From 1d3fb6810214cb56fa62168926ddebf68ba46c98 Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Sat, 11 Oct 2025 21:29:36 +0100 Subject: [PATCH 1/4] [SCEV] Improve handling of divisibility information from loop guards. At the moment, the effectivness of guards that contain divisibility information (A % B == 0 ) depends on the order of the conditions. This patch makes using divisibility information independent of the order, by collecting and applying the divisibility information separately. We first collect all conditions in a vector, then collect the divisibility information from all guards. When processing other guards, we apply divisibility info collected earlier. After all guards have been processed, we add the divisibility info, rewriting the existing rewrite. This ensures we apply the divisibility info to the largest rewrite expression. This helps to improve results in a few cases, one in https://github.com/dtcxzyw/llvm-opt-benchmark/pull/2921 and another one in a different large C/C++ based IR corpus. --- llvm/lib/Analysis/ScalarEvolution.cpp | 187 +++++++++++------- .../IndVarSimplify/loop-guard-order.ll | 5 +- 2 files changed, 117 insertions(+), 75 deletions(-) diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index c9baeda24b47b..c54d4291e1e4b 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -15510,6 +15510,79 @@ static const SCEV *getNextSCEVDivisibleByDivisor(const SCEV *Expr, return SE.getConstant(*ExprVal + DivisorVal - Rem); } +static bool collectDivisibilityInformation( + ICmpInst::Predicate Predicate, const SCEV *LHS, const SCEV *RHS, + DenseMap &DivInfo, + DenseMap &Multiples, ScalarEvolution &SE) { + // If we have LHS == 0, check if LHS is computing a property of some unknown + // SCEV %v which we can rewrite %v to express explicitly. + if (Predicate != CmpInst::ICMP_EQ || !match(RHS, m_scev_Zero())) + return false; + // If LHS is A % B, i.e. A % B == 0, rewrite A to (A /u B) * B to + // explicitly express that. + const SCEVUnknown *URemLHS = nullptr; + const SCEV *URemRHS = nullptr; + if (!match(LHS, m_scev_URem(m_SCEVUnknown(URemLHS), m_SCEV(URemRHS), SE))) + return false; + + const SCEV *Multiple = + SE.getMulExpr(SE.getUDivExpr(URemLHS, URemRHS), URemRHS); + DivInfo[URemLHS] = Multiple; + Multiples[URemLHS] = cast(URemRHS)->getAPInt(); + return true; +} + +// Check if the condition is a divisibility guard (A % B == 0). +static bool isDivisibilityGuard(const SCEV *LHS, const SCEV *RHS, + ScalarEvolution &SE) { + const SCEV *X, *Y; + return match(LHS, m_scev_URem(m_SCEV(X), m_SCEV(Y), SE)) && RHS->isZero(); +} + +// Apply divisibility by \p Divisor on MinMaxExpr with constant values, +// recursively. This is done by aligning up/down the constant value to the +// Divisor. +static const SCEV *applyDivisibilityOnMinMaxExpr(const SCEV *MinMaxExpr, + const SCEV *Divisor, + ScalarEvolution &SE) { + // Return true if \p Expr is a MinMax SCEV expression with a non-negative + // constant operand. If so, return in \p SCTy the SCEV type and in \p RHS + // the non-constant operand and in \p LHS the constant operand. + auto IsMinMaxSCEVWithNonNegativeConstant = + [&](const SCEV *Expr, SCEVTypes &SCTy, const SCEV *&LHS, + const SCEV *&RHS) { + if (auto *MinMax = dyn_cast(Expr)) { + if (MinMax->getNumOperands() != 2) + return false; + if (auto *C = dyn_cast(MinMax->getOperand(0))) { + if (C->getAPInt().isNegative()) + return false; + SCTy = MinMax->getSCEVType(); + LHS = MinMax->getOperand(0); + RHS = MinMax->getOperand(1); + return true; + } + } + return false; + }; + + const SCEV *MinMaxLHS = nullptr, *MinMaxRHS = nullptr; + SCEVTypes SCTy; + if (!IsMinMaxSCEVWithNonNegativeConstant(MinMaxExpr, SCTy, MinMaxLHS, + MinMaxRHS)) + return MinMaxExpr; + auto IsMin = isa(MinMaxExpr) || isa(MinMaxExpr); + assert(SE.isKnownNonNegative(MinMaxLHS) && "Expected non-negative operand!"); + auto *DivisibleExpr = + IsMin ? getPreviousSCEVDivisibleByDivisor( + MinMaxLHS, cast(Divisor)->getAPInt(), SE) + : getNextSCEVDivisibleByDivisor( + MinMaxLHS, cast(Divisor)->getAPInt(), SE); + SmallVector Ops = { + applyDivisibilityOnMinMaxExpr(MinMaxRHS, Divisor, SE), DivisibleExpr}; + return SE.getMinMaxExpr(SCTy, Ops); +} + void ScalarEvolution::LoopGuards::collectFromBlock( ScalarEvolution &SE, ScalarEvolution::LoopGuards &Guards, const BasicBlock *Block, const BasicBlock *Pred, @@ -15520,19 +15593,14 @@ void ScalarEvolution::LoopGuards::collectFromBlock( SmallVector ExprsToRewrite; auto CollectCondition = [&](ICmpInst::Predicate Predicate, const SCEV *LHS, const SCEV *RHS, - DenseMap - &RewriteMap) { + DenseMap &RewriteMap, + const DenseMap + &DivInfo) { // WARNING: It is generally unsound to apply any wrap flags to the proposed // replacement SCEV which isn't directly implied by the structure of that // SCEV. In particular, using contextual facts to imply flags is *NOT* // legal. See the scoping rules for flags in the header to understand why. - // If LHS is a constant, apply information to the other expression. - if (isa(LHS)) { - std::swap(LHS, RHS); - Predicate = CmpInst::getSwappedPredicate(Predicate); - } - // Check for a condition of the form (-C1 + X < C2). InstCombine will // create this form when combining two checks of the form (X u< C2 + C1) and // (X >=u C1). @@ -15565,67 +15633,6 @@ void ScalarEvolution::LoopGuards::collectFromBlock( if (MatchRangeCheckIdiom()) return; - // Return true if \p Expr is a MinMax SCEV expression with a non-negative - // constant operand. If so, return in \p SCTy the SCEV type and in \p RHS - // the non-constant operand and in \p LHS the constant operand. - auto IsMinMaxSCEVWithNonNegativeConstant = - [&](const SCEV *Expr, SCEVTypes &SCTy, const SCEV *&LHS, - const SCEV *&RHS) { - const APInt *C; - SCTy = Expr->getSCEVType(); - return match(Expr, m_scev_MinMax(m_SCEV(LHS), m_SCEV(RHS))) && - match(LHS, m_scev_APInt(C)) && C->isNonNegative(); - }; - - // Apply divisibilty by \p Divisor on MinMaxExpr with constant values, - // recursively. This is done by aligning up/down the constant value to the - // Divisor. - std::function - ApplyDivisibiltyOnMinMaxExpr = [&](const SCEV *MinMaxExpr, - const SCEV *Divisor) { - auto *ConstDivisor = dyn_cast(Divisor); - if (!ConstDivisor) - return MinMaxExpr; - const APInt &DivisorVal = ConstDivisor->getAPInt(); - - const SCEV *MinMaxLHS = nullptr, *MinMaxRHS = nullptr; - SCEVTypes SCTy; - if (!IsMinMaxSCEVWithNonNegativeConstant(MinMaxExpr, SCTy, MinMaxLHS, - MinMaxRHS)) - return MinMaxExpr; - auto