[DebugInfo] Fix ARM/AArch64 prologue_end position. Related to D11268.

Summary:
This review is related to another review request http://reviews.llvm.org/D11268, does the same and merely fixes a couple of issues with it.

D11268 is quite old and has merge conflicts against the current trunk.
This request 
 - rebases D11268 onto the new trunk;
 - resolves the merge conflicts;
 - fixes the prologue_end tests, which do not pass due to the subprogram definitions not marked as distinct.

Reviewers: echristo, rengolin, kubabrecka

Subscribers: aemerson, rengolin, jyknight, dsanders, llvm-commits, asl

Differential Revision: http://reviews.llvm.org/D14338

llvm-svn: 252177

1 files changed, 11 insertions, 7 deletions

diff --git a/llvm/lib/Target/Mips/Mips16FrameLowering.cpp b/llvm/lib/Target/Mips/Mips16FrameLowering.cpp
index 71c2bdba2f9..7994c61fcdd 100644
--- a/llvm/lib/Target/Mips/Mips16FrameLowering.cpp
+++ b/llvm/lib/Target/Mips/Mips16FrameLowering.cpp
@@ -36,13 +36,17 @@ void Mips16FrameLowering::emitPrologue(MachineFunction &MF,
                                        MachineBasicBlock &MBB) const {
   assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
   MachineFrameInfo *MFI = MF.getFrameInfo();
-  const Mips16InstrInfo &TII =
-      *static_cast<const Mips16InstrInfo *>(STI.getInstrInfo());
-  MachineBasicBlock::iterator MBBI = MBB.begin();
-  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
-  uint64_t StackSize = MFI->getStackSize();
-
-  // No need to allocate space on the stack.
+  const Mips16InstrInfo &TII =

+      *static_cast<const Mips16InstrInfo *>(STI.getInstrInfo());

+  MachineBasicBlock::iterator MBBI = MBB.begin();

+

+  // Debug location must be unknown since the first debug location is used

+  // to determine the end of the prologue.

+  DebugLoc dl;

+

+  uint64_t StackSize = MFI->getStackSize();

+

+  // No need to allocate space on the stack.

   if (StackSize == 0 && !MFI->adjustsStack()) return;
 
   MachineModuleInfo &MMI = MF.getMMI();