[llvm] r245762 - Improve the determinism of MergeFunctions
JF Bastien via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 24 09:21:06 PDT 2015
Adding Jason, who authored the patch.
On Sat, Aug 22, 2015 at 5:32 PM, Mehdi Amini <mehdi.amini at apple.com> wrote:
> Hi,
>
>
> > On Aug 21, 2015, at 4:27 PM, JF Bastien via llvm-commits <
> llvm-commits at lists.llvm.org> wrote:
> >
> > Author: jfb
> > Date: Fri Aug 21 18:27:24 2015
> > New Revision: 245762
> >
> > URL:
> https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject-3Frev-3D245762-26view-3Drev&d=BQIGaQ&c=eEvniauFctOgLOKGJOplqw&r=v-ruWq0KCv2O3thJZiK6naxuXK8mQHZUmGq5FBtAmZ4&m=8AXWbmpresvhRsDs49PoX5gvb_41wieiXuHyjTJ5YMo&s=FoM7SY1rz3BRnUS5DPo6KV91Zjpw7DxGgcFb8AWousg&e=
> > Log:
> > Improve the determinism of MergeFunctions
> >
> > Summary:
> >
> > Merge functions previously relied on unsigned comparisons of pointer
> values to
> > order functions. This caused observable non-determinism in the compiler
> for
> > large bitcode programs. Basically, opt -mergefuncs program.bc | md5sum
> produces
> > different hashes when run repeatedly on the same machine. Differing
> output was
> > observed on three large bitcodes, but it was less frequent on the
> smallest file.
> > It is possible that this only manifests on the large inputs, hence
> remaining
> > undetected until now.
> >
> > This patch fixes this by removing (almost, see below) all places where
> > comparisons between pointers are used to order functions. Most of these
> changes
> > are local, but the comparison of global values requires assigning an
> identifier
> > to each local in the order it is visited. This is very similar to the
> way the
> > comparison function identifies Value*'s defined within a function.
> Because the
> > order of visiting the functions and their subparts is deterministic, the
> > identifiers assigned to the globals will be as well, and the order of
> functions
> > will be deterministic.
> >
> > With these changes, there is no more observed non-determinism. There is
> also
> > only minor slowdowns (negligible to 4%) compared to the baseline, which
> is
> > likely a result of the fact that global comparisons involve hash lookups
> and not
> > just pointer comparisons.
> >
> > The one caveat so far is that programs containing BlockAddress constants
> can
> > still be non-deterministic. It is not clear what the right solution is
> here. In
> > particular, even if the global numbers are used to order by function, we
> still
> > need a way to order the BasicBlock*'s. Unfortunately, we cannot just
> bail out
> > and fail to order the functions or consider them equal, because we
> require a
> > total order over functions. Note that programs with BlockAddress
> constants are
> > relatively rare, so the impact of leaving this in is minor as long as
> this pass
> > is opt-in.
> >
> > Author: jrkoenig
> >
> > Reviewers: nlewycky, jfb, dschuff
> >
> > Subscribers: jevinskie, llvm-commits, chapuni
> >
> > Differential revision:
> https://urldefense.proofpoint.com/v2/url?u=http-3A__reviews.llvm.org_D12168&d=BQIGaQ&c=eEvniauFctOgLOKGJOplqw&r=v-ruWq0KCv2O3thJZiK6naxuXK8mQHZUmGq5FBtAmZ4&m=8AXWbmpresvhRsDs49PoX5gvb_41wieiXuHyjTJ5YMo&s=p-0b5PAhXedHTFOoxIbiG0nruh9yDWiUogCym25HyvQ&e=
> >
> > Added:
> > llvm/trunk/test/Transforms/MergeFunc/constant-entire-value.ll
> > Modified:
> > llvm/trunk/lib/Transforms/IPO/MergeFunctions.cpp
> >
> > Modified: llvm/trunk/lib/Transforms/IPO/MergeFunctions.cpp
> > URL:
> https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_lib_Transforms_IPO_MergeFunctions.cpp-3Frev-3D245762-26r1-3D245761-26r2-3D245762-26view-3Ddiff&d=BQIGaQ&c=eEvniauFctOgLOKGJOplqw&r=v-ruWq0KCv2O3thJZiK6naxuXK8mQHZUmGq5FBtAmZ4&m=8AXWbmpresvhRsDs49PoX5gvb_41wieiXuHyjTJ5YMo&s=mdhMReHM3LfubUScGkXKDBloDc16X-lxEn4f_KZhc6Y&e=
