[HashRecognize] Introduce new analysis (#139120)
Introduce a fresh analysis for recognizing polynomial hashes, with the rationale that several targets have specific instructions to optimize things like CRC and GHASH (eg. X86 and RISC-V crypto extension). We limit the scope to polynomial hashes computed in a Galois field of characteristic 2, since this class of operations can also be optimized in the absence of target-specific instructions to use a lookup table. At the moment, we only recognize the CRC algorithm. RFC: https://discourse.llvm.org/t/rfc-new-analysis-for-polynomial-hash-recognition/86268
This commit is contained in:
Ramkumar Ramachandra
GitHub
parent
f2582c95fe
commit
af2f8a8c14
110
llvm/include/llvm/Analysis/HashRecognize.h
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110
llvm/include/llvm/Analysis/HashRecognize.h
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@ -0,0 +1,110 @@
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//===- HashRecognize.h ------------------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// Interface for the HashRecognize analysis, which identifies hash functions
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// that can be optimized using a lookup-table or with target-specific
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// instructions.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ANALYSIS_HASHRECOGNIZE_H
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#define LLVM_ANALYSIS_HASHRECOGNIZE_H
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#include "llvm/ADT/APInt.h"
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#include "llvm/Analysis/LoopAnalysisManager.h"
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#include "llvm/Analysis/ScalarEvolution.h"
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#include "llvm/IR/PassManager.h"
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#include "llvm/IR/Value.h"
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#include "llvm/Support/KnownBits.h"
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#include "llvm/Transforms/Scalar/LoopPassManager.h"
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namespace llvm {
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/// A tuple of bits that are expected to be zero, number N of them expected to
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/// be zero, with a boolean indicating whether it's the top or bottom N bits
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/// expected to be zero.
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using ErrBits = std::tuple<KnownBits, unsigned, bool>;
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/// A custom std::array with 256 entries, that also has a print function.
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struct CRCTable : public std::array<APInt, 256> {
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void print(raw_ostream &OS) const;
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};
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/// The structure that is returned when a polynomial algorithm was recognized by
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/// the analysis. Currently, only the CRC algorithm is recognized.
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struct PolynomialInfo {
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// The small constant trip-count of the analyzed loop.
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unsigned TripCount;
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// The LHS in a polynomial operation, or the initial variable of the
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// computation, since all polynomial operations must have a constant RHS,
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// which is the generating polynomial. It is the LHS of the polynomial
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// division in the case of CRC. Since polynomial division is an XOR in
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// GF(2^m), this variable must be XOR'ed with RHS in a loop to yield the
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// ComputedValue.
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const Value *LHS;
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// The generating polynomial, or the RHS of the polynomial division in the
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// case of CRC.
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APInt RHS;
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// The final computed value. This is a remainder of a polynomial division in
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// the case of CRC, which must be zero.
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const Value *ComputedValue;
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// Set to true in the case of big-endian.
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bool ByteOrderSwapped;
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// An optional auxiliary checksum that augments the LHS. In the case of CRC,
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// it is XOR'ed with the LHS, so that the computation's final remainder is
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// zero.
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const Value *LHSAux;
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PolynomialInfo(unsigned TripCount, const Value *LHS, const APInt &RHS,
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const Value *ComputedValue, bool ByteOrderSwapped,
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const Value *LHSAux = nullptr);
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};
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/// The analysis.
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class HashRecognize {
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const Loop &L;
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ScalarEvolution &SE;
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public:
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HashRecognize(const Loop &L, ScalarEvolution &SE);
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// The main analysis entry point.
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std::variant<PolynomialInfo, ErrBits, StringRef> recognizeCRC() const;
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// Auxilary entry point after analysis to interleave the generating polynomial
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// and return a 256-entry CRC table.
