[llvm] r303497 - [SCEV] Clarify behavior around max backedge taken count
Sanjoy Das via llvm-commits
llvm-commits at lists.llvm.org
Sat May 20 21:59:30 PDT 2017
Hi Vitaly,
I'm about to revert this change, but I have a question -- what this
failure seen when the ToT clang (built with a "known good" clang +
msan) tried to build itself, or when a bootstrapped clang (i.e. a
clang built with a ToT clang + msan) tried to bootstrap itself?
Thanks
-- Sanjoy
On Sat, May 20, 2017 at 9:49 PM, Vitaly Buka <vitalybuka at google.com> wrote:
> http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/1379/steps/check-llvm%20check-clang%20stage3%2Fmsan/logs/stdio
>
> FAILED: tools/llvm-xray/CMakeFiles/llvm-xray.dir/xray-color-helper.cc.o
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm_build_msan/bin/clang++
> -DGTEST_HAS_RTTI=0 -DLLVM_BUILD_GLOBAL_ISEL -D_DEBUG -D_GNU_SOURCE
> -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
> -Itools/llvm-xray
> -I/mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/llvm-xray
> -Iinclude
> -I/mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/include
> -fPIC -fvisibility-inlines-hidden -Werror=date-time -std=c++11 -Wall -W
> -Wno-unused-parameter -Wwrite-strings -Wcast-qual
> -Wmissing-field-initializers -pedantic -Wno-long-long
> -Wcovered-switch-default -Wnon-virtual-dtor -Wdelete-non-virtual-dtor
> -Wstring-conversion -fcolor-diagnostics -ffunction-sections -fdata-sections
> -O3 -UNDEBUG -fno-exceptions -fno-rtti -MD -MT
> tools/llvm-xray/CMakeFiles/llvm-xray.dir/xray-color-helper.cc.o -MF
> tools/llvm-xray/CMakeFiles/llvm-xray.dir/xray-color-helper.cc.o.d -o
> tools/llvm-xray/CMakeFiles/llvm-xray.dir/xray-color-helper.cc.o -c
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/llvm-xray/xray-color-helper.cc
> ==969==WARNING: MemorySanitizer: use-of-uninitialized-value
> #0 0x3533258 in
> llvm::X86InstrInfo::AnalyzeBranchImpl(llvm::MachineBasicBlock&,
> llvm::MachineBasicBlock*&, llvm::MachineBasicBlock*&,
> llvm::SmallVectorImpl<llvm::MachineOperand>&,
> llvm::SmallVectorImpl<llvm::MachineInstr*>&, bool) const
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Target/X86/X86InstrInfo.cpp:6093:22
> #1 0x353333d in
> llvm::X86InstrInfo::analyzeBranch(llvm::MachineBasicBlock&,
> llvm::MachineBasicBlock*&, llvm::MachineBasicBlock*&,
> llvm::SmallVectorImpl<llvm::MachineOperand>&, bool) const
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Target/X86/X86InstrInfo.cpp:6133:10
> #2 0x42fddcc in llvm::TailDuplicator::tailDuplicate(bool,
> llvm::MachineBasicBlock*, llvm::MachineBasicBlock*,
> llvm::SmallVectorImpl<llvm::MachineBasicBlock*>&,
> llvm::SmallVectorImpl<llvm::MachineInstr*>&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/TailDuplicator.cpp:837:10
> #3 0x42fab3a in llvm::TailDuplicator::tailDuplicateAndUpdate(bool,
> llvm::MachineBasicBlock*, llvm::MachineBasicBlock*,
> llvm::SmallVectorImpl<llvm::MachineBasicBlock*>*, llvm::function_ref<void
> (llvm::MachineBasicBlock*)>*)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/TailDuplicator.cpp:148:8
> #4 0x44e921b in (anonymous
> namespace)::MachineBlockPlacement::maybeTailDuplicateBlock(llvm::MachineBasicBlock*,
> llvm::MachineBasicBlock*, (anonymous namespace)::BlockChain&,
> llvm::SmallSetVector<llvm::MachineBasicBlock const*, 16u>*,
> llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::MachineBasicBlock,
> true, false, void>, false, false>&, bool&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/MachineBlockPlacement.cpp:2620:11
> #5 0x44cef5d in repeatedlyTailDuplicateBlock
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/MachineBlockPlacement.cpp:2501:13
> #6 0x44cef5d in (anonymous
> namespace)::MachineBlockPlacement::buildChain(llvm::MachineBasicBlock
> const*, (anonymous namespace)::BlockChain&,
> llvm::SmallSetVector<llvm::MachineBasicBlock const*, 16u>*)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/MachineBlockPlacement.cpp:1699
> #7 0x44b6970 in (anonymous
> namespace)::MachineBlockPlacement::buildCFGChains()
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/MachineBlockPlacement.cpp:2278:3
> #8 0x44b14a9 in (anonymous
> namespace)::MachineBlockPlacement::runOnMachineFunction(llvm::MachineFunction&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/MachineBlockPlacement.cpp:2696:3
> #9 0x3f6dcac in
