[llvm] r327671 - [LoopUnroll] Peel off iterations if it makes conditions true/false.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Thu Mar 15 14:34:44 PDT 2018
Author: fhahn
Date: Thu Mar 15 14:34:43 2018
New Revision: 327671
URL: http://llvm.org/viewvc/llvm-project?rev=327671&view=rev
Log:
[LoopUnroll] Peel off iterations if it makes conditions true/false.
If the loop body contains conditions of the form IndVar < #constant, we
can remove the checks by peeling off #constant iterations.
This improves codegen for PR34364.
Reviewers: mkuper, mkazantsev, efriedma
Reviewed By: mkazantsev
Differential Revision: https://reviews.llvm.org/D43876
Added:
llvm/trunk/test/Transforms/LoopUnroll/peel-loop-conditions.ll
Modified:
llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h
llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp
llvm/trunk/lib/Transforms/Utils/LoopUnrollPeel.cpp
llvm/trunk/test/Transforms/LoopUnroll/complete_unroll_profitability_with_assume.ll
Modified: llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h?rev=327671&r1=327670&r2=327671&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/UnrollLoop.h Thu Mar 15 14:34:43 2018
@@ -71,7 +71,7 @@ bool UnrollRuntimeLoopRemainder(Loop *L,
void computePeelCount(Loop *L, unsigned LoopSize,
TargetTransformInfo::UnrollingPreferences &UP,
- unsigned &TripCount);
+ unsigned &TripCount, ScalarEvolution &SE);
bool peelLoop(Loop *L, unsigned PeelCount, LoopInfo *LI, ScalarEvolution *SE,
DominatorTree *DT, AssumptionCache *AC, bool PreserveLCSSA);
Modified: llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp?rev=327671&r1=327670&r2=327671&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp Thu Mar 15 14:34:43 2018
@@ -795,7 +795,7 @@ static bool computeUnrollCount(
}
// 4th priority is loop peeling
- computePeelCount(L, LoopSize, UP, TripCount);
+ computePeelCount(L, LoopSize, UP, TripCount, SE);
if (UP.PeelCount) {
UP.Runtime = false;
UP.Count = 1;
Modified: llvm/trunk/lib/Transforms/Utils/LoopUnrollPeel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopUnrollPeel.cpp?rev=327671&r1=327670&r2=327671&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopUnrollPeel.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LoopUnrollPeel.cpp Thu Mar 15 14:34:43 2018
@@ -20,6 +20,7 @@
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopIterator.h"
#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Dominators.h"
@@ -30,6 +31,7 @@
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Metadata.h"
+#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
@@ -46,6 +48,7 @@
#include <limits>
using namespace llvm;
+using namespace llvm::PatternMatch;
#define DEBUG_TYPE "loop-unroll"
@@ -136,10 +139,87 @@ static unsigned calculateIterationsToInv
return ToInvariance;
}
+// Return the number of iterations to peel off that make conditions in the
+// body true/false. For example, if we peel 2 iterations off the loop below,
+// the condition i < 2 can be evaluated at compile time.
+// for (i = 0; i < n; i++)
+// if (i < 2)
+// ..
+// else
+// ..
+// }
+static unsigned countToEliminateCompares(Loop &L, unsigned MaxPeelCount,
+ ScalarEvolution &SE) {
+ assert(L.isLoopSimplifyForm() && "Loop needs to be in loop simplify form");
+ unsigned DesiredPeelCount = 0;
+
+ for (auto *BB : L.blocks()) {
+ auto *BI = dyn_cast<BranchInst>(BB->getTerminator());
+ if (!BI || BI->isUnconditional())
+ continue;
+
+ // Ignore loop exit condition.
+ if (L.getLoopLatch() == BB)
+ continue;
+
+ Value *Condition = BI->getCondition();
+ Value *LeftVal, *RightVal;
+ CmpInst::Predicate Pred;
+ if (!match(Condition, m_ICmp(Pred, m_Value(LeftVal), m_Value(RightVal))))
+ continue;
+
+ const SCEV *LeftSCEV = SE.getSCEV(LeftVal);
+ const SCEV *RightSCEV = SE.getSCEV(RightVal);
+
+ // Do not consider predicates that are known to be true or false
+ // independently of the loop iteration.
+ if (SE.isKnownPredicate(Pred, LeftSCEV, RightSCEV) ||
+ SE.isKnownPredicate(ICmpInst::getInversePredicate(Pred), LeftSCEV,
+ RightSCEV))
+ continue;
+
+ // Check if we have a condition with one AddRec and one non AddRec
+ // expression. Normalize LeftSCEV to be the AddRec.
