[Backend] Keep call site info valid through the backend

Handle call instruction replacements and deletions in order to preserve
valid state of the call site info of the MachineFunction.

NOTE: If the call site info is enabled for a new target, the assertion from
the MachineFunction::DeleteMachineInstr() should help to locate places
where the updateCallSiteInfo() should be called in order to preserve valid
state of the call site info.

([10/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D61062

llvm-svn: 364536

1 files changed, 8 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/TargetInstrInfo.cpp b/llvm/lib/CodeGen/TargetInstrInfo.cpp
index cc3012addf2..868617ffe14 100644
--- a/llvm/lib/CodeGen/TargetInstrInfo.cpp
+++ b/llvm/lib/CodeGen/TargetInstrInfo.cpp
@@ -137,8 +137,14 @@ TargetInstrInfo::ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail,
   // Save off the debug loc before erasing the instruction.
   DebugLoc DL = Tail->getDebugLoc();
 
-  // Remove all the dead instructions from the end of MBB.
-  MBB->erase(Tail, MBB->end());
+  // Update call site info and remove all the dead instructions
+  // from the end of MBB.
+  while (Tail != MBB->end()) {
+    auto MI = Tail++;
+    if (MI->isCall())
+      MBB->getParent()->updateCallSiteInfo(&*MI);
+    MBB->erase(MI);
+  }
 
   // If MBB isn't immediately before MBB, insert a branch to it.
   if (++MachineFunction::iterator(MBB) != MachineFunction::iterator(NewDest))