================ @@ -0,0 +1,74 @@ +//===- DomConditionCache.cpp ----------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "llvm/Analysis/DomConditionCache.h" +#include "llvm/IR/PatternMatch.h" + +using namespace llvm; +using namespace llvm::PatternMatch; + +// TODO: This code is very similar to findAffectedValues() in +// AssumptionCache, but currently specialized to just the patterns that +// computeKnownBits() supports, and without the notion of result elem indices +// that are AC specific. Deduplicate this code once we have a clearer picture +// of how much they can be shared. +static void findAffectedValues(Value *Cond, + SmallVectorImpl<Value *> &Affected) { + auto AddAffected = [&Affected](Value *V) { + if (isa<Argument>(V) || isa<GlobalValue>(V)) { + Affected.push_back(V); + } else if (auto *I = dyn_cast<Instruction>(V)) { + Affected.push_back(I); + + // Peek through unary operators to find the source of the condition. + Value *Op; + if (match(I, m_PtrToInt(m_Value(Op)))) { + if (isa<Instruction>(Op) || isa<Argument>(Op)) + Affected.push_back(Op); + } + } + }; + + ICmpInst::Predicate Pred; + Value *A; + Constant *C; + if (match(Cond, m_ICmp(Pred, m_Value(A), m_Constant(C)))) { + AddAffected(A); + + if (Pred == ICmpInst::ICMP_EQ) { + Value *X; + // (X & C) or (X | C) or (X ^ C). + // (X << C) or (X >>_s C) or (X >>_u C). + if (match(A, m_BitwiseLogic(m_Value(X), m_ConstantInt())) || + match(A, m_Shift(m_Value(X), m_ConstantInt()))) + AddAffected(X); + } else if (Pred == ICmpInst::ICMP_NE) { + Value *X; + // Handle (X & pow2 != 0). + if (match(A, m_And(m_Value(X), m_Power2())) && match(C, m_Zero())) + AddAffected(X); + } else if (Pred == ICmpInst::ICMP_ULT) { ---------------- nikic wrote:
Done! I've also relaxed the condition for EQ/NE to isEquality, as we may invert the predicate. Due to canonicalization this makes essentially no difference in practice though (maybe something in multi-use scenarios). https://github.com/llvm/llvm-project/pull/73662 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
