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https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207196 91177308-0d34-0410-b5e6-96231b3b80d8
2501 lines
100 KiB
C++
2501 lines
100 KiB
C++
//===- InstCombineAndOrXor.cpp --------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the visitAnd, visitOr, and visitXor functions.
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//
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//===----------------------------------------------------------------------===//
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#include "InstCombine.h"
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#include "llvm/Analysis/InstructionSimplify.h"
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#include "llvm/IR/ConstantRange.h"
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#include "llvm/IR/Intrinsics.h"
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#include "llvm/IR/PatternMatch.h"
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#include "llvm/Transforms/Utils/CmpInstAnalysis.h"
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using namespace llvm;
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using namespace PatternMatch;
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#define DEBUG_TYPE "instcombine"
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/// isFreeToInvert - Return true if the specified value is free to invert (apply
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/// ~ to). This happens in cases where the ~ can be eliminated.
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static inline bool isFreeToInvert(Value *V) {
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// ~(~(X)) -> X.
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if (BinaryOperator::isNot(V))
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return true;
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// Constants can be considered to be not'ed values.
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if (isa<ConstantInt>(V))
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return true;
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// Compares can be inverted if they have a single use.
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if (CmpInst *CI = dyn_cast<CmpInst>(V))
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return CI->hasOneUse();
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return false;
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}
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static inline Value *dyn_castNotVal(Value *V) {
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// If this is not(not(x)) don't return that this is a not: we want the two
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// not's to be folded first.
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if (BinaryOperator::isNot(V)) {
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Value *Operand = BinaryOperator::getNotArgument(V);
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if (!isFreeToInvert(Operand))
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return Operand;
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}
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// Constants can be considered to be not'ed values...
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if (ConstantInt *C = dyn_cast<ConstantInt>(V))
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return ConstantInt::get(C->getType(), ~C->getValue());
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return nullptr;
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}
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/// getFCmpCode - Similar to getICmpCode but for FCmpInst. This encodes a fcmp
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/// predicate into a three bit mask. It also returns whether it is an ordered
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/// predicate by reference.
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static unsigned getFCmpCode(FCmpInst::Predicate CC, bool &isOrdered) {
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isOrdered = false;
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switch (CC) {
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case FCmpInst::FCMP_ORD: isOrdered = true; return 0; // 000
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case FCmpInst::FCMP_UNO: return 0; // 000
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case FCmpInst::FCMP_OGT: isOrdered = true; return 1; // 001
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case FCmpInst::FCMP_UGT: return 1; // 001
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case FCmpInst::FCMP_OEQ: isOrdered = true; return 2; // 010
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case FCmpInst::FCMP_UEQ: return 2; // 010
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case FCmpInst::FCMP_OGE: isOrdered = true; return 3; // 011
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case FCmpInst::FCMP_UGE: return 3; // 011
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case FCmpInst::FCMP_OLT: isOrdered = true; return 4; // 100
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case FCmpInst::FCMP_ULT: return 4; // 100
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case FCmpInst::FCMP_ONE: isOrdered = true; return 5; // 101
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case FCmpInst::FCMP_UNE: return 5; // 101
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case FCmpInst::FCMP_OLE: isOrdered = true; return 6; // 110
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case FCmpInst::FCMP_ULE: return 6; // 110
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// True -> 7
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default:
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// Not expecting FCMP_FALSE and FCMP_TRUE;
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llvm_unreachable("Unexpected FCmp predicate!");
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}
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}
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/// getNewICmpValue - This is the complement of getICmpCode, which turns an
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/// opcode and two operands into either a constant true or false, or a brand
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/// new ICmp instruction. The sign is passed in to determine which kind
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/// of predicate to use in the new icmp instruction.
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static Value *getNewICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS,
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InstCombiner::BuilderTy *Builder) {
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ICmpInst::Predicate NewPred;
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if (Value *NewConstant = getICmpValue(Sign, Code, LHS, RHS, NewPred))
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return NewConstant;
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return Builder->CreateICmp(NewPred, LHS, RHS);
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}
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/// getFCmpValue - This is the complement of getFCmpCode, which turns an
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/// opcode and two operands into either a FCmp instruction. isordered is passed
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/// in to determine which kind of predicate to use in the new fcmp instruction.
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static Value *getFCmpValue(bool isordered, unsigned code,
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Value *LHS, Value *RHS,
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InstCombiner::BuilderTy *Builder) {
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CmpInst::Predicate Pred;
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switch (code) {
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default: llvm_unreachable("Illegal FCmp code!");
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case 0: Pred = isordered ? FCmpInst::FCMP_ORD : FCmpInst::FCMP_UNO; break;
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case 1: Pred = isordered ? FCmpInst::FCMP_OGT : FCmpInst::FCMP_UGT; break;
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case 2: Pred = isordered ? FCmpInst::FCMP_OEQ : FCmpInst::FCMP_UEQ; break;
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case 3: Pred = isordered ? FCmpInst::FCMP_OGE : FCmpInst::FCMP_UGE; break;
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case 4: Pred = isordered ? FCmpInst::FCMP_OLT : FCmpInst::FCMP_ULT; break;
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case 5: Pred = isordered ? FCmpInst::FCMP_ONE : FCmpInst::FCMP_UNE; break;
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case 6: Pred = isordered ? FCmpInst::FCMP_OLE : FCmpInst::FCMP_ULE; break;
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case 7:
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if (!isordered) return ConstantInt::getTrue(LHS->getContext());
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Pred = FCmpInst::FCMP_ORD; break;
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}
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return Builder->CreateFCmp(Pred, LHS, RHS);
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}
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// OptAndOp - This handles expressions of the form ((val OP C1) & C2). Where
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// the Op parameter is 'OP', OpRHS is 'C1', and AndRHS is 'C2'. Op is
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// guaranteed to be a binary operator.
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Instruction *InstCombiner::OptAndOp(Instruction *Op,
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ConstantInt *OpRHS,
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ConstantInt *AndRHS,
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BinaryOperator &TheAnd) {
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Value *X = Op->getOperand(0);
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Constant *Together = nullptr;
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if (!Op->isShift())
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Together = ConstantExpr::getAnd(AndRHS, OpRHS);
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switch (Op->getOpcode()) {
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case Instruction::Xor:
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if (Op->hasOneUse()) {
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// (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
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Value *And = Builder->CreateAnd(X, AndRHS);
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And->takeName(Op);
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return BinaryOperator::CreateXor(And, Together);
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}
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break;
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case Instruction::Or:
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if (Op->hasOneUse()){
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if (Together != OpRHS) {
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// (X | C1) & C2 --> (X | (C1&C2)) & C2
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Value *Or = Builder->CreateOr(X, Together);
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Or->takeName(Op);
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return BinaryOperator::CreateAnd(Or, AndRHS);
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}
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ConstantInt *TogetherCI = dyn_cast<ConstantInt>(Together);
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if (TogetherCI && !TogetherCI->isZero()){
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// (X | C1) & C2 --> (X & (C2^(C1&C2))) | C1
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// NOTE: This reduces the number of bits set in the & mask, which
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// can expose opportunities for store narrowing.
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Together = ConstantExpr::getXor(AndRHS, Together);
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Value *And = Builder->CreateAnd(X, Together);
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And->takeName(Op);
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return BinaryOperator::CreateOr(And, OpRHS);
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}
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}
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break;
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case Instruction::Add:
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if (Op->hasOneUse()) {
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// Adding a one to a single bit bit-field should be turned into an XOR
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// of the bit. First thing to check is to see if this AND is with a
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// single bit constant.
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const APInt &AndRHSV = AndRHS->getValue();
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// If there is only one bit set.
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if (AndRHSV.isPowerOf2()) {
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// Ok, at this point, we know that we are masking the result of the
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// ADD down to exactly one bit. If the constant we are adding has
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// no bits set below this bit, then we can eliminate the ADD.
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const APInt& AddRHS = OpRHS->getValue();
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// Check to see if any bits below the one bit set in AndRHSV are set.
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if ((AddRHS & (AndRHSV-1)) == 0) {
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// If not, the only thing that can effect the output of the AND is
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// the bit specified by AndRHSV. If that bit is set, the effect of
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// the XOR is to toggle the bit. If it is clear, then the ADD has
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// no effect.
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if ((AddRHS & AndRHSV) == 0) { // Bit is not set, noop
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TheAnd.setOperand(0, X);
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return &TheAnd;
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} else {
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// Pull the XOR out of the AND.
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Value *NewAnd = Builder->CreateAnd(X, AndRHS);
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NewAnd->takeName(Op);
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return BinaryOperator::CreateXor(NewAnd, AndRHS);
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}
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}
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}
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}
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break;
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case Instruction::Shl: {
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// We know that the AND will not produce any of the bits shifted in, so if
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// the anded constant includes them, clear them now!
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//
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uint32_t BitWidth = AndRHS->getType()->getBitWidth();
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uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
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APInt ShlMask(APInt::getHighBitsSet(BitWidth, BitWidth-OpRHSVal));
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ConstantInt *CI = Builder->getInt(AndRHS->getValue() & ShlMask);
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if (CI->getValue() == ShlMask)
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// Masking out bits that the shift already masks.
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return ReplaceInstUsesWith(TheAnd, Op); // No need for the and.
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if (CI != AndRHS) { // Reducing bits set in and.
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TheAnd.setOperand(1, CI);
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return &TheAnd;
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}
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break;
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}
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case Instruction::LShr: {
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// We know that the AND will not produce any of the bits shifted in, so if
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// the anded constant includes them, clear them now! This only applies to
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// unsigned shifts, because a signed shr may bring in set bits!
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//
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uint32_t BitWidth = AndRHS->getType()->getBitWidth();
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uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
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APInt ShrMask(APInt::getLowBitsSet(BitWidth, BitWidth - OpRHSVal));
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ConstantInt *CI = Builder->getInt(AndRHS->getValue() & ShrMask);
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if (CI->getValue() == ShrMask)
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// Masking out bits that the shift already masks.
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return ReplaceInstUsesWith(TheAnd, Op);
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if (CI != AndRHS) {
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TheAnd.setOperand(1, CI); // Reduce bits set in and cst.
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return &TheAnd;
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}
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break;
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}
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case Instruction::AShr:
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// Signed shr.
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// See if this is shifting in some sign extension, then masking it out
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// with an and.
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if (Op->hasOneUse()) {
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uint32_t BitWidth = AndRHS->getType()->getBitWidth();
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uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
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APInt ShrMask(APInt::getLowBitsSet(BitWidth, BitWidth - OpRHSVal));
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Constant *C = Builder->getInt(AndRHS->getValue() & ShrMask);
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if (C == AndRHS) { // Masking out bits shifted in.
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// (Val ashr C1) & C2 -> (Val lshr C1) & C2
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// Make the argument unsigned.
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Value *ShVal = Op->getOperand(0);
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ShVal = Builder->CreateLShr(ShVal, OpRHS, Op->getName());
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return BinaryOperator::CreateAnd(ShVal, AndRHS, TheAnd.getName());
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}
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}
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break;
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}
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return nullptr;
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}
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/// Emit a computation of: (V >= Lo && V < Hi) if Inside is true, otherwise
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/// (V < Lo || V >= Hi). In practice, we emit the more efficient
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/// (V-Lo) \<u Hi-Lo. This method expects that Lo <= Hi. isSigned indicates
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/// whether to treat the V, Lo and HI as signed or not. IB is the location to
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/// insert new instructions.
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Value *InstCombiner::InsertRangeTest(Value *V, Constant *Lo, Constant *Hi,
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bool isSigned, bool Inside) {
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assert(cast<ConstantInt>(ConstantExpr::getICmp((isSigned ?
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ICmpInst::ICMP_SLE:ICmpInst::ICMP_ULE), Lo, Hi))->getZExtValue() &&
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"Lo is not <= Hi in range emission code!");
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if (Inside) {
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if (Lo == Hi) // Trivially false.
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return Builder->getFalse();
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// V >= Min && V < Hi --> V < Hi
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if (cast<ConstantInt>(Lo)->isMinValue(isSigned)) {
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ICmpInst::Predicate pred = (isSigned ?
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ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT);
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return Builder->CreateICmp(pred, V, Hi);
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}
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// Emit V-Lo <u Hi-Lo
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Constant *NegLo = ConstantExpr::getNeg(Lo);
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Value *Add = Builder->CreateAdd(V, NegLo, V->getName()+".off");
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Constant *UpperBound = ConstantExpr::getAdd(NegLo, Hi);
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return Builder->CreateICmpULT(Add, UpperBound);
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}
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if (Lo == Hi) // Trivially true.
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return Builder->getTrue();
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// V < Min || V >= Hi -> V > Hi-1
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Hi = SubOne(cast<ConstantInt>(Hi));
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if (cast<ConstantInt>(Lo)->isMinValue(isSigned)) {
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ICmpInst::Predicate pred = (isSigned ?
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ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT);
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return Builder->CreateICmp(pred, V, Hi);
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}
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// Emit V-Lo >u Hi-1-Lo
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// Note that Hi has already had one subtracted from it, above.
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ConstantInt *NegLo = cast<ConstantInt>(ConstantExpr::getNeg(Lo));
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Value *Add = Builder->CreateAdd(V, NegLo, V->getName()+".off");
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Constant *LowerBound = ConstantExpr::getAdd(NegLo, Hi);
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return Builder->CreateICmpUGT(Add, LowerBound);
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}
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// isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s with
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// any number of 0s on either side. The 1s are allowed to wrap from LSB to
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// MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs. 0x0F0F0000 is
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// not, since all 1s are not contiguous.
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static bool isRunOfOnes(ConstantInt *Val, uint32_t &MB, uint32_t &ME) {
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const APInt& V = Val->getValue();
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uint32_t BitWidth = Val->getType()->getBitWidth();
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if (!APIntOps::isShiftedMask(BitWidth, V)) return false;
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// look for the first zero bit after the run of ones
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MB = BitWidth - ((V - 1) ^ V).countLeadingZeros();
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// look for the first non-zero bit
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ME = V.getActiveBits();
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return true;
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}
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/// FoldLogicalPlusAnd - This is part of an expression (LHS +/- RHS) & Mask,
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/// where isSub determines whether the operator is a sub. If we can fold one of
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/// the following xforms:
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///
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/// ((A & N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == Mask
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/// ((A | N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == 0
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/// ((A ^ N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == 0
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///
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/// return (A +/- B).
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///
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Value *InstCombiner::FoldLogicalPlusAnd(Value *LHS, Value *RHS,
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ConstantInt *Mask, bool isSub,
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Instruction &I) {
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Instruction *LHSI = dyn_cast<Instruction>(LHS);
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if (!LHSI || LHSI->getNumOperands() != 2 ||
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!isa<ConstantInt>(LHSI->getOperand(1))) return nullptr;
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ConstantInt *N = cast<ConstantInt>(LHSI->getOperand(1));
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switch (LHSI->getOpcode()) {
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default: return nullptr;
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case Instruction::And:
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if (ConstantExpr::getAnd(N, Mask) == Mask) {
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// If the AndRHS is a power of two minus one (0+1+), this is simple.
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if ((Mask->getValue().countLeadingZeros() +
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Mask->getValue().countPopulation()) ==
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Mask->getValue().getBitWidth())
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break;
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// Otherwise, if Mask is 0+1+0+, and if B is known to have the low 0+
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// part, we don't need any explicit masks to take them out of A. If that
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// is all N is, ignore it.
