Require DominatorTree when requiring/preserving LoopInfo in the old pass manager

Summary:
Require DominatorTree when requiring/preserving LoopInfo in the old pass manager

BreakCriticalEdges tries to keep LoopInfo and DominatorTree updated if they
exist. However, since commit r321653 and r321805, to update LoopInfo we
must have a DominatorTree, or we will hit an assert.

To fix this we now make a couple of passes that only required/preserved
LoopInfo also require DominatorTree.

This solves PR37334.

Reviewers: eli.friedman, efriedma

Reviewed By: efriedma

Subscribers: efriedma, llvm-commits

Differential Revision: https://reviews.llvm.org/D46829

llvm-svn: 332583

llvm/lib/Analysis/BranchProbabilityInfo.cpp

@@ -22,6 +22,7 @@
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instruction.h"
@@ -1001,6 +1002,10 @@ void BranchProbabilityInfo::calculate(const Function &F, const LoopInfo &LI,
 
 void BranchProbabilityInfoWrapperPass::getAnalysisUsage(
     AnalysisUsage &AU) const {
+  // We require DT so it's available when LI is available. The LI updating code
+  // asserts that DT is also present so if we don't make sure that we have DT
+  // here, that assert will trigger.
+  AU.addRequired<DominatorTreeWrapperPass>();
   AU.addRequired<LoopInfoWrapperPass>();
   AU.addRequired<TargetLibraryInfoWrapperPass>();
   AU.setPreservesAll();

llvm/lib/Analysis/LazyBlockFrequencyInfo.cpp

@@ -17,6 +17,7 @@
 #include "llvm/Analysis/LazyBlockFrequencyInfo.h"
 #include "llvm/Analysis/LazyBranchProbabilityInfo.h"
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/IR/Dominators.h"
 
 using namespace llvm;
 
@@ -41,6 +42,10 @@ void LazyBlockFrequencyInfoPass::print(raw_ostream &OS, const Module *) const {
 
 void LazyBlockFrequencyInfoPass::getAnalysisUsage(AnalysisUsage &AU) const {
   LazyBranchProbabilityInfoPass::getLazyBPIAnalysisUsage(AU);
+  // We require DT so it's available when LI is available. The LI updating code
+  // asserts that DT is also present so if we don't make sure that we have DT
+  // here, that assert will trigger.
+  AU.addRequired<DominatorTreeWrapperPass>();
   AU.addRequired<LoopInfoWrapperPass>();
   AU.setPreservesAll();
 }

llvm/lib/Analysis/LazyBranchProbabilityInfo.cpp

@@ -17,6 +17,7 @@
 #include "llvm/Analysis/LazyBranchProbabilityInfo.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/IR/Dominators.h"
 
 using namespace llvm;
 
@@ -42,6 +43,10 @@ void LazyBranchProbabilityInfoPass::print(raw_ostream &OS,
 }
 
 void LazyBranchProbabilityInfoPass::getAnalysisUsage(AnalysisUsage &AU) const {
+  // We require DT so it's available when LI is available. The LI updating code
+  // asserts that DT is also present so if we don't make sure that we have DT
+  // here, that assert will trigger.
+  AU.addRequired<DominatorTreeWrapperPass>();
   AU.addRequired<LoopInfoWrapperPass>();
   AU.addRequired<TargetLibraryInfoWrapperPass>();
   AU.setPreservesAll();

llvm/test/Transforms/Util/PR37334-break-crit-edges-require-dt.ll

@@ -0,0 +1,44 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -loop-sink -break-crit-edges -branch-prob -S | FileCheck %s
+; RUN: opt < %s -loop-sink -break-crit-edges -lazy-block-freq -S | FileCheck %s
+; RUN: opt < %s -loop-sink -break-crit-edges -lazy-branch-prob -S | FileCheck %s
+
+; BreakCriticalEdges tries to update LI and DT if they are present. However,
+; updating LI actually needs a DT, so we now require DT in
+; BranchProbabilityInfo/LazyBlockFrequencyInfo/LazyBranchProbabilityInfo so it
+; is indeed available when LI is.
+
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @f1() {
+; CHECK-LABEL: @f1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[FOR_COND:%.*]]
+; CHECK:       for.cond:
+; CHECK-NEXT:    br i1 false, label [[FOR_BODY:%.*]], label [[FOR_COND_FOR_END_CRIT_EDGE:%.*]]
+; CHECK:       for.cond.for.end_crit_edge:
+; CHECK-NEXT:    br label [[FOR_END:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    br i1 true, label [[FOR_ENDSPLIT:%.*]], label [[FOR_INC:%.*]]
+; CHECK:       for.inc:
+; CHECK-NEXT:    br label [[FOR_COND]]
+; CHECK:       for.endsplit:
+; CHECK-NEXT:    br label [[FOR_END]]
+; CHECK:       for.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  br i1 undef, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  br i1 undef, label %for.end, label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  br label %for.cond
+
+for.end:                                          ; preds = %for.body, %for.cond
+  ret void
+}