From e573b777726a6633724564a7097be42963b96469 Mon Sep 17 00:00:00 2001
From: Dehao Chen <dehao@google.com>
Date: Thu, 1 Sep 2016 23:51:37 +0000
Subject: [PATCH] Explicitly require DominatorTreeAnalysis pass for
 instsimplify pass.

Summary: DominatorTreeAnalysis is always required by instsimplify.

Reviewers: davidxl, danielcdh

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24173

llvm-svn: 280432
---
 llvm/lib/Transforms/Utils/SimplifyInstructions.cpp | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/Transforms/Utils/SimplifyInstructions.cpp b/llvm/lib/Transforms/Utils/SimplifyInstructions.cpp
index 3099c49..0be0b65 100644
--- a/llvm/lib/Transforms/Utils/SimplifyInstructions.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyInstructions.cpp
@@ -90,6 +90,7 @@ namespace {
 
     void getAnalysisUsage(AnalysisUsage &AU) const override {
       AU.setPreservesCFG();
+      AU.addRequired<DominatorTreeWrapperPass>();
       AU.addRequired<AssumptionCacheTracker>();
       AU.addRequired<TargetLibraryInfoWrapperPass>();
     }
@@ -99,9 +100,8 @@ namespace {
       if (skipFunction(F))
         return false;
 
-      const DominatorTreeWrapperPass *DTWP =
-          getAnalysisIfAvailable<DominatorTreeWrapperPass>();
-      const DominatorTree *DT = DTWP ? &DTWP->getDomTree() : nullptr;
+      const DominatorTree *DT =
+          &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
       const TargetLibraryInfo *TLI =
           &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
       AssumptionCache *AC =
@@ -115,6 +115,7 @@ char InstSimplifier::ID = 0;
 INITIALIZE_PASS_BEGIN(InstSimplifier, "instsimplify",
                       "Remove redundant instructions", false, false)
 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
 INITIALIZE_PASS_END(InstSimplifier, "instsimplify",
                     "Remove redundant instructions", false, false)
@@ -127,10 +128,10 @@ FunctionPass *llvm::createInstructionSimplifierPass() {
 
 PreservedAnalyses InstSimplifierPass::run(Function &F,
                                       FunctionAnalysisManager &AM) {
-  auto *DT = AM.getCachedResult<DominatorTreeAnalysis>(F);
+  auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
   auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
   auto &AC = AM.getResult<AssumptionAnalysis>(F);
-  bool Changed = runImpl(F, DT, &TLI, &AC);
+  bool Changed = runImpl(F, &DT, &TLI, &AC);
   if (!Changed)
     return PreservedAnalyses::all();
   // FIXME: This should also 'preserve the CFG'.
-- 
2.7.4