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uint32_t MB = 0, ME = 0;
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if (isRunOfOnes(Mask, MB, ME)) { // begin/end bit of run, inclusive
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uint32_t BitWidth = cast<IntegerType>(RHS->getType())->getBitWidth();
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APInt Mask(APInt::getLowBitsSet(BitWidth, MB-1));
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if (MaskedValueIsZero(RHS, Mask))
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break;
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}
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}
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return nullptr;
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case Instruction::Or:
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case Instruction::Xor:
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// If the AndRHS is a power of two minus one (0+1+), and N&Mask == 0
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if ((Mask->getValue().countLeadingZeros() +
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Mask->getValue().countPopulation()) == Mask->getValue().getBitWidth()
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&& ConstantExpr::getAnd(N, Mask)->isNullValue())
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break;
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return nullptr;
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}
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if (isSub)
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return Builder->CreateSub(LHSI->getOperand(0), RHS, "fold");
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return Builder->CreateAdd(LHSI->getOperand(0), RHS, "fold");
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}
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/// enum for classifying (icmp eq (A & B), C) and (icmp ne (A & B), C)
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/// One of A and B is considered the mask, the other the value. This is
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/// described as the "AMask" or "BMask" part of the enum. If the enum
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/// contains only "Mask", then both A and B can be considered masks.
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/// If A is the mask, then it was proven, that (A & C) == C. This
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/// is trivial if C == A, or C == 0. If both A and C are constants, this
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/// proof is also easy.
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/// For the following explanations we assume that A is the mask.
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/// The part "AllOnes" declares, that the comparison is true only
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/// if (A & B) == A, or all bits of A are set in B.
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/// Example: (icmp eq (A & 3), 3) -> FoldMskICmp_AMask_AllOnes
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/// The part "AllZeroes" declares, that the comparison is true only
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/// if (A & B) == 0, or all bits of A are cleared in B.
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/// Example: (icmp eq (A & 3), 0) -> FoldMskICmp_Mask_AllZeroes
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/// The part "Mixed" declares, that (A & B) == C and C might or might not
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/// contain any number of one bits and zero bits.
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/// Example: (icmp eq (A & 3), 1) -> FoldMskICmp_AMask_Mixed
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/// The Part "Not" means, that in above descriptions "==" should be replaced
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/// by "!=".
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/// Example: (icmp ne (A & 3), 3) -> FoldMskICmp_AMask_NotAllOnes
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/// If the mask A contains a single bit, then the following is equivalent:
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/// (icmp eq (A & B), A) equals (icmp ne (A & B), 0)
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/// (icmp ne (A & B), A) equals (icmp eq (A & B), 0)
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enum MaskedICmpType {
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FoldMskICmp_AMask_AllOnes = 1,
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FoldMskICmp_AMask_NotAllOnes = 2,
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FoldMskICmp_BMask_AllOnes = 4,
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FoldMskICmp_BMask_NotAllOnes = 8,
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FoldMskICmp_Mask_AllZeroes = 16,
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FoldMskICmp_Mask_NotAllZeroes = 32,
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FoldMskICmp_AMask_Mixed = 64,
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FoldMskICmp_AMask_NotMixed = 128,
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FoldMskICmp_BMask_Mixed = 256,
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FoldMskICmp_BMask_NotMixed = 512
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};
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/// return the set of pattern classes (from MaskedICmpType)
|
|
/// that (icmp SCC (A & B), C) satisfies
|
|
static unsigned getTypeOfMaskedICmp(Value* A, Value* B, Value* C,
|
|
ICmpInst::Predicate SCC)
|
|
{
|
|
ConstantInt *ACst = dyn_cast<ConstantInt>(A);
|
|
ConstantInt *BCst = dyn_cast<ConstantInt>(B);
|
|
ConstantInt *CCst = dyn_cast<ConstantInt>(C);
|
|
bool icmp_eq = (SCC == ICmpInst::ICMP_EQ);
|
|
bool icmp_abit = (ACst && !ACst->isZero() &&
|
|
ACst->getValue().isPowerOf2());
|
|
bool icmp_bbit = (BCst && !BCst->isZero() &&
|
|
BCst->getValue().isPowerOf2());
|
|
unsigned result = 0;
|
|
if (CCst && CCst->isZero()) {
|
|
// if C is zero, then both A and B qualify as mask
|
|
result |= (icmp_eq ? (FoldMskICmp_Mask_AllZeroes |
|
|
FoldMskICmp_Mask_AllZeroes |
|
|
FoldMskICmp_AMask_Mixed |
|
|
FoldMskICmp_BMask_Mixed)
|
|
: (FoldMskICmp_Mask_NotAllZeroes |
|
|
FoldMskICmp_Mask_NotAllZeroes |
|
|
FoldMskICmp_AMask_NotMixed |
|
|
FoldMskICmp_BMask_NotMixed));
|
|
if (icmp_abit)
|
|
result |= (icmp_eq ? (FoldMskICmp_AMask_NotAllOnes |
|
|
FoldMskICmp_AMask_NotMixed)
|
|
: (FoldMskICmp_AMask_AllOnes |
|
|
FoldMskICmp_AMask_Mixed));
|
|
if (icmp_bbit)
|
|
result |= (icmp_eq ? (FoldMskICmp_BMask_NotAllOnes |
|
|
FoldMskICmp_BMask_NotMixed)
|
|
: (FoldMskICmp_BMask_AllOnes |
|
|
FoldMskICmp_BMask_Mixed));
|
|
return result;
|
|
}
|
|
if (A == C) {
|
|
result |= (icmp_eq ? (FoldMskICmp_AMask_AllOnes |
|
|
FoldMskICmp_AMask_Mixed)
|
|
: (FoldMskICmp_AMask_NotAllOnes |
|
|
FoldMskICmp_AMask_NotMixed));
|
|
if (icmp_abit)
|
|
result |= (icmp_eq ? (FoldMskICmp_Mask_NotAllZeroes |
|
|
FoldMskICmp_AMask_NotMixed)
|
|
: (FoldMskICmp_Mask_AllZeroes |
|
|
FoldMskICmp_AMask_Mixed));
|
|
} else if (ACst && CCst &&
|
|
ConstantExpr::getAnd(ACst, CCst) == CCst) {
|
|
result |= (icmp_eq ? FoldMskICmp_AMask_Mixed
|
|
: FoldMskICmp_AMask_NotMixed);
|
|
}
|
|
if (B == C) {
|
|
result |= (icmp_eq ? (FoldMskICmp_BMask_AllOnes |
|
|
FoldMskICmp_BMask_Mixed)
|
|
: (FoldMskICmp_BMask_NotAllOnes |
|
|
FoldMskICmp_BMask_NotMixed));
|
|
if (icmp_bbit)
|
|
result |= (icmp_eq ? (FoldMskICmp_Mask_NotAllZeroes |
|
|
FoldMskICmp_BMask_NotMixed)
|
|
: (FoldMskICmp_Mask_AllZeroes |
|
|
FoldMskICmp_BMask_Mixed));
|
|
} else if (BCst && CCst &&
|
|
ConstantExpr::getAnd(BCst, CCst) == CCst) {
|
|
result |= (icmp_eq ? FoldMskICmp_BMask_Mixed
|
|
: FoldMskICmp_BMask_NotMixed);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// Convert an analysis of a masked ICmp into its equivalent if all boolean
|
|
/// operations had the opposite sense. Since each "NotXXX" flag (recording !=)
|
|
/// is adjacent to the corresponding normal flag (recording ==), this just
|
|
/// involves swapping those bits over.
|
|
static unsigned conjugateICmpMask(unsigned Mask) {
|
|
unsigned NewMask;
|
|
NewMask = (Mask & (FoldMskICmp_AMask_AllOnes | FoldMskICmp_BMask_AllOnes |
|
|
FoldMskICmp_Mask_AllZeroes | FoldMskICmp_AMask_Mixed |
|
|
FoldMskICmp_BMask_Mixed))
|
|
<< 1;
|
|
|
|
NewMask |=
|
|
(Mask & (FoldMskICmp_AMask_NotAllOnes | FoldMskICmp_BMask_NotAllOnes |
|
|
FoldMskICmp_Mask_NotAllZeroes | FoldMskICmp_AMask_NotMixed |
|
|
FoldMskICmp_BMask_NotMixed))
|
|
>> 1;
|
|
|
|
return NewMask;
|
|
}
|
|
|
|
/// decomposeBitTestICmp - Decompose an icmp into the form ((X & Y) pred Z)
|
|
/// if possible. The returned predicate is either == or !=. Returns false if
|
|
/// decomposition fails.
|
|
static bool decomposeBitTestICmp(const ICmpInst *I, ICmpInst::Predicate &Pred,
|
|
Value *&X, Value *&Y, Value *&Z) {
|
|
ConstantInt *C = dyn_cast<ConstantInt>(I->getOperand(1));
|
|
if (!C)
|
|
return false;
|
|
|
|
switch (I->getPredicate()) {
|
|
default:
|
|
return false;
|
|
case ICmpInst::ICMP_SLT:
|
|
// X < 0 is equivalent to (X & SignBit) != 0.
|
|
if (!C->isZero())
|
|
return false;
|
|
Y = ConstantInt::get(I->getContext(), APInt::getSignBit(C->getBitWidth()));
|
|
Pred = ICmpInst::ICMP_NE;
|
|
break;
|
|
case ICmpInst::ICMP_SGT:
|
|
// X > -1 is equivalent to (X & SignBit) == 0.
|
|
if (!C->isAllOnesValue())
|
|
return false;
|
|
Y = ConstantInt::get(I->getContext(), APInt::getSignBit(C->getBitWidth()));
|
|
Pred = ICmpInst::ICMP_EQ;
|
|
break;
|
|
case ICmpInst::ICMP_ULT:
|
|
// X <u 2^n is equivalent to (X & ~(2^n-1)) == 0.
|
|
if (!C->getValue().isPowerOf2())
|
|
return false;
|
|
Y = ConstantInt::get(I->getContext(), -C->getValue());
|
|
Pred = ICmpInst::ICMP_EQ;
|
|
break;
|
|
case ICmpInst::ICMP_UGT:
|
|
// X >u 2^n-1 is equivalent to (X & ~(2^n-1)) != 0.
|
|
if (!(C->getValue() + 1).isPowerOf2())
|
|
return false;
|
|
Y = ConstantInt::get(I->getContext(), ~C->getValue());
|
|
Pred = ICmpInst::ICMP_NE;
|
|
break;
|
|
}
|
|
|
|
X = I->getOperand(0);
|
|
Z = ConstantInt::getNullValue(C->getType());
|
|
return true;
|
|
}
|
|
|
|
/// foldLogOpOfMaskedICmpsHelper:
|
|
/// handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
|
|
/// return the set of pattern classes (from MaskedICmpType)
|
|
/// that both LHS and RHS satisfy
|
|
static unsigned foldLogOpOfMaskedICmpsHelper(Value*& A,
|
|
Value*& B, Value*& C,
|
|
Value*& D, Value*& E,
|
|
ICmpInst *LHS, ICmpInst *RHS,
|
|
ICmpInst::Predicate &LHSCC,
|
|
ICmpInst::Predicate &RHSCC) {
|
|
if (LHS->getOperand(0)->getType() != RHS->getOperand(0)->getType()) return 0;
|
|
// vectors are not (yet?) supported
|
|
if (LHS->getOperand(0)->getType()->isVectorTy()) return 0;
|
|
|
|
// Here comes the tricky part:
|
|
// LHS might be of the form L11 & L12 == X, X == L21 & L22,
|
|
// and L11 & L12 == L21 & L22. The same goes for RHS.
|
|
// Now we must find those components L** and R**, that are equal, so
|
|
// that we can extract the parameters A, B, C, D, and E for the canonical
|
|
// above.
|
|
Value *L1 = LHS->getOperand(0);
|
|
Value *L2 = LHS->getOperand(1);
|
|
Value *L11,*L12,*L21,*L22;
|
|
// Check whether the icmp can be decomposed into a bit test.
|
|
if (decomposeBitTestICmp(LHS, LHSCC, L11, L12, L2)) {
|
|
L21 = L22 = L1 = nullptr;
|
|
} else {
|
|
// Look for ANDs in the LHS icmp.
|
|
if (!L1->getType()->isIntegerTy()) {
|
|
// You can icmp pointers, for example. They really aren't masks.
|
|
L11 = L12 = nullptr;
|
|
} else if (!match(L1, m_And(m_Value(L11), m_Value(L12)))) {
|
|
// Any icmp can be viewed as being trivially masked; if it allows us to
|
|
// remove one, it's worth it.
|
|
L11 = L1;
|
|
L12 = Constant::getAllOnesValue(L1->getType());
|
|
}
|
|
|
|
if (!L2->getType()->isIntegerTy()) {
|
|
// You can icmp pointers, for example. They really aren't masks.
|
|
L21 = L22 = nullptr;
|
|
} else if (!match(L2, m_And(m_Value(L21), m_Value(L22)))) {
|
|
L21 = L2;
|
|
L22 = Constant::getAllOnesValue(L2->getType());
|
|
}
|
|
}
|
|
|
|
// Bail if LHS was a icmp that can't be decomposed into an equality.
|
|
if (!ICmpInst::isEquality(LHSCC))
|
|
return 0;
|
|
|
|
Value *R1 = RHS->getOperand(0);
|
|
Value *R2 = RHS->getOperand(1);
|
|
Value *R11,*R12;
|
|
bool ok = false;
|
|
if (decomposeBitTestICmp(RHS, RHSCC, R11, R12, R2)) {
|
|
if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
|
|
A = R11; D = R12;
|
|
} else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
|
|
A = R12; D = R11;
|
|
} else {
|
|
return 0;
|
|
}
|
|
E = R2; R1 = nullptr; ok = true;
|
|
} else if (R1->getType()->isIntegerTy()) {
|
|
if (!match(R1, m_And(m_Value(R11), m_Value(R12)))) {
|
|
// As before, model no mask as a trivial mask if it'll let us do an
|
|
// optimisation.
|
|
R11 = R1;
|
|
R12 = Constant::getAllOnesValue(R1->getType());
|
|
}
|
|
|
|
if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
|
|
A = R11; D = R12; E = R2; ok = true;
|
|
} else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
|
|
A = R12; D = R11; E = R2; ok = true;
|
|
}
|
|
}
|
|
|
|
// Bail if RHS was a icmp that can't be decomposed into an equality.
|
|
if (!ICmpInst::isEquality(RHSCC))
|
|
return 0;
|
|
|
|
// Look for ANDs in on the right side of the RHS icmp.