> llvm::MachineFunctionPass::runOnFunction(llvm::Function&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/MachineFunctionPass.cpp:62:13
> #10 0x48e2bee in llvm::FPPassManager::runOnFunction(llvm::Function&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1519:27
> #11 0x48e32b4 in llvm::FPPassManager::runOnModule(llvm::Module&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1540:16
> #12 0x48e45d3 in runOnModule
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1596:27
> #13 0x48e45d3 in llvm::legacy::PassManagerImpl::run(llvm::Module&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1699
> #14 0x5d3e27e in EmitAssembly
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/lib/CodeGen/BackendUtil.cpp:792:19
> #15 0x5d3e27e in clang::EmitBackendOutput(clang::DiagnosticsEngine&,
> clang::HeaderSearchOptions const&, clang::CodeGenOptions const&,
> clang::TargetOptions const&, clang::LangOptions const&, llvm::DataLayout
> const&, llvm::Module*, clang::BackendAction,
> std::__1::unique_ptr<llvm::raw_pwrite_stream,
> std::__1::default_delete<llvm::raw_pwrite_stream> >)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/lib/CodeGen/BackendUtil.cpp:1101
> #16 0x74dfefe in
> clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/lib/CodeGen/CodeGenAction.cpp:258:7
> #17 0x848e176 in clang::ParseAST(clang::Sema&, bool, bool)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/lib/Parse/ParseAST.cpp:159:13
> #18 0x69f82ba in clang::FrontendAction::Execute()
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/lib/Frontend/FrontendAction.cpp:837:8
> #19 0x693a02c in
> clang::CompilerInstance::ExecuteAction(clang::FrontendAction&)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/lib/Frontend/CompilerInstance.cpp:970:11
> #20 0x6bc3705 in
> clang::ExecuteCompilerInvocation(clang::CompilerInstance*)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:249:25
> #21 0x976e25 in cc1_main(llvm::ArrayRef<char const*>, char const*,
> void*)
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/tools/driver/cc1_main.cpp:221:13
> #22 0x970ce7 in ExecuteCC1Tool
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/tools/driver/driver.cpp:299:12
> #23 0x970ce7 in main
> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/clang/tools/driver/driver.cpp:380
> #24 0x7f561ec5c82f in __libc_start_main
> (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
> #25 0x8f0d38 in _start
> (/mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm_build_msan/bin/clang-5.0+0x8f0d38)
>
>
> On Sat, May 20, 2017 at 6:47 PM, Sanjoy Das via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
>>
>> Author: sanjoy
>> Date: Sat May 20 20:47:50 2017
>> New Revision: 303497
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=303497&view=rev
>> Log:
>> [SCEV] Clarify behavior around max backedge taken count
>>
>> This change makes the split between the "exact" backedge taken count
>> and the "maximum" backedge taken count a bit more obvious. Both of
>> these are upper bounds on the number of times the loop header
>> executes (since SCEV does not account for most kinds of abnormal
>> control flow), but the latter is guaranteed to be a constant.
>>
>> There were a few places where the max backedge taken count *was* a
>> non-constant; I've changed those to compute constants instead.
>>
>> At this point, I'm not sure if the constant max backedge count can be
>> computed by calling `getUnsignedRange(Exact).getUnsignedMax()` without
>> losing precision. If it can, we can simplify even further by making
>> `getMaxBackedgeTakenCount` a thin wrapper around
>> `getBackedgeTakenCount` and `getUnsignedRange`.
>>
>> Modified:
>> llvm/trunk/include/llvm/Analysis/ScalarEvolution.h
>> llvm/trunk/lib/Analysis/ScalarEvolution.cpp
>> llvm/trunk/test/Analysis/ScalarEvolution/nsw.ll
>> llvm/trunk/test/Analysis/ScalarEvolution/trip-count-pow2.ll
>>
>> Modified: llvm/trunk/include/llvm/Analysis/ScalarEvolution.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ScalarEvolution.h?rev=303497&r1=303496&r2=303497&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/include/llvm/Analysis/ScalarEvolution.h (original)
>> +++ llvm/trunk/include/llvm/Analysis/ScalarEvolution.h Sat May 20 20:47:50
>> 2017
>> @@ -656,10 +656,12 @@ private:
>> /// Test whether this BackedgeTakenInfo contains complete
>> information.
