//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "instsimplify"
+#include "llvm/GlobalAlias.h"
+#include "llvm/Operator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/SetVector.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Support/ConstantRange.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/PatternMatch.h"
#include "llvm/Support/ValueHandle.h"
#include "llvm/Target/TargetData.h"
using namespace llvm;
using namespace llvm::PatternMatch;
-#define RecursionLimit 3
+enum { RecursionLimit = 3 };
+
+STATISTIC(NumExpand, "Number of expansions");
+STATISTIC(NumFactor , "Number of factorizations");
+STATISTIC(NumReassoc, "Number of reassociations");
+
+struct Query {
+ const TargetData *TD;
+ const TargetLibraryInfo *TLI;
+ const DominatorTree *DT;
+
+ Query(const TargetData *td, const TargetLibraryInfo *tli,
+ const DominatorTree *dt) : TD(td), TLI(tli), DT(dt) {}
+};
+
+static Value *SimplifyAndInst(Value *, Value *, const Query &, unsigned);
+static Value *SimplifyBinOp(unsigned, Value *, Value *, const Query &,
+ unsigned);
+static Value *SimplifyCmpInst(unsigned, Value *, Value *, const Query &,
+ unsigned);
+static Value *SimplifyOrInst(Value *, Value *, const Query &, unsigned);
+static Value *SimplifyXorInst(Value *, Value *, const Query &, unsigned);
+static Value *SimplifyTruncInst(Value *, Type *, const Query &, unsigned);
+
+/// getFalse - For a boolean type, or a vector of boolean type, return false, or
+/// a vector with every element false, as appropriate for the type.
+static Constant *getFalse(Type *Ty) {
+ assert(Ty->getScalarType()->isIntegerTy(1) &&
+ "Expected i1 type or a vector of i1!");
+ return Constant::getNullValue(Ty);
+}
+
+/// getTrue - For a boolean type, or a vector of boolean type, return true, or
+/// a vector with every element true, as appropriate for the type.
+static Constant *getTrue(Type *Ty) {
+ assert(Ty->getScalarType()->isIntegerTy(1) &&
+ "Expected i1 type or a vector of i1!");
+ return Constant::getAllOnesValue(Ty);
+}
-static Value *SimplifyBinOp(unsigned, Value *, Value *, const TargetData *,
- const DominatorTree *, unsigned);
-static Value *SimplifyCmpInst(unsigned, Value *, Value *, const TargetData *,
- const DominatorTree *, unsigned);
+/// isSameCompare - Is V equivalent to the comparison "LHS Pred RHS"?
+static bool isSameCompare(Value *V, CmpInst::Predicate Pred, Value *LHS,
+ Value *RHS) {
+ CmpInst *Cmp = dyn_cast<CmpInst>(V);
+ if (!Cmp)
+ return false;
+ CmpInst::Predicate CPred = Cmp->getPredicate();
+ Value *CLHS = Cmp->getOperand(0), *CRHS = Cmp->getOperand(1);
+ if (CPred == Pred && CLHS == LHS && CRHS == RHS)
+ return true;
+ return CPred == CmpInst::getSwappedPredicate(Pred) && CLHS == RHS &&
+ CRHS == LHS;
+}
/// ValueDominatesPHI - Does the given value dominate the specified phi node?
static bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) {
// Arguments and constants dominate all instructions.
return true;
+ // If we are processing instructions (and/or basic blocks) that have not been
+ // fully added to a function, the parent nodes may still be null. Simply
+ // return the conservative answer in these cases.
+ if (!I->getParent() || !P->getParent() || !I->getParent()->getParent())
+ return false;
+
// If we have a DominatorTree then do a precise test.
- if (DT)
+ if (DT) {
+ if (!DT->isReachableFromEntry(P->getParent()))
+ return true;
+ if (!DT->isReachableFromEntry(I->getParent()))
+ return false;
return DT->dominates(I, P);
+ }
// Otherwise, if the instruction is in the entry block, and is not an invoke,
// then it obviously dominates all phi nodes.
return false;
}
-// SimplifyAssociativeBinOp - Generic simplifications for associative binary
-// operations. Returns the simpler value, or null if none was found.
-static Value *SimplifyAssociativeBinOp(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD,
- const DominatorTree *DT,
- unsigned MaxRecurse) {
+/// ExpandBinOp - Simplify "A op (B op' C)" by distributing op over op', turning
+/// it into "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is
+/// given by OpcodeToExpand, while "A" corresponds to LHS and "B op' C" to RHS.
+/// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)".
+/// Returns the simplified value, or null if no simplification was performed.
+static Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS,
+ unsigned OpcToExpand, const Query &Q,
+ unsigned MaxRecurse) {
+ Instruction::BinaryOps OpcodeToExpand = (Instruction::BinaryOps)OpcToExpand;
+ // Recursion is always used, so bail out at once if we already hit the limit.
+ if (!MaxRecurse--)
+ return 0;
+
+ // Check whether the expression has the form "(A op' B) op C".
+ if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS))
+ if (Op0->getOpcode() == OpcodeToExpand) {
+ // It does! Try turning it into "(A op C) op' (B op C)".
+ Value *A = Op0->getOperand(0), *B = Op0->getOperand(1), *C = RHS;
+ // Do "A op C" and "B op C" both simplify?
+ if (Value *L = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse))
+ if (Value *R = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
+ // They do! Return "L op' R" if it simplifies or is already available.
+ // If "L op' R" equals "A op' B" then "L op' R" is just the LHS.
+ if ((L == A && R == B) || (Instruction::isCommutative(OpcodeToExpand)
+ && L == B && R == A)) {
+ ++NumExpand;
+ return LHS;
+ }
+ // Otherwise return "L op' R" if it simplifies.
+ if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
+ ++NumExpand;
+ return V;
+ }
+ }
+ }
+
+ // Check whether the expression has the form "A op (B op' C)".
+ if (BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS))
+ if (Op1->getOpcode() == OpcodeToExpand) {
+ // It does! Try turning it into "(A op B) op' (A op C)".
+ Value *A = LHS, *B = Op1->getOperand(0), *C = Op1->getOperand(1);
+ // Do "A op B" and "A op C" both simplify?
+ if (Value *L = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse))
+ if (Value *R = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse)) {
+ // They do! Return "L op' R" if it simplifies or is already available.
+ // If "L op' R" equals "B op' C" then "L op' R" is just the RHS.
+ if ((L == B && R == C) || (Instruction::isCommutative(OpcodeToExpand)
+ && L == C && R == B)) {
+ ++NumExpand;
+ return RHS;
+ }
+ // Otherwise return "L op' R" if it simplifies.
+ if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
+ ++NumExpand;
+ return V;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/// FactorizeBinOp - Simplify "LHS Opcode RHS" by factorizing out a common term
+/// using the operation OpCodeToExtract. For example, when Opcode is Add and
+/// OpCodeToExtract is Mul then this tries to turn "(A*B)+(A*C)" into "A*(B+C)".
+/// Returns the simplified value, or null if no simplification was performed.
+static Value *FactorizeBinOp(unsigned Opcode, Value *LHS, Value *RHS,
+ unsigned OpcToExtract, const Query &Q,
+ unsigned MaxRecurse) {
+ Instruction::BinaryOps OpcodeToExtract = (Instruction::BinaryOps)OpcToExtract;
+ // Recursion is always used, so bail out at once if we already hit the limit.
+ if (!MaxRecurse--)
+ return 0;
+
+ BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
+ BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
+
+ if (!Op0 || Op0->getOpcode() != OpcodeToExtract ||
+ !Op1 || Op1->getOpcode() != OpcodeToExtract)
+ return 0;
+
+ // The expression has the form "(A op' B) op (C op' D)".
+ Value *A = Op0->getOperand(0), *B = Op0->getOperand(1);
+ Value *C = Op1->getOperand(0), *D = Op1->getOperand(1);
+
+ // Use left distributivity, i.e. "X op' (Y op Z) = (X op' Y) op (X op' Z)".
+ // Does the instruction have the form "(A op' B) op (A op' D)" or, in the
+ // commutative case, "(A op' B) op (C op' A)"?
+ if (A == C || (Instruction::isCommutative(OpcodeToExtract) && A == D)) {
+ Value *DD = A == C ? D : C;
+ // Form "A op' (B op DD)" if it simplifies completely.
+ // Does "B op DD" simplify?
+ if (Value *V = SimplifyBinOp(Opcode, B, DD, Q, MaxRecurse)) {
+ // It does! Return "A op' V" if it simplifies or is already available.
+ // If V equals B then "A op' V" is just the LHS. If V equals DD then
+ // "A op' V" is just the RHS.
+ if (V == B || V == DD) {
+ ++NumFactor;
+ return V == B ? LHS : RHS;
+ }
+ // Otherwise return "A op' V" if it simplifies.
+ if (Value *W = SimplifyBinOp(OpcodeToExtract, A, V, Q, MaxRecurse)) {
+ ++NumFactor;
+ return W;
+ }
+ }
+ }
+
+ // Use right distributivity, i.e. "(X op Y) op' Z = (X op' Z) op (Y op' Z)".
+ // Does the instruction have the form "(A op' B) op (C op' B)" or, in the
+ // commutative case, "(A op' B) op (B op' D)"?
+ if (B == D || (Instruction::isCommutative(OpcodeToExtract) && B == C)) {
+ Value *CC = B == D ? C : D;
+ // Form "(A op CC) op' B" if it simplifies completely..
+ // Does "A op CC" simplify?
+ if (Value *V = SimplifyBinOp(Opcode, A, CC, Q, MaxRecurse)) {
+ // It does! Return "V op' B" if it simplifies or is already available.
+ // If V equals A then "V op' B" is just the LHS. If V equals CC then
+ // "V op' B" is just the RHS.
+ if (V == A || V == CC) {
+ ++NumFactor;
+ return V == A ? LHS : RHS;
+ }
+ // Otherwise return "V op' B" if it simplifies.
+ if (Value *W = SimplifyBinOp(OpcodeToExtract, V, B, Q, MaxRecurse)) {
+ ++NumFactor;
+ return W;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/// SimplifyAssociativeBinOp - Generic simplifications for associative binary
+/// operations. Returns the simpler value, or null if none was found.
+static Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS,
+ const Query &Q, unsigned MaxRecurse) {
+ Instruction::BinaryOps Opcode = (Instruction::BinaryOps)Opc;
assert(Instruction::isAssociative(Opcode) && "Not an associative operation!");
// Recursion is always used, so bail out at once if we already hit the limit.
Value *C = RHS;
// Does "B op C" simplify?
- if (Value *V = SimplifyBinOp(Opcode, B, C, TD, DT, MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
// It does! Return "A op V" if it simplifies or is already available.
// If V equals B then "A op V" is just the LHS.
- if (V == B)
- return LHS;
+ if (V == B) return LHS;
// Otherwise return "A op V" if it simplifies.
- if (Value *W = SimplifyBinOp(Opcode, A, V, TD, DT, MaxRecurse))
+ if (Value *W = SimplifyBinOp(Opcode, A, V, Q, MaxRecurse)) {
+ ++NumReassoc;
return W;
+ }
}
}
Value *C = Op1->getOperand(1);
// Does "A op B" simplify?
- if (Value *V = SimplifyBinOp(Opcode, A, B, TD, DT, MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse)) {
// It does! Return "V op C" if it simplifies or is already available.