|
|
if (!ok && R2->getType()->isIntegerTy()) {
|
|
if (!match(R2, m_And(m_Value(R11), m_Value(R12)))) {
|
|
R11 = R2;
|
|
R12 = Constant::getAllOnesValue(R2->getType());
|
|
}
|
|
|
|
if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
|
|
A = R11; D = R12; E = R1; ok = true;
|
|
} else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
|
|
A = R12; D = R11; E = R1; ok = true;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
if (!ok)
|
|
return 0;
|
|
|
|
if (L11 == A) {
|
|
B = L12; C = L2;
|
|
} else if (L12 == A) {
|
|
B = L11; C = L2;
|
|
} else if (L21 == A) {
|
|
B = L22; C = L1;
|
|
} else if (L22 == A) {
|
|
B = L21; C = L1;
|
|
}
|
|
|
|
unsigned left_type = getTypeOfMaskedICmp(A, B, C, LHSCC);
|
|
unsigned right_type = getTypeOfMaskedICmp(A, D, E, RHSCC);
|
|
return left_type & right_type;
|
|
}
|
|
/// foldLogOpOfMaskedICmps:
|
|
/// try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
|
|
/// into a single (icmp(A & X) ==/!= Y)
|
|
static Value* foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
|
|
llvm::InstCombiner::BuilderTy* Builder) {
|
|
Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr, *E = nullptr;
|
|
ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
|
|
unsigned mask = foldLogOpOfMaskedICmpsHelper(A, B, C, D, E, LHS, RHS,
|
|
LHSCC, RHSCC);
|
|
if (mask == 0) return nullptr;
|
|
assert(ICmpInst::isEquality(LHSCC) && ICmpInst::isEquality(RHSCC) &&
|
|
"foldLogOpOfMaskedICmpsHelper must return an equality predicate.");
|
|
|
|
// In full generality:
|
|
// (icmp (A & B) Op C) | (icmp (A & D) Op E)
|
|
// == ![ (icmp (A & B) !Op C) & (icmp (A & D) !Op E) ]
|
|
//
|
|
// If the latter can be converted into (icmp (A & X) Op Y) then the former is
|
|
// equivalent to (icmp (A & X) !Op Y).
|
|
//
|
|
// Therefore, we can pretend for the rest of this function that we're dealing
|
|
// with the conjunction, provided we flip the sense of any comparisons (both
|
|
// input and output).
|
|
|
|
// In most cases we're going to produce an EQ for the "&&" case.
|
|
ICmpInst::Predicate NEWCC = IsAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE;
|
|
if (!IsAnd) {
|
|
// Convert the masking analysis into its equivalent with negated
|
|
// comparisons.
|
|
mask = conjugateICmpMask(mask);
|
|
}
|
|
|
|
if (mask & FoldMskICmp_Mask_AllZeroes) {
|
|
// (icmp eq (A & B), 0) & (icmp eq (A & D), 0)
|
|
// -> (icmp eq (A & (B|D)), 0)
|
|
Value* newOr = Builder->CreateOr(B, D);
|
|
Value* newAnd = Builder->CreateAnd(A, newOr);
|
|
// we can't use C as zero, because we might actually handle
|
|
// (icmp ne (A & B), B) & (icmp ne (A & D), D)
|
|
// with B and D, having a single bit set
|
|
Value* zero = Constant::getNullValue(A->getType());
|
|
return Builder->CreateICmp(NEWCC, newAnd, zero);
|
|
}
|
|
if (mask & FoldMskICmp_BMask_AllOnes) {
|
|
// (icmp eq (A & B), B) & (icmp eq (A & D), D)
|
|
// -> (icmp eq (A & (B|D)), (B|D))
|
|
Value* newOr = Builder->CreateOr(B, D);
|
|
Value* newAnd = Builder->CreateAnd(A, newOr);
|
|
return Builder->CreateICmp(NEWCC, newAnd, newOr);
|
|
}
|
|
if (mask & FoldMskICmp_AMask_AllOnes) {
|
|
// (icmp eq (A & B), A) & (icmp eq (A & D), A)
|
|
// -> (icmp eq (A & (B&D)), A)
|
|
Value* newAnd1 = Builder->CreateAnd(B, D);
|
|
Value* newAnd = Builder->CreateAnd(A, newAnd1);
|
|
return Builder->CreateICmp(NEWCC, newAnd, A);
|
|
}
|
|
|
|
// Remaining cases assume at least that B and D are constant, and depend on
|
|
// their actual values. This isn't strictly, necessary, just a "handle the
|
|
// easy cases for now" decision.
|
|
ConstantInt *BCst = dyn_cast<ConstantInt>(B);
|
|
if (!BCst) return nullptr;
|
|
ConstantInt *DCst = dyn_cast<ConstantInt>(D);
|
|
if (!DCst) return nullptr;
|
|
|
|
if (mask & (FoldMskICmp_Mask_NotAllZeroes | FoldMskICmp_BMask_NotAllOnes)) {
|
|
// (icmp ne (A & B), 0) & (icmp ne (A & D), 0) and
|
|
// (icmp ne (A & B), B) & (icmp ne (A & D), D)
|
|
// -> (icmp ne (A & B), 0) or (icmp ne (A & D), 0)
|
|
// Only valid if one of the masks is a superset of the other (check "B&D" is
|
|
// the same as either B or D).
|
|
APInt NewMask = BCst->getValue() & DCst->getValue();
|
|
|
|
if (NewMask == BCst->getValue())
|
|
return LHS;
|
|
else if (NewMask == DCst->getValue())
|
|
return RHS;
|
|
}
|
|
if (mask & FoldMskICmp_AMask_NotAllOnes) {
|
|
// (icmp ne (A & B), B) & (icmp ne (A & D), D)
|
|
// -> (icmp ne (A & B), A) or (icmp ne (A & D), A)
|
|
// Only valid if one of the masks is a superset of the other (check "B|D" is
|
|
// the same as either B or D).
|
|
APInt NewMask = BCst->getValue() | DCst->getValue();
|
|
|
|
if (NewMask == BCst->getValue())
|
|
return LHS;
|
|
else if (NewMask == DCst->getValue())
|
|
return RHS;
|
|
}
|
|
if (mask & FoldMskICmp_BMask_Mixed) {
|
|
// (icmp eq (A & B), C) & (icmp eq (A & D), E)
|
|
// We already know that B & C == C && D & E == E.
|
|
// If we can prove that (B & D) & (C ^ E) == 0, that is, the bits of
|
|
// C and E, which are shared by both the mask B and the mask D, don't
|
|
// contradict, then we can transform to
|
|
// -> (icmp eq (A & (B|D)), (C|E))
|
|
// Currently, we only handle the case of B, C, D, and E being constant.
|
|
// we can't simply use C and E, because we might actually handle
|
|
// (icmp ne (A & B), B) & (icmp eq (A & D), D)
|
|
// with B and D, having a single bit set
|
|
ConstantInt *CCst = dyn_cast<ConstantInt>(C);
|
|
if (!CCst) return nullptr;
|
|
if (LHSCC != NEWCC)
|
|
CCst = dyn_cast<ConstantInt>( ConstantExpr::getXor(BCst, CCst) );
|
|
ConstantInt *ECst = dyn_cast<ConstantInt>(E);
|
|
if (!ECst) return nullptr;
|
|
if (RHSCC != NEWCC)
|
|
ECst = dyn_cast<ConstantInt>( ConstantExpr::getXor(DCst, ECst) );
|
|
ConstantInt* MCst = dyn_cast<ConstantInt>(
|
|
ConstantExpr::getAnd(ConstantExpr::getAnd(BCst, DCst),
|
|
ConstantExpr::getXor(CCst, ECst)) );
|
|
// if there is a conflict we should actually return a false for the
|
|
// whole construct
|
|
if (!MCst->isZero())
|
|
return nullptr;
|
|
Value *newOr1 = Builder->CreateOr(B, D);
|
|
Value *newOr2 = ConstantExpr::getOr(CCst, ECst);
|
|
Value *newAnd = Builder->CreateAnd(A, newOr1);
|
|
return Builder->CreateICmp(NEWCC, newAnd, newOr2);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
/// FoldAndOfICmps - Fold (icmp)&(icmp) if possible.
|
|
Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
|
|
ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
|
|
|
|
// (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
|
|
if (PredicatesFoldable(LHSCC, RHSCC)) {
|
|
if (LHS->getOperand(0) == RHS->getOperand(1) &&
|
|
LHS->getOperand(1) == RHS->getOperand(0))
|
|
LHS->swapOperands();
|
|
if (LHS->getOperand(0) == RHS->getOperand(0) &&
|
|
LHS->getOperand(1) == RHS->getOperand(1)) {
|
|
Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
|
|
unsigned Code = getICmpCode(LHS) & getICmpCode(RHS);
|
|
bool isSigned = LHS->isSigned() || RHS->isSigned();
|
|
return getNewICmpValue(isSigned, Code, Op0, Op1, Builder);
|
|
}
|
|
}
|
|
|
|
// handle (roughly): (icmp eq (A & B), C) & (icmp eq (A & D), E)
|
|
if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, true, Builder))
|
|
return V;
|
|
|
|
// This only handles icmp of constants: (icmp1 A, C1) & (icmp2 B, C2).
|
|
Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0);
|
|
ConstantInt *LHSCst = dyn_cast<ConstantInt>(LHS->getOperand(1));
|
|
ConstantInt *RHSCst = dyn_cast<ConstantInt>(RHS->getOperand(1));
|
|
if (!LHSCst || !RHSCst) return nullptr;
|
|
|
|
if (LHSCst == RHSCst && LHSCC == RHSCC) {
|
|
// (icmp ult A, C) & (icmp ult B, C) --> (icmp ult (A|B), C)
|
|
// where C is a power of 2
|
|
if (LHSCC == ICmpInst::ICMP_ULT &&
|
|
LHSCst->getValue().isPowerOf2()) {
|
|
Value *NewOr = Builder->CreateOr(Val, Val2);
|
|
return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
|
|
}
|
|
|
|
// (icmp eq A, 0) & (icmp eq B, 0) --> (icmp eq (A|B), 0)
|
|
if (LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero()) {
|
|
Value *NewOr = Builder->CreateOr(Val, Val2);
|
|
return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
|
|
}
|
|
}
|
|
|
|
// (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2
|
|
// where CMAX is the all ones value for the truncated type,
|
|
// iff the lower bits of C2 and CA are zero.
|
|
if (LHSCC == ICmpInst::ICMP_EQ && LHSCC == RHSCC &&
|
|
LHS->hasOneUse() && RHS->hasOneUse()) {
|
|
Value *V;
|
|
ConstantInt *AndCst, *SmallCst = nullptr, *BigCst = nullptr;
|
|
|
|
// (trunc x) == C1 & (and x, CA) == C2
|
|
// (and x, CA) == C2 & (trunc x) == C1
|
|
if (match(Val2, m_Trunc(m_Value(V))) &&
|
|
match(Val, m_And(m_Specific(V), m_ConstantInt(AndCst)))) {
|
|
SmallCst = RHSCst;
|
|
BigCst = LHSCst;
|
|
} else if (match(Val, m_Trunc(m_Value(V))) &&
|
|
match(Val2, m_And(m_Specific(V), m_ConstantInt(AndCst)))) {
|
|
SmallCst = LHSCst;
|
|
BigCst = RHSCst;
|
|
}
|
|
|
|
if (SmallCst && BigCst) {
|
|
unsigned BigBitSize = BigCst->getType()->getBitWidth();
|
|
unsigned SmallBitSize = SmallCst->getType()->getBitWidth();
|
|
|
|
// Check that the low bits are zero.
|
|
APInt Low = APInt::getLowBitsSet(BigBitSize, SmallBitSize);
|
|
if ((Low & AndCst->getValue()) == 0 && (Low & BigCst->getValue()) == 0) {
|
|
Value *NewAnd = Builder->CreateAnd(V, Low | AndCst->getValue());
|
|
APInt N = SmallCst->getValue().zext(BigBitSize) | BigCst->getValue();
|
|
Value *NewVal = ConstantInt::get(AndCst->getType()->getContext(), N);
|
|
return Builder->CreateICmp(LHSCC, NewAnd, NewVal);
|
|
}
|
|
}
|
|
}
|
|
|
|
// From here on, we only handle:
|
|
// (icmp1 A, C1) & (icmp2 A, C2) --> something simpler.
|
|
if (Val != Val2) return nullptr;
|
|
|
|
// ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere.
|
|
if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE ||
|
|
RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE ||
|
|
LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE ||
|
|
RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE)
|
|
return nullptr;
|
|
|
|
// Make a constant range that's the intersection of the two icmp ranges.
|
|
// If the intersection is empty, we know that the result is false.
|
|
ConstantRange LHSRange =
|
|
ConstantRange::makeICmpRegion(LHSCC, LHSCst->getValue());
|
|
ConstantRange RHSRange =
|
|
ConstantRange::makeICmpRegion(RHSCC, RHSCst->getValue());
|
|
|
|
if (LHSRange.intersectWith(RHSRange).isEmptySet())
|
|
return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
|
|
|
|
// We can't fold (ugt x, C) & (sgt x, C2).
|
|
if (!PredicatesFoldable(LHSCC, RHSCC))
|
|
return nullptr;
|
|
|
|
// Ensure that the larger constant is on the RHS.
|
|
bool ShouldSwap;
|
|
if (CmpInst::isSigned(LHSCC) ||
|
|
(ICmpInst::isEquality(LHSCC) &&
|
|
CmpInst::isSigned(RHSCC)))
|
|
ShouldSwap = LHSCst->getValue().sgt(RHSCst->getValue());
|
|
else
|
|
ShouldSwap = LHSCst->getValue().ugt(RHSCst->getValue());
|
|
|
|
if (ShouldSwap) {
|
|
std::swap(LHS, RHS);
|
|
std::swap(LHSCst, RHSCst);
|
|
std::swap(LHSCC, RHSCC);
|
|
}
|
|
|
|
// At this point, we know we have two icmp instructions
|
|
// comparing a value against two constants and and'ing the result
|
|
// together. Because of the above check, we know that we only have
|
|
// icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know
|
|
// (from the icmp folding check above), that the two constants
|
|
// are not equal and that the larger constant is on the RHS
|
|
assert(LHSCst != RHSCst && "Compares not folded above?");
|
|
|
|
switch (LHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_NE: // (X == 13 & X != 15) -> X == 13
|
|
case ICmpInst::ICMP_ULT: // (X == 13 & X < 15) -> X == 13
|
|
case ICmpInst::ICMP_SLT: // (X == 13 & X < 15) -> X == 13
|
|
return LHS;
|
|
}
|
|
case ICmpInst::ICMP_NE:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_ULT:
|
|
if (LHSCst == SubOne(RHSCst)) // (X != 13 & X u< 14) -> X < 13
|
|
return Builder->CreateICmpULT(Val, LHSCst);
|
|
break; // (X != 13 & X u< 15) -> no change
|
|
case ICmpInst::ICMP_SLT:
|
|
if (LHSCst == SubOne(RHSCst)) // (X != 13 & X s< 14) -> X < 13
|
|
return Builder->CreateICmpSLT(Val, LHSCst);
|
|
break; // (X != 13 & X s< 15) -> no change
|
|
case ICmpInst::ICMP_EQ: // (X != 13 & X == 15) -> X == 15
|
|
case ICmpInst::ICMP_UGT: // (X != 13 & X u> 15) -> X u> 15
|
|
case ICmpInst::ICMP_SGT: // (X != 13 & X s> 15) -> X s> 15
|
|
return RHS;
|
|
case ICmpInst::ICMP_NE:
|
|
// Special case to get the ordering right when the values wrap around
|
|
// zero.