> >
> ==============================================================================
> > --- llvm/trunk/lib/Transforms/IPO/MergeFunctions.cpp (original)
> > +++ llvm/trunk/lib/Transforms/IPO/MergeFunctions.cpp Fri Aug 21 18:27:24
> 2015
> > @@ -106,6 +106,7 @@
> > #include "llvm/IR/Module.h"
> > #include "llvm/IR/Operator.h"
> > #include "llvm/IR/ValueHandle.h"
> > +#include "llvm/IR/ValueMap.h"
> > #include "llvm/Pass.h"
> > #include "llvm/Support/CommandLine.h"
> > #include "llvm/Support/Debug.h"
> > @@ -130,14 +131,50 @@ static cl::opt<unsigned> NumFunctionsFor
> >
> > namespace {
> >
> > +/// GlobalNumberState assigns an integer to each global value in the
> program,
> > +/// which is used by the comparison routine to order references to
> globals. This
> > +/// state must be preserved throughout the pass, because Functions and
> other
> > +/// globals need to maintain their relative order. Globals are assigned
> a number
> > +/// when they are first visited. This order is deterministic, and so the
> > +/// assigned numbers are as well. When two functions are merged,
> neither number
> > +/// is updated. If the symbols are weak, this would be incorrect. If
> they are
> > +/// strong, then one will be replaced at all references to the other,
> and so
> > +/// direct callsites will now see one or the other symbol, and no
> update is
> > +/// necessary. Note that if we were guaranteed unique names, we could
> just
> > +/// compare those, but this would not work for stripped bitcodes or for
> those
> > +/// few symbols without a name.
> > +class GlobalNumberState {
> > + struct Config : ValueMapConfig<GlobalValue*> {
> > + enum { FollowRAUW = false };
> > + };
> > + // Each GlobalValue is mapped to an identifier. The Config ensures
> when RAUW
> > + // occurs, the mapping does not change. Tracking changes is
> unnecessary, and
> > + // also problematic for weak symbols (which may be overwritten).
> > + typedef ValueMap<GlobalValue *, uint64_t, Config> ValueNumberMap;
> > + ValueNumberMap GlobalNumbers;
> > + // The next unused serial number to assign to a global.
> > + uint64_t NextNumber;
> > + public:
> > + GlobalNumberState() : GlobalNumbers(), NextNumber(0) {}
> > + uint64_t getNumber(GlobalValue* Global) {
> > + ValueNumberMap::iterator MapIter;
> > + bool Inserted;
> > + std::tie(MapIter, Inserted) = GlobalNumbers.insert({Global,
> NextNumber});
> > + if (Inserted)
> > + NextNumber++;
> > + return MapIter->second;
> > + }
> > +};
> > +
> > /// FunctionComparator - Compares two functions to determine whether or
> not
> > /// they will generate machine code with the same behaviour. DataLayout
> is
> > /// used if available. The comparator always fails conservatively
> (erring on the
> > /// side of claiming that two functions are different).
> > class FunctionComparator {
> > public:
> > - FunctionComparator(const Function *F1, const Function *F2)
> > - : FnL(F1), FnR(F2) {}
> > + FunctionComparator(const Function *F1, const Function *F2,
> > + GlobalNumberState* GN)
> > + : FnL(F1), FnR(F2), GlobalNumbers(GN) {}
> >
> > /// Test whether the two functions have equivalent behaviour.
> > int compare();
> > @@ -148,7 +185,7 @@ public:
> >
> > private:
> > /// Test whether two basic blocks have equivalent behaviour.
> > - int compare(const BasicBlock *BBL, const BasicBlock *BBR);
> > + int cmpBasicBlocks(const BasicBlock *BBL, const BasicBlock *BBR);
> >
> > /// Constants comparison.
> > /// Its analog to lexicographical comparison between hypothetical
> numbers
> > @@ -254,6 +291,10 @@ private:
> > /// If these properties are equal - compare their contents.