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CRCTable genSarwateTable(const APInt &GenPoly, bool ByteOrderSwapped) const;
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void print(raw_ostream &OS) const;
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};
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class HashRecognizePrinterPass
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: public PassInfoMixin<HashRecognizePrinterPass> {
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raw_ostream &OS;
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public:
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explicit HashRecognizePrinterPass(raw_ostream &OS) : OS(OS) {}
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PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
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LoopStandardAnalysisResults &AR, LPMUpdater &);
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};
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class HashRecognizeAnalysis : public AnalysisInfoMixin<HashRecognizeAnalysis> {
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friend AnalysisInfoMixin<HashRecognizeAnalysis>;
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static AnalysisKey Key;
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public:
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using Result = HashRecognize;
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Result run(Loop &L, LoopAnalysisManager &AM, LoopStandardAnalysisResults &AR);
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};
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} // namespace llvm
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#endif
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@ -78,6 +78,7 @@ add_llvm_component_library(LLVMAnalysis
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FunctionPropertiesAnalysis.cpp
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GlobalsModRef.cpp
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GuardUtils.cpp
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HashRecognize.cpp
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HeatUtils.cpp
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IR2Vec.cpp
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IRSimilarityIdentifier.cpp
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690
llvm/lib/Analysis/HashRecognize.cpp
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llvm/lib/Analysis/HashRecognize.cpp
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//===- HashRecognize.h ------------------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// The HashRecognize analysis recognizes unoptimized polynomial hash functions
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// with operations over a Galois field of characteristic 2, also called binary
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// fields, or GF(2^n): this class of hash functions can be optimized using a
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// lookup-table-driven implementation, or with target-specific instructions.
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// Examples:
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//
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// 1. Cyclic redundancy check (CRC), which is a polynomial division in GF(2).
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// 2. Rabin fingerprint, a component of the Rabin-Karp algorithm, which is a
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// rolling hash polynomial division in GF(2).
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// 3. Rijndael MixColumns, a step in AES computation, which is a polynomial
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// multiplication in GF(2^3).
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// 4. GHASH, the authentication mechanism in AES Galois/Counter Mode (GCM),
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// which is a polynomial evaluation in GF(2^128).
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//
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// All of them use an irreducible generating polynomial of degree m,
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//
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// c_m * x^m + c_(m-1) * x^(m-1) + ... + c_0 * x^0
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//
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// where each coefficient c is can take values in GF(2^n), where 2^n is termed
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// the order of the Galois field. For GF(2), each coefficient can take values
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// either 0 or 1, and the polynomial is simply represented by m+1 bits,
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// corresponding to the coefficients. The different variants of CRC are named by
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// degree of generating polynomial used: so CRC-32 would use a polynomial of
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// degree 32.
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//
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// The reason algorithms on GF(2^n) can be optimized with a lookup-table is the
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// following: in such fields, polynomial addition and subtraction are identical
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// and equivalent to XOR, polynomial multiplication is an AND, and polynomial
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// division is identity: the XOR and AND operations in unoptimized
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// implementations are performed bit-wise, and can be optimized to be performed
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// chunk-wise, by interleaving copies of the generating polynomial, and storing
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// the pre-computed values in a table.
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//
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// A generating polynomial of m bits always has the MSB set, so we usually
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// omit it. An example of a 16-bit polynomial is the CRC-16-CCITT polynomial:
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//
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// (x^16) + x^12 + x^5 + 1 = (1) 0001 0000 0010 0001 = 0x1021
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//
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// Transmissions are either in big-endian or little-endian form, and hash
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// algorithms are written according to this. For example, IEEE 802 and RS-232
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// specify little-endian transmission.
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//
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//===----------------------------------------------------------------------===//
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//
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// At the moment, we only recognize the CRC algorithm.
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// Documentation on CRC32 from the kernel:
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// https://www.kernel.org/doc/Documentation/crc32.txt
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//
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/HashRecognize.h"
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#include "llvm/ADT/APInt.h"
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#include "llvm/Analysis/LoopAnalysisManager.h"
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#include "llvm/Analysis/LoopInfo.h"
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#include "llvm/Analysis/ScalarEvolution.h"
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#include "llvm/Analysis/ScalarEvolutionPatternMatch.h"
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#include "llvm/Analysis/ValueTracking.h"
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#include "llvm/IR/PatternMatch.h"
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#include "llvm/Support/KnownBits.h"
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using namespace llvm;
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using namespace PatternMatch;
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using namespace SCEVPatternMatch;
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#define DEBUG_TYPE "hash-recognize"
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// KnownBits for a PHI node. There are at most two PHI nodes, corresponding to
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// the Simple Recurrence and Conditional Recurrence. The IndVar PHI is not
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// relevant.
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using KnownPhiMap = SmallDenseMap<const PHINode *, KnownBits, 2>;
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// A pair of a PHI node along with its incoming value from within a loop.
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using PhiStepPair = std::pair<const PHINode *, const Instruction *>;
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/// A much simpler version of ValueTracking, in that it computes KnownBits of
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/// values, except that it computes the evolution of KnownBits in a loop with a
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/// given trip count, and predication is specialized for a significant-bit
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/// check.