>> bool hasFullInfo() const { return isComplete(); }
>>
>> - /// Return an expression indicating the exact backedge-taken count of
>> the
>> - /// loop if it is known or SCEVCouldNotCompute otherwise. This is the
>> - /// number of times the loop header can be guaranteed to execute,
>> minus
>> - /// one.
>> + /// Return an expression indicating the exact *backedge-taken*
>> + /// count of the loop if it is known or SCEVCouldNotCompute
>> + /// otherwise. If execution makes it to the backedge on every
>> + /// iteration (i.e. there are no abnormal exists like exception
>> + /// throws and thread exits) then this is the number of times the
>> + /// loop header will execute minus one.
>> ///
>> /// If the SCEV predicate associated with the answer can be different
>> /// from AlwaysTrue, we must add a (non null) Predicates argument.
>> @@ -1398,11 +1400,11 @@ public:
>> const SCEV *getExitCount(const Loop *L, BasicBlock *ExitingBlock);
>>
>> /// If the specified loop has a predictable backedge-taken count,
>> return it,
>> - /// otherwise return a SCEVCouldNotCompute object. The backedge-taken
>> count
>> - /// is the number of times the loop header will be branched to from
>> within
>> - /// the loop. This is one less than the trip count of the loop, since
>> it
>> - /// doesn't count the first iteration, when the header is branched to
>> from
>> - /// outside the loop.
>> + /// otherwise return a SCEVCouldNotCompute object. The backedge-taken
>> count is
>> + /// the number of times the loop header will be branched to from within
>> the
>> + /// loop, assuming there are no abnormal exists like exception throws.
>> This is
>> + /// one less than the trip count of the loop, since it doesn't count
>> the first
>> + /// iteration, when the header is branched to from outside the loop.
>> ///
>> /// Note that it is not valid to call this method on a loop without a
>> /// loop-invariant backedge-taken count (see
>> @@ -1417,8 +1419,10 @@ public:
>> const SCEV *getPredicatedBackedgeTakenCount(const Loop *L,
>> SCEVUnionPredicate
>> &Predicates);
>>
>> - /// Similar to getBackedgeTakenCount, except return the least SCEV
>> value
>> - /// that is known never to be less than the actual backedge taken
>> count.
>> + /// When successful, this returns a SCEVConstant that is greater than
>> or equal
>> + /// to (i.e. a "conservative over-approximation") of the value returend
>> by
>> + /// getBackedgeTakenCount. If such a value cannot be computed, it
>> returns the
>> + /// SCEVCouldNotCompute object.
>> const SCEV *getMaxBackedgeTakenCount(const Loop *L);
>>
>> /// Return true if the backedge taken count is either the value
>> returned by
>>
>> Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=303497&r1=303496&r2=303497&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
>> +++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Sat May 20 20:47:50 2017
>> @@ -5947,6 +5947,8 @@ ScalarEvolution::BackedgeTakenInfo::getM
>> if (any_of(ExitNotTaken, PredicateNotAlwaysTrue) || !getMax())
>> return SE->getCouldNotCompute();
>>
>> + assert((isa<SCEVCouldNotCompute>(getMax()) ||
>> isa<SCEVConstant>(getMax())) &&
>> + "No point in having a non-constant max backedge taken count!");