+ if (!isa<SCEVAddRecExpr>(LeftSCEV)) {
+ if (isa<SCEVAddRecExpr>(RightSCEV)) {
+ std::swap(LeftSCEV, RightSCEV);
+ Pred = ICmpInst::getSwappedPredicate(Pred);
+ } else
+ continue;
+ }
+
+ const SCEVAddRecExpr *LeftAR = cast<SCEVAddRecExpr>(LeftSCEV);
+
+ // Avoid huge SCEV computations in the loop below and make sure we only
+ // consider AddRecs of the loop we are trying to peel.
+ if (!LeftAR->isAffine() || LeftAR->getLoop() != &L)
+ continue;
+
+ // Check if extending DesiredPeelCount lets us evaluate Pred.
+ const SCEV *IterVal = LeftAR->evaluateAtIteration(
+ SE.getConstant(LeftSCEV->getType(), DesiredPeelCount), SE);
+
+ // If the original condition is not known, get the negated predicate
+ // (which holds on the else branch) and check if it is known. This allows
+ // us to peel of iterations that make the original condition false.
+ if (!SE.isKnownPredicate(Pred, IterVal, RightSCEV))
+ Pred = ICmpInst::getInversePredicate(Pred);
+
+ const SCEV *Step = LeftAR->getStepRecurrence(SE);
+ while (DesiredPeelCount < MaxPeelCount &&
+ SE.isKnownPredicate(Pred, IterVal, RightSCEV)) {
+ IterVal = SE.getAddExpr(IterVal, Step);
+ DesiredPeelCount++;
+ }
+ }
+
+ return DesiredPeelCount;
+}
+
// Return the number of iterations we want to peel off.
void llvm::computePeelCount(Loop *L, unsigned LoopSize,
TargetTransformInfo::UnrollingPreferences &UP,
- unsigned &TripCount) {
+ unsigned &TripCount, ScalarEvolution &SE) {
assert(LoopSize > 0 && "Zero loop size is not allowed!");
UP.PeelCount = 0;
if (!canPeel(L))
@@ -170,10 +250,15 @@ void llvm::computePeelCount(Loop *L, uns
if (ToInvariance != InfiniteIterationsToInvariance)
DesiredPeelCount = std::max(DesiredPeelCount, ToInvariance);
}
+
+ // Pay respect to limitations implied by loop size and the max peel count.
+ unsigned MaxPeelCount = UnrollPeelMaxCount;
+ MaxPeelCount = std::min(MaxPeelCount, UP.Threshold / LoopSize - 1);
+
+ DesiredPeelCount = std::max(DesiredPeelCount,
+ countToEliminateCompares(*L, MaxPeelCount, SE));
+
if (DesiredPeelCount > 0) {
- // Pay respect to limitations implied by loop size and the max peel count.
- unsigned MaxPeelCount = UnrollPeelMaxCount;
- MaxPeelCount = std::min(MaxPeelCount, UP.Threshold / LoopSize - 1);
DesiredPeelCount = std::min(DesiredPeelCount, MaxPeelCount);
// Consider max peel count limitation.
assert(DesiredPeelCount > 0 && "Wrong loop size estimation?");
Modified: llvm/trunk/test/Transforms/LoopUnroll/complete_unroll_profitability_with_assume.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/complete_unroll_profitability_with_assume.ll?rev=327671&r1=327670&r2=327671&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopUnroll/complete_unroll_profitability_with_assume.ll (original)
+++ llvm/trunk/test/Transforms/LoopUnroll/complete_unroll_profitability_with_assume.ll Thu Mar 15 14:34:43 2018
@@ -10,7 +10,7 @@
; not unrolled without such analysis:
; RUN: opt -S < %s -loop-unroll -unroll-threshold=42 -unroll-max-iteration-count-to-analyze=2 \
-; RUN: | FileCheck %s --check-prefix=DONT-ANALYZE-FULL
+; RUN: -unroll-peel-max-count=0 | FileCheck %s --check-prefix=DONT-ANALYZE-FULL
; Function Attrs: nounwind
declare void @llvm.assume(i1) #1
Added: llvm/trunk/test/Transforms/LoopUnroll/peel-loop-conditions.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/peel-loop-conditions.ll?rev=327671&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopUnroll/peel-loop-conditions.ll (added)
+++ llvm/trunk/test/Transforms/LoopUnroll/peel-loop-conditions.ll Thu Mar 15 14:34:43 2018
@@ -0,0 +1,613 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -S -loop-unroll -verify-dom-info | FileCheck %s
+
+declare void @f1()
+declare void @f2()
+
+; Check that we can peel off iterations that make conditions true.