|
|
if (LHSCst->getValue() == 0 && RHSCst->getValue().isAllOnesValue())
|
|
std::swap(LHSCst, RHSCst);
|
|
if (LHSCst == SubOne(RHSCst)){// (X != 13 & X != 14) -> X-13 >u 1
|
|
Constant *AddCST = ConstantExpr::getNeg(LHSCst);
|
|
Value *Add = Builder->CreateAdd(Val, AddCST, Val->getName()+".off");
|
|
return Builder->CreateICmpUGT(Add, ConstantInt::get(Add->getType(), 1),
|
|
Val->getName()+".cmp");
|
|
}
|
|
break; // (X != 13 & X != 15) -> no change
|
|
}
|
|
break;
|
|
case ICmpInst::ICMP_ULT:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ: // (X u< 13 & X == 15) -> false
|
|
case ICmpInst::ICMP_UGT: // (X u< 13 & X u> 15) -> false
|
|
return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
|
|
case ICmpInst::ICMP_SGT: // (X u< 13 & X s> 15) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE: // (X u< 13 & X != 15) -> X u< 13
|
|
case ICmpInst::ICMP_ULT: // (X u< 13 & X u< 15) -> X u< 13
|
|
return LHS;
|
|
case ICmpInst::ICMP_SLT: // (X u< 13 & X s< 15) -> no change
|
|
break;
|
|
}
|
|
break;
|
|
case ICmpInst::ICMP_SLT:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE: // (X s< 13 & X != 15) -> X < 13
|
|
case ICmpInst::ICMP_SLT: // (X s< 13 & X s< 15) -> X < 13
|
|
return LHS;
|
|
case ICmpInst::ICMP_ULT: // (X s< 13 & X u< 15) -> no change
|
|
break;
|
|
}
|
|
break;
|
|
case ICmpInst::ICMP_UGT:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ: // (X u> 13 & X == 15) -> X == 15
|
|
case ICmpInst::ICMP_UGT: // (X u> 13 & X u> 15) -> X u> 15
|
|
return RHS;
|
|
case ICmpInst::ICMP_SGT: // (X u> 13 & X s> 15) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE:
|
|
if (RHSCst == AddOne(LHSCst)) // (X u> 13 & X != 14) -> X u> 14
|
|
return Builder->CreateICmp(LHSCC, Val, RHSCst);
|
|
break; // (X u> 13 & X != 15) -> no change
|
|
case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) -> (X-14) <u 1
|
|
return InsertRangeTest(Val, AddOne(LHSCst), RHSCst, false, true);
|
|
case ICmpInst::ICMP_SLT: // (X u> 13 & X s< 15) -> no change
|
|
break;
|
|
}
|
|
break;
|
|
case ICmpInst::ICMP_SGT:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ: // (X s> 13 & X == 15) -> X == 15
|
|
case ICmpInst::ICMP_SGT: // (X s> 13 & X s> 15) -> X s> 15
|
|
return RHS;
|
|
case ICmpInst::ICMP_UGT: // (X s> 13 & X u> 15) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE:
|
|
if (RHSCst == AddOne(LHSCst)) // (X s> 13 & X != 14) -> X s> 14
|
|
return Builder->CreateICmp(LHSCC, Val, RHSCst);
|
|
break; // (X s> 13 & X != 15) -> no change
|
|
case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) -> (X-14) s< 1
|
|
return InsertRangeTest(Val, AddOne(LHSCst), RHSCst, true, true);
|
|
case ICmpInst::ICMP_ULT: // (X s> 13 & X u< 15) -> no change
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
/// FoldAndOfFCmps - Optimize (fcmp)&(fcmp). NOTE: Unlike the rest of
|
|
/// instcombine, this returns a Value which should already be inserted into the
|
|
/// function.
|
|
Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
|
|
if (LHS->getPredicate() == FCmpInst::FCMP_ORD &&
|
|
RHS->getPredicate() == FCmpInst::FCMP_ORD) {
|
|
if (LHS->getOperand(0)->getType() != RHS->getOperand(0)->getType())
|
|
return nullptr;
|
|
|
|
// (fcmp ord x, c) & (fcmp ord y, c) -> (fcmp ord x, y)
|
|
if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
|
|
if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
|
|
// If either of the constants are nans, then the whole thing returns
|
|
// false.
|
|
if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN())
|
|
return Builder->getFalse();
|
|
return Builder->CreateFCmpORD(LHS->getOperand(0), RHS->getOperand(0));
|
|
}
|
|
|
|
// Handle vector zeros. This occurs because the canonical form of
|
|
// "fcmp ord x,x" is "fcmp ord x, 0".
|
|
if (isa<ConstantAggregateZero>(LHS->getOperand(1)) &&
|
|
isa<ConstantAggregateZero>(RHS->getOperand(1)))
|
|
return Builder->CreateFCmpORD(LHS->getOperand(0), RHS->getOperand(0));
|
|
return nullptr;
|
|
}
|
|
|
|
Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
|
|
Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
|
|
FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
|
|
|
|
|
|
if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) {
|
|
// Swap RHS operands to match LHS.
|
|
Op1CC = FCmpInst::getSwappedPredicate(Op1CC);
|
|
std::swap(Op1LHS, Op1RHS);
|
|
}
|
|
|
|
if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) {
|
|
// Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y).
|
|
if (Op0CC == Op1CC)
|
|
return Builder->CreateFCmp((FCmpInst::Predicate)Op0CC, Op0LHS, Op0RHS);
|
|
if (Op0CC == FCmpInst::FCMP_FALSE || Op1CC == FCmpInst::FCMP_FALSE)
|
|
return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
|
|
if (Op0CC == FCmpInst::FCMP_TRUE)
|
|
return RHS;
|
|
if (Op1CC == FCmpInst::FCMP_TRUE)
|
|
return LHS;
|
|
|
|
bool Op0Ordered;
|
|
bool Op1Ordered;
|
|
unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
|
|
unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
|
|
// uno && ord -> false
|
|
if (Op0Pred == 0 && Op1Pred == 0 && Op0Ordered != Op1Ordered)
|
|
return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
|
|
if (Op1Pred == 0) {
|
|
std::swap(LHS, RHS);
|
|
std::swap(Op0Pred, Op1Pred);
|
|
std::swap(Op0Ordered, Op1Ordered);
|
|
}
|
|
if (Op0Pred == 0) {
|
|
// uno && ueq -> uno && (uno || eq) -> uno
|
|
// ord && olt -> ord && (ord && lt) -> olt
|
|
if (!Op0Ordered && (Op0Ordered == Op1Ordered))
|
|
return LHS;
|
|
if (Op0Ordered && (Op0Ordered == Op1Ordered))
|
|
return RHS;
|
|
|
|
// uno && oeq -> uno && (ord && eq) -> false
|
|
if (!Op0Ordered)
|
|
return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
|
|
// ord && ueq -> ord && (uno || eq) -> oeq
|
|
return getFCmpValue(true, Op1Pred, Op0LHS, Op0RHS, Builder);
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
|
|
Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
|
|
bool Changed = SimplifyAssociativeOrCommutative(I);
|
|
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
|
|
|
|
if (Value *V = SimplifyAndInst(Op0, Op1, DL))
|
|
return ReplaceInstUsesWith(I, V);
|
|
|
|
// (A|B)&(A|C) -> A|(B&C) etc
|
|
if (Value *V = SimplifyUsingDistributiveLaws(I))
|
|
return ReplaceInstUsesWith(I, V);
|
|
|
|
// See if we can simplify any instructions used by the instruction whose sole
|
|
// purpose is to compute bits we don't care about.
|
|
if (SimplifyDemandedInstructionBits(I))
|
|
return &I;
|
|
|
|
if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(Op1)) {
|
|
const APInt &AndRHSMask = AndRHS->getValue();
|
|
|
|
// Optimize a variety of ((val OP C1) & C2) combinations...
|
|
if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
|
|
Value *Op0LHS = Op0I->getOperand(0);
|
|
Value *Op0RHS = Op0I->getOperand(1);
|
|
switch (Op0I->getOpcode()) {
|
|
default: break;
|
|
case Instruction::Xor:
|
|
case Instruction::Or: {
|
|
// If the mask is only needed on one incoming arm, push it up.
|
|
if (!Op0I->hasOneUse()) break;
|
|
|
|
APInt NotAndRHS(~AndRHSMask);
|
|
if (MaskedValueIsZero(Op0LHS, NotAndRHS)) {
|
|
// Not masking anything out for the LHS, move to RHS.
|
|
Value *NewRHS = Builder->CreateAnd(Op0RHS, AndRHS,
|
|
Op0RHS->getName()+".masked");
|
|
return BinaryOperator::Create(Op0I->getOpcode(), Op0LHS, NewRHS);
|
|
}
|
|
if (!isa<Constant>(Op0RHS) &&
|
|
MaskedValueIsZero(Op0RHS, NotAndRHS)) {
|
|
// Not masking anything out for the RHS, move to LHS.
|
|
Value *NewLHS = Builder->CreateAnd(Op0LHS, AndRHS,
|
|
Op0LHS->getName()+".masked");
|
|
return BinaryOperator::Create(Op0I->getOpcode(), NewLHS, Op0RHS);
|
|
}
|
|
|
|
break;
|
|
}
|
|
case Instruction::Add:
|
|
// ((A & N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == AndRHS.
|
|
// ((A | N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == 0
|
|
// ((A ^ N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == 0
|
|
if (Value *V = FoldLogicalPlusAnd(Op0LHS, Op0RHS, AndRHS, false, I))
|
|
return BinaryOperator::CreateAnd(V, AndRHS);
|
|
if (Value *V = FoldLogicalPlusAnd(Op0RHS, Op0LHS, AndRHS, false, I))
|
|
return BinaryOperator::CreateAnd(V, AndRHS); // Add commutes
|
|
break;
|
|
|
|
case Instruction::Sub:
|
|
// ((A & N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == AndRHS.
|
|
// ((A | N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == 0
|
|
// ((A ^ N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == 0
|
|
if (Value *V = FoldLogicalPlusAnd(Op0LHS, Op0RHS, AndRHS, true, I))
|
|
return BinaryOperator::CreateAnd(V, AndRHS);
|
|
|
|
// (A - N) & AndRHS -> -N & AndRHS iff A&AndRHS==0 and AndRHS
|
|
// has 1's for all bits that the subtraction with A might affect.
|
|
if (Op0I->hasOneUse() && !match(Op0LHS, m_Zero())) {
|
|
uint32_t BitWidth = AndRHSMask.getBitWidth();
|
|
uint32_t Zeros = AndRHSMask.countLeadingZeros();
|
|
APInt Mask = APInt::getLowBitsSet(BitWidth, BitWidth - Zeros);
|
|
|
|
if (MaskedValueIsZero(Op0LHS, Mask)) {
|
|
Value *NewNeg = Builder->CreateNeg(Op0RHS);
|
|
return BinaryOperator::CreateAnd(NewNeg, AndRHS);
|
|
}
|
|
}
|
|
break;
|
|
|
|
case Instruction::Shl:
|
|
case Instruction::LShr:
|
|
// (1 << x) & 1 --> zext(x == 0)
|
|
// (1 >> x) & 1 --> zext(x == 0)
|
|
if (AndRHSMask == 1 && Op0LHS == AndRHS) {
|
|
Value *NewICmp =
|
|
Builder->CreateICmpEQ(Op0RHS, Constant::getNullValue(I.getType()));
|
|
return new ZExtInst(NewICmp, I.getType());
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
|
|
if (Instruction *Res = OptAndOp(Op0I, Op0CI, AndRHS, I))
|
|
return Res;
|
|
}
|
|
|
|
// If this is an integer truncation, and if the source is an 'and' with
|
|
// immediate, transform it. This frequently occurs for bitfield accesses.
|
|
{
|
|
Value *X = nullptr; ConstantInt *YC = nullptr;
|
|
if (match(Op0, m_Trunc(m_And(m_Value(X), m_ConstantInt(YC))))) {
|
|
// Change: and (trunc (and X, YC) to T), C2
|
|
// into : and (trunc X to T), trunc(YC) & C2
|
|
// This will fold the two constants together, which may allow
|
|
// other simplifications.
|
|
Value *NewCast = Builder->CreateTrunc(X, I.getType(), "and.shrunk");
|
|
Constant *C3 = ConstantExpr::getTrunc(YC, I.getType());
|
|
C3 = ConstantExpr::getAnd(C3, AndRHS);
|
|
return BinaryOperator::CreateAnd(NewCast, C3);
|
|
}
|
|
}
|
|
|
|
// Try to fold constant and into select arguments.
|
|
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
|
|
if (Instruction *R = FoldOpIntoSelect(I, SI))
|
|
return R;
|
|
if (isa<PHINode>(Op0))
|
|
if (Instruction *NV = FoldOpIntoPhi(I))
|
|
return NV;
|
|
}
|
|
|
|
|
|
// (~A & ~B) == (~(A | B)) - De Morgan's Law
|
|
if (Value *Op0NotVal = dyn_castNotVal(Op0))
|
|
if (Value *Op1NotVal = dyn_castNotVal(Op1))
|
|
if (Op0->hasOneUse() && Op1->hasOneUse()) {
|
|
Value *Or = Builder->CreateOr(Op0NotVal, Op1NotVal,
|
|
I.getName()+".demorgan");
|
|
return BinaryOperator::CreateNot(Or);
|
|
}
|
|
|
|
{
|
|
Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr;
|
|
// (A|B) & ~(A&B) -> A^B
|
|
if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
|
|
match(Op1, m_Not(m_And(m_Value(C), m_Value(D)))) &&
|
|
((A == C && B == D) || (A == D && B == C)))
|
|
return BinaryOperator::CreateXor(A, B);
|
|
|
|
// ~(A&B) & (A|B) -> A^B
|
|
if (match(Op1, m_Or(m_Value(A), m_Value(B))) &&
|
|
match(Op0, m_Not(m_And(m_Value(C), m_Value(D)))) &&
|
|
((A == C && B == D) || (A == D && B == C)))
|
|
return BinaryOperator::CreateXor(A, B);
|
|
|
|
// A&(A^B) => A & ~B
|
|
{
|
|
Value *tmpOp0 = Op0;
|
|
Value *tmpOp1 = Op1;
|
|
if (Op0->hasOneUse() &&
|
|
match(Op0, m_Xor(m_Value(A), m_Value(B)))) {
|
|
if (A == Op1 || B == Op1 ) {
|
|
tmpOp1 = Op0;
|
|
tmpOp0 = Op1;
|
|
// Simplify below
|
|
}
|
|
}
|
|
|
|
if (tmpOp1->hasOneUse() &&
|
|
match(tmpOp1, m_Xor(m_Value(A), m_Value(B)))) {
|
|
if (B == tmpOp0) {
|
|
std::swap(A, B);
|
|
}
|
|
// Notice that the patten (A&(~B)) is actually (A&(-1^B)), so if
|
|
// A is originally -1 (or a vector of -1 and undefs), then we enter
|
|
// an endless loop. By checking that A is non-constant we ensure that
|
|
// we will never get to the loop.
|
|
if (A == tmpOp0 && !isa<Constant>(A)) // A&(A^B) -> A & ~B
|
|
return BinaryOperator::CreateAnd(A, Builder->CreateNot(B));
|
|
}
|
|
}
|
|
|
|
// (A&((~A)|B)) -> A&B
|
|
if (match(Op0, m_Or(m_Not(m_Specific(Op1)), m_Value(A))) ||
|
|
match(Op0, m_Or(m_Value(A), m_Not(m_Specific(Op1)))))
|
|
return BinaryOperator::CreateAnd(A, Op1);
|
|
if (match(Op1, m_Or(m_Not(m_Specific(Op0)), m_Value(A))) ||
|
|
match(Op1, m_Or(m_Value(A), m_Not(m_Specific(Op0)))))
|
|
return BinaryOperator::CreateAnd(A, Op0);
|
|
}
|
|
|
|
if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1))
|
|
if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0))
|
|
if (Value *Res = FoldAndOfICmps(LHS, RHS))
|
|
return ReplaceInstUsesWith(I, Res);
|
|
|
|
// If and'ing two fcmp, try combine them into one.
