From 55f38c1a98c8a954322686503093c62a5c8d940b Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Wed, 21 Oct 2020 23:44:45 -0700
Subject: [PATCH] [ShrinkWrap] Delete unneeded nullptr checks for the save
 point. NFC

findNearestCommonDominator never returns nullptr.
---
 lib/CodeGen/ShrinkWrap.cpp | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/lib/CodeGen/ShrinkWrap.cpp b/lib/CodeGen/ShrinkWrap.cpp
index a51053b991c..f89069e9f72 100644
--- a/lib/CodeGen/ShrinkWrap.cpp
+++ b/lib/CodeGen/ShrinkWrap.cpp
@@ -331,11 +331,7 @@ void ShrinkWrap::updateSaveRestorePoints(MachineBasicBlock &MBB,
     Save = &MBB;
   else
     Save = MDT->findNearestCommonDominator(Save, &MBB);
-
-  if (!Save) {
-    LLVM_DEBUG(dbgs() << "Found a block that is not reachable from Entry\n");
-    return;
-  }
+  assert(Save);
 
   if (!Restore)
     Restore = &MBB;
@@ -381,7 +377,7 @@ void ShrinkWrap::updateSaveRestorePoints(MachineBasicBlock &MBB,
   // C. Save and Restore are in the same loop.
   bool SaveDominatesRestore = false;
   bool RestorePostDominatesSave = false;
-  while (Save && Restore &&
+  while (Restore &&
          (!(SaveDominatesRestore = MDT->dominates(Save, Restore)) ||
           !(RestorePostDominatesSave = MPDT->dominates(Restore, Save)) ||
           // Post-dominance is not enough in loops to ensure that all uses/defs
@@ -412,8 +408,7 @@ void ShrinkWrap::updateSaveRestorePoints(MachineBasicBlock &MBB,
       Restore = MPDT->findNearestCommonDominator(Restore, Save);
 
     // Fix (C).
-    if (Save && Restore &&
-        (MLI->getLoopFor(Save) || MLI->getLoopFor(Restore))) {
+    if (Restore && (MLI->getLoopFor(Save) || MLI->getLoopFor(Restore))) {
       if (MLI->getLoopDepth(Save) > MLI->getLoopDepth(Restore)) {
         // Push Save outside of this loop if immediate dominator is different
         // from save block. If immediate dominator is not different, bail out.