+define void @test1(i32 %k) {
+; CHECK-LABEL: @test1(
+; CHECK-NEXT: for.body.lr.ph:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_BEGIN:%.*]]
+; CHECK: for.body.peel.begin:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL:%.*]]
+; CHECK: for.body.peel:
+; CHECK-NEXT: [[CMP1_PEEL:%.*]] = icmp ult i32 0, 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL]], label [[IF_THEN_PEEL:%.*]], label [[IF_ELSE_PEEL:%.*]]
+; CHECK: if.else.peel:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC_PEEL:%.*]]
+; CHECK: if.then.peel:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL]]
+; CHECK: for.inc.peel:
+; CHECK-NEXT: [[INC_PEEL:%.*]] = add nsw i32 0, 1
+; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
+; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
+; CHECK: for.body.peel.next:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL2:%.*]]
+; CHECK: for.body.peel2:
+; CHECK-NEXT: [[CMP1_PEEL3:%.*]] = icmp ult i32 [[INC_PEEL]], 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL3]], label [[IF_THEN_PEEL5:%.*]], label [[IF_ELSE_PEEL4:%.*]]
+; CHECK: if.else.peel4:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC_PEEL6:%.*]]
+; CHECK: if.then.peel5:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL6]]
+; CHECK: for.inc.peel6:
+; CHECK-NEXT: [[INC_PEEL7:%.*]] = add nsw i32 [[INC_PEEL]], 1
+; CHECK-NEXT: [[CMP_PEEL8:%.*]] = icmp slt i32 [[INC_PEEL7]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL8]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next1:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_NEXT9:%.*]]
+; CHECK: for.body.peel.next9:
+; CHECK-NEXT: br label [[FOR_BODY_LR_PH_PEEL_NEWPH:%.*]]
+; CHECK: for.body.lr.ph.peel.newph:
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.body:
+; CHECK-NEXT: [[I_05:%.*]] = phi i32 [ [[INC_PEEL7]], [[FOR_BODY_LR_PH_PEEL_NEWPH]] ], [ [[INC:%.*]], [[FOR_INC:%.*]] ]
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i32 [[I_05]], 2
+; CHECK-NEXT: br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK: if.then:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: if.else:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: for.inc:
+; CHECK-NEXT: [[INC]] = add nsw i32 [[I_05]], 1
+; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
+; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !0
+; CHECK: for.end.loopexit:
+; CHECK-NEXT: br label [[FOR_END]]
+; CHECK: for.end:
+; CHECK-NEXT: ret void
+;
+for.body.lr.ph:
+ br label %for.body
+
+for.body:
+ %i.05 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.inc ]
+ %cmp1 = icmp ult i32 %i.05, 2
+ br i1 %cmp1, label %if.then, label %if.else
+
+if.then:
+ call void @f1()
+ br label %for.inc
+
+if.else:
+ call void @f2()
+ br label %for.inc
+
+for.inc:
+ %inc = add nsw i32 %i.05, 1
+ %cmp = icmp slt i32 %inc, %k
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end:
+ ret void
+}
+
+; Check we peel off the maximum number of iterations that make conditions true.