// If V equals B then "V op C" is just the RHS.
- if (V == B)
- return RHS;
+ if (V == B) return RHS;
// Otherwise return "V op C" if it simplifies.
- if (Value *W = SimplifyBinOp(Opcode, V, C, TD, DT, MaxRecurse))
+ if (Value *W = SimplifyBinOp(Opcode, V, C, Q, MaxRecurse)) {
+ ++NumReassoc;
return W;
+ }
}
}
Value *C = RHS;
// Does "C op A" simplify?
- if (Value *V = SimplifyBinOp(Opcode, C, A, TD, DT, MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
// It does! Return "V op B" if it simplifies or is already available.
// If V equals A then "V op B" is just the LHS.
- if (V == A)
- return LHS;
+ if (V == A) return LHS;
// Otherwise return "V op B" if it simplifies.
- if (Value *W = SimplifyBinOp(Opcode, V, B, TD, DT, MaxRecurse))
+ if (Value *W = SimplifyBinOp(Opcode, V, B, Q, MaxRecurse)) {
+ ++NumReassoc;
return W;
+ }
}
}
Value *C = Op1->getOperand(1);
// Does "C op A" simplify?
- if (Value *V = SimplifyBinOp(Opcode, C, A, TD, DT, MaxRecurse)) {
+ if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
// It does! Return "B op V" if it simplifies or is already available.
// If V equals C then "B op V" is just the RHS.
- if (V == C)
- return RHS;
+ if (V == C) return RHS;
// Otherwise return "B op V" if it simplifies.
- if (Value *W = SimplifyBinOp(Opcode, B, V, TD, DT, MaxRecurse))
+ if (Value *W = SimplifyBinOp(Opcode, B, V, Q, MaxRecurse)) {
+ ++NumReassoc;
return W;
+ }
}
}
/// evaluating it on both branches of the select results in the same value.
/// Returns the common value if so, otherwise returns null.
static Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD,
- const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
return 0;
Value *TV;
Value *FV;
if (SI == LHS) {
- TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, TD, DT, MaxRecurse);
- FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, TD, DT, MaxRecurse);
+ TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, Q, MaxRecurse);
+ FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, Q, MaxRecurse);
} else {
- TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), TD, DT, MaxRecurse);
- FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), TD, DT, MaxRecurse);
+ TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), Q, MaxRecurse);
+ FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), Q, MaxRecurse);
}
// If they simplified to the same value, then return the common value.
/// result in the same value. Returns the common value if so, otherwise returns
/// null.
static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS,
- Value *RHS, const TargetData *TD,
- const DominatorTree *DT,
+ Value *RHS, const Query &Q,
unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
}
assert(isa<SelectInst>(LHS) && "Not comparing with a select instruction!");
SelectInst *SI = cast<SelectInst>(LHS);
+ Value *Cond = SI->getCondition();
+ Value *TV = SI->getTrueValue();
+ Value *FV = SI->getFalseValue();
- // Now that we have "cmp select(cond, TV, FV), RHS", analyse it.
+ // Now that we have "cmp select(Cond, TV, FV), RHS", analyse it.
// Does "cmp TV, RHS" simplify?
- if (Value *TCmp = SimplifyCmpInst(Pred, SI->getTrueValue(), RHS, TD, DT,
- MaxRecurse))
- // It does! Does "cmp FV, RHS" simplify?
- if (Value *FCmp = SimplifyCmpInst(Pred, SI->getFalseValue(), RHS, TD, DT,
- MaxRecurse))
- // It does! If they simplified to the same value, then use it as the
- // result of the original comparison.
- if (TCmp == FCmp)
- return TCmp;
+ Value *TCmp = SimplifyCmpInst(Pred, TV, RHS, Q, MaxRecurse);
+ if (TCmp == Cond) {
+ // It not only simplified, it simplified to the select condition. Replace
+ // it with 'true'.
+ TCmp = getTrue(Cond->getType());
+ } else if (!TCmp) {
+ // It didn't simplify. However if "cmp TV, RHS" is equal to the select
+ // condition then we can replace it with 'true'. Otherwise give up.
+ if (!isSameCompare(Cond, Pred, TV, RHS))
+ return 0;
+ TCmp = getTrue(Cond->getType());
+ }
+
+ // Does "cmp FV, RHS" simplify?
+ Value *FCmp = SimplifyCmpInst(Pred, FV, RHS, Q, MaxRecurse);
+ if (FCmp == Cond) {
+ // It not only simplified, it simplified to the select condition. Replace
+ // it with 'false'.
+ FCmp = getFalse(Cond->getType());
+ } else if (!FCmp) {
+ // It didn't simplify. However if "cmp FV, RHS" is equal to the select
+ // condition then we can replace it with 'false'. Otherwise give up.
+ if (!isSameCompare(Cond, Pred, FV, RHS))
+ return 0;
+ FCmp = getFalse(Cond->getType());
+ }
+
+ // If both sides simplified to the same value, then use it as the result of
+ // the original comparison.
+ if (TCmp == FCmp)
+ return TCmp;
+
+ // The remaining cases only make sense if the select condition has the same
+ // type as the result of the comparison, so bail out if this is not so.
+ if (Cond->getType()->isVectorTy() != RHS->getType()->isVectorTy())
+ return 0;
+ // If the false value simplified to false, then the result of the compare
+ // is equal to "Cond && TCmp". This also catches the case when the false
+ // value simplified to false and the true value to true, returning "Cond".
+ if (match(FCmp, m_Zero()))
+ if (Value *V = SimplifyAndInst(Cond, TCmp, Q, MaxRecurse))
+ return V;
+ // If the true value simplified to true, then the result of the compare
+ // is equal to "Cond || FCmp".
+ if (match(TCmp, m_One()))
+ if (Value *V = SimplifyOrInst(Cond, FCmp, Q, MaxRecurse))
+ return V;
+ // Finally, if the false value simplified to true and the true value to
+ // false, then the result of the compare is equal to "!Cond".
+ if (match(FCmp, m_One()) && match(TCmp, m_Zero()))
+ if (Value *V =
+ SimplifyXorInst(Cond, Constant::getAllOnesValue(Cond->getType()),
+ Q, MaxRecurse))
+ return V;
+
return 0;
}
/// it on the incoming phi values yields the same result for every value. If so
/// returns the common value, otherwise returns null.
static Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
return 0;
if (isa<PHINode>(LHS)) {
PI = cast<PHINode>(LHS);
// Bail out if RHS and the phi may be mutually interdependent due to a loop.
- if (!ValueDominatesPHI(RHS, PI, DT))
+ if (!ValueDominatesPHI(RHS, PI, Q.DT))
return 0;
} else {
assert(isa<PHINode>(RHS) && "No PHI instruction operand!");
PI = cast<PHINode>(RHS);
// Bail out if LHS and the phi may be mutually interdependent due to a loop.
- if (!ValueDominatesPHI(LHS, PI, DT))
+ if (!ValueDominatesPHI(LHS, PI, Q.DT))
return 0;
}
// If the incoming value is the phi node itself, it can safely be skipped.
if (Incoming == PI) continue;
Value *V = PI == LHS ?
- SimplifyBinOp(Opcode, Incoming, RHS, TD, DT, MaxRecurse) :
- SimplifyBinOp(Opcode, LHS, Incoming, TD, DT, MaxRecurse);
+ SimplifyBinOp(Opcode, Incoming, RHS, Q, MaxRecurse) :
+ SimplifyBinOp(Opcode, LHS, Incoming, Q, MaxRecurse);
// If the operation failed to simplify, or simplified to a different value
// to previously, then give up.
if (!V || (CommonValue && V != CommonValue))
/// incoming phi values yields the same result every time. If so returns the
/// common result, otherwise returns null.
static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
// Recursion is always used, so bail out at once if we already hit the limit.
if (!MaxRecurse--)
return 0;
PHINode *PI = cast<PHINode>(LHS);
// Bail out if RHS and the phi may be mutually interdependent due to a loop.
- if (!ValueDominatesPHI(RHS, PI, DT))
+ if (!ValueDominatesPHI(RHS, PI, Q.DT))
return 0;
// Evaluate the BinOp on the incoming phi values.
Value *Incoming = PI->getIncomingValue(i);
// If the incoming value is the phi node itself, it can safely be skipped.
if (Incoming == PI) continue;
- Value *V = SimplifyCmpInst(Pred, Incoming, RHS, TD, DT, MaxRecurse);
+ Value *V = SimplifyCmpInst(Pred, Incoming, RHS, Q, MaxRecurse);
// If the operation failed to simplify, or simplified to a different value
// to previously, then give up.
if (!V || (CommonValue && V != CommonValue))
/// SimplifyAddInst - Given operands for an Add, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
- return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(),
- Ops, 2, TD);
+ return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(), Ops,
+ Q.TD, Q.TLI);
}
// Canonicalize the constant to the RHS.
}
// X + undef -> undef
- if (isa<UndefValue>(Op1))
+ if (match(Op1, m_Undef()))
return Op1;
// X + 0 -> X
match(Op1, m_Not(m_Specific(Op0))))
return Constant::getAllOnesValue(Op0->getType());
+ /// i1 add -> xor.
+ if (MaxRecurse && Op0->getType()->isIntegerTy(1))
+ if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
+ return V;
+
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, Q,
MaxRecurse))
return V;
+ // Mul distributes over Add. Try some generic simplifications based on this.
+ if (Value *V = FactorizeBinOp(Instruction::Add, Op0, Op1, Instruction::Mul,
+ Q, MaxRecurse))
+ return V;
+
// Threading Add over selects and phi nodes is pointless, so don't bother.
// Threading over the select in "A + select(cond, B, C)" means evaluating
// "A+B" and "A+C" and seeing if they are equal; but they are equal if and
}
Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit);
+ const TargetData *TD, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT),
+ RecursionLimit);
+}
+
+/// \brief Accumulate the constant integer offset a GEP represents.
+///
+/// Given a getelementptr instruction/constantexpr, accumulate the constant
+/// offset from the base pointer into the provided APInt 'Offset'. Returns true
+/// if the GEP has all-constant indices. Returns false if any non-constant
+/// index is encountered leaving the 'Offset' in an undefined state. The
+/// 'Offset' APInt must be the bitwidth of the target's pointer size.
+static bool accumulateGEPOffset(const TargetData &TD, GEPOperator *GEP,
+ APInt &Offset) {
+ unsigned IntPtrWidth = TD.getPointerSizeInBits();
+ assert(IntPtrWidth == Offset.getBitWidth());
+
+ gep_type_iterator GTI = gep_type_begin(GEP);
+ for (User::op_iterator I = GEP->op_begin() + 1, E = GEP->op_end(); I != E;
+ ++I, ++GTI) {
+ ConstantInt *OpC = dyn_cast<ConstantInt>(*I);
+ if (!OpC) return false;
+ if (OpC->isZero()) continue;
+
+ // Handle a struct index, which adds its field offset to the pointer.
+ if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+ unsigned ElementIdx = OpC->getZExtValue();
+ const StructLayout *SL = TD.getStructLayout(STy);
+ Offset += APInt(IntPtrWidth, SL->getElementOffset(ElementIdx));
+ continue;
+ }
+
+ APInt TypeSize(IntPtrWidth, TD.getTypeAllocSize(GTI.getIndexedType()));
+ Offset += OpC->getValue().sextOrTrunc(IntPtrWidth) * TypeSize;
+ }
+ return true;
+}
+
+/// \brief Compute the base pointer and cumulative constant offsets for V.