> > int cmpConstants(const Constant *L, const Constant *R);
> >
> > + /// Compares two global values by number. Uses the GlobalNumbersState
> to
> > + /// identify the same gobals across function calls.
> > + int cmpGlobalValues(GlobalValue *L, GlobalValue *R);
> > +
> > /// Assign or look up previously assigned numbers for the two values,
> and
> > /// return whether the numbers are equal. Numbers are assigned in the
> order
> > /// visited.
> > @@ -333,8 +374,9 @@ private:
> > ///
> > /// 1. If types are of different kind (different type IDs).
> > /// Return result of type IDs comparison, treating them as numbers.
> > - /// 2. If types are vectors or integers, compare Type* values as
> numbers.
> > - /// 3. Types has same ID, so check whether they belongs to the next
> group:
> > + /// 2. If types are integers, check that they have the same width. If
> they
> > + /// are vectors, check that they have the same count and subtype.
> > + /// 3. Types have the same ID, so check whether they are one of:
> > /// * Void
> > /// * Float
> > /// * Double
> > @@ -343,8 +385,7 @@ private:
> > /// * PPC_FP128
> > /// * Label
> > /// * Metadata
> > - /// If so - return 0, yes - we can treat these types as equal only
> because
> > - /// their IDs are same.
> > + /// We can treat these types as equal whenever their IDs are same.
> > /// 4. If Left and Right are pointers, return result of address space
> > /// comparison (numbers comparison). We can treat pointer types of same
> > /// address space as equal.
> > @@ -359,7 +400,8 @@ private:
> >
> > int cmpAPInts(const APInt &L, const APInt &R) const;
> > int cmpAPFloats(const APFloat &L, const APFloat &R) const;
> > - int cmpStrings(StringRef L, StringRef R) const;
> > + int cmpInlineAsm(const InlineAsm *L, const InlineAsm *R) const;
> > + int cmpMem(StringRef L, StringRef R) const;
> > int cmpAttrs(const AttributeSet L, const AttributeSet R) const;
> >
> > // The two functions undergoing comparison.
> > @@ -399,33 +441,28 @@ private:
> > /// could be operands from further BBs we didn't scan yet.
> > /// So it's impossible to use dominance properties in general.
> > DenseMap<const Value*, int> sn_mapL, sn_mapR;
> > +
> > + // The global state we will use
> > + GlobalNumberState* GlobalNumbers;
> > };
> >
> > class FunctionNode {
> > mutable AssertingVH<Function> F;
> > FunctionComparator::FunctionHash Hash;
> > -
> > public:
> > // Note the hash is recalculated potentially multiple times, but it is
> cheap.
> > - FunctionNode(Function *F) : F(F),
> Hash(FunctionComparator::functionHash(*F)){}
> > + FunctionNode(Function *F)
> > + : F(F), Hash(FunctionComparator::functionHash(*F)) {}
> > Function *getFunc() const { return F; }
> > + FunctionComparator::FunctionHash getHash() const { return Hash; }
> >
> > /// Replace the reference to the function F by the function G,
> assuming their
> > /// implementations are equal.
> > void replaceBy(Function *G) const {
> > - assert(!(*this < FunctionNode(G)) && !(FunctionNode(G) < *this) &&
> > - "The two functions must be equal");
> > -
> > F = G;
> > }
> >
> > void release() { F = 0; }
> > - bool operator<(const FunctionNode &RHS) const {
> > - // Order first by hashes, then full function comparison.
> > - if (Hash != RHS.Hash)
> > - return Hash < RHS.Hash;
> > - return (FunctionComparator(F, RHS.getFunc()).compare()) == -1;
> > - }
> > };
> > }
> >
> > @@ -444,13 +481,17 @@ int FunctionComparator::cmpAPInts(const
> > }
> >
> > int FunctionComparator::cmpAPFloats(const APFloat &L, const APFloat &R)
> const {
> > - if (int Res = cmpNumbers((uint64_t)&L.getSemantics(),
> > - (uint64_t)&R.getSemantics()))
> > + // TODO: This correctly handles all existing fltSemantics, because
> they all
> > + // have different precisions. This isn't very robust, however, if new
> types
> > + // with different exponent ranges are introduced.