IsMin = - isa(MinMaxExpr) || isa(MinMaxExpr); - assert(SE.isKnownNonNegative(MinMaxLHS) && - "Expected non-negative operand!"); - auto *DivisibleExpr = - IsMin - ? getPreviousSCEVDivisibleByDivisor(MinMaxLHS, DivisorVal, SE) - : getNextSCEVDivisibleByDivisor(MinMaxLHS, DivisorVal, SE); - SmallVector Ops = { - ApplyDivisibiltyOnMinMaxExpr(MinMaxRHS, Divisor), DivisibleExpr}; - return SE.getMinMaxExpr(SCTy, Ops); - }; - - // If we have LHS == 0, check if LHS is computing a property of some unknown - // SCEV %v which we can rewrite %v to express explicitly. - if (Predicate == CmpInst::ICMP_EQ && match(RHS, m_scev_Zero())) { - // If LHS is A % B, i.e. A % B == 0, rewrite A to (A /u B) * B to - // explicitly express that. - const SCEVUnknown *URemLHS = nullptr; - const SCEV *URemRHS = nullptr; - if (match(LHS, - m_scev_URem(m_SCEVUnknown(URemLHS), m_SCEV(URemRHS), SE))) { - auto I = RewriteMap.find(URemLHS); - const SCEV *RewrittenLHS = I != RewriteMap.end() ? I->second : URemLHS; - RewrittenLHS = ApplyDivisibiltyOnMinMaxExpr(RewrittenLHS, URemRHS); - const auto *Multiple = - SE.getMulExpr(SE.getUDivExpr(RewrittenLHS, URemRHS), URemRHS); - RewriteMap[URemLHS] = Multiple; - ExprsToRewrite.push_back(URemLHS); - return; - } - } - // Do not apply information for constants or if RHS contains an AddRec. if (isa(LHS) || SE.containsAddRecurrence(RHS)) return; @@ -15655,7 +15662,11 @@ void ScalarEvolution::LoopGuards::collectFromBlock( }; const SCEV *RewrittenLHS = GetMaybeRewritten(LHS); - const APInt &DividesBy = SE.getConstantMultiple(RewrittenLHS); + // Apply divisibility information when computing the constant multiple. + LoopGuards DivGuards(SE); + DivGuards.RewriteMap = DivInfo; + const APInt &DividesBy = + SE.getConstantMultiple(DivGuards.rewrite(RewrittenLHS)); // Collect rewrites for LHS and its transitive operands based on the // condition. @@ -15840,8 +15851,11 @@ void ScalarEvolution::LoopGuards::collectFromBlock( // Now apply the information from the collected conditions to // Guards.RewriteMap. Conditions are processed in reverse order, so the - // earliest conditions is processed first. This ensures the SCEVs with the + // earliest conditions is processed first, except guards with divisibility + // information, which are moved to the back. This ensures the SCEVs with the // shortest dependency chains are constructed first. + SmallVector> + GuardsToProcess; for (auto [Term, EnterIfTrue] : reverse(Terms)) { SmallVector Worklist; SmallPtrSet Visited; @@ -15856,7 +15870,12 @@ void ScalarEvolution::LoopGuards::collectFromBlock( EnterIfTrue ? Cmp->getPredicate() : Cmp->getInversePredicate(); const auto *LHS = SE.getSCEV(Cmp->getOperand(0)); const auto *RHS = SE.getSCEV(Cmp->getOperand(1)); - CollectCondition(Predicate, LHS, RHS, Guards.RewriteMap); + // If LHS is a constant, apply information to the other expression. + if (isa(LHS)) { + std::swap(LHS, RHS); + Predicate = CmpInst::getSwappedPredicate(Predicate); + } + GuardsToProcess.emplace_back(Predicate, LHS, RHS); continue; } @@ -15869,6 +15888,30 @@ void ScalarEvolution::LoopGuards::collectFromBlock( } } + // Process divisibility guards in reverse order to populate DivInfo early. + DenseMap Multiples; + DenseMap DivInfo; + for (const auto &[Predicate, LHS, RHS] : GuardsToProcess) { + if (!isDivisibilityGuard(LHS, RHS, SE)) + continue; + collectDivisibilityInformation(Predicate, LHS, RHS, DivInfo, Multiples, SE); + } + + for (const auto &[Predicate, LHS, RHS] : GuardsToProcess) + CollectCondition(Predicate, LHS, RHS, Guards.RewriteMap, DivInfo); + + // Apply divisibility information last. This ensures it is applied to the + // outermost expression after other rewrites for the given value. + for (const auto &[K, V] : Multiples) { + const SCEV *DivisorSCEV = SE.getConstant(V); + Guards.RewriteMap[K] = + SE.getMulExpr(SE.getUDivExpr(applyDivisibilityOnMinMaxExpr( + Guards.rewrite(K), DivisorSCEV, SE), + DivisorSCEV), + DivisorSCEV); + ExprsToRewrite.push_back(K); + } + // Let the rewriter preserve NUW/NSW flags if the unsigned/signed ranges of // the replacement expressions are contained in the ranges of the replaced // expressions. diff --git a/llvm/test/Transforms/IndVarSimplify/loop-guard-order.ll b/llvm/test/Transforms/IndVarSimplify/loop-guard-order.ll index 14ee00d77197c..2763860e79875 100644 --- a/llvm/test/Transforms/IndVarSimplify/loop-guard-order.ll +++ b/llvm/test/Transforms/IndVarSimplify/loop-guard-order.ll @@ -114,7 +114,7 @@ define i32 @urem_order1(i32 %n) { ; CHECK: [[LOOP]]: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[LOOP_PREHEADER]] ] ; CHECK-NEXT: call void @foo() -; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 3 +; CHECK-NEXT: [[IV_NEXT]] = add nuw i32 [[IV]], 3 ; CHECK-NEXT: [[EC:%.*]] = icmp eq i32 [[IV_NEXT]], [[N]] ; CHECK-NEXT: br i1 [[EC]], label %[[EXIT_LOOPEXIT:.*]], label %[[LOOP]] ; CHECK: [[EXIT_LOOPEXIT]]: @@ -205,13 +205,12 @@ define i64 @test_loop_with_div_order_1(i64 %n) { ; CHECK-NEXT: [[PARITY_CHECK:%.*]] = icmp eq i64 [[IS_ODD]], 0 ; CHECK-NEXT: br i1 [[PARITY_CHECK]], label %[[LOOP_PREHEADER:.*]], label %[[EXIT]] ; CHECK: [[LOOP_PREHEADER]]: -; CHECK-NEXT: [[UMAX:%.*]] = call i64 @llvm.umax.i64(i64 [[UPPER_BOUND]], i64 1) ; CHECK-NEXT: br label %[[LOOP:.*]] ; CHECK: [[LOOP]]: ; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[DUMMY:%.*]] = load volatile i64, ptr null, align 8 ; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1 -; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], [[UMAX]] +; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[IV_NEXT]], [[UPPER_BOUND]] ; CHECK-NEXT: br i1 [[EXITCOND]], label %[[LOOP]], label %[[EXIT_LOOPEXIT:.*]] ; CHECK: [[EXIT_LOOPEXIT]]: ; CHECK-NEXT: br label %[[EXIT]] From 0957c18c36ad5ab4c59d3449bc35ab277661090c Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Tue, 14 Oct 2025 22:00:22 +0100 Subject: [PATCH 2/4] !fixup avoid copying map and add TODO --- llvm/lib/Analysis/ScalarEvolution.cpp | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index c54d4291e1e4b..580bf28d91eaf 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -15594,8 +15594,7 @@ void ScalarEvolution::LoopGuards::collectFromBlock( auto CollectCondition = [&](ICmpInst::Predicate Predicate, const SCEV *LHS, const SCEV *RHS, DenseMap &RewriteMap, - const DenseMap - &DivInfo) { + const LoopGuards &DivGuards) { // WARNING: It is generally unsound to apply any wrap flags to the proposed // replacement SCEV which isn't directly implied by the structure