->begin(), DBE = LLVMBB->end();
-           DBI != DBE; ++DBI) {
-        if (const DbgInfoIntrinsic *DI = dyn_cast<DbgInfoIntrinsic>(DBI)) {
-          const DebugLoc DL = DI->getDebugLoc();
-          SDB->setCurDebugLoc(DL);
-          break;
-        }
-      }
+    if (LLVMBB == &Fn.getEntryBlock())
       LowerArguments(LLVMBB);
-    }
 
     // Before doing SelectionDAG ISel, see if FastISel has been requested.
     if (FastIS) {