+///
+/// This strips all constant offsets off of V, leaving it the base pointer, and
+/// accumulates the total constant offset applied in the returned constant. It
+/// returns 0 if V is not a pointer, and returns the constant '0' if there are
+/// no constant offsets applied.
+static Constant *stripAndComputeConstantOffsets(const TargetData &TD,
+ Value *&V) {
+ if (!V->getType()->isPointerTy())
+ return 0;
+
+ unsigned IntPtrWidth = TD.getPointerSizeInBits();
+ APInt Offset = APInt::getNullValue(IntPtrWidth);
+
+ // Even though we don't look through PHI nodes, we could be called on an
+ // instruction in an unreachable block, which may be on a cycle.
+ SmallPtrSet<Value *, 4> Visited;
+ Visited.insert(V);
+ do {
+ if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
+ if (!GEP->isInBounds() || !accumulateGEPOffset(TD, GEP, Offset))
+ break;
+ V = GEP->getPointerOperand();
+ } else if (Operator::getOpcode(V) == Instruction::BitCast) {
+ V = cast<Operator>(V)->getOperand(0);
+ } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
+ if (GA->mayBeOverridden())
+ break;
+ V = GA->getAliasee();
+ } else {
+ break;
+ }
+ assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+ } while (Visited.insert(V));
+
+ Type *IntPtrTy = TD.getIntPtrType(V->getContext());
+ return ConstantInt::get(IntPtrTy, Offset);
+}
+
+/// \brief Compute the constant difference between two pointer values.
+/// If the difference is not a constant, returns zero.
+static Constant *computePointerDifference(const TargetData &TD,
+ Value *LHS, Value *RHS) {
+ Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS);
+ if (!LHSOffset)
+ return 0;
+ Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS);
+ if (!RHSOffset)
+ return 0;
+
+ // If LHS and RHS are not related via constant offsets to the same base
+ // value, there is nothing we can do here.
+ if (LHS != RHS)
+ return 0;
+
+ // Otherwise, the difference of LHS - RHS can be computed as:
+ // LHS - RHS
+ // = (LHSOffset + Base) - (RHSOffset + Base)
+ // = LHSOffset - RHSOffset
+ return ConstantExpr::getSub(LHSOffset, RHSOffset);
}
/// SimplifySubInst - Given operands for a Sub, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0))
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(),
- Ops, 2, TD);
+ Ops, Q.TD, Q.TLI);
}
// X - undef -> undef
// undef - X -> undef
- if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1))
+ if (match(Op0, m_Undef()) || match(Op1, m_Undef()))
return UndefValue::get(Op0->getType());
// X - 0 -> X
if (Op0 == Op1)
return Constant::getNullValue(Op0->getType());
- // (X + Y) - Y -> X
- // (Y + X) - Y -> X
- Value *X = 0;
- if (match(Op0, m_Add(m_Value(X), m_Specific(Op1))) ||
- match(Op0, m_Add(m_Specific(Op1), m_Value(X))))
+ // (X*2) - X -> X
+ // (X<<1) - X -> X
+ Value *X = 0;
+ if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) ||
+ match(Op0, m_Shl(m_Specific(Op1), m_One())))
+ return Op1;
+
+ // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
+ // For example, (X + Y) - Y -> X; (Y + X) - Y -> X
+ Value *Y = 0, *Z = Op1;
+ if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z
+ // See if "V === Y - Z" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, Q, MaxRecurse-1))
+ // It does! Now see if "X + V" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Add, X, V, Q, MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+ // See if "V === X - Z" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
+ // It does! Now see if "Y + V" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, Q, MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+ }
+
+ // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies.
+ // For example, X - (X + 1) -> -1
+ X = Op0;
+ if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z)
+ // See if "V === X - Y" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
+ // It does! Now see if "V - Z" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, Q, MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+ // See if "V === X - Z" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
+ // It does! Now see if "V - Y" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, Q, MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+ }
+
+ // Z - (X - Y) -> (Z - X) + Y if everything simplifies.
+ // For example, X - (X - Y) -> Y.
+ Z = Op0;
+ if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y)
+ // See if "V === Z - X" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, Q, MaxRecurse-1))
+ // It does! Now see if "V + Y" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, Q, MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+
+ // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies.
+ if (MaxRecurse && match(Op0, m_Trunc(m_Value(X))) &&
+ match(Op1, m_Trunc(m_Value(Y))))
+ if (X->getType() == Y->getType())
+ // See if "V === X - Y" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
+ // It does! Now see if "trunc V" simplifies.
+ if (Value *W = SimplifyTruncInst(V, Op0->getType(), Q, MaxRecurse-1))
+ // It does, return the simplified "trunc V".
+ return W;
+
+ // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...).
+ if (Q.TD && match(Op0, m_PtrToInt(m_Value(X))) &&
+ match(Op1, m_PtrToInt(m_Value(Y))))
+ if (Constant *Result = computePointerDifference(*Q.TD, X, Y))
+ return ConstantExpr::getIntegerCast(Result, Op0->getType(), true);
+
+ // Mul distributes over Sub. Try some generic simplifications based on this.
+ if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul,
+ Q, MaxRecurse))
+ return V;
+
+ // i1 sub -> xor.
+ if (MaxRecurse && Op0->getType()->isIntegerTy(1))
+ if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
+ return V;
+
+ // Threading Sub over selects and phi nodes is pointless, so don't bother.
+ // Threading over the select in "A - select(cond, B, C)" means evaluating
+ // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
+ // only if B and C are equal. If B and C are equal then (since we assume
+ // that operands have already been simplified) "select(cond, B, C)" should
+ // have been simplified to the common value of B and C already. Analysing
+ // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
+ // for threading over phi nodes.
+
+ return 0;
+}
+
+Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const TargetData *TD, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT),
+ RecursionLimit);
+}
+
+/// SimplifyMulInst - Given operands for a Mul, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(),
+ Ops, Q.TD, Q.TLI);
+ }
+
+ // Canonicalize the constant to the RHS.
+ std::swap(Op0, Op1);
+ }
+
+ // X * undef -> 0
+ if (match(Op1, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // X * 0 -> 0
+ if (match(Op1, m_Zero()))
+ return Op1;
+
+ // X * 1 -> X
+ if (match(Op1, m_One()))
+ return Op0;
+
+ // (X / Y) * Y -> X if the division is exact.
+ Value *X = 0;
+ if (match(Op0, m_Exact(m_IDiv(m_Value(X), m_Specific(Op1)))) || // (X / Y) * Y
+ match(Op1, m_Exact(m_IDiv(m_Value(X), m_Specific(Op0))))) // Y * (X / Y)
+ return X;
+
+ // i1 mul -> and.
+ if (MaxRecurse && Op0->getType()->isIntegerTy(1))
+ if (Value *V = SimplifyAndInst(Op0, Op1, Q, MaxRecurse-1))
+ return V;
+
+ // Try some generic simplifications for associative operations.
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, Q,
+ MaxRecurse))
+ return V;
+
+ // Mul distributes over Add. Try some generic simplifications based on this.
+ if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add,
+ Q, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, Q,
+ MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, Q,
+ MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyMulInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
+}
+
+/// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Constant *C0 = dyn_cast<Constant>(Op0)) {
+ if (Constant *C1 = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { C0, C1 };
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
+ }
+ }
+
+ bool isSigned = Opcode == Instruction::SDiv;
+
+ // X / undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ // undef / X -> 0
+ if (match(Op0, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // 0 / X -> 0, we don't need to preserve faults!
+ if (match(Op0, m_Zero()))
+ return Op0;
+
+ // X / 1 -> X
+ if (match(Op1, m_One()))
+ return Op0;
+
+ if (Op0->getType()->isIntegerTy(1))
+ // It can't be division by zero, hence it must be division by one.
+ return Op0;
+
+ // X / X -> 1
+ if (Op0 == Op1)
+ return ConstantInt::get(Op0->getType(), 1);
+
+ // (X * Y) / Y -> X if the multiplication does not overflow.
+ Value *X = 0, *Y = 0;
+ if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) {
+ if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
+ OverflowingBinaryOperator *Mul = cast<OverflowingBinaryOperator>(Op0);
+ // If the Mul knows it does not overflow, then we are good to go.
+ if ((isSigned && Mul->hasNoSignedWrap()) ||
+ (!isSigned && Mul->hasNoUnsignedWrap()))
+ return X;
+ // If X has the form X = A / Y then X * Y cannot overflow.
+ if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X))
+ if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y)
+ return X;
+ }
+
+ // (X rem Y) / Y -> 0
+ if ((isSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
+ (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
+ return Constant::getNullValue(Op0->getType());
+
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+/// SimplifySDivInst - Given operands for an SDiv, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifySDivInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifySDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
+}
+
+/// SimplifyUDivInst - Given operands for a UDiv, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyUDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
+}
+
+static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned) {
+ // undef / X -> undef (the undef could be a snan).
+ if (match(Op0, m_Undef()))
+ return Op0;
+
+ // X / undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ return 0;
+}
+
+Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyFDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
+}
+
+/// SimplifyRem - Given operands for an SRem or URem, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Constant *C0 = dyn_cast<Constant>(Op0)) {
+ if (Constant *C1 = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { C0, C1 };
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
+ }
+ }
+
+ // X % undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ // undef % X -> 0
+ if (match(Op0, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // 0 % X -> 0, we don't need to preserve faults!
+ if (match(Op0, m_Zero()))
+ return Op0;
+
+ // X % 0 -> undef, we don't need to preserve faults!
+ if (match(Op1, m_Zero()))
+ return UndefValue::get(Op0->getType());
+
+ // X % 1 -> 0
+ if (match(Op1, m_One()))
+ return Constant::getNullValue(Op0->getType());
+
+ if (Op0->getType()->isIntegerTy(1))
+ // It can't be remainder by zero, hence it must be remainder by one.
+ return Constant::getNullValue(Op0->getType());
+
+ // X % X -> 0
+ if (Op0 == Op1)
+ return Constant::getNullValue(Op0->getType());
+
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+/// SimplifySRemInst - Given operands for an SRem, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifySRemInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifySRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
+}
+
+/// SimplifyURemInst - Given operands for a URem, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyURemInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyURemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
+}
+
+static Value *SimplifyFRemInst(Value *Op0, Value *Op1, const Query &,
+ unsigned) {
+ // undef % X -> undef (the undef could be a snan).
+ if (match(Op0, m_Undef()))
+ return Op0;
+
+ // X % undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ return 0;
+}
+
+Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyFRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
+}
+
+/// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Constant *C0 = dyn_cast<Constant>(Op0)) {
+ if (Constant *C1 = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { C0, C1 };
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
+ }
+ }
+
+ // 0 shift by X -> 0
+ if (match(Op0, m_Zero()))
+ return Op0;
+
+ // X shift by 0 -> X
+ if (match(Op1, m_Zero()))
+ return Op0;
+
+ // X shift by undef -> undef because it may shift by the bitwidth.
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ // Shifting by the bitwidth or more is undefined.