+define void @test2(i32 %k) {
+; CHECK-LABEL: @test2(
+; CHECK-NEXT: for.body.lr.ph:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_BEGIN:%.*]]
+; CHECK: for.body.peel.begin:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL:%.*]]
+; CHECK: for.body.peel:
+; CHECK-NEXT: [[CMP1_PEEL:%.*]] = icmp ult i32 0, 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL]], label [[IF_THEN_PEEL:%.*]], label [[IF_ELSE_PEEL:%.*]]
+; CHECK: if.else.peel:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[IF2_PEEL:%.*]]
+; CHECK: if.then.peel:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[IF2_PEEL]]
+; CHECK: if2.peel:
+; CHECK-NEXT: [[CMP2_PEEL:%.*]] = icmp ult i32 0, 4
+; CHECK-NEXT: br i1 [[CMP2_PEEL]], label [[IF_THEN2_PEEL:%.*]], label [[FOR_INC_PEEL:%.*]]
+; CHECK: if.then2.peel:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL]]
+; CHECK: for.inc.peel:
+; CHECK-NEXT: [[INC_PEEL:%.*]] = add nsw i32 0, 1
+; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
+; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
+; CHECK: for.body.peel.next:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL2:%.*]]
+; CHECK: for.body.peel2:
+; CHECK-NEXT: [[CMP1_PEEL3:%.*]] = icmp ult i32 [[INC_PEEL]], 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL3]], label [[IF_THEN_PEEL5:%.*]], label [[IF_ELSE_PEEL4:%.*]]
+; CHECK: if.else.peel4:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[IF2_PEEL6:%.*]]
+; CHECK: if.then.peel5:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[IF2_PEEL6]]
+; CHECK: if2.peel6:
+; CHECK-NEXT: [[CMP2_PEEL7:%.*]] = icmp ult i32 [[INC_PEEL]], 4
+; CHECK-NEXT: br i1 [[CMP2_PEEL7]], label [[IF_THEN2_PEEL8:%.*]], label [[FOR_INC_PEEL9:%.*]]
+; CHECK: if.then2.peel8:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL9]]
+; CHECK: for.inc.peel9:
+; CHECK-NEXT: [[INC_PEEL10:%.*]] = add nsw i32 [[INC_PEEL]], 1
+; CHECK-NEXT: [[CMP_PEEL11:%.*]] = icmp slt i32 [[INC_PEEL10]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL11]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next1:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL13:%.*]]
+; CHECK: for.body.peel13:
+; CHECK-NEXT: [[CMP1_PEEL14:%.*]] = icmp ult i32 [[INC_PEEL10]], 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL14]], label [[IF_THEN_PEEL16:%.*]], label [[IF_ELSE_PEEL15:%.*]]
+; CHECK: if.else.peel15:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[IF2_PEEL17:%.*]]
+; CHECK: if.then.peel16:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[IF2_PEEL17]]
+; CHECK: if2.peel17:
+; CHECK-NEXT: [[CMP2_PEEL18:%.*]] = icmp ult i32 [[INC_PEEL10]], 4
+; CHECK-NEXT: br i1 [[CMP2_PEEL18]], label [[IF_THEN2_PEEL19:%.*]], label [[FOR_INC_PEEL20:%.*]]
+; CHECK: if.then2.peel19:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL20]]
+; CHECK: for.inc.peel20:
+; CHECK-NEXT: [[INC_PEEL21:%.*]] = add nsw i32 [[INC_PEEL10]], 1
+; CHECK-NEXT: [[CMP_PEEL22:%.*]] = icmp slt i32 [[INC_PEEL21]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL22]], label [[FOR_BODY_PEEL_NEXT12:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next12:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL24:%.*]]
+; CHECK: for.body.peel24:
+; CHECK-NEXT: [[CMP1_PEEL25:%.*]] = icmp ult i32 [[INC_PEEL21]], 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL25]], label [[IF_THEN_PEEL27:%.*]], label [[IF_ELSE_PEEL26:%.*]]
+; CHECK: if.else.peel26:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[IF2_PEEL28:%.*]]
+; CHECK: if.then.peel27:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[IF2_PEEL28]]
+; CHECK: if2.peel28:
+; CHECK-NEXT: [[CMP2_PEEL29:%.*]] = icmp ult i32 [[INC_PEEL21]], 4
+; CHECK-NEXT: br i1 [[CMP2_PEEL29]], label [[IF_THEN2_PEEL30:%.*]], label [[FOR_INC_PEEL31:%.*]]
+; CHECK: if.then2.peel30:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL31]]
+; CHECK: for.inc.peel31:
+; CHECK-NEXT: [[INC_PEEL32:%.*]] = add nsw i32 [[INC_PEEL21]], 1
+; CHECK-NEXT: [[CMP_PEEL33:%.*]] = icmp slt i32 [[INC_PEEL32]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL33]], label [[FOR_BODY_PEEL_NEXT23:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next23:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_NEXT34:%.*]]
+; CHECK: for.body.peel.next34:
+; CHECK-NEXT: br label [[FOR_BODY_LR_PH_PEEL_NEWPH:%.*]]
+; CHECK: for.body.lr.ph.peel.newph:
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.body:
+; CHECK-NEXT: [[I_05:%.*]] = phi i32 [ [[INC_PEEL32]], [[FOR_BODY_LR_PH_PEEL_NEWPH]] ], [ [[INC:%.*]], [[FOR_INC:%.*]] ]
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i32 [[I_05]], 2
+; CHECK-NEXT: br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK: if.then:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[IF2:%.*]]
+; CHECK: if.else:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[IF2]]
+; CHECK: if2:
+; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i32 [[I_05]], 4
+; CHECK-NEXT: br i1 [[CMP2]], label [[IF_THEN2:%.*]], label [[FOR_INC]]
+; CHECK: if.then2:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: for.inc:
+; CHECK-NEXT: [[INC]] = add nsw i32 [[I_05]], 1
+; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
+; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !2
+; CHECK: for.end.loopexit:
+; CHECK-NEXT: br label [[FOR_END]]
+; CHECK: for.end:
+; CHECK-NEXT: ret void
+;
+for.body.lr.ph:
+ br label %for.body
+
+for.body:
+ %i.05 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.inc ]
+ %cmp1 = icmp ult i32 %i.05, 2
+ br i1 %cmp1, label %if.then, label %if.else
+
+if.then:
+ call void @f1()
+ br label %if2
+
+if.else:
+ call void @f2()
+ br label %if2
+
+if2:
+ %cmp2 = icmp ult i32 %i.05, 4
+ br i1 %cmp2, label %if.then2, label %for.inc
+
+if.then2:
+ call void @f1()
+ br label %for.inc
+
+for.inc:
+ %inc = add nsw i32 %i.05, 1
+ %cmp = icmp slt i32 %inc, %k
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end:
+ ret void
+}
+
+; Check that we can peel off iterations that make a condition false.
+define void @test3(i32 %k) {
+; CHECK-LABEL: @test3(
+; CHECK-NEXT: for.body.lr.ph:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_BEGIN:%.*]]
+; CHECK: for.body.peel.begin:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL:%.*]]
+; CHECK: for.body.peel:
+; CHECK-NEXT: [[CMP1_PEEL:%.*]] = icmp ugt i32 0, 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL]], label [[IF_THEN_PEEL:%.*]], label [[IF_ELSE_PEEL:%.*]]
+; CHECK: if.else.peel:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC_PEEL:%.*]]
+; CHECK: if.then.peel:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL]]
+; CHECK: for.inc.peel:
+; CHECK-NEXT: [[INC_PEEL:%.*]] = add nsw i32 0, 1
+; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
+; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
+; CHECK: for.body.peel.next:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL2:%.*]]
+; CHECK: for.body.peel2:
+; CHECK-NEXT: [[CMP1_PEEL3:%.*]] = icmp ugt i32 [[INC_PEEL]], 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL3]], label [[IF_THEN_PEEL5:%.*]], label [[IF_ELSE_PEEL4:%.*]]
+; CHECK: if.else.peel4:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC_PEEL6:%.*]]
+; CHECK: if.then.peel5:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL6]]
+; CHECK: for.inc.peel6:
+; CHECK-NEXT: [[INC_PEEL7:%.*]] = add nsw i32 [[INC_PEEL]], 1
+; CHECK-NEXT: [[CMP_PEEL8:%.*]] = icmp slt i32 [[INC_PEEL7]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL8]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next1:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL10:%.*]]
+; CHECK: for.body.peel10:
+; CHECK-NEXT: [[CMP1_PEEL11:%.*]] = icmp ugt i32 [[INC_PEEL7]], 2
+; CHECK-NEXT: br i1 [[CMP1_PEEL11]], label [[IF_THEN_PEEL13:%.*]], label [[IF_ELSE_PEEL12:%.*]]