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class ValueEvolution {
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const unsigned TripCount;
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const bool ByteOrderSwapped;
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APInt GenPoly;
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StringRef ErrStr;
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// Compute the KnownBits of a BinaryOperator.
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KnownBits computeBinOp(const BinaryOperator *I);
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// Compute the KnownBits of an Instruction.
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KnownBits computeInstr(const Instruction *I);
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// Compute the KnownBits of a Value.
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KnownBits compute(const Value *V);
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public:
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// ValueEvolution is meant to be constructed with the TripCount of the loop,
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// and whether the polynomial algorithm is big-endian, for the significant-bit
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// check.
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ValueEvolution(unsigned TripCount, bool ByteOrderSwapped);
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// Given a list of PHI nodes along with their incoming value from within the
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// loop, computeEvolutions computes the KnownBits of each of the PHI nodes on
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// the final iteration. Returns true on success and false on error.
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bool computeEvolutions(ArrayRef<PhiStepPair> PhiEvolutions);
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// In case ValueEvolution encounters an error, this is meant to be used for a
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// precise error message.
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StringRef getError() const { return ErrStr; }
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// The computed KnownBits for each PHI node, which is populated after
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// computeEvolutions is called.
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KnownPhiMap KnownPhis;
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};
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ValueEvolution::ValueEvolution(unsigned TripCount, bool ByteOrderSwapped)
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: TripCount(TripCount), ByteOrderSwapped(ByteOrderSwapped) {}
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KnownBits ValueEvolution::computeBinOp(const BinaryOperator *I) {
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KnownBits KnownL(compute(I->getOperand(0)));
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KnownBits KnownR(compute(I->getOperand(1)));
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switch (I->getOpcode()) {
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case Instruction::BinaryOps::And:
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return KnownL & KnownR;
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case Instruction::BinaryOps::Or:
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return KnownL | KnownR;
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case Instruction::BinaryOps::Xor:
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return KnownL ^ KnownR;
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case Instruction::BinaryOps::Shl: {
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auto *OBO = cast<OverflowingBinaryOperator>(I);
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return KnownBits::shl(KnownL, KnownR, OBO->hasNoUnsignedWrap(),
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OBO->hasNoSignedWrap());
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}
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case Instruction::BinaryOps::LShr:
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return KnownBits::lshr(KnownL, KnownR);
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case Instruction::BinaryOps::AShr:
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return KnownBits::ashr(KnownL, KnownR);
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case Instruction::BinaryOps::Add: {
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auto *OBO = cast<OverflowingBinaryOperator>(I);
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return KnownBits::add(KnownL, KnownR, OBO->hasNoUnsignedWrap(),
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OBO->hasNoSignedWrap());
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}
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case Instruction::BinaryOps::Sub: {
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auto *OBO = cast<OverflowingBinaryOperator>(I);
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return KnownBits::sub(KnownL, KnownR, OBO->hasNoUnsignedWrap(),
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OBO->hasNoSignedWrap());
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}
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case Instruction::BinaryOps::Mul: {
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Value *Op0 = I->getOperand(0);
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Value *Op1 = I->getOperand(1);
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bool SelfMultiply = Op0 == Op1 && isGuaranteedNotToBeUndef(Op0);
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return KnownBits::mul(KnownL, KnownR, SelfMultiply);
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}
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case Instruction::BinaryOps::UDiv:
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return KnownBits::udiv(KnownL, KnownR);
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case Instruction::BinaryOps::SDiv:
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return KnownBits::sdiv(KnownL, KnownR);
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case Instruction::BinaryOps::URem:
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return KnownBits::urem(KnownL, KnownR);
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case Instruction::BinaryOps::SRem:
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return KnownBits::srem(KnownL, KnownR);
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default:
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ErrStr = "Unknown BinaryOperator";
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unsigned BitWidth = I->getType()->getScalarSizeInBits();
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return {BitWidth};
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}
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}
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KnownBits ValueEvolution::computeInstr(const Instruction *I) {
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unsigned BitWidth = I->getType()->getScalarSizeInBits();
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// We look up in the map that contains the KnownBits of the PHI from the
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// previous iteration.
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if (const PHINode *P = dyn_cast<PHINode>(I))
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return KnownPhis.lookup_or(P, BitWidth);
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// Compute the KnownBits for a Select(Cmp()), forcing it to take the branch
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// that is predicated on the (least|most)-significant-bit check.