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1))
+ if (CI->getValue().getLimitedValue() >=
+ Op0->getType()->getScalarSizeInBits())
+ return UndefValue::get(Op0->getType());
+
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+/// SimplifyShlInst - Given operands for an Shl, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ // undef << X -> 0
+ if (match(Op0, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // (X >> A) << A -> X
+ Value *X;
+ if (match(Op0, m_Exact(m_Shr(m_Value(X), m_Specific(Op1)))))
+ return X;
+ return 0;
+}
+
+Value *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const TargetData *TD, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT),
+ RecursionLimit);
+}
+
+/// SimplifyLShrInst - Given operands for an LShr, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Value *V = SimplifyShift(Instruction::LShr, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ // undef >>l X -> 0
+ if (match(Op0, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // (X << A) >> A -> X
+ Value *X;
+ if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) &&
+ cast<OverflowingBinaryOperator>(Op0)->hasNoUnsignedWrap())
+ return X;
+
+ return 0;
+}
+
+Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyLShrInst(Op0, Op1, isExact, Query (TD, TLI, DT),
+ RecursionLimit);
+}
+
+/// SimplifyAShrInst - Given operands for an AShr, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
+ const Query &Q, unsigned MaxRecurse) {
+ if (Value *V = SimplifyShift(Instruction::AShr, Op0, Op1, Q, MaxRecurse))
+ return V;
+
+ // all ones >>a X -> all ones
+ if (match(Op0, m_AllOnes()))
+ return Op0;
+
+ // undef >>a X -> all ones
+ if (match(Op0, m_Undef()))
+ return Constant::getAllOnesValue(Op0->getType());
+
+ // (X << A) >> A -> X
+ Value *X;
+ if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) &&
+ cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap())
return X;
- // Threading Sub over selects and phi nodes is pointless, so don't bother.
- // Threading over the select in "A - select(cond, B, C)" means evaluating
- // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
- // only if B and C are equal. If B and C are equal then (since we assume
- // that operands have already been simplified) "select(cond, B, C)" should
- // have been simplified to the common value of B and C already. Analysing
- // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
- // for threading over phi nodes.
-
return 0;
}
-Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit);
+Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyAShrInst(Op0, Op1, isExact, Query (TD, TLI, DT),
+ RecursionLimit);
}
/// SimplifyAndInst - Given operands for an And, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
+static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::And, CLHS->getType(),
- Ops, 2, TD);
+ Ops, Q.TD, Q.TLI);
}
// Canonicalize the constant to the RHS.
}
// X & undef -> 0
- if (isa<UndefValue>(Op1))
+ if (match(Op1, m_Undef()))
return Constant::getNullValue(Op0->getType());
// X & X = X
return Op0;
// A & ~A = ~A & A = 0
- Value *A = 0, *B = 0;
- if ((match(Op0, m_Not(m_Value(A))) && A == Op1) ||
- (match(Op1, m_Not(m_Value(A))) && A == Op0))
+ if (match(Op0, m_Not(m_Specific(Op1))) ||
+ match(Op1, m_Not(m_Specific(Op0))))
return Constant::getNullValue(Op0->getType());
// (A | ?) & A = A
+ Value *A = 0, *B = 0;
if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
(A == Op1 || B == Op1))
return Op1;
(A == Op0 || B == Op0))
return Op0;
+ // A & (-A) = A if A is a power of two or zero.
+ if (match(Op0, m_Neg(m_Specific(Op1))) ||
+ match(Op1, m_Neg(m_Specific(Op0)))) {
+ if (isPowerOfTwo(Op0, Q.TD, /*OrZero*/true))
+ return Op0;
+ if (isPowerOfTwo(Op1, Q.TD, /*OrZero*/true))
+ return Op1;
+ }
+
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, Q,
MaxRecurse))
return V;
+ // And distributes over Or. Try some generic simplifications based on this.
+ if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or,
+ Q, MaxRecurse))
+ return V;
+
+ // And distributes over Xor. Try some generic simplifications based on this.
+ if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor,
+ Q, MaxRecurse))
+ return V;
+
+ // Or distributes over And. Try some generic simplifications based on this.
+ if (Value *V = FactorizeBinOp(Instruction::And, Op0, Op1, Instruction::Or,
+ Q, MaxRecurse))
+ return V;
+
// If the operation is with the result of a select instruction, check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
- if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, TD, DT,
+ if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, Q,
MaxRecurse))
return V;
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
- if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, TD, DT,
+ if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, Q,
MaxRecurse))
return V;
}
Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
const DominatorTree *DT) {
- return ::SimplifyAndInst(Op0, Op1, TD, DT, RecursionLimit);
+ return ::SimplifyAndInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
}
/// SimplifyOrInst - Given operands for an Or, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
+static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(),
- Ops, 2, TD);
+ Ops, Q.TD, Q.TLI);
}
// Canonicalize the constant to the RHS.
}
// X | undef -> -1
- if (isa<UndefValue>(Op1))
+ if (match(Op1, m_Undef()))
return Constant::getAllOnesValue(Op0->getType());
// X | X = X
return Op1;
// A | ~A = ~A | A = -1
- Value *A = 0, *B = 0;
- if ((match(Op0, m_Not(m_Value(A))) && A == Op1) ||
- (match(Op1, m_Not(m_Value(A))) && A == Op0))
+ if (match(Op0, m_Not(m_Specific(Op1))) ||
+ match(Op1, m_Not(m_Specific(Op0))))
return Constant::getAllOnesValue(Op0->getType());
// (A & ?) | A = A
+ Value *A = 0, *B = 0;
if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
(A == Op1 || B == Op1))
return Op1;
(A == Op0 || B == Op0))
return Op0;
+ // ~(A & ?) | A = -1
+ if (match(Op0, m_Not(m_And(m_Value(A), m_Value(B)))) &&
+ (A == Op1 || B == Op1))
+ return Constant::getAllOnesValue(Op1->getType());
+
+ // A | ~(A & ?) = -1
+ if (match(Op1, m_Not(m_And(m_Value(A), m_Value(B)))) &&
+ (A == Op0 || B == Op0))
+ return Constant::getAllOnesValue(Op0->getType());
+
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, Q,
MaxRecurse))
return V;
+ // Or distributes over And. Try some generic simplifications based on this.
+ if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, Q,
+ MaxRecurse))
+ return V;
+
+ // And distributes over Or. Try some generic simplifications based on this.
+ if (Value *V = FactorizeBinOp(Instruction::Or, Op0, Op1, Instruction::And,
+ Q, MaxRecurse))
+ return V;
+
// If the operation is with the result of a select instruction, check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
- if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, TD, DT,
+ if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, Q,
MaxRecurse))
return V;
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
- if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, TD, DT,
- MaxRecurse))
+ if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, Q, MaxRecurse))
return V;
return 0;
}
Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
const DominatorTree *DT) {
- return ::SimplifyOrInst(Op0, Op1, TD, DT, RecursionLimit);
+ return ::SimplifyOrInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
}
/// SimplifyXorInst - Given operands for a Xor, see if we can
/// fold the result. If not, this returns null.
-static Value *SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD,
- const DominatorTree *DT, unsigned MaxRecurse) {
+static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q,
+ unsigned MaxRecurse) {
if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
Constant *Ops[] = { CLHS, CRHS };
return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(),
- Ops, 2, TD);
+ Ops, Q.TD, Q.TLI);
}
// Canonicalize the constant to the RHS.
}
// A ^ undef -> undef
- if (isa<UndefValue>(Op1))
+ if (match(Op1, m_Undef()))
return Op1;
// A ^ 0 = A
return Constant::getNullValue(Op0->getType());
// A ^ ~A = ~A ^ A = -1
- Value *A = 0;
- if ((match(Op0, m_Not(m_Value(A))) && A == Op1) ||
- (match(Op1, m_Not(m_Value(A))) && A == Op0))
+ if (match(Op0, m_Not(m_Specific(Op1))) ||
+ match(Op1, m_Not(m_Specific(Op0))))
return Constant::getAllOnesValue(Op0->getType());
// Try some generic simplifications for associative operations.
- if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, TD, DT,
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, Q,
MaxRecurse))
return V;
+ // And distributes over Xor. Try some generic simplifications based on this.
+ if (Value *V = FactorizeBinOp(Instruction::Xor, Op0, Op1, Instruction::And,
+ Q, MaxRecurse))
+ return V;
+
// Threading Xor over selects and phi nodes is pointless, so don't bother.
// Threading over the select in "A ^ select(cond, B, C)" means evaluating
// "A^B" and "A^C" and seeing if they are equal; but they are equal if and
}
Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
const DominatorTree *DT) {
- return ::SimplifyXorInst(Op0, Op1, TD, DT, RecursionLimit);
+ return ::SimplifyXorInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
}
-static const Type *GetCompareTy(Value *Op) {
+static Type *GetCompareTy(Value *Op) {
return CmpInst::makeCmpResultType(Op->getType());
}
+/// ExtractEquivalentCondition - Rummage around inside V looking for something
+/// equivalent to the comparison "LHS Pred RHS". Return such a value if found,
+/// otherwise return null. Helper function for analyzing max/min idioms.
+static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred,
+ Value *LHS, Value *RHS) {
+ SelectInst *SI = dyn_cast<SelectInst>(V);
+ if (!SI)
+ return 0;
+ CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition());
+ if (!Cmp)
+ return 0;
+ Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1);
+ if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS)
+ return Cmp;
+ if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) &&
+ LHS == CmpRHS && RHS == CmpLHS)
+ return Cmp;
+ return 0;
+}
+
+static Constant *computePointerICmp(const TargetData &TD,
+ CmpInst::Predicate Pred,
+ Value *LHS, Value *RHS) {
+ // We can only fold certain predicates on pointer comparisons.
+ switch (Pred) {
+ default:
+ return 0;
+
+ // Equality comaprisons are easy to fold.
+ case CmpInst::ICMP_EQ:
+ case CmpInst::ICMP_NE:
+ break;
+
+ // We can only handle unsigned relational comparisons because 'inbounds' on
+ // a GEP only protects against unsigned wrapping.
+ case CmpInst::ICMP_UGT:
+ case CmpInst::ICMP_UGE:
+ case CmpInst::ICMP_ULT:
+ case CmpInst::ICMP_ULE:
+ // However, we have to switch them to their signed variants to handle
+ // negative indices from the base pointer.
+ Pred = ICmpInst::getSignedPredicate(Pred);
+ break;
+ }
+
+ Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS);
+ if (!LHSOffset)
+ return 0;
+ Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS);
+ if (!RHSOffset)
+ return 0;
+
+ // If LHS and RHS are not related via constant offsets to the same base
+ // value, there is nothing we can do here.
+ if (LHS != RHS)
+ return 0;
+
+ return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset);
+}
+
/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!");
if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
if (Constant *CRHS = dyn_cast<Constant>(RHS))
- return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD);
+ return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI);
// If we have a constant, make sure it is on the RHS.
std::swap(LHS, RHS);
Pred = CmpInst::getSwappedPredicate(Pred);
}
- // ITy - This is the return type of the compare we're considering.
- const Type *ITy = GetCompareTy(LHS);
+ Type *ITy = GetCompareTy(LHS); // The return type.
+ Type *OpTy = LHS->getType(); // The operand type.