>> return getMax();
>> }
>>
>> @@ -5972,7 +5974,11 @@ bool ScalarEvolution::BackedgeTakenInfo:
>> }
>>
>> ScalarEvolution::ExitLimit::ExitLimit(const SCEV *E)
>> - : ExactNotTaken(E), MaxNotTaken(E), MaxOrZero(false) {}
>> + : ExactNotTaken(E), MaxNotTaken(E), MaxOrZero(false) {
>> + assert((isa<SCEVCouldNotCompute>(MaxNotTaken) ||
>> + isa<SCEVConstant>(MaxNotTaken)) &&
>> + "No point in having a non-constant max backedge taken count!");
>> +}
>>
>> ScalarEvolution::ExitLimit::ExitLimit(
>> const SCEV *E, const SCEV *M, bool MaxOrZero,
>> @@ -5981,6 +5987,9 @@ ScalarEvolution::ExitLimit::ExitLimit(
>> assert((isa<SCEVCouldNotCompute>(ExactNotTaken) ||
>> !isa<SCEVCouldNotCompute>(MaxNotTaken)) &&
>> "Exact is not allowed to be less precise than Max");
>> + assert((isa<SCEVCouldNotCompute>(MaxNotTaken) ||
>> + isa<SCEVConstant>(MaxNotTaken)) &&
>> + "No point in having a non-constant max backedge taken count!");
>> for (auto *PredSet : PredSetList)
>> for (auto *P : *PredSet)
>> addPredicate(P);
>> @@ -5989,11 +5998,19 @@ ScalarEvolution::ExitLimit::ExitLimit(
>> ScalarEvolution::ExitLimit::ExitLimit(
>> const SCEV *E, const SCEV *M, bool MaxOrZero,
>> const SmallPtrSetImpl<const SCEVPredicate *> &PredSet)
>> - : ExitLimit(E, M, MaxOrZero, {&PredSet}) {}
>> + : ExitLimit(E, M, MaxOrZero, {&PredSet}) {
>> + assert((isa<SCEVCouldNotCompute>(MaxNotTaken) ||
>> + isa<SCEVConstant>(MaxNotTaken)) &&
>> + "No point in having a non-constant max backedge taken count!");
>> +}
>>
>> ScalarEvolution::ExitLimit::ExitLimit(const SCEV *E, const SCEV *M,
>> bool MaxOrZero)
>> - : ExitLimit(E, M, MaxOrZero, None) {}
>> + : ExitLimit(E, M, MaxOrZero, None) {
>> + assert((isa<SCEVCouldNotCompute>(MaxNotTaken) ||
>> + isa<SCEVConstant>(MaxNotTaken)) &&
>> + "No point in having a non-constant max backedge taken count!");
>> +}
>>
>> /// Allocate memory for BackedgeTakenInfo and copy the not-taken count of
>> each
>> /// computable exit into a persistent ExitNotTakenInfo array.
>> @@ -6018,6 +6035,8 @@ ScalarEvolution::BackedgeTakenInfo::Back
>>
>> return ExitNotTakenInfo(ExitBB, EL.ExactNotTaken,
>> std::move(Predicate));
>> });
>> + assert((isa<SCEVCouldNotCompute>(MaxCount) ||
>> isa<SCEVConstant>(MaxCount)) &&
>> + "No point in having a non-constant max backedge taken count!");
>> }
>>
>> /// Invalidate this result and free the ExitNotTakenInfo array.
>> @@ -6279,7 +6298,7 @@ ScalarEvolution::ExitLimit ScalarEvoluti
>> // to not.
>> if (isa<SCEVCouldNotCompute>(MaxBECount) &&
>> !isa<SCEVCouldNotCompute>(BECount))
>> - MaxBECount = BECount;
>> + MaxBECount =
>> getConstant(getUnsignedRange(BECount).getUnsignedMax());
>>
>> return ExitLimit(BECount, MaxBECount, false,
>> {&EL0.Predicates, &EL1.Predicates});
>> @@ -7583,13 +7602,20 @@ ScalarEvolution::howFarToZero(const SCEV
>> loopHasNoAbnormalExits(AddRec->getLoop())) {
>> const SCEV *Exact =
>> getUDivExpr(Distance, CountDown ? getNegativeSCEV(Step) : Step);
>> - return ExitLimit(Exact, Exact, false, Predicates);
>> + const SCEV *Max =
>> + Exact == getCouldNotCompute()
>> + ? Exact
>> + : getConstant(getUnsignedRange(Exact).getUnsignedMax());
>> + return ExitLimit(Exact, Max, false, Predicates);
>> }
>>
>> // Solve the general equation.