of that // SCEV. In particular, using contextual facts to imply flags is *NOT* @@ -15637,12 +15636,6 @@ void ScalarEvolution::LoopGuards::collectFromBlock( if (isa(LHS) || SE.containsAddRecurrence(RHS)) return; - // If RHS is SCEVUnknown, make sure the information is applied to it. - if (!isa(LHS) && isa(RHS)) { - std::swap(LHS, RHS); - Predicate = CmpInst::getSwappedPredicate(Predicate); - } - // Puts rewrite rule \p From -> \p To into the rewrite map. Also if \p From // and \p FromRewritten are the same (i.e. there has been no rewrite // registered for \p From), then puts this value in the list of rewritten @@ -15663,8 +15656,6 @@ void ScalarEvolution::LoopGuards::collectFromBlock( const SCEV *RewrittenLHS = GetMaybeRewritten(LHS); // Apply divisibility information when computing the constant multiple. - LoopGuards DivGuards(SE); - DivGuards.RewriteMap = DivInfo; const APInt &DividesBy = SE.getConstantMultiple(DivGuards.rewrite(RewrittenLHS)); @@ -15871,6 +15862,8 @@ void ScalarEvolution::LoopGuards::collectFromBlock( const auto *LHS = SE.getSCEV(Cmp->getOperand(0)); const auto *RHS = SE.getSCEV(Cmp->getOperand(1)); // If LHS is a constant, apply information to the other expression. + // TODO: If LHS is not a constant, check if using CompareSCEVComplexity + // can improve results. if (isa(LHS)) { std::swap(LHS, RHS); Predicate = CmpInst::getSwappedPredicate(Predicate); @@ -15888,17 +15881,18 @@ void ScalarEvolution::LoopGuards::collectFromBlock( } } - // Process divisibility guards in reverse order to populate DivInfo early. + // Process divisibility guards in reverse order to populate DivGuards early. DenseMap Multiples; - DenseMap DivInfo; + LoopGuards DivGuards(SE); for (const auto &[Predicate, LHS, RHS] : GuardsToProcess) { if (!isDivisibilityGuard(LHS, RHS, SE)) continue; - collectDivisibilityInformation(Predicate, LHS, RHS, DivInfo, Multiples, SE); + collectDivisibilityInformation(Predicate, LHS, RHS, DivGuards.RewriteMap, + Multiples, SE); } for (const auto &[Predicate, LHS, RHS] : GuardsToProcess) - CollectCondition(Predicate, LHS, RHS, Guards.RewriteMap, DivInfo); + CollectCondition(Predicate, LHS, RHS, Guards.RewriteMap, DivGuards); // Apply divisibility information last. This ensures it is applied to the // outermost expression after other rewrites for the given value. From 91b1fe1d0bd7f5b93949d182127a80662040f909 Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Wed, 15 Oct 2025 13:42:06 +0100 Subject: [PATCH 3/4] !fixup also move logic to swap unknowns --- llvm/lib/Analysis/ScalarEvolution.cpp | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 580bf28d91eaf..f8c43234ed47e 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -15867,6 +15867,10 @@ void ScalarEvolution::LoopGuards::collectFromBlock( if (isa(LHS)) { std::swap(LHS, RHS); Predicate = CmpInst::getSwappedPredicate(Predicate); + } else if (!isa(LHS) && isa(RHS)) { + // If RHS is SCEVUnknown, make sure the information is applied to it. + std::swap(LHS, RHS); + Predicate = CmpInst::getSwappedPredicate(Predicate); } GuardsToProcess.emplace_back(Predicate, LHS, RHS); continue; From 11aea0e2fc9262e2bbd119c73fd02c56d10446af Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Mon, 20 Oct 2025 12:56:05 +0100 Subject: [PATCH 4/4] !fixup check for SCEVConstant. --- llvm/lib/Analysis/ScalarEvolution.cpp | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index f8c43234ed47e..e0c2649333837 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -15528,7 +15528,8 @@ static bool collectDivisibilityInformation( const SCEV *Multiple = SE.getMulExpr(SE.getUDivExpr(URemLHS, URemRHS), URemRHS); DivInfo[URemLHS] = Multiple; - Multiples[URemLHS] = cast(URemRHS)->getAPInt(); + if (auto *C = dyn_cast(URemRHS)) + Multiples[URemLHS] = C->getAPInt(); return true; } @@ -15543,7 +15544,7 @@ static bool isDivisibilityGuard(const SCEV *LHS, const SCEV *RHS, // recursively. This is done by aligning up/down the constant value to the // Divisor. static const SCEV *applyDivisibilityOnMinMaxExpr(const SCEV *MinMaxExpr, - const SCEV *Divisor, + APInt Divisor, ScalarEvolution &SE) { // Return true if \p Expr is a MinMax SCEV expression with a non-negative // constant operand. If so, return in \p SCTy the SCEV type and in \p RHS @@ -15574,10 +15575,8 @@ static const SCEV *applyDivisibilityOnMinMaxExpr(const SCEV *MinMaxExpr, auto IsMin = isa(MinMaxExpr) || isa(MinMaxExpr); assert(SE.isKnownNonNegative(MinMaxLHS) && "Expected non-negative operand!"); auto *DivisibleExpr = - IsMin ? getPreviousSCEVDivisibleByDivisor( - MinMaxLHS, cast(Divisor)->getAPInt(), SE) - : getNextSCEVDivisibleByDivisor( - MinMaxLHS, cast(Divisor)->getAPInt(), SE); + IsMin ? getPreviousSCEVDivisibleByDivisor(MinMaxLHS, Divisor, SE) + : getNextSCEVDivisibleByDivisor(MinMaxLHS, Divisor, SE); SmallVector Ops = { applyDivisibilityOnMinMaxExpr(MinMaxRHS, Divisor, SE), DivisibleExpr}; return SE.getMinMaxExpr(SCTy, Ops); @@ -15636,6 +15635,12 @@ void ScalarEvolution::LoopGuards::collectFromBlock( if (isa(LHS) || SE.containsAddRecurrence(RHS)) return; + // If RHS is SCEVUnknown, make sure the information is applied to it. + if (!isa(LHS) && isa(RHS)) { + std::swap(LHS, RHS); + Predicate = CmpInst::getSwappedPredicate(Predicate); + } + // Puts rewrite rule \p From -> \p To into the rewrite map. Also if \p From // and \p FromRewritten are the same (i.e. there has been no rewrite // registered for \p From), then puts this value in the list of rewritten @@ -15867,10 +15872,6 @@ void ScalarEvolution::LoopGuards::collectFromBlock( if (isa(LHS)) { std::swap(LHS, RHS); Predicate = CmpInst::getSwappedPredicate(Predicate); - } else if (!isa(LHS) && isa(RHS)) { - // If RHS is SCEVUnknown, make sure the information is applied to it. - std::swap(LHS, RHS); - Predicate = CmpInst::getSwappedPredicate(Predicate); } GuardsToProcess.emplace_back(Predicate, LHS, RHS); continue; @@ -15900,11 +15901,11 @@ void ScalarEvolution::LoopGuards::collectFromBlock( // Apply divisibility information last. This ensures it is applied to the // outermost expression after other rewrites for the given value. - for (const auto &[K, V] : Multiples) { - const SCEV *DivisorSCEV = SE.getConstant(V); + for (const auto &[K, Divisor] : Multiples) { + const SCEV *DivisorSCEV = SE.getConstant(Divisor); Guards.RewriteMap[K] = SE.getMulExpr(SE.getUDivExpr(applyDivisibilityOnMinMaxExpr( - Guards.rewrite(K), DivisorSCEV, SE), + Guards.rewrite(K), Divisor, SE), DivisorSCEV), DivisorSCEV); ExprsToRewrite.push_back(K);