|
|
if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
|
|
if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
|
|
if (Value *Res = FoldAndOfFCmps(LHS, RHS))
|
|
return ReplaceInstUsesWith(I, Res);
|
|
|
|
|
|
// fold (and (cast A), (cast B)) -> (cast (and A, B))
|
|
if (CastInst *Op0C = dyn_cast<CastInst>(Op0))
|
|
if (CastInst *Op1C = dyn_cast<CastInst>(Op1)) {
|
|
Type *SrcTy = Op0C->getOperand(0)->getType();
|
|
if (Op0C->getOpcode() == Op1C->getOpcode() && // same cast kind ?
|
|
SrcTy == Op1C->getOperand(0)->getType() &&
|
|
SrcTy->isIntOrIntVectorTy()) {
|
|
Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0);
|
|
|
|
// Only do this if the casts both really cause code to be generated.
|
|
if (ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
|
|
ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
|
|
Value *NewOp = Builder->CreateAnd(Op0COp, Op1COp, I.getName());
|
|
return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
|
|
}
|
|
|
|
// If this is and(cast(icmp), cast(icmp)), try to fold this even if the
|
|
// cast is otherwise not optimizable. This happens for vector sexts.
|
|
if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
|
|
if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
|
|
if (Value *Res = FoldAndOfICmps(LHS, RHS))
|
|
return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
|
|
|
|
// If this is and(cast(fcmp), cast(fcmp)), try to fold this even if the
|
|
// cast is otherwise not optimizable. This happens for vector sexts.
|
|
if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
|
|
if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
|
|
if (Value *Res = FoldAndOfFCmps(LHS, RHS))
|
|
return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
|
|
}
|
|
}
|
|
|
|
// (X >> Z) & (Y >> Z) -> (X&Y) >> Z for all shifts.
|
|
if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
|
|
if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
|
|
if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() &&
|
|
SI0->getOperand(1) == SI1->getOperand(1) &&
|
|
(SI0->hasOneUse() || SI1->hasOneUse())) {
|
|
Value *NewOp =
|
|
Builder->CreateAnd(SI0->getOperand(0), SI1->getOperand(0),
|
|
SI0->getName());
|
|
return BinaryOperator::Create(SI1->getOpcode(), NewOp,
|
|
SI1->getOperand(1));
|
|
}
|
|
}
|
|
|
|
{
|
|
Value *X = nullptr;
|
|
bool OpsSwapped = false;
|
|
// Canonicalize SExt or Not to the LHS
|
|
if (match(Op1, m_SExt(m_Value())) ||
|
|
match(Op1, m_Not(m_Value()))) {
|
|
std::swap(Op0, Op1);
|
|
OpsSwapped = true;
|
|
}
|
|
|
|
// Fold (and (sext bool to A), B) --> (select bool, B, 0)
|
|
if (match(Op0, m_SExt(m_Value(X))) &&
|
|
X->getType()->getScalarType()->isIntegerTy(1)) {
|
|
Value *Zero = Constant::getNullValue(Op1->getType());
|
|
return SelectInst::Create(X, Op1, Zero);
|
|
}
|
|
|
|
// Fold (and ~(sext bool to A), B) --> (select bool, 0, B)
|
|
if (match(Op0, m_Not(m_SExt(m_Value(X)))) &&
|
|
X->getType()->getScalarType()->isIntegerTy(1)) {
|
|
Value *Zero = Constant::getNullValue(Op0->getType());
|
|
return SelectInst::Create(X, Zero, Op1);
|
|
}
|
|
|
|
if (OpsSwapped)
|
|
std::swap(Op0, Op1);
|
|
}
|
|
|
|
return Changed ? &I : nullptr;
|
|
}
|
|
|
|
/// CollectBSwapParts - Analyze the specified subexpression and see if it is
|
|
/// capable of providing pieces of a bswap. The subexpression provides pieces
|
|
/// of a bswap if it is proven that each of the non-zero bytes in the output of
|
|
/// the expression came from the corresponding "byte swapped" byte in some other
|
|
/// value. For example, if the current subexpression is "(shl i32 %X, 24)" then
|
|
/// we know that the expression deposits the low byte of %X into the high byte
|
|
/// of the bswap result and that all other bytes are zero. This expression is
|
|
/// accepted, the high byte of ByteValues is set to X to indicate a correct
|
|
/// match.
|
|
///
|
|
/// This function returns true if the match was unsuccessful and false if so.
|
|
/// On entry to the function the "OverallLeftShift" is a signed integer value
|
|
/// indicating the number of bytes that the subexpression is later shifted. For
|
|
/// example, if the expression is later right shifted by 16 bits, the
|
|
/// OverallLeftShift value would be -2 on entry. This is used to specify which
|
|
/// byte of ByteValues is actually being set.
|
|
///
|
|
/// Similarly, ByteMask is a bitmask where a bit is clear if its corresponding
|
|
/// byte is masked to zero by a user. For example, in (X & 255), X will be
|
|
/// processed with a bytemask of 1. Because bytemask is 32-bits, this limits
|
|
/// this function to working on up to 32-byte (256 bit) values. ByteMask is
|
|
/// always in the local (OverallLeftShift) coordinate space.
|
|
///
|
|
static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask,
|
|
SmallVectorImpl<Value *> &ByteValues) {
|
|
if (Instruction *I = dyn_cast<Instruction>(V)) {
|
|
// If this is an or instruction, it may be an inner node of the bswap.
|
|
if (I->getOpcode() == Instruction::Or) {
|
|
return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
|
|
ByteValues) ||
|
|
CollectBSwapParts(I->getOperand(1), OverallLeftShift, ByteMask,
|
|
ByteValues);
|
|
}
|
|
|
|
// If this is a logical shift by a constant multiple of 8, recurse with
|
|
// OverallLeftShift and ByteMask adjusted.
|
|
if (I->isLogicalShift() && isa<ConstantInt>(I->getOperand(1))) {
|
|
unsigned ShAmt =
|
|
cast<ConstantInt>(I->getOperand(1))->getLimitedValue(~0U);
|
|
// Ensure the shift amount is defined and of a byte value.
|
|
if ((ShAmt & 7) || (ShAmt > 8*ByteValues.size()))
|
|
return true;
|
|
|
|
unsigned ByteShift = ShAmt >> 3;
|
|
if (I->getOpcode() == Instruction::Shl) {
|
|
// X << 2 -> collect(X, +2)
|
|
OverallLeftShift += ByteShift;
|
|
ByteMask >>= ByteShift;
|
|
} else {
|
|
// X >>u 2 -> collect(X, -2)
|
|
OverallLeftShift -= ByteShift;
|
|
ByteMask <<= ByteShift;
|
|
ByteMask &= (~0U >> (32-ByteValues.size()));
|
|
}
|
|
|
|
if (OverallLeftShift >= (int)ByteValues.size()) return true;
|
|
if (OverallLeftShift <= -(int)ByteValues.size()) return true;
|
|
|
|
return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
|
|
ByteValues);
|
|
}
|
|
|
|
// If this is a logical 'and' with a mask that clears bytes, clear the
|
|
// corresponding bytes in ByteMask.
|
|
if (I->getOpcode() == Instruction::And &&
|
|
isa<ConstantInt>(I->getOperand(1))) {
|
|
// Scan every byte of the and mask, seeing if the byte is either 0 or 255.
|
|
unsigned NumBytes = ByteValues.size();
|
|
APInt Byte(I->getType()->getPrimitiveSizeInBits(), 255);
|
|
const APInt &AndMask = cast<ConstantInt>(I->getOperand(1))->getValue();
|
|
|
|
for (unsigned i = 0; i != NumBytes; ++i, Byte <<= 8) {
|
|
// If this byte is masked out by a later operation, we don't care what
|
|
// the and mask is.
|
|
if ((ByteMask & (1 << i)) == 0)
|
|
continue;
|
|
|
|
// If the AndMask is all zeros for this byte, clear the bit.
|
|
APInt MaskB = AndMask & Byte;
|
|
if (MaskB == 0) {
|
|
ByteMask &= ~(1U << i);
|
|
continue;
|
|
}
|
|
|
|
// If the AndMask is not all ones for this byte, it's not a bytezap.
|
|
if (MaskB != Byte)
|
|
return true;
|
|
|
|
// Otherwise, this byte is kept.
|
|
}
|
|
|
|
return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
|
|
ByteValues);
|
|
}
|
|
}
|
|
|
|
// Okay, we got to something that isn't a shift, 'or' or 'and'. This must be
|
|
// the input value to the bswap. Some observations: 1) if more than one byte
|
|
// is demanded from this input, then it could not be successfully assembled
|
|
// into a byteswap. At least one of the two bytes would not be aligned with
|
|
// their ultimate destination.
|
|
if (!isPowerOf2_32(ByteMask)) return true;
|
|
unsigned InputByteNo = countTrailingZeros(ByteMask);
|
|
|
|
// 2) The input and ultimate destinations must line up: if byte 3 of an i32
|
|
// is demanded, it needs to go into byte 0 of the result. This means that the
|
|
// byte needs to be shifted until it lands in the right byte bucket. The
|
|
// shift amount depends on the position: if the byte is coming from the high
|
|
// part of the value (e.g. byte 3) then it must be shifted right. If from the
|
|
// low part, it must be shifted left.
|
|
unsigned DestByteNo = InputByteNo + OverallLeftShift;
|
|
if (ByteValues.size()-1-DestByteNo != InputByteNo)
|
|
return true;
|
|
|
|
// If the destination byte value is already defined, the values are or'd
|
|
// together, which isn't a bswap (unless it's an or of the same bits).
|
|
if (ByteValues[DestByteNo] && ByteValues[DestByteNo] != V)
|
|
return true;
|
|
ByteValues[DestByteNo] = V;
|
|
return false;
|
|
}
|
|
|
|
/// MatchBSwap - Given an OR instruction, check to see if this is a bswap idiom.
|
|
/// If so, insert the new bswap intrinsic and return it.
|
|
Instruction *InstCombiner::MatchBSwap(BinaryOperator &I) {
|
|
IntegerType *ITy = dyn_cast<IntegerType>(I.getType());
|
|
if (!ITy || ITy->getBitWidth() % 16 ||
|
|
// ByteMask only allows up to 32-byte values.
|
|
ITy->getBitWidth() > 32*8)
|
|
return nullptr; // Can only bswap pairs of bytes. Can't do vectors.
|
|
|
|
/// ByteValues - For each byte of the result, we keep track of which value
|
|
/// defines each byte.
|
|
SmallVector<Value*, 8> ByteValues;
|
|
ByteValues.resize(ITy->getBitWidth()/8);
|
|
|
|
// Try to find all the pieces corresponding to the bswap.
|
|
uint32_t ByteMask = ~0U >> (32-ByteValues.size());
|
|
if (CollectBSwapParts(&I, 0, ByteMask, ByteValues))
|
|
return nullptr;
|
|
|
|
// Check to see if all of the bytes come from the same value.
|
|
Value *V = ByteValues[0];
|
|
if (!V) return nullptr; // Didn't find a byte? Must be zero.
|
|
|
|
// Check to make sure that all of the bytes come from the same value.
|
|
for (unsigned i = 1, e = ByteValues.size(); i != e; ++i)
|
|
if (ByteValues[i] != V)
|
|
return nullptr;
|
|
Module *M = I.getParent()->getParent()->getParent();
|
|
Function *F = Intrinsic::getDeclaration(M, Intrinsic::bswap, ITy);
|
|
return CallInst::Create(F, V);
|
|
}
|
|
|
|
/// MatchSelectFromAndOr - We have an expression of the form (A&C)|(B&D). Check
|
|
/// If A is (cond?-1:0) and either B or D is ~(cond?-1,0) or (cond?0,-1), then
|
|
/// we can simplify this expression to "cond ? C : D or B".
|
|
static Instruction *MatchSelectFromAndOr(Value *A, Value *B,
|
|
Value *C, Value *D) {
|
|
// If A is not a select of -1/0, this cannot match.
|
|
Value *Cond = nullptr;
|
|
if (!match(A, m_SExt(m_Value(Cond))) ||
|
|
!Cond->getType()->isIntegerTy(1))
|
|
return nullptr;
|
|
|
|
// ((cond?-1:0)&C) | (B&(cond?0:-1)) -> cond ? C : B.
|
|
if (match(D, m_Not(m_SExt(m_Specific(Cond)))))
|
|
return SelectInst::Create(Cond, C, B);
|
|
if (match(D, m_SExt(m_Not(m_Specific(Cond)))))
|
|
return SelectInst::Create(Cond, C, B);
|
|
|
|
// ((cond?-1:0)&C) | ((cond?0:-1)&D) -> cond ? C : D.
|
|
if (match(B, m_Not(m_SExt(m_Specific(Cond)))))
|
|
return SelectInst::Create(Cond, C, D);
|
|
if (match(B, m_SExt(m_Not(m_Specific(Cond)))))
|
|
return SelectInst::Create(Cond, C, D);
|
|
return nullptr;
|
|
}
|
|
|
|
/// FoldOrOfICmps - Fold (icmp)|(icmp) if possible.
|
|
Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
|
|
ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
|
|
|
|
// Fold (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2)
|
|
// if K1 and K2 are a one-bit mask.