>> - const SCEV *E = SolveLinEquationWithOverflow(
>> - StepC->getAPInt(), getNegativeSCEV(Start), *this);
>> - return ExitLimit(E, E, false, Predicates);
>> + const SCEV *E = SolveLinEquationWithOverflow(StepC->getAPInt(),
>> + getNegativeSCEV(Start),
>> *this);
>> + const SCEV *M = E == getCouldNotCompute()
>> + ? E
>> + :
>> getConstant(getUnsignedRange(E).getUnsignedMax());
>> + return ExitLimit(E, M, false, Predicates);
>> }
>>
>> ScalarEvolution::ExitLimit
>> @@ -9218,8 +9244,9 @@ ScalarEvolution::howManyLessThans(const
>> getConstant(StrideForMaxBECount), false);
>> }
>>
>> - if (isa<SCEVCouldNotCompute>(MaxBECount))
>> - MaxBECount = BECount;
>> + if (isa<SCEVCouldNotCompute>(MaxBECount) &&
>> + !isa<SCEVCouldNotCompute>(BECount))
>> + MaxBECount = getConstant(getUnsignedRange(BECount).getUnsignedMax());
>>
>> return ExitLimit(BECount, MaxBECount, MaxOrZero, Predicates);
>> }
>>
>> Modified: llvm/trunk/test/Analysis/ScalarEvolution/nsw.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/ScalarEvolution/nsw.ll?rev=303497&r1=303496&r2=303497&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/test/Analysis/ScalarEvolution/nsw.ll (original)
>> +++ llvm/trunk/test/Analysis/ScalarEvolution/nsw.ll Sat May 20 20:47:50
>> 2017
>> @@ -102,7 +102,7 @@ for.body.i.i:
>> %cmp.i.i = icmp eq i32* %ptrincdec.i.i, %end
>> br i1 %cmp.i.i, label %_ZSt4fillIPiiEvT_S1_RKT0_.exit, label
>> %for.body.i.i
>> ; CHECK: Loop %for.body.i.i: backedge-taken count is ((-4 + (-1 * %begin)
>> + %end) /u 4)
>> -; CHECK: Loop %for.body.i.i: max backedge-taken count is ((-4 + (-1 *
>> %begin) + %end) /u 4)
>> +; CHECK: Loop %for.body.i.i: max backedge-taken count is
>> 4611686018427387903
>> _ZSt4fillIPiiEvT_S1_RKT0_.exit: ; preds =
>> %for.body.i.i, %entry
>> ret void
>> }
>>
>> Modified: llvm/trunk/test/Analysis/ScalarEvolution/trip-count-pow2.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/ScalarEvolution/trip-count-pow2.ll?rev=303497&r1=303496&r2=303497&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/test/Analysis/ScalarEvolution/trip-count-pow2.ll (original)
>> +++ llvm/trunk/test/Analysis/ScalarEvolution/trip-count-pow2.ll Sat May 20
>> 20:47:50 2017
>> @@ -14,7 +14,7 @@ exit:
>>
>> ; CHECK-LABEL: @test1
>> ; CHECK: Loop %loop: backedge-taken count is ((-32 + (96 * %n)) /u 32)
>> -; CHECK: Loop %loop: max backedge-taken count is ((-32 + (96 * %n)) /u
>> 32)
>> +; CHECK: Loop %loop: max backedge-taken count is 134217727
>> }
>>
>> ; PR19183
>> @@ -32,7 +32,7 @@ exit:
>>
>> ; CHECK-LABEL: @test2
>> ; CHECK: Loop %loop: backedge-taken count is ((-32 + (32 * (%n /u 32)))
>> /u 32)
>> -; CHECK: Loop %loop: max backedge-taken count is ((-32 + (32 * (%n /u
>> 32))) /u 32)
>> +; CHECK: Loop %loop: max backedge-taken count is 134217727
>> }
>>
>> define void @test3(i32 %n) {
>> @@ -49,7 +49,7 @@ exit:
>>
>> ; CHECK-LABEL: @test3
>> ; CHECK: Loop %loop: backedge-taken count is ((-32 + (32 * %n)) /u 32)
>> -; CHECK: Loop %loop: max backedge-taken count is ((-32 + (32 * %n)) /u
>> 32)
>> +; CHECK: Loop %loop: max backedge-taken count is 134217727
>> }
>>
>> define void @test4(i32 %n) {
>> @@ -66,7 +66,7 @@ exit:
>>
>> ; CHECK-LABEL: @test4
>> ; CHECK: Loop %loop: backedge-taken count is ((-4 + (-1431655764 * %n))
>> /u 4)
>> -; CHECK: Loop %loop: max backedge-taken count is ((-4 + (-1431655764 *
>> %n)) /u 4)
>> +; CHECK: Loop %loop: max backedge-taken count is 1073741823
>> }
>>
>> define void @test5(i32 %n) {
>> @@ -83,5 +83,5 @@ exit:
>>
>> ; CHECK-LABEL: @test5
>> ; CHECK: Loop %loop: backedge-taken count is ((-4 + (4 * %n)) /u 4)
>> -; CHECK: Loop %loop: max backedge-taken count is ((-4 + (4 * %n)) /u 4)
>> +; CHECK: Loop %loop: max backedge-taken count is 1073741823
>> }
>>
>>
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