+; CHECK: if.else.peel12:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC_PEEL14:%.*]]
+; CHECK: if.then.peel13:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL14]]
+; CHECK: for.inc.peel14:
+; CHECK-NEXT: [[INC_PEEL15:%.*]] = add nsw i32 [[INC_PEEL7]], 1
+; CHECK-NEXT: [[CMP_PEEL16:%.*]] = icmp slt i32 [[INC_PEEL15]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL16]], label [[FOR_BODY_PEEL_NEXT9:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next9:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_NEXT17:%.*]]
+; CHECK: for.body.peel.next17:
+; CHECK-NEXT: br label [[FOR_BODY_LR_PH_PEEL_NEWPH:%.*]]
+; CHECK: for.body.lr.ph.peel.newph:
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.body:
+; CHECK-NEXT: [[I_05:%.*]] = phi i32 [ [[INC_PEEL15]], [[FOR_BODY_LR_PH_PEEL_NEWPH]] ], [ [[INC:%.*]], [[FOR_INC:%.*]] ]
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt i32 [[I_05]], 2
+; CHECK-NEXT: br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK: if.then:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: if.else:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: for.inc:
+; CHECK-NEXT: [[INC]] = add nsw i32 [[I_05]], 1
+; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
+; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !3
+; CHECK: for.end.loopexit:
+; CHECK-NEXT: br label [[FOR_END]]
+; CHECK: for.end:
+; CHECK-NEXT: ret void
+;
+for.body.lr.ph:
+ br label %for.body
+
+for.body:
+ %i.05 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.inc ]
+ %cmp1 = icmp ugt i32 %i.05, 2
+ br i1 %cmp1, label %if.then, label %if.else
+
+if.then:
+ call void @f1()
+ br label %for.inc
+
+if.else:
+ call void @f2()
+ br label %for.inc
+
+for.inc:
+ %inc = add nsw i32 %i.05, 1
+ %cmp = icmp slt i32 %inc, %k
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end:
+ ret void
+}
+
+; Test that we respect MaxPeelCount
+define void @test4(i32 %k) {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT: for.body.lr.ph:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_BEGIN:%.*]]
+; CHECK: for.body.peel.begin:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL:%.*]]
+; CHECK: for.body.peel:
+; CHECK-NEXT: [[CMP1_PEEL:%.*]] = icmp ugt i32 0, 9999
+; CHECK-NEXT: br i1 [[CMP1_PEEL]], label [[IF_THEN_PEEL:%.*]], label [[FOR_INC_PEEL:%.*]]
+; CHECK: if.then.peel:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL]]
+; CHECK: for.inc.peel:
+; CHECK-NEXT: [[INC_PEEL:%.*]] = add nsw i32 0, 1
+; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
+; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
+; CHECK: for.body.peel.next:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL2:%.*]]
+; CHECK: for.body.peel2:
+; CHECK-NEXT: [[CMP1_PEEL3:%.*]] = icmp ugt i32 [[INC_PEEL]], 9999
+; CHECK-NEXT: br i1 [[CMP1_PEEL3]], label [[IF_THEN_PEEL4:%.*]], label [[FOR_INC_PEEL5:%.*]]
+; CHECK: if.then.peel4:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL5]]
+; CHECK: for.inc.peel5:
+; CHECK-NEXT: [[INC_PEEL6:%.*]] = add nsw i32 [[INC_PEEL]], 1
+; CHECK-NEXT: [[CMP_PEEL7:%.*]] = icmp slt i32 [[INC_PEEL6]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL7]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next1:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL9:%.*]]
+; CHECK: for.body.peel9:
+; CHECK-NEXT: [[CMP1_PEEL10:%.*]] = icmp ugt i32 [[INC_PEEL6]], 9999
+; CHECK-NEXT: br i1 [[CMP1_PEEL10]], label [[IF_THEN_PEEL11:%.*]], label [[FOR_INC_PEEL12:%.*]]
+; CHECK: if.then.peel11:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL12]]
+; CHECK: for.inc.peel12:
+; CHECK-NEXT: [[INC_PEEL13:%.*]] = add nsw i32 [[INC_PEEL6]], 1
+; CHECK-NEXT: [[CMP_PEEL14:%.*]] = icmp slt i32 [[INC_PEEL13]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL14]], label [[FOR_BODY_PEEL_NEXT8:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next8:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL16:%.*]]