> > + const fltSemantics &SL = L.getSemantics(), &SR = R.getSemantics();
> > + if (int Res = cmpNumbers(APFloat::semanticsPrecision(SL),
> > + APFloat::semanticsPrecision(SR)))
> > return Res;
> > return cmpAPInts(L.bitcastToAPInt(), R.bitcastToAPInt());
> > }
> >
> > -int FunctionComparator::cmpStrings(StringRef L, StringRef R) const {
> > +int FunctionComparator::cmpMem(StringRef L, StringRef R) const {
> > // Prevent heavy comparison, compare sizes first.
> > if (int Res = cmpNumbers(L.size(), R.size()))
> > return Res;
> > @@ -556,9 +597,25 @@ int FunctionComparator::cmpConstants(con
> > if (!L->isNullValue() && R->isNullValue())
> > return -1;
> >
> > + auto GlobalValueL =
> const_cast<GlobalValue*>(dyn_cast<GlobalValue>(L));
> > + auto GlobalValueR =
> const_cast<GlobalValue*>(dyn_cast<GlobalValue>(R));
> > + if (GlobalValueL && GlobalValueR) {
> > + return cmpGlobalValues(GlobalValueL, GlobalValueR);
> > + }
> > +
> > if (int Res = cmpNumbers(L->getValueID(), R->getValueID()))
> > return Res;
> >
> > + if (const auto *SeqL = dyn_cast<ConstantDataSequential>(L)) {
> > + const auto *SeqR = dyn_cast<ConstantDataSequential>(R);
> > + // This handles ConstantDataArray and ConstantDataVector. Note that
> we
> > + // compare the two raw data arrays, which might differ depending on
> the host
> > + // endianness. This isn't a problem though, because the endiness of
> a module
> > + // will affect the order of the constants, but this order is the
> same
> > + // for a given input module and host platform.
> > + return cmpMem(SeqL->getRawDataValues(), SeqR->getRawDataValues());
>
>
> You are dereferencing SeqR after a dyn_cast<>. There is something fishy
> here.
> Can you have a look?
>
> Thanks,
>
> Mehdi
>
>
>
> > + }
> > +
> > switch (L->getValueID()) {
> > case Value::UndefValueVal: return TypesRes;
> > case Value::ConstantIntVal: {
> > @@ -627,12 +684,21 @@ int FunctionComparator::cmpConstants(con
> > }
> > return 0;
> > }
> > - case Value::FunctionVal:
> > - case Value::GlobalVariableVal:
> > - case Value::GlobalAliasVal:
> > - default: // Unknown constant, cast L and R pointers to numbers and
> compare.
> > + case Value::BlockAddressVal: {
> > + // FIXME: This still uses a pointer comparison. It isn't clear how
> to remove
> > + // this. This only affects programs which take BlockAddresses and
> store them
> > + // as constants, which is limited to interepreters, etc.
> > return cmpNumbers((uint64_t)L, (uint64_t)R);
> > }
> > + default: // Unknown constant, abort.
> > + DEBUG(dbgs() << "Looking at valueID " << L->getValueID() << "\n");
> > + llvm_unreachable("Constant ValueID not recognized.");
> > + return -1;
> > + }
> > +}
> > +
> > +int FunctionComparator::cmpGlobalValues(GlobalValue *L, GlobalValue* R)
> {
> > + return cmpNumbers(GlobalNumbers->getNumber(L),
> GlobalNumbers->getNumber(R));
> > }
> >
> > /// cmpType - compares two types,
> > @@ -660,10 +726,15 @@ int FunctionComparator::cmpTypes(Type *T
> > llvm_unreachable("Unknown type!");
> > // Fall through in Release mode.
> > case Type::IntegerTyID:
> > - case Type::VectorTyID:
> > - // TyL == TyR would have returned true earlier.
> > - return cmpNumbers((uint64_t)TyL, (uint64_t)TyR);
> > -
> > + return cmpNumbers(cast<IntegerType>(TyL)->getBitWidth(),
> > + cast<IntegerType>(TyR)->getBitWidth());
> > + case Type::VectorTyID: {
> > + VectorType *VTyL = cast<VectorType>(TyL), *VTyR =
> cast<VectorType>(TyR);
> > + if (int Res = cmpNumbers(VTyL->getNumElements(),
> VTyR->getNumElements()))
> > + return Res;
> > + return cmpTypes(VTyL->getElementType(), VTyR->getElementType());
> > + }
> > + // TyL == TyR would have returned true earlier, because types are
> uniqued.