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CmpPredicate Pred;
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Value *L, *R, *TV, *FV;
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if (match(I, m_Select(m_ICmp(Pred, m_Value(L), m_Value(R)), m_Value(TV),
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m_Value(FV)))) {
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// We need to check LCR against [0, 2) in the little-endian case, because
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// the RCR check is insufficient: it is simply [0, 1).
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if (!ByteOrderSwapped) {
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KnownBits KnownL = compute(L);
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unsigned ICmpBW = KnownL.getBitWidth();
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auto LCR = ConstantRange::fromKnownBits(KnownL, false);
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auto CheckLCR = ConstantRange(APInt::getZero(ICmpBW), APInt(ICmpBW, 2));
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if (LCR != CheckLCR) {
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ErrStr = "Bad LHS of significant-bit-check";
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return {BitWidth};
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}
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}
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// Check that the predication is on (most|least) significant bit.
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KnownBits KnownR = compute(R);
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unsigned ICmpBW = KnownR.getBitWidth();
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auto RCR = ConstantRange::fromKnownBits(KnownR, false);
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auto AllowedR = ConstantRange::makeAllowedICmpRegion(Pred, RCR);
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ConstantRange CheckRCR(APInt::getZero(ICmpBW),
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ByteOrderSwapped ? APInt::getSignedMinValue(ICmpBW)
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: APInt(ICmpBW, 1));
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if (AllowedR == CheckRCR)
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return compute(TV);
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if (AllowedR.inverse() == CheckRCR)
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return compute(FV);
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ErrStr = "Bad RHS of significant-bit-check";
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return {BitWidth};
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}
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if (auto *BO = dyn_cast<BinaryOperator>(I))
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return computeBinOp(BO);
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switch (I->getOpcode()) {
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case Instruction::CastOps::Trunc:
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return compute(I->getOperand(0)).trunc(BitWidth);
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case Instruction::CastOps::ZExt:
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return compute(I->getOperand(0)).zext(BitWidth);
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case Instruction::CastOps::SExt:
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return compute(I->getOperand(0)).sext(BitWidth);
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default:
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ErrStr = "Unknown Instruction";
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return {BitWidth};
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}
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}
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KnownBits ValueEvolution::compute(const Value *V) {
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if (auto *CI = dyn_cast<ConstantInt>(V))
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return KnownBits::makeConstant(CI->getValue());
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if (auto *I = dyn_cast<Instruction>(V))
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return computeInstr(I);
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ErrStr = "Unknown Value";
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unsigned BitWidth = V->getType()->getScalarSizeInBits();
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return {BitWidth};
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}
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bool ValueEvolution::computeEvolutions(ArrayRef<PhiStepPair> PhiEvolutions) {
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for (unsigned I = 0; I < TripCount; ++I) {
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for (auto [Phi, Step] : PhiEvolutions) {
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KnownBits KnownAtIter = computeInstr(Step);
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if (KnownAtIter.getBitWidth() < I + 1) {
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ErrStr = "Loop iterations exceed bitwidth of result";
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return false;
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}
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KnownPhis.emplace_or_assign(Phi, KnownAtIter);
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}
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}
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return ErrStr.empty();
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}
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/// A structure that can hold either a Simple Recurrence or a Conditional
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/// Recurrence. Note that in the case of a Simple Recurrence, Step is an operand
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/// of the BO, while in a Conditional Recurrence, it is a SelectInst.
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struct RecurrenceInfo {
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const Loop &L;
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const PHINode *Phi = nullptr;
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BinaryOperator *BO = nullptr;
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Value *Start = nullptr;
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Value *Step = nullptr;
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std::optional<APInt> ExtraConst;
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RecurrenceInfo(const Loop &L) : L(L) {}
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operator bool() const { return BO; }
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void print(raw_ostream &OS, unsigned Indent) const {
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OS.indent(Indent) << "Phi: ";
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Phi->print(OS);
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OS << "\n";
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OS.indent(Indent) << "BinaryOperator: ";
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BO->print(OS);
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OS << "\n";
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OS.indent(Indent) << "Start: ";
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Start->print(OS);
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OS << "\n";
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OS.indent(Indent) << "Step: ";
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Step->print(OS);
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OS << "\n";
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if (ExtraConst) {
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OS.indent(Indent) << "ExtraConst: ";
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ExtraConst->print(OS, false);
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OS << "\n";
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}
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}
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bool matchSimpleRecurrence(const PHINode *P);
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bool matchConditionalRecurrence(
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const PHINode *P,
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Instruction::BinaryOps BOWithConstOpToMatch = Instruction::BinaryOpsEnd);
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private:
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BinaryOperator *digRecurrence(
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Instruction *V,
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Instruction::BinaryOps BOWithConstOpToMatch = Instruction::BinaryOpsEnd);
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};
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/// Wraps llvm::matchSimpleRecurrence. Match a simple first order recurrence
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/// cycle of the form:
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///
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/// loop:
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/// %rec = phi [%start, %entry], [%BO, %loop]
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/// ...