+; CHECK: for.body.peel16:
+; CHECK-NEXT: [[CMP1_PEEL17:%.*]] = icmp ugt i32 [[INC_PEEL13]], 9999
+; CHECK-NEXT: br i1 [[CMP1_PEEL17]], label [[IF_THEN_PEEL18:%.*]], label [[FOR_INC_PEEL19:%.*]]
+; CHECK: if.then.peel18:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL19]]
+; CHECK: for.inc.peel19:
+; CHECK-NEXT: [[INC_PEEL20:%.*]] = add nsw i32 [[INC_PEEL13]], 1
+; CHECK-NEXT: [[CMP_PEEL21:%.*]] = icmp slt i32 [[INC_PEEL20]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL21]], label [[FOR_BODY_PEEL_NEXT15:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next15:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL23:%.*]]
+; CHECK: for.body.peel23:
+; CHECK-NEXT: [[CMP1_PEEL24:%.*]] = icmp ugt i32 [[INC_PEEL20]], 9999
+; CHECK-NEXT: br i1 [[CMP1_PEEL24]], label [[IF_THEN_PEEL25:%.*]], label [[FOR_INC_PEEL26:%.*]]
+; CHECK: if.then.peel25:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL26]]
+; CHECK: for.inc.peel26:
+; CHECK-NEXT: [[INC_PEEL27:%.*]] = add nsw i32 [[INC_PEEL20]], 1
+; CHECK-NEXT: [[CMP_PEEL28:%.*]] = icmp slt i32 [[INC_PEEL27]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL28]], label [[FOR_BODY_PEEL_NEXT22:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next22:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL30:%.*]]
+; CHECK: for.body.peel30:
+; CHECK-NEXT: [[CMP1_PEEL31:%.*]] = icmp ugt i32 [[INC_PEEL27]], 9999
+; CHECK-NEXT: br i1 [[CMP1_PEEL31]], label [[IF_THEN_PEEL32:%.*]], label [[FOR_INC_PEEL33:%.*]]
+; CHECK: if.then.peel32:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL33]]
+; CHECK: for.inc.peel33:
+; CHECK-NEXT: [[INC_PEEL34:%.*]] = add nsw i32 [[INC_PEEL27]], 1
+; CHECK-NEXT: [[CMP_PEEL35:%.*]] = icmp slt i32 [[INC_PEEL34]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL35]], label [[FOR_BODY_PEEL_NEXT29:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next29:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL37:%.*]]
+; CHECK: for.body.peel37:
+; CHECK-NEXT: [[CMP1_PEEL38:%.*]] = icmp ugt i32 [[INC_PEEL34]], 9999
+; CHECK-NEXT: br i1 [[CMP1_PEEL38]], label [[IF_THEN_PEEL39:%.*]], label [[FOR_INC_PEEL40:%.*]]
+; CHECK: if.then.peel39:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL40]]
+; CHECK: for.inc.peel40:
+; CHECK-NEXT: [[INC_PEEL41:%.*]] = add nsw i32 [[INC_PEEL34]], 1
+; CHECK-NEXT: [[CMP_PEEL42:%.*]] = icmp slt i32 [[INC_PEEL41]], [[K]]
+; CHECK-NEXT: br i1 [[CMP_PEEL42]], label [[FOR_BODY_PEEL_NEXT36:%.*]], label [[FOR_END]]
+; CHECK: for.body.peel.next36:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_NEXT43:%.*]]
+; CHECK: for.body.peel.next43:
+; CHECK-NEXT: br label [[FOR_BODY_LR_PH_PEEL_NEWPH:%.*]]
+; CHECK: for.body.lr.ph.peel.newph:
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.body:
+; CHECK-NEXT: [[I_05:%.*]] = phi i32 [ [[INC_PEEL41]], [[FOR_BODY_LR_PH_PEEL_NEWPH]] ], [ [[INC:%.*]], [[FOR_INC:%.*]] ]
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt i32 [[I_05]], 9999
+; CHECK-NEXT: br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[FOR_INC]]
+; CHECK: if.then:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: for.inc:
+; CHECK-NEXT: [[INC]] = add nsw i32 [[I_05]], 1
+; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
+; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !4
+; CHECK: for.end.loopexit:
+; CHECK-NEXT: br label [[FOR_END]]
+; CHECK: for.end:
+; CHECK-NEXT: ret void
+;
+for.body.lr.ph:
+ br label %for.body
+
+for.body:
+ %i.05 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.inc ]
+ %cmp1 = icmp ugt i32 %i.05, 9999
+ br i1 %cmp1, label %if.then, label %for.inc
+
+if.then:
+ call void @f1()
+ br label %for.inc
+
+for.inc:
+ %inc = add nsw i32 %i.05, 1
+ %cmp = icmp slt i32 %inc, %k
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end:
+ ret void
+}
+
+; In this case we cannot peel the inner loop, because the condition involves
+; the outer induction variable.