> > case Type::VoidTyID:
> > case Type::FloatTyID:
> > case Type::DoubleTyID:
> > @@ -895,9 +966,8 @@ int FunctionComparator::cmpGEPs(const GE
> > if (GEPL->accumulateConstantOffset(DL, OffsetL) &&
> > GEPR->accumulateConstantOffset(DL, OffsetR))
> > return cmpAPInts(OffsetL, OffsetR);
> > -
> > - if (int Res =
> cmpNumbers((uint64_t)GEPL->getPointerOperand()->getType(),
> > -
> (uint64_t)GEPR->getPointerOperand()->getType()))
> > + if (int Res = cmpTypes(GEPL->getPointerOperand()->getType(),
> > + GEPR->getPointerOperand()->getType()))
> > return Res;
> >
> > if (int Res = cmpNumbers(GEPL->getNumOperands(),
> GEPR->getNumOperands()))
> > @@ -911,6 +981,28 @@ int FunctionComparator::cmpGEPs(const GE
> > return 0;
> > }
> >
> > +int FunctionComparator::cmpInlineAsm(const InlineAsm *L,
> > + const InlineAsm *R) const {
> > + // InlineAsm's are uniqued. If they are the same pointer, obviously
> they are
> > + // the same, otherwise compare the fields.
> > + if (L == R)
> > + return 0;
> > + if (int Res = cmpTypes(L->getFunctionType(), R->getFunctionType()))
> > + return Res;
> > + if (int Res = cmpMem(L->getAsmString(), R->getAsmString()))
> > + return Res;
> > + if (int Res = cmpMem(L->getConstraintString(),
> R->getConstraintString()))
> > + return Res;
> > + if (int Res = cmpNumbers(L->hasSideEffects(), R->hasSideEffects()))
> > + return Res;
> > + if (int Res = cmpNumbers(L->isAlignStack(), R->isAlignStack()))
> > + return Res;
> > + if (int Res = cmpNumbers(L->getDialect(), R->getDialect()))
> > + return Res;
> > + llvm_unreachable("InlineAsm blocks were not uniqued.");
> > + return 0;
> > +}
> > +
> > /// Compare two values used by the two functions under pair-wise
> comparison. If
> > /// this is the first time the values are seen, they're added to the
> mapping so
> > /// that we will detect mismatches on next use.
> > @@ -945,7 +1037,7 @@ int FunctionComparator::cmpValues(const
> > const InlineAsm *InlineAsmR = dyn_cast<InlineAsm>(R);
> >
> > if (InlineAsmL && InlineAsmR)
> > - return cmpNumbers((uint64_t)L, (uint64_t)R);
> > + return cmpInlineAsm(InlineAsmL, InlineAsmR);
> > if (InlineAsmL)
> > return 1;
> > if (InlineAsmR)
> > @@ -957,7 +1049,8 @@ int FunctionComparator::cmpValues(const
> > return cmpNumbers(LeftSN.first->second, RightSN.first->second);
> > }
> > // Test whether two basic blocks have equivalent behaviour.