|
|
ConstantInt *LHSCst = dyn_cast<ConstantInt>(LHS->getOperand(1));
|
|
ConstantInt *RHSCst = dyn_cast<ConstantInt>(RHS->getOperand(1));
|
|
|
|
if (LHS->getPredicate() == ICmpInst::ICMP_EQ && LHSCst && LHSCst->isZero() &&
|
|
RHS->getPredicate() == ICmpInst::ICMP_EQ && RHSCst && RHSCst->isZero()) {
|
|
|
|
BinaryOperator *LAnd = dyn_cast<BinaryOperator>(LHS->getOperand(0));
|
|
BinaryOperator *RAnd = dyn_cast<BinaryOperator>(RHS->getOperand(0));
|
|
if (LAnd && RAnd && LAnd->hasOneUse() && RHS->hasOneUse() &&
|
|
LAnd->getOpcode() == Instruction::And &&
|
|
RAnd->getOpcode() == Instruction::And) {
|
|
|
|
Value *Mask = nullptr;
|
|
Value *Masked = nullptr;
|
|
if (LAnd->getOperand(0) == RAnd->getOperand(0) &&
|
|
isKnownToBeAPowerOfTwo(LAnd->getOperand(1)) &&
|
|
isKnownToBeAPowerOfTwo(RAnd->getOperand(1))) {
|
|
Mask = Builder->CreateOr(LAnd->getOperand(1), RAnd->getOperand(1));
|
|
Masked = Builder->CreateAnd(LAnd->getOperand(0), Mask);
|
|
} else if (LAnd->getOperand(1) == RAnd->getOperand(1) &&
|
|
isKnownToBeAPowerOfTwo(LAnd->getOperand(0)) &&
|
|
isKnownToBeAPowerOfTwo(RAnd->getOperand(0))) {
|
|
Mask = Builder->CreateOr(LAnd->getOperand(0), RAnd->getOperand(0));
|
|
Masked = Builder->CreateAnd(LAnd->getOperand(1), Mask);
|
|
}
|
|
|
|
if (Masked)
|
|
return Builder->CreateICmp(ICmpInst::ICMP_NE, Masked, Mask);
|
|
}
|
|
}
|
|
|
|
// (icmp1 A, B) | (icmp2 A, B) --> (icmp3 A, B)
|
|
if (PredicatesFoldable(LHSCC, RHSCC)) {
|
|
if (LHS->getOperand(0) == RHS->getOperand(1) &&
|
|
LHS->getOperand(1) == RHS->getOperand(0))
|
|
LHS->swapOperands();
|
|
if (LHS->getOperand(0) == RHS->getOperand(0) &&
|
|
LHS->getOperand(1) == RHS->getOperand(1)) {
|
|
Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
|
|
unsigned Code = getICmpCode(LHS) | getICmpCode(RHS);
|
|
bool isSigned = LHS->isSigned() || RHS->isSigned();
|
|
return getNewICmpValue(isSigned, Code, Op0, Op1, Builder);
|
|
}
|
|
}
|
|
|
|
// handle (roughly):
|
|
// (icmp ne (A & B), C) | (icmp ne (A & D), E)
|
|
if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, false, Builder))
|
|
return V;
|
|
|
|
Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0);
|
|
if (LHS->hasOneUse() || RHS->hasOneUse()) {
|
|
// (icmp eq B, 0) | (icmp ult A, B) -> (icmp ule A, B-1)
|
|
// (icmp eq B, 0) | (icmp ugt B, A) -> (icmp ule A, B-1)
|
|
Value *A = nullptr, *B = nullptr;
|
|
if (LHSCC == ICmpInst::ICMP_EQ && LHSCst && LHSCst->isZero()) {
|
|
B = Val;
|
|
if (RHSCC == ICmpInst::ICMP_ULT && Val == RHS->getOperand(1))
|
|
A = Val2;
|
|
else if (RHSCC == ICmpInst::ICMP_UGT && Val == Val2)
|
|
A = RHS->getOperand(1);
|
|
}
|
|
// (icmp ult A, B) | (icmp eq B, 0) -> (icmp ule A, B-1)
|
|
// (icmp ugt B, A) | (icmp eq B, 0) -> (icmp ule A, B-1)
|
|
else if (RHSCC == ICmpInst::ICMP_EQ && RHSCst && RHSCst->isZero()) {
|
|
B = Val2;
|
|
if (LHSCC == ICmpInst::ICMP_ULT && Val2 == LHS->getOperand(1))
|
|
A = Val;
|
|
else if (LHSCC == ICmpInst::ICMP_UGT && Val2 == Val)
|
|
A = LHS->getOperand(1);
|
|
}
|
|
if (A && B)
|
|
return Builder->CreateICmp(
|
|
ICmpInst::ICMP_UGE,
|
|
Builder->CreateAdd(B, ConstantInt::getSigned(B->getType(), -1)), A);
|
|
}
|
|
|
|
// This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2).
|
|
if (!LHSCst || !RHSCst) return nullptr;
|
|
|
|
if (LHSCst == RHSCst && LHSCC == RHSCC) {
|
|
// (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
|
|
if (LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) {
|
|
Value *NewOr = Builder->CreateOr(Val, Val2);
|
|
return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
|
|
}
|
|
}
|
|
|
|
// (icmp ult (X + CA), C1) | (icmp eq X, C2) -> (icmp ule (X + CA), C1)
|
|
// iff C2 + CA == C1.
|
|
if (LHSCC == ICmpInst::ICMP_ULT && RHSCC == ICmpInst::ICMP_EQ) {
|
|
ConstantInt *AddCst;
|
|
if (match(Val, m_Add(m_Specific(Val2), m_ConstantInt(AddCst))))
|
|
if (RHSCst->getValue() + AddCst->getValue() == LHSCst->getValue())
|
|
return Builder->CreateICmpULE(Val, LHSCst);
|
|
}
|
|
|
|
// From here on, we only handle:
|
|
// (icmp1 A, C1) | (icmp2 A, C2) --> something simpler.
|
|
if (Val != Val2) return nullptr;
|
|
|
|
// ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere.
|
|
if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE ||
|
|
RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE ||
|
|
LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE ||
|
|
RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE)
|
|
return nullptr;
|
|
|
|
// We can't fold (ugt x, C) | (sgt x, C2).
|
|
if (!PredicatesFoldable(LHSCC, RHSCC))
|
|
return nullptr;
|
|
|
|
// Ensure that the larger constant is on the RHS.
|
|
bool ShouldSwap;
|
|
if (CmpInst::isSigned(LHSCC) ||
|
|
(ICmpInst::isEquality(LHSCC) &&
|
|
CmpInst::isSigned(RHSCC)))
|
|
ShouldSwap = LHSCst->getValue().sgt(RHSCst->getValue());
|
|
else
|
|
ShouldSwap = LHSCst->getValue().ugt(RHSCst->getValue());
|
|
|
|
if (ShouldSwap) {
|
|
std::swap(LHS, RHS);
|
|
std::swap(LHSCst, RHSCst);
|
|
std::swap(LHSCC, RHSCC);
|
|
}
|
|
|
|
// At this point, we know we have two icmp instructions
|
|
// comparing a value against two constants and or'ing the result
|
|
// together. Because of the above check, we know that we only have
|
|
// ICMP_EQ, ICMP_NE, ICMP_LT, and ICMP_GT here. We also know (from the
|
|
// icmp folding check above), that the two constants are not
|
|
// equal.
|
|
assert(LHSCst != RHSCst && "Compares not folded above?");
|
|
|
|
switch (LHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ:
|
|
if (LHS->getOperand(0) == RHS->getOperand(0)) {
|
|
// if LHSCst and RHSCst differ only by one bit:
|
|
// (A == C1 || A == C2) -> (A & ~(C1 ^ C2)) == C1
|
|
assert(LHSCst->getValue().ule(LHSCst->getValue()));
|
|
|
|
APInt Xor = LHSCst->getValue() ^ RHSCst->getValue();
|
|
if (Xor.isPowerOf2()) {
|
|
Value *NegCst = Builder->getInt(~Xor);
|
|
Value *And = Builder->CreateAnd(LHS->getOperand(0), NegCst);
|
|
return Builder->CreateICmp(ICmpInst::ICMP_EQ, And, LHSCst);
|
|
}
|
|
}
|
|
|
|
if (LHSCst == SubOne(RHSCst)) {
|
|
// (X == 13 | X == 14) -> X-13 <u 2
|
|
Constant *AddCST = ConstantExpr::getNeg(LHSCst);
|
|
Value *Add = Builder->CreateAdd(Val, AddCST, Val->getName()+".off");
|
|
AddCST = ConstantExpr::getSub(AddOne(RHSCst), LHSCst);
|
|
return Builder->CreateICmpULT(Add, AddCST);
|
|
}
|
|
|
|
break; // (X == 13 | X == 15) -> no change
|
|
case ICmpInst::ICMP_UGT: // (X == 13 | X u> 14) -> no change
|
|
case ICmpInst::ICMP_SGT: // (X == 13 | X s> 14) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE: // (X == 13 | X != 15) -> X != 15
|
|
case ICmpInst::ICMP_ULT: // (X == 13 | X u< 15) -> X u< 15
|
|
case ICmpInst::ICMP_SLT: // (X == 13 | X s< 15) -> X s< 15
|
|
return RHS;
|
|
}
|
|
break;
|
|
case ICmpInst::ICMP_NE:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ: // (X != 13 | X == 15) -> X != 13
|
|
case ICmpInst::ICMP_UGT: // (X != 13 | X u> 15) -> X != 13
|
|
case ICmpInst::ICMP_SGT: // (X != 13 | X s> 15) -> X != 13
|
|
return LHS;
|
|
case ICmpInst::ICMP_NE: // (X != 13 | X != 15) -> true
|
|
case ICmpInst::ICMP_ULT: // (X != 13 | X u< 15) -> true
|
|
case ICmpInst::ICMP_SLT: // (X != 13 | X s< 15) -> true
|
|
return Builder->getTrue();
|
|
}
|
|
case ICmpInst::ICMP_ULT:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ: // (X u< 13 | X == 14) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_UGT: // (X u< 13 | X u> 15) -> (X-13) u> 2
|
|
// If RHSCst is [us]MAXINT, it is always false. Not handling
|
|
// this can cause overflow.
|
|
if (RHSCst->isMaxValue(false))
|
|
return LHS;
|
|
return InsertRangeTest(Val, LHSCst, AddOne(RHSCst), false, false);
|
|
case ICmpInst::ICMP_SGT: // (X u< 13 | X s> 15) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE: // (X u< 13 | X != 15) -> X != 15
|
|
case ICmpInst::ICMP_ULT: // (X u< 13 | X u< 15) -> X u< 15
|
|
return RHS;
|
|
case ICmpInst::ICMP_SLT: // (X u< 13 | X s< 15) -> no change
|
|
break;
|
|
}
|
|
break;
|
|
case ICmpInst::ICMP_SLT:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ: // (X s< 13 | X == 14) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_SGT: // (X s< 13 | X s> 15) -> (X-13) s> 2
|
|
// If RHSCst is [us]MAXINT, it is always false. Not handling
|
|
// this can cause overflow.
|
|
if (RHSCst->isMaxValue(true))
|
|
return LHS;
|
|
return InsertRangeTest(Val, LHSCst, AddOne(RHSCst), true, false);
|
|
case ICmpInst::ICMP_UGT: // (X s< 13 | X u> 15) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE: // (X s< 13 | X != 15) -> X != 15
|
|
case ICmpInst::ICMP_SLT: // (X s< 13 | X s< 15) -> X s< 15
|
|
return RHS;
|
|
case ICmpInst::ICMP_ULT: // (X s< 13 | X u< 15) -> no change
|
|
break;
|
|
}
|
|
break;
|
|
case ICmpInst::ICMP_UGT:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ: // (X u> 13 | X == 15) -> X u> 13
|
|
case ICmpInst::ICMP_UGT: // (X u> 13 | X u> 15) -> X u> 13
|
|
return LHS;
|
|
case ICmpInst::ICMP_SGT: // (X u> 13 | X s> 15) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE: // (X u> 13 | X != 15) -> true
|
|
case ICmpInst::ICMP_ULT: // (X u> 13 | X u< 15) -> true
|
|
return Builder->getTrue();
|
|
case ICmpInst::ICMP_SLT: // (X u> 13 | X s< 15) -> no change
|
|
break;
|
|
}
|
|
break;
|
|
case ICmpInst::ICMP_SGT:
|
|
switch (RHSCC) {
|
|
default: llvm_unreachable("Unknown integer condition code!");
|
|
case ICmpInst::ICMP_EQ: // (X s> 13 | X == 15) -> X > 13
|
|
case ICmpInst::ICMP_SGT: // (X s> 13 | X s> 15) -> X > 13
|
|
return LHS;
|
|
case ICmpInst::ICMP_UGT: // (X s> 13 | X u> 15) -> no change
|
|
break;
|
|
case ICmpInst::ICMP_NE: // (X s> 13 | X != 15) -> true
|
|
case ICmpInst::ICMP_SLT: // (X s> 13 | X s< 15) -> true
|
|
return Builder->getTrue();
|
|
case ICmpInst::ICMP_ULT: // (X s> 13 | X u< 15) -> no change
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
/// FoldOrOfFCmps - Optimize (fcmp)|(fcmp). NOTE: Unlike the rest of
|
|
/// instcombine, this returns a Value which should already be inserted into the
|
|
/// function.
|
|
Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
|
|
if (LHS->getPredicate() == FCmpInst::FCMP_UNO &&
|
|
RHS->getPredicate() == FCmpInst::FCMP_UNO &&
|
|
LHS->getOperand(0)->getType() == RHS->getOperand(0)->getType()) {
|
|
if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
|
|
if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
|
|
// If either of the constants are nans, then the whole thing returns
|
|
// true.
|
|
if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN())
|
|
return Builder->getTrue();
|
|
|
|
// Otherwise, no need to compare the two constants, compare the
|
|
// rest.
|
|
return Builder->CreateFCmpUNO(LHS->getOperand(0), RHS->getOperand(0));
|
|
}
|
|
|
|
// Handle vector zeros. This occurs because the canonical form of
|
|
// "fcmp uno x,x" is "fcmp uno x, 0".
|
|
if (isa<ConstantAggregateZero>(LHS->getOperand(1)) &&
|
|
isa<ConstantAggregateZero>(RHS->getOperand(1)))
|
|
return Builder->CreateFCmpUNO(LHS->getOperand(0), RHS->getOperand(0));
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
|
|
Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
|
|
FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
|
|
|
|
if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) {
|
|
// Swap RHS operands to match LHS.
|
|
Op1CC = FCmpInst::getSwappedPredicate(Op1CC);
|
|
std::swap(Op1LHS, Op1RHS);
|
|
}
|
|
if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) {
|
|
// Simplify (fcmp cc0 x, y) | (fcmp cc1 x, y).
|
|
if (Op0CC == Op1CC)
|
|
return Builder->CreateFCmp((FCmpInst::Predicate)Op0CC, Op0LHS, Op0RHS);
|
|
if (Op0CC == FCmpInst::FCMP_TRUE || Op1CC == FCmpInst::FCMP_TRUE)
|
|
return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1);
|
|
if (Op0CC == FCmpInst::FCMP_FALSE)
|
|
return RHS;
|
|
if (Op1CC == FCmpInst::FCMP_FALSE)
|
|
return LHS;
|
|
bool Op0Ordered;
|
|
bool Op1Ordered;
|
|
unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
|
|
unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
|
|
if (Op0Ordered == Op1Ordered) {
|
|
// If both are ordered or unordered, return a new fcmp with
|
|
// or'ed predicates.
|
|
return getFCmpValue(Op0Ordered, Op0Pred|Op1Pred, Op0LHS, Op0RHS, Builder);
|
|
}
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
/// FoldOrWithConstants - This helper function folds:
|
|
///
|
|
/// ((A | B) & C1) | (B & C2)
|
|
///
|
|
/// into:
|
|
///
|
|
/// (A & C1) | B
|
|
///
|
|
/// when the XOR of the two constants is "all ones" (-1).
|
|
Instruction *InstCombiner::FoldOrWithConstants(BinaryOperator &I, Value *Op,
|
|
Value *A, Value *B, Value *C) {
|
|
ConstantInt *CI1 = dyn_cast<ConstantInt>(C);
|
|
if (!CI1) return nullptr;
|
|
|
|
Value *V1 = nullptr;
|
|
ConstantInt *CI2 = nullptr;
|
|
if (!match(Op, m_And(m_Value(V1), m_ConstantInt(CI2)))) return nullptr;
|
|
|
|
APInt Xor = CI1->getValue() ^ CI2->getValue();
|
|
if (!Xor.isAllOnesValue()) return nullptr;
|
|
|
|
if (V1 == A || V1 == B) {
|
|
Value *NewOp = Builder->CreateAnd((V1 == A) ? B : A, CI1);
|
|
return BinaryOperator::CreateOr(NewOp, V1);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Instruction *InstCombiner::visitOr(BinaryOperator &I) {
|
|
bool Changed = SimplifyAssociativeOrCommutative(I);
|
|
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
|
|
|
|
if (Value *V = SimplifyOrInst(Op0, Op1, DL))
|
|
return ReplaceInstUsesWith(I, V);
|
|
|
|
// (A&B)|(A&C) -> A&(B|C) etc
|
|
if (Value *V = SimplifyUsingDistributiveLaws(I))
|
|
return ReplaceInstUsesWith(I, V);
|
|
|
|
// See if we can simplify any instructions used by the instruction whose sole
|
|
// purpose is to compute bits we don't care about.