// icmp X, X -> true/false
// X icmp undef -> true/false. For example, icmp ugt %X, undef -> false
if (LHS == RHS || isa<UndefValue>(RHS))
return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
- // icmp <global/alloca*/null>, <global/alloca*/null> - Global/Stack value
- // addresses never equal each other! We already know that Op0 != Op1.
- if ((isa<GlobalValue>(LHS) || isa<AllocaInst>(LHS) ||
- isa<ConstantPointerNull>(LHS)) &&
- (isa<GlobalValue>(RHS) || isa<AllocaInst>(RHS) ||
- isa<ConstantPointerNull>(RHS)))
- return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred));
-
- // See if we are doing a comparison with a constant.
- if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
- // If we have an icmp le or icmp ge instruction, turn it into the
- // appropriate icmp lt or icmp gt instruction. This allows us to rely on
- // them being folded in the code below.
+ // Special case logic when the operands have i1 type.
+ if (OpTy->getScalarType()->isIntegerTy(1)) {
switch (Pred) {
default: break;
+ case ICmpInst::ICMP_EQ:
+ // X == 1 -> X
+ if (match(RHS, m_One()))
+ return LHS;
+ break;
+ case ICmpInst::ICMP_NE:
+ // X != 0 -> X
+ if (match(RHS, m_Zero()))
+ return LHS;
+ break;
+ case ICmpInst::ICMP_UGT:
+ // X >u 0 -> X
+ if (match(RHS, m_Zero()))
+ return LHS;
+ break;
+ case ICmpInst::ICMP_UGE:
+ // X >=u 1 -> X
+ if (match(RHS, m_One()))
+ return LHS;
+ break;
+ case ICmpInst::ICMP_SLT:
+ // X <s 0 -> X
+ if (match(RHS, m_Zero()))
+ return LHS;
+ break;
+ case ICmpInst::ICMP_SLE:
+ // X <=s -1 -> X
+ if (match(RHS, m_One()))
+ return LHS;
+ break;
+ }
+ }
+
+ // icmp <object*>, <object*/null> - Different identified objects have
+ // different addresses (unless null), and what's more the address of an
+ // identified local is never equal to another argument (again, barring null).
+ // Note that generalizing to the case where LHS is a global variable address
+ // or null is pointless, since if both LHS and RHS are constants then we
+ // already constant folded the compare, and if only one of them is then we
+ // moved it to RHS already.
+ Value *LHSPtr = LHS->stripPointerCasts();
+ Value *RHSPtr = RHS->stripPointerCasts();
+ if (LHSPtr == RHSPtr)
+ return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
+
+ // Be more aggressive about stripping pointer adjustments when checking a
+ // comparison of an alloca address to another object. We can rip off all
+ // inbounds GEP operations, even if they are variable.
+ LHSPtr = LHSPtr->stripInBoundsOffsets();
+ if (llvm::isIdentifiedObject(LHSPtr)) {
+ RHSPtr = RHSPtr->stripInBoundsOffsets();
+ if (llvm::isKnownNonNull(LHSPtr) || llvm::isKnownNonNull(RHSPtr)) {
+ // If both sides are different identified objects, they aren't equal
+ // unless they're null.
+ if (LHSPtr != RHSPtr && llvm::isIdentifiedObject(RHSPtr) &&
+ Pred == CmpInst::ICMP_EQ)
+ return ConstantInt::get(ITy, false);
+
+ // A local identified object (alloca or noalias call) can't equal any
+ // incoming argument, unless they're both null.
+ if (isa<Instruction>(LHSPtr) && isa<Argument>(RHSPtr) &&
+ Pred == CmpInst::ICMP_EQ)
+ return ConstantInt::get(ITy, false);
+ }
+
+ // Assume that the constant null is on the right.
+ if (llvm::isKnownNonNull(LHSPtr) && isa<ConstantPointerNull>(RHSPtr)) {
+ if (Pred == CmpInst::ICMP_EQ)
+ return ConstantInt::get(ITy, false);
+ else if (Pred == CmpInst::ICMP_NE)
+ return ConstantInt::get(ITy, true);
+ }
+ } else if (isa<Argument>(LHSPtr)) {
+ RHSPtr = RHSPtr->stripInBoundsOffsets();
+ // An alloca can't be equal to an argument.
+ if (isa<AllocaInst>(RHSPtr)) {
+ if (Pred == CmpInst::ICMP_EQ)
+ return ConstantInt::get(ITy, false);
+ else if (Pred == CmpInst::ICMP_NE)
+ return ConstantInt::get(ITy, true);
+ }
+ }
+
+ // If we are comparing with zero then try hard since this is a common case.
+ if (match(RHS, m_Zero())) {
+ bool LHSKnownNonNegative, LHSKnownNegative;
+ switch (Pred) {
+ default: llvm_unreachable("Unknown ICmp predicate!");
+ case ICmpInst::ICMP_ULT:
+ return getFalse(ITy);
+ case ICmpInst::ICMP_UGE:
+ return getTrue(ITy);
+ case ICmpInst::ICMP_EQ:
case ICmpInst::ICMP_ULE:
- if (CI->isMaxValue(false)) // A <=u MAX -> TRUE
- return ConstantInt::getTrue(CI->getContext());
+ if (isKnownNonZero(LHS, Q.TD))
+ return getFalse(ITy);
+ break;
+ case ICmpInst::ICMP_NE:
+ case ICmpInst::ICMP_UGT:
+ if (isKnownNonZero(LHS, Q.TD))
+ return getTrue(ITy);
+ break;
+ case ICmpInst::ICMP_SLT:
+ ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
+ if (LHSKnownNegative)
+ return getTrue(ITy);
+ if (LHSKnownNonNegative)
+ return getFalse(ITy);
break;
case ICmpInst::ICMP_SLE:
- if (CI->isMaxValue(true)) // A <=s MAX -> TRUE
- return ConstantInt::getTrue(CI->getContext());
+ ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
+ if (LHSKnownNegative)
+ return getTrue(ITy);
+ if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD))
+ return getFalse(ITy);
+ break;
+ case ICmpInst::ICMP_SGE:
+ ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
+ if (LHSKnownNegative)
+ return getFalse(ITy);
+ if (LHSKnownNonNegative)
+ return getTrue(ITy);
+ break;
+ case ICmpInst::ICMP_SGT:
+ ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
+ if (LHSKnownNegative)
+ return getFalse(ITy);
+ if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD))
+ return getTrue(ITy);
+ break;
+ }
+ }
+
+ // See if we are doing a comparison with a constant integer.
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
+ // Rule out tautological comparisons (eg., ult 0 or uge 0).
+ ConstantRange RHS_CR = ICmpInst::makeConstantRange(Pred, CI->getValue());
+ if (RHS_CR.isEmptySet())
+ return ConstantInt::getFalse(CI->getContext());
+ if (RHS_CR.isFullSet())
+ return ConstantInt::getTrue(CI->getContext());
+
+ // Many binary operators with constant RHS have easy to compute constant
+ // range. Use them to check whether the comparison is a tautology.
+ uint32_t Width = CI->getBitWidth();
+ APInt Lower = APInt(Width, 0);
+ APInt Upper = APInt(Width, 0);
+ ConstantInt *CI2;
+ if (match(LHS, m_URem(m_Value(), m_ConstantInt(CI2)))) {
+ // 'urem x, CI2' produces [0, CI2).
+ Upper = CI2->getValue();
+ } else if (match(LHS, m_SRem(m_Value(), m_ConstantInt(CI2)))) {
+ // 'srem x, CI2' produces (-|CI2|, |CI2|).
+ Upper = CI2->getValue().abs();
+ Lower = (-Upper) + 1;
+ } else if (match(LHS, m_UDiv(m_ConstantInt(CI2), m_Value()))) {
+ // 'udiv CI2, x' produces [0, CI2].
+ Upper = CI2->getValue() + 1;
+ } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) {
+ // 'udiv x, CI2' produces [0, UINT_MAX / CI2].
+ APInt NegOne = APInt::getAllOnesValue(Width);
+ if (!CI2->isZero())
+ Upper = NegOne.udiv(CI2->getValue()) + 1;
+ } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) {
+ // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2].
+ APInt IntMin = APInt::getSignedMinValue(Width);
+ APInt IntMax = APInt::getSignedMaxValue(Width);
+ APInt Val = CI2->getValue().abs();
+ if (!Val.isMinValue()) {
+ Lower = IntMin.sdiv(Val);
+ Upper = IntMax.sdiv(Val) + 1;
+ }
+ } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) {
+ // 'lshr x, CI2' produces [0, UINT_MAX >> CI2].
+ APInt NegOne = APInt::getAllOnesValue(Width);
+ if (CI2->getValue().ult(Width))
+ Upper = NegOne.lshr(CI2->getValue()) + 1;
+ } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) {
+ // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2].
+ APInt IntMin = APInt::getSignedMinValue(Width);
+ APInt IntMax = APInt::getSignedMaxValue(Width);
+ if (CI2->getValue().ult(Width)) {
+ Lower = IntMin.ashr(CI2->getValue());
+ Upper = IntMax.ashr(CI2->getValue()) + 1;
+ }
+ } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) {
+ // 'or x, CI2' produces [CI2, UINT_MAX].
+ Lower = CI2->getValue();
+ } else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) {
+ // 'and x, CI2' produces [0, CI2].
+ Upper = CI2->getValue() + 1;
+ }
+ if (Lower != Upper) {
+ ConstantRange LHS_CR = ConstantRange(Lower, Upper);
+ if (RHS_CR.contains(LHS_CR))
+ return ConstantInt::getTrue(RHS->getContext());
+ if (RHS_CR.inverse().contains(LHS_CR))
+ return ConstantInt::getFalse(RHS->getContext());
+ }
+ }
+
+ // Compare of cast, for example (zext X) != 0 -> X != 0
+ if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) {
+ Instruction *LI = cast<CastInst>(LHS);
+ Value *SrcOp = LI->getOperand(0);
+ Type *SrcTy = SrcOp->getType();
+ Type *DstTy = LI->getType();
+
+ // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
+ // if the integer type is the same size as the pointer type.
+ if (MaxRecurse && Q.TD && isa<PtrToIntInst>(LI) &&
+ Q.TD->getPointerSizeInBits() == DstTy->getPrimitiveSizeInBits()) {
+ if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
+ // Transfer the cast to the constant.
+ if (Value *V = SimplifyICmpInst(Pred, SrcOp,
+ ConstantExpr::getIntToPtr(RHSC, SrcTy),
+ Q, MaxRecurse-1))
+ return V;
+ } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) {
+ if (RI->getOperand(0)->getType() == SrcTy)
+ // Compare without the cast.
+ if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
+ Q, MaxRecurse-1))
+ return V;
+ }
+ }
+
+ if (isa<ZExtInst>(LHS)) {
+ // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the
+ // same type.
+ if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) {
+ if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
+ // Compare X and Y. Note that signed predicates become unsigned.
+ if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
+ SrcOp, RI->getOperand(0), Q,
+ MaxRecurse-1))
+ return V;
+ }
+ // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended
+ // too. If not, then try to deduce the result of the comparison.
+ else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
+ // Compute the constant that would happen if we truncated to SrcTy then
+ // reextended to DstTy.
+ Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
+ Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy);
+
+ // If the re-extended constant didn't change then this is effectively
+ // also a case of comparing two zero-extended values.