> > -int FunctionComparator::compare(const BasicBlock *BBL, const BasicBlock
> *BBR) {
> > +int FunctionComparator::cmpBasicBlocks(const BasicBlock *BBL,
> > + const BasicBlock *BBR) {
> > BasicBlock::const_iterator InstL = BBL->begin(), InstLE = BBL->end();
> > BasicBlock::const_iterator InstR = BBR->begin(), InstRE = BBR->end();
> >
> > @@ -1020,7 +1113,7 @@ int FunctionComparator::compare() {
> > return Res;
> >
> > if (FnL->hasGC()) {
> > - if (int Res = cmpNumbers((uint64_t)FnL->getGC(),
> (uint64_t)FnR->getGC()))
> > + if (int Res = cmpMem(FnL->getGC(), FnR->getGC()))
> > return Res;
> > }
> >
> > @@ -1028,7 +1121,7 @@ int FunctionComparator::compare() {
> > return Res;
> >
> > if (FnL->hasSection()) {
> > - if (int Res = cmpStrings(FnL->getSection(), FnR->getSection()))
> > + if (int Res = cmpMem(FnL->getSection(), FnR->getSection()))
> > return Res;
> > }
> >
> > @@ -1074,7 +1167,7 @@ int FunctionComparator::compare() {
> > if (int Res = cmpValues(BBL, BBR))
> > return Res;
> >
> > - if (int Res = compare(BBL, BBR))
> > + if (int Res = cmpBasicBlocks(BBL, BBR))
> > return Res;
> >
> > const TerminatorInst *TermL = BBL->getTerminator();
> > @@ -1129,7 +1222,7 @@ FunctionComparator::FunctionHash Functio
> > SmallVector<const BasicBlock *, 8> BBs;
> > SmallSet<const BasicBlock *, 16> VisitedBBs;
> >
> > - // Walk the blocks in the same order as FunctionComparator::compare(),
> > + // Walk the blocks in the same order as
> FunctionComparator::cmpBasicBlocks(),
> > // accumulating the hash of the function "structure." (BB and opcode
> sequence)
> > BBs.push_back(&F.getEntryBlock());
> > VisitedBBs.insert(BBs[0]);
> > @@ -1163,14 +1256,31 @@ class MergeFunctions : public ModulePass
> > public:
> > static char ID;
> > MergeFunctions()
> > - : ModulePass(ID), HasGlobalAliases(false) {
> > + : ModulePass(ID), FnTree(FunctionNodeCmp(&GlobalNumbers)),
> > + HasGlobalAliases(false) {
> > initializeMergeFunctionsPass(*PassRegistry::getPassRegistry());
> > }
> >
> > bool runOnModule(Module &M) override;
> >
> > private:
> > - typedef std::set<FunctionNode> FnTreeType;
> > + // The function comparison operator is provided here so that
> FunctionNodes do
> > + // not need to become larger with another pointer.
> > + class FunctionNodeCmp {
> > + GlobalNumberState* GlobalNumbers;
> > + public:
> > + FunctionNodeCmp(GlobalNumberState* GN) : GlobalNumbers(GN) {}
> > + bool operator()(const FunctionNode &LHS, const FunctionNode &RHS)
> const {
> > + // Order first by hashes, then full function comparison.
> > + if (LHS.getHash() != RHS.getHash())
> > + return LHS.getHash() < RHS.getHash();
> > + FunctionComparator FCmp(LHS.getFunc(), RHS.getFunc(),
> GlobalNumbers);
> > + return FCmp.compare() == -1;
> > + }
> > + };
> > + typedef std::set<FunctionNode, FunctionNodeCmp> FnTreeType;
> > +
> > + GlobalNumberState GlobalNumbers;
> >
> > /// A work queue of functions that may have been modified and should be
> > /// analyzed again.
> > @@ -1245,8 +1355,8 @@ bool MergeFunctions::doSanityCheck(std::
> > for (std::vector<WeakVH>::iterator J = I; J != E && j < Max; ++J,
> ++j) {
> > Function *F1 = cast<Function>(*I);
> > Function *F2 = cast<Function>(*J);
> > - int Res1 = FunctionComparator(F1, F2).compare();
> > - int Res2 = FunctionComparator(F2, F1).compare();
> > + int Res1 = FunctionComparator(F1, F2, &GlobalNumbers).compare();
> > + int Res2 = FunctionComparator(F2, F1, &GlobalNumbers).compare();
> >
> > // If F1 <= F2, then F2 >= F1, otherwise report failure.