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/// %BO = binop %rec, %step
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///
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/// or
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///
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/// loop:
|
||||
/// %rec = phi [%start, %entry], [%BO, %loop]
|
||||
/// ...
|
||||
/// %BO = binop %step, %rec
|
||||
///
|
||||
bool RecurrenceInfo::matchSimpleRecurrence(const PHINode *P) {
|
||||
Phi = P;
|
||||
return llvm::matchSimpleRecurrence(Phi, BO, Start, Step);
|
||||
}
|
||||
|
||||
/// Digs for a recurrence starting with \p V hitting the PHI node in a use-def
|
||||
/// chain. Used by matchConditionalRecurrence.
|
||||
BinaryOperator *
|
||||
RecurrenceInfo::digRecurrence(Instruction *V,
|
||||
Instruction::BinaryOps BOWithConstOpToMatch) {
|
||||
SmallVector<Instruction *> Worklist;
|
||||
Worklist.push_back(V);
|
||||
while (!Worklist.empty()) {
|
||||
Instruction *I = Worklist.pop_back_val();
|
||||
|
||||
// Don't add a PHI's operands to the Worklist.
|
||||
if (isa<PHINode>(I))
|
||||
continue;
|
||||
|
||||
// Find a recurrence over a BinOp, by matching either of its operands
|
||||
// with with the PHINode.
|
||||
if (match(I, m_c_BinOp(m_Value(), m_Specific(Phi))))
|
||||
return cast<BinaryOperator>(I);
|
||||
|
||||
// Bind to ExtraConst, if we match exactly one.
|
||||
if (I->getOpcode() == BOWithConstOpToMatch) {
|
||||
if (ExtraConst)
|
||||
return nullptr;
|
||||
const APInt *C = nullptr;
|
||||
if (match(I, m_c_BinOp(m_APInt(C), m_Value())))
|
||||
ExtraConst = *C;
|
||||
}
|
||||
|
||||
// Continue along the use-def chain.
|
||||
for (Use &U : I->operands())
|
||||
if (auto *UI = dyn_cast<Instruction>(U))
|
||||
if (L.contains(UI))
|
||||
Worklist.push_back(UI);
|
||||
}
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
/// A Conditional Recurrence is a recurrence of the form:
|
||||
///
|
||||
/// loop:
|
||||
/// %rec = [%start, %entry], [%step, %loop]
|
||||
/// ...
|
||||
/// %step = select _, %tv, %fv
|
||||
///
|
||||
/// where %tv and %fv ultimately end up using %rec via the same %BO instruction,
|
||||
/// after digging through the use-def chain.
|
||||
///
|
||||
/// ExtraConst is relevant if \p BOWithConstOpToMatch is supplied: when digging
|
||||
/// the use-def chain, a BinOp with opcode \p BOWithConstOpToMatch is matched,
|
||||
/// and ExtraConst is a constant operand of that BinOp. This peculiarity exists,
|
||||
/// because in a CRC algorithm, the \p BOWithConstOpToMatch is an XOR, and the
|
||||
/// ExtraConst ends up being the generating polynomial.
|
||||
bool RecurrenceInfo::matchConditionalRecurrence(
|
||||
const PHINode *P, Instruction::BinaryOps BOWithConstOpToMatch) {
|
||||
Phi = P;
|
||||
if (Phi->getNumIncomingValues() != 2)
|
||||
return false;
|
||||
|
||||
for (unsigned Idx = 0; Idx != 2; ++Idx) {
|
||||
Value *FoundStep = Phi->getIncomingValue(Idx);
|
||||
Value *FoundStart = Phi->getIncomingValue(!Idx);
|
||||
|
||||
Instruction *TV, *FV;
|
||||
if (!match(FoundStep,
|
||||
m_Select(m_Cmp(), m_Instruction(TV), m_Instruction(FV))))
|
||||
continue;
|
||||
|
||||
// For a conditional recurrence, both the true and false values of the
|
||||
// select must ultimately end up in the same recurrent BinOp.