+ if (RExt == CI && MaxRecurse)
+ if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
+ SrcOp, Trunc, Q, MaxRecurse-1))
+ return V;
+
+ // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
+ // there. Use this to work out the result of the comparison.
+ if (RExt != CI) {
+ switch (Pred) {
+ default: llvm_unreachable("Unknown ICmp predicate!");
+ // LHS <u RHS.
+ case ICmpInst::ICMP_EQ:
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_UGE:
+ return ConstantInt::getFalse(CI->getContext());
+
+ case ICmpInst::ICMP_NE:
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_ULE:
+ return ConstantInt::getTrue(CI->getContext());
+
+ // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS
+ // is non-negative then LHS <s RHS.
+ case ICmpInst::ICMP_SGT:
+ case ICmpInst::ICMP_SGE:
+ return CI->getValue().isNegative() ?
+ ConstantInt::getTrue(CI->getContext()) :
+ ConstantInt::getFalse(CI->getContext());
+
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_SLE:
+ return CI->getValue().isNegative() ?
+ ConstantInt::getFalse(CI->getContext()) :
+ ConstantInt::getTrue(CI->getContext());
+ }
+ }
+ }
+ }
+
+ if (isa<SExtInst>(LHS)) {
+ // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the
+ // same type.
+ if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) {
+ if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
+ // Compare X and Y. Note that the predicate does not change.
+ if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
+ Q, MaxRecurse-1))
+ return V;
+ }
+ // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
+ // too. If not, then try to deduce the result of the comparison.
+ else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
+ // Compute the constant that would happen if we truncated to SrcTy then
+ // reextended to DstTy.
+ Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
+ Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy);
+
+ // If the re-extended constant didn't change then this is effectively
+ // also a case of comparing two sign-extended values.
+ if (RExt == CI && MaxRecurse)
+ if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, Q, MaxRecurse-1))
+ return V;
+
+ // Otherwise the upper bits of LHS are all equal, while RHS has varying
+ // bits there. Use this to work out the result of the comparison.
+ if (RExt != CI) {
+ switch (Pred) {
+ default: llvm_unreachable("Unknown ICmp predicate!");
+ case ICmpInst::ICMP_EQ:
+ return ConstantInt::getFalse(CI->getContext());
+ case ICmpInst::ICMP_NE:
+ return ConstantInt::getTrue(CI->getContext());
+
+ // If RHS is non-negative then LHS <s RHS. If RHS is negative then
+ // LHS >s RHS.
+ case ICmpInst::ICMP_SGT:
+ case ICmpInst::ICMP_SGE:
+ return CI->getValue().isNegative() ?
+ ConstantInt::getTrue(CI->getContext()) :
+ ConstantInt::getFalse(CI->getContext());
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_SLE:
+ return CI->getValue().isNegative() ?
+ ConstantInt::getFalse(CI->getContext()) :
+ ConstantInt::getTrue(CI->getContext());
+
+ // If LHS is non-negative then LHS <u RHS. If LHS is negative then
+ // LHS >u RHS.
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_UGE:
+ // Comparison is true iff the LHS <s 0.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp,
+ Constant::getNullValue(SrcTy),
+ Q, MaxRecurse-1))
+ return V;
+ break;
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_ULE:
+ // Comparison is true iff the LHS >=s 0.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp,
+ Constant::getNullValue(SrcTy),
+ Q, MaxRecurse-1))
+ return V;
+ break;
+ }
+ }
+ }
+ }
+ }
+
+ // Special logic for binary operators.
+ BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS);
+ BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
+ if (MaxRecurse && (LBO || RBO)) {
+ // Analyze the case when either LHS or RHS is an add instruction.
+ Value *A = 0, *B = 0, *C = 0, *D = 0;
+ // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
+ bool NoLHSWrapProblem = false, NoRHSWrapProblem = false;
+ if (LBO && LBO->getOpcode() == Instruction::Add) {
+ A = LBO->getOperand(0); B = LBO->getOperand(1);
+ NoLHSWrapProblem = ICmpInst::isEquality(Pred) ||
+ (CmpInst::isUnsigned(Pred) && LBO->hasNoUnsignedWrap()) ||
+ (CmpInst::isSigned(Pred) && LBO->hasNoSignedWrap());
+ }
+ if (RBO && RBO->getOpcode() == Instruction::Add) {
+ C = RBO->getOperand(0); D = RBO->getOperand(1);
+ NoRHSWrapProblem = ICmpInst::isEquality(Pred) ||
+ (CmpInst::isUnsigned(Pred) && RBO->hasNoUnsignedWrap()) ||
+ (CmpInst::isSigned(Pred) && RBO->hasNoSignedWrap());
+ }
+
+ // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow.
+ if ((A == RHS || B == RHS) && NoLHSWrapProblem)
+ if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A,
+ Constant::getNullValue(RHS->getType()),
+ Q, MaxRecurse-1))
+ return V;
+
+ // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
+ if ((C == LHS || D == LHS) && NoRHSWrapProblem)
+ if (Value *V = SimplifyICmpInst(Pred,
+ Constant::getNullValue(LHS->getType()),
+ C == LHS ? D : C, Q, MaxRecurse-1))
+ return V;
+
+ // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
+ if (A && C && (A == C || A == D || B == C || B == D) &&
+ NoLHSWrapProblem && NoRHSWrapProblem) {
+ // Determine Y and Z in the form icmp (X+Y), (X+Z).
+ Value *Y = (A == C || A == D) ? B : A;
+ Value *Z = (C == A || C == B) ? D : C;
+ if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1))
+ return V;
+ }
+ }
+
+ if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
+ bool KnownNonNegative, KnownNegative;
+ switch (Pred) {
+ default:
break;
+ case ICmpInst::ICMP_SGT:
+ case ICmpInst::ICMP_SGE:
+ ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
+ if (!KnownNonNegative)
+ break;
+ // fall-through
+ case ICmpInst::ICMP_EQ:
+ case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE:
- if (CI->isMinValue(false)) // A >=u MIN -> TRUE
- return ConstantInt::getTrue(CI->getContext());
+ return getFalse(ITy);
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_SLE:
+ ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
+ if (!KnownNonNegative)
+ break;
+ // fall-through
+ case ICmpInst::ICMP_NE:
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_ULE:
+ return getTrue(ITy);
+ }
+ }
+ if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
+ bool KnownNonNegative, KnownNegative;
+ switch (Pred) {
+ default:
break;
+ case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE:
- if (CI->isMinValue(true)) // A >=s MIN -> TRUE
- return ConstantInt::getTrue(CI->getContext());
+ ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
+ if (!KnownNonNegative)
+ break;
+ // fall-through
+ case ICmpInst::ICMP_NE:
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_UGE:
+ return getTrue(ITy);
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_SLE:
+ ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
+ if (!KnownNonNegative)
+ break;
+ // fall-through
+ case ICmpInst::ICMP_EQ:
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_ULE:
+ return getFalse(ITy);
+ }
+ }
+
+ // x udiv y <=u x.
+ if (LBO && match(LBO, m_UDiv(m_Specific(RHS), m_Value()))) {
+ // icmp pred (X /u Y), X
+ if (Pred == ICmpInst::ICMP_UGT)
+ return getFalse(ITy);
+ if (Pred == ICmpInst::ICMP_ULE)
+ return getTrue(ITy);
+ }
+
+ if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() &&
+ LBO->getOperand(1) == RBO->getOperand(1)) {
+ switch (LBO->getOpcode()) {
+ default: break;
+ case Instruction::UDiv:
+ case Instruction::LShr:
+ if (ICmpInst::isSigned(Pred))
+ break;
+ // fall-through
+ case Instruction::SDiv:
+ case Instruction::AShr:
+ if (!LBO->isExact() || !RBO->isExact())
+ break;
+ if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
+ RBO->getOperand(0), Q, MaxRecurse-1))
+ return V;
+ break;
+ case Instruction::Shl: {
+ bool NUW = LBO->hasNoUnsignedWrap() && RBO->hasNoUnsignedWrap();
+ bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap();
+ if (!NUW && !NSW)
+ break;
+ if (!NSW && ICmpInst::isSigned(Pred))
+ break;
+ if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
+ RBO->getOperand(0), Q, MaxRecurse-1))
+ return V;
+ break;
+ }
+ }
+ }
+
+ // Simplify comparisons involving max/min.
+ Value *A, *B;
+ CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE;
+ CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
+
+ // Signed variants on "max(a,b)>=a -> true".
+ if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
+ if (A != RHS) std::swap(A, B); // smax(A, B) pred A.
+ EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
+ // We analyze this as smax(A, B) pred A.
+ P = Pred;
+ } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) &&
+ (A == LHS || B == LHS)) {
+ if (A != LHS) std::swap(A, B); // A pred smax(A, B).
+ EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
+ // We analyze this as smax(A, B) swapped-pred A.
+ P = CmpInst::getSwappedPredicate(Pred);
+ } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
+ (A == RHS || B == RHS)) {
+ if (A != RHS) std::swap(A, B); // smin(A, B) pred A.
+ EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
+ // We analyze this as smax(-A, -B) swapped-pred -A.
+ // Note that we do not need to actually form -A or -B thanks to EqP.
+ P = CmpInst::getSwappedPredicate(Pred);
+ } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) &&
+ (A == LHS || B == LHS)) {
+ if (A != LHS) std::swap(A, B); // A pred smin(A, B).
+ EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
+ // We analyze this as smax(-A, -B) pred -A.
+ // Note that we do not need to actually form -A or -B thanks to EqP.
+ P = Pred;
+ }
+ if (P != CmpInst::BAD_ICMP_PREDICATE) {
+ // Cases correspond to "max(A, B) p A".
+ switch (P) {
+ default:
+ break;
+ case CmpInst::ICMP_EQ:
+ case CmpInst::ICMP_SLE:
+ // Equivalent to "A EqP B". This may be the same as the condition tested
+ // in the max/min; if so, we can just return that.
+ if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
+ return V;
+ if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
+ return V;
+ // Otherwise, see if "A EqP B" simplifies.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
+ return V;
+ break;
+ case CmpInst::ICMP_NE:
+ case CmpInst::ICMP_SGT: {
+ CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
+ // Equivalent to "A InvEqP B". This may be the same as the condition
+ // tested in the max/min; if so, we can just return that.
+ if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
+ return V;
+ if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
+ return V;
+ // Otherwise, see if "A InvEqP B" simplifies.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
+ return V;
+ break;
+ }
+ case CmpInst::ICMP_SGE:
+ // Always true.
+ return getTrue(ITy);
+ case CmpInst::ICMP_SLT:
+ // Always false.
+ return getFalse(ITy);
+ }
+ }
+
+ // Unsigned variants on "max(a,b)>=a -> true".
+ P = CmpInst::BAD_ICMP_PREDICATE;
+ if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
+ if (A != RHS) std::swap(A, B); // umax(A, B) pred A.
+ EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
+ // We analyze this as umax(A, B) pred A.
+ P = Pred;
+ } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) &&
+ (A == LHS || B == LHS)) {
+ if (A != LHS) std::swap(A, B); // A pred umax(A, B).
+ EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
+ // We analyze this as umax(A, B) swapped-pred A.
+ P = CmpInst::getSwappedPredicate(Pred);
+ } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
+ (A == RHS || B == RHS)) {
+ if (A != RHS) std::swap(A, B); // umin(A, B) pred A.
+ EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
+ // We analyze this as umax(-A, -B) swapped-pred -A.
+ // Note that we do not need to actually form -A or -B thanks to EqP.
+ P = CmpInst::getSwappedPredicate(Pred);
+ } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) &&
+ (A == LHS || B == LHS)) {
+ if (A != LHS) std::swap(A, B); // A pred umin(A, B).
+ EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
+ // We analyze this as umax(-A, -B) pred -A.
+ // Note that we do not need to actually form -A or -B thanks to EqP.
+ P = Pred;
+ }
+ if (P != CmpInst::BAD_ICMP_PREDICATE) {
+ // Cases correspond to "max(A, B) p A".
+ switch (P) {
+ default:
+ break;
+ case CmpInst::ICMP_EQ:
+ case CmpInst::ICMP_ULE:
+ // Equivalent to "A EqP B". This may be the same as the condition tested
+ // in the max/min; if so, we can just return that.
+ if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
+ return V;
+ if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
+ return V;
+ // Otherwise, see if "A EqP B" simplifies.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
+ return V;
break;
+ case CmpInst::ICMP_NE:
+ case CmpInst::ICMP_UGT: {
+ CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
+ // Equivalent to "A InvEqP B". This may be the same as the condition
+ // tested in the max/min; if so, we can just return that.
+ if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
+ return V;
+ if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
+ return V;
+ // Otherwise, see if "A InvEqP B" simplifies.
+ if (MaxRecurse)
+ if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
+ return V;
+ break;
+ }
+ case CmpInst::ICMP_UGE:
+ // Always true.
+ return getTrue(ITy);
+ case CmpInst::ICMP_ULT:
+ // Always false.
+ return getFalse(ITy);
+ }
+ }
+
+ // Variants on "max(x,y) >= min(x,z)".
+ Value *C, *D;
+ if (match(LHS, m_SMax(m_Value(A), m_Value(B))) &&
+ match(RHS, m_SMin(m_Value(C), m_Value(D))) &&
+ (A == C || A == D || B == C || B == D)) {
+ // max(x, ?) pred min(x, ?).
+ if (Pred == CmpInst::ICMP_SGE)
+ // Always true.
+ return getTrue(ITy);
+ if (Pred == CmpInst::ICMP_SLT)
+ // Always false.
+ return getFalse(ITy);
+ } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
+ match(RHS, m_SMax(m_Value(C), m_Value(D))) &&
+ (A == C || A == D || B == C || B == D)) {
+ // min(x, ?) pred max(x, ?).
+ if (Pred == CmpInst::ICMP_SLE)
+ // Always true.
+ return getTrue(ITy);
+ if (Pred == CmpInst::ICMP_SGT)
+ // Always false.
+ return getFalse(ITy);
+ } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) &&
+ match(RHS, m_UMin(m_Value(C), m_Value(D))) &&
+ (A == C || A == D || B == C || B == D)) {
+ // max(x, ?) pred min(x, ?).
+ if (Pred == CmpInst::ICMP_UGE)
+ // Always true.
+ return getTrue(ITy);
+ if (Pred == CmpInst::ICMP_ULT)
+ // Always false.
+ return getFalse(ITy);
+ } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
+ match(RHS, m_UMax(m_Value(C), m_Value(D))) &&
+ (A == C || A == D || B == C || B == D)) {
+ // min(x, ?) pred max(x, ?).
+ if (Pred == CmpInst::ICMP_ULE)
+ // Always true.
+ return getTrue(ITy);
+ if (Pred == CmpInst::ICMP_UGT)
+ // Always false.
+ return getFalse(ITy);
+ }
+
+ // Simplify comparisons of related pointers using a powerful, recursive
+ // GEP-walk when we have target data available..
+ if (Q.TD && LHS->getType()->isPointerTy() && RHS->getType()->isPointerTy())
+ if (Constant *C = computePointerICmp(*Q.TD, Pred, LHS, RHS))
+ return C;
+
+ if (GetElementPtrInst *GLHS = dyn_cast<GetElementPtrInst>(LHS)) {
+ if (GEPOperator *GRHS = dyn_cast<GEPOperator>(RHS)) {
+ if (GLHS->getPointerOperand() == GRHS->getPointerOperand() &&
+ GLHS->hasAllConstantIndices() && GRHS->hasAllConstantIndices() &&
+ (ICmpInst::isEquality(Pred) ||
+ (GLHS->isInBounds() && GRHS->isInBounds() &&
+ Pred == ICmpInst::getSignedPredicate(Pred)))) {
+ // The bases are equal and the indices are constant. Build a constant
+ // expression GEP with the same indices and a null base pointer to see
+ // what constant folding can make out of it.
+ Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType());
+ SmallVector<Value *, 4> IndicesLHS(GLHS->idx_begin(), GLHS->idx_end());
+ Constant *NewLHS = ConstantExpr::getGetElementPtr(Null, IndicesLHS);
+
+ SmallVector<Value *, 4> IndicesRHS(GRHS->idx_begin(), GRHS->idx_end());
+ Constant *NewRHS = ConstantExpr::getGetElementPtr(Null, IndicesRHS);
+ return ConstantExpr::getICmp(Pred, NewLHS, NewRHS);
+ }
}
}
// If the comparison is with the result of a select instruction, check whether
// comparing with either branch of the select always yields the same value.
if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
- if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
return V;
// If the comparison is with the result of a phi instruction, check whether
// doing the compare with each incoming phi value yields a common result.
if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
- if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
return V;
return 0;
}
Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyICmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit);
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyICmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
+ RecursionLimit);
}
/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
if (Constant *CRHS = dyn_cast<Constant>(RHS))
- return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD);
+ return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI);
// If we have a constant, make sure it is on the RHS.
std::swap(LHS, RHS);
// If the comparison is with the result of a select instruction, check whether
// comparing with either branch of the select always yields the same value.
if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
- if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
return V;
// If the comparison is with the result of a phi instruction, check whether
// doing the compare with each incoming phi value yields a common result.
if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
- if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
return V;
return 0;
}
Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyFCmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit);
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
+ RecursionLimit);
}
/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
/// the result. If not, this returns null.
-Value *llvm::SimplifySelectInst(Value *CondVal, Value *TrueVal, Value *FalseVal,
- const TargetData *TD, const DominatorTree *) {
+static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal,
+ Value *FalseVal, const Query &Q,
+ unsigned MaxRecurse) {
// select true, X, Y -> X
// select false, X, Y -> Y
if (ConstantInt *CB = dyn_cast<ConstantInt>(CondVal))
if (TrueVal == FalseVal)
return TrueVal;
- if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
- return FalseVal;
- if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
- return TrueVal;
if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
if (isa<Constant>(TrueVal))
return TrueVal;
return FalseVal;
}
+ if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
+ return FalseVal;
+ if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
+ return TrueVal;
return 0;
}
+Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifySelectInst(Cond, TrueVal, FalseVal, Query (TD, TLI, DT),
+ RecursionLimit);
+}
+
/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
/// fold the result. If not, this returns null.
-Value *llvm::SimplifyGEPInst(Value *const *Ops, unsigned NumOps,
- const TargetData *TD, const DominatorTree *) {
+static Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const Query &Q, unsigned) {
// The type of the GEP pointer operand.
- const PointerType *PtrTy = cast<PointerType>(Ops[0]->getType());
+ PointerType *PtrTy = dyn_cast<PointerType>(Ops[0]->getType());
+ // The GEP pointer operand is not a pointer, it's a vector of pointers.
+ if (!PtrTy)
+ return 0;
// getelementptr P -> P.
- if (NumOps == 1)
+ if (Ops.size() == 1)
return Ops[0];
if (isa<UndefValue>(Ops[0])) {
// Compute the (pointer) type returned by the GEP instruction.
- const Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, &Ops[1],
- NumOps-1);
- const Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace());
+ Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, Ops.slice(1));
+ Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace());
return UndefValue::get(GEPTy);
}
- if (NumOps == 2) {
+ if (Ops.size() == 2) {
// getelementptr P, 0 -> P.
if (ConstantInt *C = dyn_cast<ConstantInt>(Ops[1]))
if (C->isZero())
return Ops[0];
// getelementptr P, N -> P if P points to a type of zero size.
- if (TD) {
- const Type *Ty = PtrTy->getElementType();
- if (Ty->isSized() && TD->getTypeAllocSize(Ty) == 0)
+ if (Q.TD) {
+ Type *Ty = PtrTy->getElementType();
+ if (Ty->isSized() && Q.TD->getTypeAllocSize(Ty) == 0)
return Ops[0];
}
}
// Check to see if this is constant foldable.
- for (unsigned i = 0; i != NumOps; ++i)
+ for (unsigned i = 0, e = Ops.size(); i != e; ++i)
if (!isa<Constant>(Ops[i]))
return 0;
- return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]),
- (Constant *const*)Ops+1, NumOps-1);
+ return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]), Ops.slice(1));
+}
+
+Value *llvm::SimplifyGEPInst(ArrayRef<Value *> Ops, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyGEPInst(Ops, Query (TD, TLI, DT), RecursionLimit);
+}
+
+/// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
+/// can fold the result. If not, this returns null.
+static Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
+ ArrayRef<unsigned> Idxs, const Query &Q,
+ unsigned) {
+ if (Constant *CAgg = dyn_cast<Constant>(Agg))
+ if (Constant *CVal = dyn_cast<Constant>(Val))
+ return ConstantFoldInsertValueInstruction(CAgg, CVal, Idxs);
+
+ // insertvalue x, undef, n -> x
+ if (match(Val, m_Undef()))
+ return Agg;
+
+ // insertvalue x, (extractvalue y, n), n
+ if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Val))
+ if (EV->getAggregateOperand()->getType() == Agg->getType() &&
+ EV->getIndices() == Idxs) {
+ // insertvalue undef, (extractvalue y, n), n -> y
+ if (match(Agg, m_Undef()))
+ return EV->getAggregateOperand();
+
+ // insertvalue y, (extractvalue y, n), n -> y
+ if (Agg == EV->getAggregateOperand())
+ return Agg;
+ }
+
+ return 0;
+}
+
+Value *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val,
+ ArrayRef<unsigned> Idxs,
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query (TD, TLI, DT),
+ RecursionLimit);
}
/// SimplifyPHINode - See if we can fold the given phi. If not, returns null.
-static Value *SimplifyPHINode(PHINode *PN, const DominatorTree *DT) {
+static Value *SimplifyPHINode(PHINode *PN, const Query &Q) {
// If all of the PHI's incoming values are the same then replace the PHI node
// with the common value.
Value *CommonValue = 0;
// instruction, we cannot return X as the result of the PHI node unless it
// dominates the PHI block.
if (HasUndefInput)
- return ValueDominatesPHI(CommonValue, PN, DT) ? CommonValue : 0;
+ return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : 0;
return CommonValue;
}
+static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) {
+ if (Constant *C = dyn_cast<Constant>(Op))
+ return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.TD, Q.TLI);
+
+ return 0;
+}
+
+Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyTruncInst(Op, Ty, Query (TD, TLI, DT), RecursionLimit);
+}
//=== Helper functions for higher up the class hierarchy.