> > if (Res1 != -Res2) {
> > @@ -1267,8 +1377,8 @@ bool MergeFunctions::doSanityCheck(std::
> > continue;
> >
> > Function *F3 = cast<Function>(*K);
> > - int Res3 = FunctionComparator(F1, F3).compare();
> > - int Res4 = FunctionComparator(F2, F3).compare();
> > + int Res3 = FunctionComparator(F1, F3,
> &GlobalNumbers).compare();
> > + int Res4 = FunctionComparator(F2, F3,
> &GlobalNumbers).compare();
> >
> > bool Transitive = true;
> >
> > @@ -1556,6 +1666,8 @@ void MergeFunctions::replaceFunctionInTr
> > (!F->mayBeOverridden() && !G->mayBeOverridden())) &&
> > "Only change functions if both are strong or both are weak");
> > (void)F;
> > + assert(FunctionComparator(F, G, &GlobalNumbers).compare() == 0 &&
> > + "The two functions must be equal");
> >
> > IterToF->replaceBy(G);
> > }
> >
> > Added: llvm/trunk/test/Transforms/MergeFunc/constant-entire-value.ll
> > URL:
> https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_viewvc_llvm-2Dproject_llvm_trunk_test_Transforms_MergeFunc_constant-2Dentire-2Dvalue.ll-3Frev-3D245762-26view-3Dauto&d=BQIGaQ&c=eEvniauFctOgLOKGJOplqw&r=v-ruWq0KCv2O3thJZiK6naxuXK8mQHZUmGq5FBtAmZ4&m=8AXWbmpresvhRsDs49PoX5gvb_41wieiXuHyjTJ5YMo&s=XV-m4M5ffPZ4yM6fTcQlJGawM37EGxaZ-ixc9lXpz7w&e=
> >
> ==============================================================================
> > --- llvm/trunk/test/Transforms/MergeFunc/constant-entire-value.ll (added)
> > +++ llvm/trunk/test/Transforms/MergeFunc/constant-entire-value.ll Fri
> Aug 21 18:27:24 2015
> > @@ -0,0 +1,42 @@
> > +; RUN: opt -S -mergefunc < %s | FileCheck %s
> > +
> > +; RUN: opt -S -mergefunc < %s | FileCheck -check-prefix=NOPLUS %s
> > +
> > +; This makes sure that zeros in constants don't cause problems with
> string based
> > +; memory comparisons
> > +define internal i32 @sum(i32 %x, i32 %y) {
> > +; CHECK-LABEL: @sum
> > + %sum = add i32 %x, %y
> > + %1 = extractvalue [3 x i32] [ i32 3, i32 0, i32 2 ], 2
> > + %sum2 = add i32 %sum, %1
> > + %sum3 = add i32 %sum2, %y
> > + ret i32 %sum3
> > +}
> > +
> > +define internal i32 @add(i32 %x, i32 %y) {
> > +; CHECK-LABEL: @add
> > + %sum = add i32 %x, %y
> > + %1 = extractvalue [3 x i32] [ i32 3, i32 0, i32 1 ], 2
> > + %sum2 = add i32 %sum, %1
> > + %sum3 = add i32 %sum2, %y
> > + ret i32 %sum3
> > +}
> > +
> > +define internal i32 @plus(i32 %x, i32 %y) {
> > +; NOPLUS-NOT: @plus
> > + %sum = add i32 %x, %y
> > + %1 = extractvalue [3 x i32] [ i32 3, i32 0, i32 5 ], 2
> > + %sum2 = add i32 %sum, %1
> > + %sum3 = add i32 %sum2, %y
> > + ret i32 %sum3
> > +}
> > +
> > +define internal i32 @next(i32 %x, i32 %y) {
> > +; CHECK-LABEL: @next
> > + %sum = add i32 %x, %y
> > + %1 = extractvalue [3 x i32] [ i32 3, i32 0, i32 5 ], 2
> > + %sum2 = add i32 %sum, %1
> > + %sum3 = add i32 %sum2, %y
> > + ret i32 %sum3
> > +}
> > +
> >
> >
> > _______________________________________________
> > llvm-commits mailing list
> > llvm-commits at lists.llvm.org
> >
> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.llvm.org_cgi-2Dbin_mailman_listinfo_llvm-2Dcommits&d=BQIGaQ&c=eEvniauFctOgLOKGJOplqw&r=v-ruWq0KCv2O3thJZiK6naxuXK8mQHZUmGq5FBtAmZ4&m=8AXWbmpresvhRsDs49PoX5gvb_41wieiXuHyjTJ5YMo&s=UpG70G8xAGjnGmVMInrkg28NaSY3FySnGQbQHEpKGaY&e=
>
>
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