|
||||
BinaryOperator *FoundBO = digRecurrence(TV, BOWithConstOpToMatch);
|
||||
BinaryOperator *AltBO = digRecurrence(FV, BOWithConstOpToMatch);
|
||||
if (!FoundBO || FoundBO != AltBO)
|
||||
return false;
|
||||
|
||||
if (BOWithConstOpToMatch != Instruction::BinaryOpsEnd && !ExtraConst) {
|
||||
LLVM_DEBUG(dbgs() << "HashRecognize: Unable to match single BinaryOp "
|
||||
"with constant in conditional recurrence\n");
|
||||
return false;
|
||||
}
|
||||
|
||||
BO = FoundBO;
|
||||
Start = FoundStart;
|
||||
Step = FoundStep;
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
/// Iterates over all the phis in \p LoopLatch, and attempts to extract a
|
||||
/// Conditional Recurrence and an optional Simple Recurrence.
|
||||
static std::optional<std::pair<RecurrenceInfo, RecurrenceInfo>>
|
||||
getRecurrences(BasicBlock *LoopLatch, const PHINode *IndVar, const Loop &L) {
|
||||
auto Phis = LoopLatch->phis();
|
||||
unsigned NumPhis = std::distance(Phis.begin(), Phis.end());
|
||||
if (NumPhis != 2 && NumPhis != 3)
|
||||
return {};
|
||||
|
||||
RecurrenceInfo SimpleRecurrence(L);
|
||||
RecurrenceInfo ConditionalRecurrence(L);
|
||||
for (PHINode &P : Phis) {
|
||||
if (&P == IndVar)
|
||||
continue;
|
||||
if (!SimpleRecurrence)
|
||||
SimpleRecurrence.matchSimpleRecurrence(&P);
|
||||
if (!ConditionalRecurrence)
|
||||
ConditionalRecurrence.matchConditionalRecurrence(
|
||||
&P, Instruction::BinaryOps::Xor);
|
||||
}
|
||||
if (NumPhis == 3 && (!SimpleRecurrence || !ConditionalRecurrence))
|
||||
return {};
|
||||
return std::make_pair(SimpleRecurrence, ConditionalRecurrence);
|
||||
}
|
||||
|
||||
PolynomialInfo::PolynomialInfo(unsigned TripCount, const Value *LHS,
|
||||
const APInt &RHS, const Value *ComputedValue,
|
||||
bool ByteOrderSwapped, const Value *LHSAux)
|
||||
: TripCount(TripCount), LHS(LHS), RHS(RHS), ComputedValue(ComputedValue),
|
||||
ByteOrderSwapped(ByteOrderSwapped), LHSAux(LHSAux) {}
|
||||
|
||||
/// In the big-endian case, checks the bottom N bits against CheckFn, and that
|
||||
/// the rest are unknown. In the little-endian case, checks the top N bits
|
||||
/// against CheckFn, and that the rest are unknown. Callers usually call this
|
||||
/// function with N = TripCount, and CheckFn checking that the remainder bits of
|
||||
/// the CRC polynomial division are zero.
|
||||
static bool checkExtractBits(const KnownBits &Known, unsigned N,
|
||||
function_ref<bool(const KnownBits &)> CheckFn,
|
||||
bool ByteOrderSwapped) {
|
||||
// Check that the entire thing is a constant.
|
||||
if (N == Known.getBitWidth())
|
||||
return CheckFn(Known.extractBits(N, 0));
|
||||
|
||||
// Check that the {top, bottom} N bits are not unknown and that the {bottom,
|
||||
// top} N bits are known.
|
||||
unsigned BitPos = ByteOrderSwapped ? 0 : Known.getBitWidth() - N;
|
||||
unsigned SwappedBitPos = ByteOrderSwapped ? N : 0;
|
||||
return CheckFn(Known.extractBits(N, BitPos)) &&
|
||||
Known.extractBits(Known.getBitWidth() - N, SwappedBitPos).isUnknown();
|
||||
}
|
||||
|
||||
/// Generate a lookup table of 256 entries by interleaving the generating
|
||||
/// polynomial. The optimization technique of table-lookup for CRC is also
|
||||
/// called the Sarwate algorithm.