/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
/// fold the result. If not, this returns null.
static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
switch (Opcode) {
- case Instruction::And: return SimplifyAndInst(LHS, RHS, TD, DT, MaxRecurse);
- case Instruction::Or: return SimplifyOrInst(LHS, RHS, TD, DT, MaxRecurse);
- case Instruction::Xor: return SimplifyXorInst(LHS, RHS, TD, DT, MaxRecurse);
- case Instruction::Add: return SimplifyAddInst(LHS, RHS, /* isNSW */ false,
- /* isNUW */ false, TD, DT,
- MaxRecurse);
- case Instruction::Sub: return SimplifySubInst(LHS, RHS, /* isNSW */ false,
- /* isNUW */ false, TD, DT,
- MaxRecurse);
+ case Instruction::Add:
+ return SimplifyAddInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
+ Q, MaxRecurse);
+ case Instruction::Sub:
+ return SimplifySubInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
+ Q, MaxRecurse);
+ case Instruction::Mul: return SimplifyMulInst (LHS, RHS, Q, MaxRecurse);
+ case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::FDiv: return SimplifyFDivInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::SRem: return SimplifySRemInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::URem: return SimplifyURemInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::FRem: return SimplifyFRemInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::Shl:
+ return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
+ Q, MaxRecurse);
+ case Instruction::LShr:
+ return SimplifyLShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
+ case Instruction::AShr:
+ return SimplifyAShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
+ case Instruction::And: return SimplifyAndInst(LHS, RHS, Q, MaxRecurse);
+ case Instruction::Or: return SimplifyOrInst (LHS, RHS, Q, MaxRecurse);
+ case Instruction::Xor: return SimplifyXorInst(LHS, RHS, Q, MaxRecurse);
default:
if (Constant *CLHS = dyn_cast<Constant>(LHS))
if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
Constant *COps[] = {CLHS, CRHS};
- return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, 2, TD);
+ return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.TD,
+ Q.TLI);
}
// If the operation is associative, try some generic simplifications.
if (Instruction::isAssociative(Opcode))
- if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, TD, DT,
- MaxRecurse))
+ if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, Q, MaxRecurse))
return V;
- // If the operation is with the result of a select instruction, check whether
+ // If the operation is with the result of a select instruction check whether
// operating on either branch of the select always yields the same value.
if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
- if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, TD, DT,
- MaxRecurse))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, Q, MaxRecurse))
return V;
// If the operation is with the result of a phi instruction, check whether
// operating on all incoming values of the phi always yields the same value.
if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
- if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, TD, DT, MaxRecurse))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse))
return V;
return 0;
}
Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyBinOp(Opcode, LHS, RHS, TD, DT, RecursionLimit);
+ const TargetData *TD, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyBinOp(Opcode, LHS, RHS, Query (TD, TLI, DT), RecursionLimit);
}
/// SimplifyCmpInst - Given operands for a CmpInst, see if we can
/// fold the result.
static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT,
- unsigned MaxRecurse) {
+ const Query &Q, unsigned MaxRecurse) {
if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
- return SimplifyICmpInst(Predicate, LHS, RHS, TD, DT, MaxRecurse);
- return SimplifyFCmpInst(Predicate, LHS, RHS, TD, DT, MaxRecurse);
+ return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
+ return SimplifyFCmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
}
Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
- const TargetData *TD, const DominatorTree *DT) {
- return ::SimplifyCmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit);
+ const TargetData *TD, const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return ::SimplifyCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
+ RecursionLimit);
+}
+
+static Value *SimplifyCallInst(CallInst *CI, const Query &) {
+ // call undef -> undef
+ if (isa<UndefValue>(CI->getCalledValue()))
+ return UndefValue::get(CI->getType());
+
+ return 0;
}
/// SimplifyInstruction - See if we can compute a simplified version of this
/// instruction. If not, this returns null.
Value *llvm::SimplifyInstruction(Instruction *I, const TargetData *TD,
+ const TargetLibraryInfo *TLI,
const DominatorTree *DT) {
Value *Result;
switch (I->getOpcode()) {
default:
- Result = ConstantFoldInstruction(I, TD);
+ Result = ConstantFoldInstruction(I, TD, TLI);
break;
case Instruction::Add:
Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1),
cast<BinaryOperator>(I)->hasNoSignedWrap(),
cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
- TD, DT);
+ TD, TLI, DT);
break;
case Instruction::Sub:
Result = SimplifySubInst(I->getOperand(0), I->getOperand(1),
cast<BinaryOperator>(I)->hasNoSignedWrap(),
cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
- TD, DT);
+ TD, TLI, DT);
+ break;
+ case Instruction::Mul:
+ Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
+ break;
+ case Instruction::SDiv:
+ Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
+ break;
+ case Instruction::UDiv:
+ Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
+ break;
+ case Instruction::FDiv:
+ Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
+ break;
+ case Instruction::SRem:
+ Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
+ break;
+ case Instruction::URem:
+ Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
+ break;
+ case Instruction::FRem:
+ Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
+ break;
+ case Instruction::Shl:
+ Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1),
+ cast<BinaryOperator>(I)->hasNoSignedWrap(),
+ cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
+ TD, TLI, DT);
+ break;
+ case Instruction::LShr:
+ Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1),
+ cast<BinaryOperator>(I)->isExact(),
+ TD, TLI, DT);
+ break;
+ case Instruction::AShr:
+ Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1),
+ cast<BinaryOperator>(I)->isExact(),
+ TD, TLI, DT);
break;
case Instruction::And:
- Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
break;
case Instruction::Or:
- Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
break;
case Instruction::Xor:
- Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, DT);
+ Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
break;
case Instruction::ICmp:
Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(),
- I->getOperand(0), I->getOperand(1), TD, DT);
+ I->getOperand(0), I->getOperand(1), TD, TLI, DT);
break;
case Instruction::FCmp:
Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(),
- I->getOperand(0), I->getOperand(1), TD, DT);
+ I->getOperand(0), I->getOperand(1), TD, TLI, DT);
break;
case Instruction::Select:
Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1),
- I->getOperand(2), TD, DT);
+ I->getOperand(2), TD, TLI, DT);
break;
case Instruction::GetElementPtr: {
SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end());
- Result = SimplifyGEPInst(&Ops[0], Ops.size(), TD, DT);
+ Result = SimplifyGEPInst(Ops, TD, TLI, DT);
+ break;
+ }
+ case Instruction::InsertValue: {
+ InsertValueInst *IV = cast<InsertValueInst>(I);
+ Result = SimplifyInsertValueInst(IV->getAggregateOperand(),
+ IV->getInsertedValueOperand(),
+ IV->getIndices(), TD, TLI, DT);
break;
}
case Instruction::PHI:
- Result = SimplifyPHINode(cast<PHINode>(I), DT);
+ Result = SimplifyPHINode(cast<PHINode>(I), Query (TD, TLI, DT));
+ break;
+ case Instruction::Call:
+ Result = SimplifyCallInst(cast<CallInst>(I), Query (TD, TLI, DT));
+ break;
+ case Instruction::Trunc:
+ Result = SimplifyTruncInst(I->getOperand(0), I->getType(), TD, TLI, DT);
break;
}
return Result == I ? UndefValue::get(I->getType()) : Result;
}
-/// ReplaceAndSimplifyAllUses - Perform From->replaceAllUsesWith(To) and then
-/// delete the From instruction. In addition to a basic RAUW, this does a
-/// recursive simplification of the newly formed instructions. This catches
-/// things where one simplification exposes other opportunities. This only
-/// simplifies and deletes scalar operations, it does not change the CFG.
+/// \brief Implementation of recursive simplification through an instructions
+/// uses.
///
-void llvm::ReplaceAndSimplifyAllUses(Instruction *From, Value *To,
- const TargetData *TD,
- const DominatorTree *DT) {
- assert(From != To && "ReplaceAndSimplifyAllUses(X,X) is not valid!");
-
- // FromHandle/ToHandle - This keeps a WeakVH on the from/to values so that
- // we can know if it gets deleted out from under us or replaced in a
- // recursive simplification.
- WeakVH FromHandle(From);
- WeakVH ToHandle(To);
-
- while (!From->use_empty()) {
- // Update the instruction to use the new value.
- Use &TheUse = From->use_begin().getUse();
- Instruction *User = cast<Instruction>(TheUse.getUser());
- TheUse = To;
-
- // Check to see if the instruction can be folded due to the operand
- // replacement. For example changing (or X, Y) into (or X, -1) can replace
- // the 'or' with -1.
- Value *SimplifiedVal;
- {
- // Sanity check to make sure 'User' doesn't dangle across
- // SimplifyInstruction.
- AssertingVH<> UserHandle(User);
-
- SimplifiedVal = SimplifyInstruction(User, TD, DT);
- if (SimplifiedVal == 0) continue;
- }
+/// This is the common implementation of the recursive simplification routines.
+/// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
+/// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
+/// instructions to process and attempt to simplify it using
+/// InstructionSimplify.
+///
+/// This routine returns 'true' only when *it* simplifies something. The passed
+/// in simplified value does not count toward this.
+static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ bool Simplified = false;
+ SmallSetVector<Instruction *, 8> Worklist;
+
+ // If we have an explicit value to collapse to, do that round of the
+ // simplification loop by hand initially.
+ if (SimpleV) {
+ for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
+ ++UI)
+ if (*UI != I)
+ Worklist.insert(cast<Instruction>(*UI));
+
+ // Replace the instruction with its simplified value.
+ I->replaceAllUsesWith(SimpleV);
+
+ // Gracefully handle edge cases where the instruction is not wired into any
+ // parent block.
+ if (I->getParent())
+ I->eraseFromParent();
+ } else {
+ Worklist.insert(I);
+ }
+
+ // Note that we must test the size on each iteration, the worklist can grow.
+ for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) {
+ I = Worklist[Idx];
+
+ // See if this instruction simplifies.
+ SimpleV = SimplifyInstruction(I, TD, TLI, DT);
+ if (!SimpleV)
+ continue;
+
+ Simplified = true;
- // Recursively simplify this user to the new value.
- ReplaceAndSimplifyAllUses(User, SimplifiedVal, TD, DT);
- From = dyn_cast_or_null<Instruction>((Value*)FromHandle);
- To = ToHandle;
+ // Stash away all the uses of the old instruction so we can check them for
+ // recursive simplifications after a RAUW. This is cheaper than checking all
+ // uses of To on the recursive step in most cases.
+ for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
+ ++UI)
+ Worklist.insert(cast<Instruction>(*UI));
- assert(ToHandle && "To value deleted by recursive simplification?");
+ // Replace the instruction with its simplified value.
+ I->replaceAllUsesWith(SimpleV);
- // If the recursive simplification ended up revisiting and deleting
- // 'From' then we're done.
- if (From == 0)
- return;
+ // Gracefully handle edge cases where the instruction is not wired into any
+ // parent block.
+ if (I->getParent())
+ I->eraseFromParent();
}
+ return Simplified;
+}
- // If 'From' has value handles referring to it, do a real RAUW to update them.
- From->replaceAllUsesWith(To);
+bool llvm::recursivelySimplifyInstruction(Instruction *I,
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ return replaceAndRecursivelySimplifyImpl(I, 0, TD, TLI, DT);
+}
- From->eraseFromParent();
+bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
+ const TargetData *TD,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT) {
+ assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!");
+ assert(SimpleV && "Must provide a simplified value.");
+ return replaceAndRecursivelySimplifyImpl(I, SimpleV, TD, TLI, DT);
}