|
|
if (SimplifyDemandedInstructionBits(I))
|
|
return &I;
|
|
|
|
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
|
|
ConstantInt *C1 = nullptr; Value *X = nullptr;
|
|
// (X & C1) | C2 --> (X | C2) & (C1|C2)
|
|
// iff (C1 & C2) == 0.
|
|
if (match(Op0, m_And(m_Value(X), m_ConstantInt(C1))) &&
|
|
(RHS->getValue() & C1->getValue()) != 0 &&
|
|
Op0->hasOneUse()) {
|
|
Value *Or = Builder->CreateOr(X, RHS);
|
|
Or->takeName(Op0);
|
|
return BinaryOperator::CreateAnd(Or,
|
|
Builder->getInt(RHS->getValue() | C1->getValue()));
|
|
}
|
|
|
|
// (X ^ C1) | C2 --> (X | C2) ^ (C1&~C2)
|
|
if (match(Op0, m_Xor(m_Value(X), m_ConstantInt(C1))) &&
|
|
Op0->hasOneUse()) {
|
|
Value *Or = Builder->CreateOr(X, RHS);
|
|
Or->takeName(Op0);
|
|
return BinaryOperator::CreateXor(Or,
|
|
Builder->getInt(C1->getValue() & ~RHS->getValue()));
|
|
}
|
|
|
|
// Try to fold constant and into select arguments.
|
|
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
|
|
if (Instruction *R = FoldOpIntoSelect(I, SI))
|
|
return R;
|
|
|
|
if (isa<PHINode>(Op0))
|
|
if (Instruction *NV = FoldOpIntoPhi(I))
|
|
return NV;
|
|
}
|
|
|
|
Value *A = nullptr, *B = nullptr;
|
|
ConstantInt *C1 = nullptr, *C2 = nullptr;
|
|
|
|
// (A | B) | C and A | (B | C) -> bswap if possible.
|
|
// (A >> B) | (C << D) and (A << B) | (B >> C) -> bswap if possible.
|
|
if (match(Op0, m_Or(m_Value(), m_Value())) ||
|
|
match(Op1, m_Or(m_Value(), m_Value())) ||
|
|
(match(Op0, m_LogicalShift(m_Value(), m_Value())) &&
|
|
match(Op1, m_LogicalShift(m_Value(), m_Value())))) {
|
|
if (Instruction *BSwap = MatchBSwap(I))
|
|
return BSwap;
|
|
}
|
|
|
|
// (X^C)|Y -> (X|Y)^C iff Y&C == 0
|
|
if (Op0->hasOneUse() &&
|
|
match(Op0, m_Xor(m_Value(A), m_ConstantInt(C1))) &&
|
|
MaskedValueIsZero(Op1, C1->getValue())) {
|
|
Value *NOr = Builder->CreateOr(A, Op1);
|
|
NOr->takeName(Op0);
|
|
return BinaryOperator::CreateXor(NOr, C1);
|
|
}
|
|
|
|
// Y|(X^C) -> (X|Y)^C iff Y&C == 0
|
|
if (Op1->hasOneUse() &&
|
|
match(Op1, m_Xor(m_Value(A), m_ConstantInt(C1))) &&
|
|
MaskedValueIsZero(Op0, C1->getValue())) {
|
|
Value *NOr = Builder->CreateOr(A, Op0);
|
|
NOr->takeName(Op0);
|
|
return BinaryOperator::CreateXor(NOr, C1);
|
|
}
|
|
|
|
// (A & C)|(B & D)
|
|
Value *C = nullptr, *D = nullptr;
|
|
if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
|
|
match(Op1, m_And(m_Value(B), m_Value(D)))) {
|
|
Value *V1 = nullptr, *V2 = nullptr;
|
|
C1 = dyn_cast<ConstantInt>(C);
|
|
C2 = dyn_cast<ConstantInt>(D);
|
|
if (C1 && C2) { // (A & C1)|(B & C2)
|
|
// If we have: ((V + N) & C1) | (V & C2)
|
|
// .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
|
|
// replace with V+N.
|
|
if (C1->getValue() == ~C2->getValue()) {
|
|
if ((C2->getValue() & (C2->getValue()+1)) == 0 && // C2 == 0+1+
|
|
match(A, m_Add(m_Value(V1), m_Value(V2)))) {
|
|
// Add commutes, try both ways.
|
|
if (V1 == B && MaskedValueIsZero(V2, C2->getValue()))
|
|
return ReplaceInstUsesWith(I, A);
|
|
if (V2 == B && MaskedValueIsZero(V1, C2->getValue()))
|
|
return ReplaceInstUsesWith(I, A);
|
|
}
|
|
// Or commutes, try both ways.
|
|
if ((C1->getValue() & (C1->getValue()+1)) == 0 &&
|
|
match(B, m_Add(m_Value(V1), m_Value(V2)))) {
|
|
// Add commutes, try both ways.
|
|
if (V1 == A && MaskedValueIsZero(V2, C1->getValue()))
|
|
return ReplaceInstUsesWith(I, B);
|
|
if (V2 == A && MaskedValueIsZero(V1, C1->getValue()))
|
|
return ReplaceInstUsesWith(I, B);
|
|
}
|
|
}
|
|
|
|
if ((C1->getValue() & C2->getValue()) == 0) {
|
|
// ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2)
|
|
// iff (C1&C2) == 0 and (N&~C1) == 0
|
|
if (match(A, m_Or(m_Value(V1), m_Value(V2))) &&
|
|
((V1 == B && MaskedValueIsZero(V2, ~C1->getValue())) || // (V|N)
|
|
(V2 == B && MaskedValueIsZero(V1, ~C1->getValue())))) // (N|V)
|
|
return BinaryOperator::CreateAnd(A,
|
|
Builder->getInt(C1->getValue()|C2->getValue()));
|
|
// Or commutes, try both ways.
|
|
if (match(B, m_Or(m_Value(V1), m_Value(V2))) &&
|
|
((V1 == A && MaskedValueIsZero(V2, ~C2->getValue())) || // (V|N)
|
|
(V2 == A && MaskedValueIsZero(V1, ~C2->getValue())))) // (N|V)
|
|
return BinaryOperator::CreateAnd(B,
|
|
Builder->getInt(C1->getValue()|C2->getValue()));
|
|
|
|
// ((V|C3)&C1) | ((V|C4)&C2) --> (V|C3|C4)&(C1|C2)
|
|
// iff (C1&C2) == 0 and (C3&~C1) == 0 and (C4&~C2) == 0.
|
|
ConstantInt *C3 = nullptr, *C4 = nullptr;
|
|
if (match(A, m_Or(m_Value(V1), m_ConstantInt(C3))) &&
|
|
(C3->getValue() & ~C1->getValue()) == 0 &&
|
|
match(B, m_Or(m_Specific(V1), m_ConstantInt(C4))) &&
|
|
(C4->getValue() & ~C2->getValue()) == 0) {
|
|
V2 = Builder->CreateOr(V1, ConstantExpr::getOr(C3, C4), "bitfield");
|
|
return BinaryOperator::CreateAnd(V2,
|
|
Builder->getInt(C1->getValue()|C2->getValue()));
|
|
}
|
|
}
|
|
}
|
|
|
|
// (A & (C0?-1:0)) | (B & ~(C0?-1:0)) -> C0 ? A : B, and commuted variants.
|
|
// Don't do this for vector select idioms, the code generator doesn't handle
|
|
// them well yet.
|
|
if (!I.getType()->isVectorTy()) {
|
|
if (Instruction *Match = MatchSelectFromAndOr(A, B, C, D))
|
|
return Match;
|
|
if (Instruction *Match = MatchSelectFromAndOr(B, A, D, C))
|
|
return Match;
|
|
if (Instruction *Match = MatchSelectFromAndOr(C, B, A, D))
|
|
return Match;
|
|
if (Instruction *Match = MatchSelectFromAndOr(D, A, B, C))
|
|
return Match;
|
|
}
|
|
|
|
// ((A&~B)|(~A&B)) -> A^B
|
|
if ((match(C, m_Not(m_Specific(D))) &&
|
|
match(B, m_Not(m_Specific(A)))))
|
|
return BinaryOperator::CreateXor(A, D);
|
|
// ((~B&A)|(~A&B)) -> A^B
|
|
if ((match(A, m_Not(m_Specific(D))) &&
|
|
match(B, m_Not(m_Specific(C)))))
|
|
return BinaryOperator::CreateXor(C, D);
|
|
// ((A&~B)|(B&~A)) -> A^B
|
|
if ((match(C, m_Not(m_Specific(B))) &&
|
|
match(D, m_Not(m_Specific(A)))))
|
|
return BinaryOperator::CreateXor(A, B);
|
|
// ((~B&A)|(B&~A)) -> A^B
|
|
if ((match(A, m_Not(m_Specific(B))) &&
|
|
match(D, m_Not(m_Specific(C)))))
|
|
return BinaryOperator::CreateXor(C, B);
|
|
|
|
// ((A|B)&1)|(B&-2) -> (A&1) | B
|
|
if (match(A, m_Or(m_Value(V1), m_Specific(B))) ||
|
|
match(A, m_Or(m_Specific(B), m_Value(V1)))) {
|
|
Instruction *Ret = FoldOrWithConstants(I, Op1, V1, B, C);
|
|
if (Ret) return Ret;
|
|
}
|
|
// (B&-2)|((A|B)&1) -> (A&1) | B
|
|
if (match(B, m_Or(m_Specific(A), m_Value(V1))) ||
|
|
match(B, m_Or(m_Value(V1), m_Specific(A)))) {
|
|
Instruction *Ret = FoldOrWithConstants(I, Op0, A, V1, D);
|
|
if (Ret) return Ret;
|
|
}
|
|
}
|
|
|
|
// (X >> Z) | (Y >> Z) -> (X|Y) >> Z for all shifts.
|
|
if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
|
|
if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
|
|
if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() &&
|
|
SI0->getOperand(1) == SI1->getOperand(1) &&
|
|
(SI0->hasOneUse() || SI1->hasOneUse())) {
|
|
Value *NewOp = Builder->CreateOr(SI0->getOperand(0), SI1->getOperand(0),
|
|
SI0->getName());
|
|
return BinaryOperator::Create(SI1->getOpcode(), NewOp,
|
|
SI1->getOperand(1));
|
|
}
|
|
}
|
|
|
|
// (~A | ~B) == (~(A & B)) - De Morgan's Law
|
|
if (Value *Op0NotVal = dyn_castNotVal(Op0))
|
|
if (Value *Op1NotVal = dyn_castNotVal(Op1))
|
|
if (Op0->hasOneUse() && Op1->hasOneUse()) {
|
|
Value *And = Builder->CreateAnd(Op0NotVal, Op1NotVal,
|
|
I.getName()+".demorgan");
|
|
return BinaryOperator::CreateNot(And);
|
|
}
|
|
|
|
// Canonicalize xor to the RHS.
|
|
bool SwappedForXor = false;
|
|
if (match(Op0, m_Xor(m_Value(), m_Value()))) {
|
|
std::swap(Op0, Op1);
|
|
SwappedForXor = true;
|
|
}
|
|
|
|
// A | ( A ^ B) -> A | B
|
|
// A | (~A ^ B) -> A | ~B
|
|
// (A & B) | (A ^ B)
|
|
if (match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
|
|
if (Op0 == A || Op0 == B)
|
|
return BinaryOperator::CreateOr(A, B);
|
|
|
|
if (match(Op0, m_And(m_Specific(A), m_Specific(B))) ||
|
|
match(Op0, m_And(m_Specific(B), m_Specific(A))))
|
|
return BinaryOperator::CreateOr(A, B);
|
|
|
|
if (Op1->hasOneUse() && match(A, m_Not(m_Specific(Op0)))) {
|
|
Value *Not = Builder->CreateNot(B, B->getName()+".not");
|
|
return BinaryOperator::CreateOr(Not, Op0);
|
|
}
|
|
if (Op1->hasOneUse() && match(B, m_Not(m_Specific(Op0)))) {
|
|
Value *Not = Builder->CreateNot(A, A->getName()+".not");
|
|
return BinaryOperator::CreateOr(Not, Op0);
|
|
}
|
|
}
|
|
|
|
// A | ~(A | B) -> A | ~B
|
|
// A | ~(A ^ B) -> A | ~B
|
|
if (match(Op1, m_Not(m_Value(A))))
|
|
if (BinaryOperator *B = dyn_cast<BinaryOperator>(A))
|
|
if ((Op0 == B->getOperand(0) || Op0 == B->getOperand(1)) &&
|
|
Op1->hasOneUse() && (B->getOpcode() == Instruction::Or ||
|
|
B->getOpcode() == Instruction::Xor)) {
|
|
Value *NotOp = Op0 == B->getOperand(0) ? B->getOperand(1) :
|
|
B->getOperand(0);
|
|
Value *Not = Builder->CreateNot(NotOp, NotOp->getName()+".not");
|
|
return BinaryOperator::CreateOr(Not, Op0);
|
|
}
|
|
|
|
if (SwappedForXor)
|
|
std::swap(Op0, Op1);
|
|
|
|
if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
|
|
if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
|
|
if (Value *Res = FoldOrOfICmps(LHS, RHS))
|
|
return ReplaceInstUsesWith(I, Res);
|
|
|
|
// (fcmp uno x, c) | (fcmp uno y, c) -> (fcmp uno x, y)
|
|
if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
|
|
if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
|
|
if (Value *Res = FoldOrOfFCmps(LHS, RHS))
|
|
return ReplaceInstUsesWith(I, Res);
|
|
|
|
// fold (or (cast A), (cast B)) -> (cast (or A, B))
|
|
if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
|
|
CastInst *Op1C = dyn_cast<CastInst>(Op1);
|
|
if (Op1C && Op0C->getOpcode() == Op1C->getOpcode()) {// same cast kind ?
|
|
Type *SrcTy = Op0C->getOperand(0)->getType();
|
|
if (SrcTy == Op1C->getOperand(0)->getType() &&
|
|
SrcTy->isIntOrIntVectorTy()) {
|
|
Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0);
|
|
|
|
if ((!isa<ICmpInst>(Op0COp) || !isa<ICmpInst>(Op1COp)) &&
|
|
// Only do this if the casts both really cause code to be
|
|
// generated.
|
|
ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
|
|
ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
|
|
Value *NewOp = Builder->CreateOr(Op0COp, Op1COp, I.getName());
|
|
return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
|
|
}
|
|
|
|
// If this is or(cast(icmp), cast(icmp)), try to fold this even if the
|
|
// cast is otherwise not optimizable. This happens for vector sexts.
|
|
if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
|
|
if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
|
|
if (Value *Res = FoldOrOfICmps(LHS, RHS))
|
|
return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
|
|
|
|
// If this is or(cast(fcmp), cast(fcmp)), try to fold this even if the
|
|
// cast is otherwise not optimizable. This happens for vector sexts.
