[X86] Fix emitEpilogue() to make less assumptions about pops

This is the mirror image of r242395.
When X86FrameLowering::emitEpilogue() looks for where to insert the %esp addition that
deallocates stack space used for local allocations, it assumes that any sequence of pop
instructions from function exit backwards consists purely of restoring callee-save registers.

This may be false, since from some point backward, the pops may be clean-up of stack space
allocated for arguments to a call.

Patch by: amjad.aboud@intel.com
Differential Revision: http://reviews.llvm.org/D12688

llvm-svn: 247784

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 036965bf965..f2984b2ae0e 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -1735,13 +1735,16 @@ void MachineInstr::print(raw_ostream &OS, ModuleSlotTracker &MST,
   }
 
   bool HaveSemi = false;
-  const unsigned PrintableFlags = FrameSetup;
+  const unsigned PrintableFlags = FrameSetup | FrameDestroy;
   if (Flags & PrintableFlags) {
     if (!HaveSemi) OS << ";"; HaveSemi = true;
     OS << " flags: ";
 
     if (Flags & FrameSetup)
       OS << "FrameSetup";
+
+    if (Flags & FrameDestroy)
+      OS << "FrameDestroy";
   }
 
   if (!memoperands_empty()) {