+define void @test5(i32 %k) {
+; CHECK-LABEL: @test5(
+; CHECK-NEXT: for.body.lr.ph:
+; CHECK-NEXT: br label [[OUTER_HEADER:%.*]]
+; CHECK: outer.header:
+; CHECK-NEXT: [[J:%.*]] = phi i32 [ 0, [[FOR_BODY_LR_PH:%.*]] ], [ [[J_INC:%.*]], [[OUTER_INC:%.*]] ]
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.body:
+; CHECK-NEXT: [[I_05:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[INC:%.*]], [[FOR_INC:%.*]] ]
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i32 [[J]], 2
+; CHECK-NEXT: br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK: if.then:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: if.else:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: for.inc:
+; CHECK-NEXT: [[INC]] = add nsw i32 [[I_05]], 1
+; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K:%.*]]
+; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[OUTER_INC]]
+; CHECK: outer.inc:
+; CHECK-NEXT: [[J_INC]] = add nsw i32 [[J]], 1
+; CHECK-NEXT: [[OUTER_CMP:%.*]] = icmp slt i32 [[J_INC]], [[K]]
+; CHECK-NEXT: br i1 [[OUTER_CMP]], label [[OUTER_HEADER]], label [[FOR_END:%.*]]
+; CHECK: for.end:
+; CHECK-NEXT: ret void
+;
+for.body.lr.ph:
+ br label %outer.header
+
+outer.header:
+ %j = phi i32 [ 0, %for.body.lr.ph ], [ %j.inc, %outer.inc ]
+ br label %for.body
+
+for.body:
+ %i.05 = phi i32 [ 0, %outer.header ], [ %inc, %for.inc ]
+ %cmp1 = icmp ult i32 %j, 2
+ br i1 %cmp1, label %if.then, label %if.else
+
+if.then:
+ call void @f1()
+ br label %for.inc
+
+if.else:
+ call void @f2()
+ br label %for.inc
+
+for.inc:
+ %inc = add nsw i32 %i.05, 1
+ %cmp = icmp slt i32 %inc, %k
+ br i1 %cmp, label %for.body, label %outer.inc
+
+outer.inc:
+ %j.inc = add nsw i32 %j, 1
+ %outer.cmp = icmp slt i32 %j.inc, %k
+ br i1 %outer.cmp, label %outer.header, label %for.end
+
+
+for.end:
+ ret void
+}
+
+define void @test6(i32 %k) {
+; CHECK-LABEL: @test6(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_BEGIN:%.*]]
+; CHECK: for.body.peel.begin:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL:%.*]]
+; CHECK: for.body.peel:
+; CHECK-NEXT: [[CMP1_PEEL:%.*]] = icmp ult i32 0, 4
+; CHECK-NEXT: br i1 [[CMP1_PEEL]], label [[IF_THEN_PEEL:%.*]], label [[IF_ELSE_PEEL:%.*]]
+; CHECK: if.else.peel:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC_PEEL:%.*]]
+; CHECK: if.then.peel:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC_PEEL]]
+; CHECK: for.inc.peel:
+; CHECK-NEXT: [[INC_PEEL:%.*]] = add nsw i32 0, 2
+; CHECK-NEXT: [[J_INC_PEEL:%.*]] = add nsw i32 4, 1
+; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
+; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
+; CHECK: for.body.peel.next:
+; CHECK-NEXT: br label [[FOR_BODY_PEEL_NEXT1:%.*]]
+; CHECK: for.body.peel.next1:
+; CHECK-NEXT: br label [[ENTRY_PEEL_NEWPH:%.*]]
+; CHECK: entry.peel.newph:
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.body:
+; CHECK-NEXT: [[I_05:%.*]] = phi i32 [ [[INC_PEEL]], [[ENTRY_PEEL_NEWPH]] ], [ [[INC:%.*]], [[FOR_INC:%.*]] ]
+; CHECK-NEXT: [[J:%.*]] = phi i32 [ [[INC_PEEL]], [[ENTRY_PEEL_NEWPH]] ], [ [[INC]], [[FOR_INC]] ]
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i32 [[I_05]], [[J]]
+; CHECK-NEXT: br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK: if.then:
+; CHECK-NEXT: call void @f1()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: if.else:
+; CHECK-NEXT: call void @f2()
+; CHECK-NEXT: br label [[FOR_INC]]
+; CHECK: for.inc:
+; CHECK-NEXT: [[INC]] = add nsw i32 [[I_05]], 2
+; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
+; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !5
+; CHECK: for.end.loopexit:
+; CHECK-NEXT: br label [[FOR_END]]
+; CHECK: for.end:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %for.body
+
+for.body:
+ %i.05 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
+ %j = phi i32 [ 4, %entry ], [ %inc, %for.inc ]
+ %cmp1 = icmp ult i32 %i.05, %j
+ br i1 %cmp1, label %if.then, label %if.else
+
+if.then:
+ call void @f1()
+ br label %for.inc
+
+if.else:
+ call void @f2()
+ br label %for.inc
+
+for.inc:
+ %inc = add nsw i32 %i.05, 2
+ %j.inc = add nsw i32 %j, 1
+ %cmp = icmp slt i32 %inc, %k
+ br i1 %cmp, label %for.body, label %for.end
+
+for.end:
+ ret void
+}
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