|
|
if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
|
|
if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
|
|
if (Value *Res = FoldOrOfFCmps(LHS, RHS))
|
|
return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
|
|
}
|
|
}
|
|
}
|
|
|
|
// or(sext(A), B) -> A ? -1 : B where A is an i1
|
|
// or(A, sext(B)) -> B ? -1 : A where B is an i1
|
|
if (match(Op0, m_SExt(m_Value(A))) && A->getType()->isIntegerTy(1))
|
|
return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op1);
|
|
if (match(Op1, m_SExt(m_Value(A))) && A->getType()->isIntegerTy(1))
|
|
return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op0);
|
|
|
|
// Note: If we've gotten to the point of visiting the outer OR, then the
|
|
// inner one couldn't be simplified. If it was a constant, then it won't
|
|
// be simplified by a later pass either, so we try swapping the inner/outer
|
|
// ORs in the hopes that we'll be able to simplify it this way.
|
|
// (X|C) | V --> (X|V) | C
|
|
if (Op0->hasOneUse() && !isa<ConstantInt>(Op1) &&
|
|
match(Op0, m_Or(m_Value(A), m_ConstantInt(C1)))) {
|
|
Value *Inner = Builder->CreateOr(A, Op1);
|
|
Inner->takeName(Op0);
|
|
return BinaryOperator::CreateOr(Inner, C1);
|
|
}
|
|
|
|
// Change (or (bool?A:B),(bool?C:D)) --> (bool?(or A,C):(or B,D))
|
|
// Since this OR statement hasn't been optimized further yet, we hope
|
|
// that this transformation will allow the new ORs to be optimized.
|
|
{
|
|
Value *X = nullptr, *Y = nullptr;
|
|
if (Op0->hasOneUse() && Op1->hasOneUse() &&
|
|
match(Op0, m_Select(m_Value(X), m_Value(A), m_Value(B))) &&
|
|
match(Op1, m_Select(m_Value(Y), m_Value(C), m_Value(D))) && X == Y) {
|
|
Value *orTrue = Builder->CreateOr(A, C);
|
|
Value *orFalse = Builder->CreateOr(B, D);
|
|
return SelectInst::Create(X, orTrue, orFalse);
|
|
}
|
|
}
|
|
|
|
return Changed ? &I : nullptr;
|
|
}
|
|
|
|
Instruction *InstCombiner::visitXor(BinaryOperator &I) {
|
|
bool Changed = SimplifyAssociativeOrCommutative(I);
|
|
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
|
|
|
|
if (Value *V = SimplifyXorInst(Op0, Op1, DL))
|
|
return ReplaceInstUsesWith(I, V);
|
|
|
|
// (A&B)^(A&C) -> A&(B^C) etc
|
|
if (Value *V = SimplifyUsingDistributiveLaws(I))
|
|
return ReplaceInstUsesWith(I, V);
|
|
|
|
// See if we can simplify any instructions used by the instruction whose sole
|
|
// purpose is to compute bits we don't care about.
|
|
if (SimplifyDemandedInstructionBits(I))
|
|
return &I;
|
|
|
|
// Is this a ~ operation?
|
|
if (Value *NotOp = dyn_castNotVal(&I)) {
|
|
if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(NotOp)) {
|
|
if (Op0I->getOpcode() == Instruction::And ||
|
|
Op0I->getOpcode() == Instruction::Or) {
|
|
// ~(~X & Y) --> (X | ~Y) - De Morgan's Law
|
|
// ~(~X | Y) === (X & ~Y) - De Morgan's Law
|
|
if (dyn_castNotVal(Op0I->getOperand(1)))
|
|
Op0I->swapOperands();
|
|
if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0))) {
|
|
Value *NotY =
|
|
Builder->CreateNot(Op0I->getOperand(1),
|
|
Op0I->getOperand(1)->getName()+".not");
|
|
if (Op0I->getOpcode() == Instruction::And)
|
|
return BinaryOperator::CreateOr(Op0NotVal, NotY);
|
|
return BinaryOperator::CreateAnd(Op0NotVal, NotY);
|
|
}
|
|
|
|
// ~(X & Y) --> (~X | ~Y) - De Morgan's Law
|
|
// ~(X | Y) === (~X & ~Y) - De Morgan's Law
|
|
if (isFreeToInvert(Op0I->getOperand(0)) &&
|
|
isFreeToInvert(Op0I->getOperand(1))) {
|
|
Value *NotX =
|
|
Builder->CreateNot(Op0I->getOperand(0), "notlhs");
|
|
Value *NotY =
|
|
Builder->CreateNot(Op0I->getOperand(1), "notrhs");
|
|
if (Op0I->getOpcode() == Instruction::And)
|
|
return BinaryOperator::CreateOr(NotX, NotY);
|
|
return BinaryOperator::CreateAnd(NotX, NotY);
|
|
}
|
|
|
|
} else if (Op0I->getOpcode() == Instruction::AShr) {
|
|
// ~(~X >>s Y) --> (X >>s Y)
|
|
if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0)))
|
|
return BinaryOperator::CreateAShr(Op0NotVal, Op0I->getOperand(1));
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
|
|
if (RHS->isOne() && Op0->hasOneUse())
|
|
// xor (cmp A, B), true = not (cmp A, B) = !cmp A, B
|
|
if (CmpInst *CI = dyn_cast<CmpInst>(Op0))
|
|
return CmpInst::Create(CI->getOpcode(),
|
|
CI->getInversePredicate(),
|
|
CI->getOperand(0), CI->getOperand(1));
|
|
|
|
// fold (xor(zext(cmp)), 1) and (xor(sext(cmp)), -1) to ext(!cmp).
|
|
if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
|
|
if (CmpInst *CI = dyn_cast<CmpInst>(Op0C->getOperand(0))) {
|
|
if (CI->hasOneUse() && Op0C->hasOneUse()) {
|
|
Instruction::CastOps Opcode = Op0C->getOpcode();
|
|
if ((Opcode == Instruction::ZExt || Opcode == Instruction::SExt) &&
|
|
(RHS == ConstantExpr::getCast(Opcode, Builder->getTrue(),
|
|
Op0C->getDestTy()))) {
|
|
CI->setPredicate(CI->getInversePredicate());
|
|
return CastInst::Create(Opcode, CI, Op0C->getType());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
|
|
// ~(c-X) == X-c-1 == X+(-c-1)
|
|
if (Op0I->getOpcode() == Instruction::Sub && RHS->isAllOnesValue())
|
|
if (Constant *Op0I0C = dyn_cast<Constant>(Op0I->getOperand(0))) {
|
|
Constant *NegOp0I0C = ConstantExpr::getNeg(Op0I0C);
|
|
Constant *ConstantRHS = ConstantExpr::getSub(NegOp0I0C,
|
|
ConstantInt::get(I.getType(), 1));
|
|
return BinaryOperator::CreateAdd(Op0I->getOperand(1), ConstantRHS);
|
|
}
|
|
|
|
if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
|
|
if (Op0I->getOpcode() == Instruction::Add) {
|
|
// ~(X-c) --> (-c-1)-X
|
|
if (RHS->isAllOnesValue()) {
|
|
Constant *NegOp0CI = ConstantExpr::getNeg(Op0CI);
|
|
return BinaryOperator::CreateSub(
|
|
ConstantExpr::getSub(NegOp0CI,
|
|
ConstantInt::get(I.getType(), 1)),
|
|
Op0I->getOperand(0));
|
|
} else if (RHS->getValue().isSignBit()) {
|
|
// (X + C) ^ signbit -> (X + C + signbit)
|
|
Constant *C = Builder->getInt(RHS->getValue() + Op0CI->getValue());
|
|
return BinaryOperator::CreateAdd(Op0I->getOperand(0), C);
|
|
|
|
}
|
|
} else if (Op0I->getOpcode() == Instruction::Or) {
|
|
// (X|C1)^C2 -> X^(C1|C2) iff X&~C1 == 0
|
|
if (MaskedValueIsZero(Op0I->getOperand(0), Op0CI->getValue())) {
|
|
Constant *NewRHS = ConstantExpr::getOr(Op0CI, RHS);
|
|
// Anything in both C1 and C2 is known to be zero, remove it from
|
|
// NewRHS.
|
|
Constant *CommonBits = ConstantExpr::getAnd(Op0CI, RHS);
|
|
NewRHS = ConstantExpr::getAnd(NewRHS,
|
|
ConstantExpr::getNot(CommonBits));
|
|
Worklist.Add(Op0I);
|
|
I.setOperand(0, Op0I->getOperand(0));
|
|
I.setOperand(1, NewRHS);
|
|
return &I;
|
|
}
|
|
} else if (Op0I->getOpcode() == Instruction::LShr) {
|
|
// ((X^C1) >> C2) ^ C3 -> (X>>C2) ^ ((C1>>C2)^C3)
|
|
// E1 = "X ^ C1"
|
|
BinaryOperator *E1;
|
|
ConstantInt *C1;
|
|
if (Op0I->hasOneUse() &&
|
|
(E1 = dyn_cast<BinaryOperator>(Op0I->getOperand(0))) &&
|
|
E1->getOpcode() == Instruction::Xor &&
|
|
(C1 = dyn_cast<ConstantInt>(E1->getOperand(1)))) {
|
|
// fold (C1 >> C2) ^ C3
|
|
ConstantInt *C2 = Op0CI, *C3 = RHS;
|
|
APInt FoldConst = C1->getValue().lshr(C2->getValue());
|
|
FoldConst ^= C3->getValue();
|
|
// Prepare the two operands.
|
|
Value *Opnd0 = Builder->CreateLShr(E1->getOperand(0), C2);
|
|
Opnd0->takeName(Op0I);
|
|
cast<Instruction>(Opnd0)->setDebugLoc(I.getDebugLoc());
|
|
Value *FoldVal = ConstantInt::get(Opnd0->getType(), FoldConst);
|
|
|
|
return BinaryOperator::CreateXor(Opnd0, FoldVal);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Try to fold constant and into select arguments.
|
|
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
|
|
if (Instruction *R = FoldOpIntoSelect(I, SI))
|
|
return R;
|
|
if (isa<PHINode>(Op0))
|
|
if (Instruction *NV = FoldOpIntoPhi(I))
|
|
return NV;
|
|
}
|
|
|
|
BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1);
|
|
if (Op1I) {
|
|
Value *A, *B;
|
|
if (match(Op1I, m_Or(m_Value(A), m_Value(B)))) {
|
|
if (A == Op0) { // B^(B|A) == (A|B)^B
|
|
Op1I->swapOperands();
|
|
I.swapOperands();
|
|
std::swap(Op0, Op1);
|
|
} else if (B == Op0) { // B^(A|B) == (A|B)^B
|
|
I.swapOperands(); // Simplified below.
|
|
std::swap(Op0, Op1);
|
|
}
|
|
} else if (match(Op1I, m_And(m_Value(A), m_Value(B))) &&
|
|
Op1I->hasOneUse()){
|
|
if (A == Op0) { // A^(A&B) -> A^(B&A)
|
|
Op1I->swapOperands();
|
|
std::swap(A, B);
|
|
}
|
|
if (B == Op0) { // A^(B&A) -> (B&A)^A
|
|
I.swapOperands(); // Simplified below.
|
|
std::swap(Op0, Op1);
|
|
}
|
|
}
|
|
}
|
|
|
|
BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0);
|
|
if (Op0I) {
|
|
Value *A, *B;
|
|
if (match(Op0I, m_Or(m_Value(A), m_Value(B))) &&
|
|
Op0I->hasOneUse()) {
|
|
if (A == Op1) // (B|A)^B == (A|B)^B
|
|
std::swap(A, B);
|
|
if (B == Op1) // (A|B)^B == A & ~B
|
|
return BinaryOperator::CreateAnd(A, Builder->CreateNot(Op1));
|
|
} else if (match(Op0I, m_And(m_Value(A), m_Value(B))) &&
|
|
Op0I->hasOneUse()){
|
|
if (A == Op1) // (A&B)^A -> (B&A)^A
|
|
std::swap(A, B);
|
|
if (B == Op1 && // (B&A)^A == ~B & A
|
|
!isa<ConstantInt>(Op1)) { // Canonical form is (B&C)^C
|
|
return BinaryOperator::CreateAnd(Builder->CreateNot(A), Op1);
|
|
}
|
|
}
|
|
}
|
|
|
|
// (X >> Z) ^ (Y >> Z) -> (X^Y) >> Z for all shifts.
|
|
if (Op0I && Op1I && Op0I->isShift() &&
|
|
Op0I->getOpcode() == Op1I->getOpcode() &&
|
|
Op0I->getOperand(1) == Op1I->getOperand(1) &&
|
|
(Op0I->hasOneUse() || Op1I->hasOneUse())) {
|
|
Value *NewOp =
|
|
Builder->CreateXor(Op0I->getOperand(0), Op1I->getOperand(0),
|
|
Op0I->getName());
|
|
return BinaryOperator::Create(Op1I->getOpcode(), NewOp,
|
|
Op1I->getOperand(1));
|
|
}
|
|
|
|
if (Op0I && Op1I) {
|
|
Value *A, *B, *C, *D;
|
|
// (A & B)^(A | B) -> A ^ B
|
|
if (match(Op0I, m_And(m_Value(A), m_Value(B))) &&
|
|
match(Op1I, m_Or(m_Value(C), m_Value(D)))) {
|
|
if ((A == C && B == D) || (A == D && B == C))
|
|
return BinaryOperator::CreateXor(A, B);
|
|
}
|
|
// (A | B)^(A & B) -> A ^ B
|
|
if (match(Op0I, m_Or(m_Value(A), m_Value(B))) &&
|
|
match(Op1I, m_And(m_Value(C), m_Value(D)))) {
|
|
if ((A == C && B == D) || (A == D && B == C))
|
|
return BinaryOperator::CreateXor(A, B);
|
|
}
|
|
}
|
|
|
|
// (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)
|
|
if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
|
|
if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
|
|
if (PredicatesFoldable(LHS->getPredicate(), RHS->getPredicate())) {
|
|
if (LHS->getOperand(0) == RHS->getOperand(1) &&
|
|
LHS->getOperand(1) == RHS->getOperand(0))
|
|
LHS->swapOperands();
|
|
if (LHS->getOperand(0) == RHS->getOperand(0) &&
|
|
LHS->getOperand(1) == RHS->getOperand(1)) {
|
|
Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
|
|
unsigned Code = getICmpCode(LHS) ^ getICmpCode(RHS);
|
|
bool isSigned = LHS->isSigned() || RHS->isSigned();
|
|
return ReplaceInstUsesWith(I,
|
|
getNewICmpValue(isSigned, Code, Op0, Op1,
|
|
Builder));
|
|
}
|
|
}
|
|
|
|
// fold (xor (cast A), (cast B)) -> (cast (xor A, B))
|
|
if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
|
|
if (CastInst *Op1C = dyn_cast<CastInst>(Op1))
|
|
if (Op0C->getOpcode() == Op1C->getOpcode()) { // same cast kind?
|
|
Type *SrcTy = Op0C->getOperand(0)->getType();
|
|
if (SrcTy == Op1C->getOperand(0)->getType() && SrcTy->isIntegerTy() &&
|
|
// Only do this if the casts both really cause code to be generated.
|
|
ShouldOptimizeCast(Op0C->getOpcode(), Op0C->getOperand(0),
|
|
I.getType()) &&
|
|
ShouldOptimizeCast(Op1C->getOpcode(), Op1C->getOperand(0),
|
|
I.getType())) {
|
|
Value *NewOp = Builder->CreateXor(Op0C->getOperand(0),
|
|
Op1C->getOperand(0), I.getName());
|
|
return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
|
|
}
|
|
}
|
|
}
|
|
|
|
return Changed ? &I : nullptr;
|
|
}
|