|
||||
CRCTable HashRecognize::genSarwateTable(const APInt &GenPoly,
|
||||
bool ByteOrderSwapped) const {
|
||||
unsigned BW = GenPoly.getBitWidth();
|
||||
CRCTable Table;
|
||||
Table[0] = APInt::getZero(BW);
|
||||
|
||||
if (ByteOrderSwapped) {
|
||||
APInt CRCInit(BW, 128);
|
||||
for (unsigned I = 1; I < 256; I <<= 1) {
|
||||
CRCInit = CRCInit.shl(1) ^
|
||||
(CRCInit.isSignBitSet() ? GenPoly : APInt::getZero(BW));
|
||||
for (unsigned J = 0; J < I; ++J)
|
||||
Table[I + J] = CRCInit ^ Table[J];
|
||||
}
|
||||
return Table;
|
||||
}
|
||||
|
||||
APInt CRCInit(BW, 1);
|
||||
for (unsigned I = 128; I; I >>= 1) {
|
||||
CRCInit = CRCInit.lshr(1) ^ (CRCInit[0] ? GenPoly : APInt::getZero(BW));
|
||||
for (unsigned J = 0; J < 256; J += (I << 1))
|
||||
Table[I + J] = CRCInit ^ Table[J];
|
||||
}
|
||||
return Table;
|
||||
}
|
||||
|
||||
/// Checks if \p Reference is reachable from \p Needle on the use-def chain, and
|
||||
/// that there are no stray PHI nodes while digging the use-def chain. \p
|
||||
/// BOToMatch is a CRC peculiarity: at least one of the Users of Needle needs to
|
||||
/// match this OpCode, which is XOR for CRC.
|
||||
static bool arePHIsIntertwined(
|
||||
const PHINode *Needle, const PHINode *Reference, const Loop &L,
|
||||
Instruction::BinaryOps BOToMatch = Instruction::BinaryOpsEnd) {
|
||||
// Initialize the worklist with Users of the Needle.
|
||||
SmallVector<const Instruction *> Worklist;
|
||||
for (const User *U : Needle->users()) {
|
||||
if (auto *UI = dyn_cast<Instruction>(U))
|
||||
if (L.contains(UI))
|
||||
Worklist.push_back(UI);
|
||||
}
|
||||
|
||||
// BOToMatch is usually XOR for CRC.
|
||||
if (BOToMatch != Instruction::BinaryOpsEnd) {
|
||||
if (count_if(Worklist, [BOToMatch](const Instruction *I) {
|
||||
return I->getOpcode() == BOToMatch;
|
||||
}) != 1)
|
||||
return false;
|
||||
}
|
||||
|
||||
while (!Worklist.empty()) {
|
||||
const Instruction *I = Worklist.pop_back_val();
|
||||
|
||||
// Since Needle is never pushed onto the Worklist, I must either be the
|
||||
// Reference PHI node (in which case we're done), or a stray PHI node (in
|
||||
// which case we abort).
|
||||
if (isa<PHINode>(I))
|
||||
return I == Reference;
|
||||
|
||||
for (const Use &U : I->operands())
|
||||
if (auto *UI = dyn_cast<Instruction>(U))
|
||||
// Don't push Needle back onto the Worklist.
|
||||
if (UI != Needle && L.contains(UI))
|
||||
Worklist.push_back(UI);
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
// Recognizes a multiplication or division by the constant two, using SCEV. By
|
||||
// doing this, we're immune to whether the IR expression is mul/udiv or
|
||||
// equivalently shl/lshr. Return false when it is a UDiv, true when it is a Mul,
|
||||
// and std::nullopt otherwise.
|
||||
static std::optional<bool> isBigEndianBitShift(const SCEV *E) {
|
||||
if (match(E, m_scev_UDiv(m_SCEV(), m_scev_SpecificInt(2))))
|
||||
return false;
|
||||
if (match(E, m_scev_Mul(m_scev_SpecificInt(2), m_SCEV())))
|
||||
return true;
|
||||
return {};
|
||||
}
|
||||
|
||||
/// The main entry point for analyzing a loop and recognizing the CRC algorithm.
|
||||
/// Returns a PolynomialInfo on success, and either an ErrBits or a StringRef on
|
||||
/// failure.
|
||||
std::variant<PolynomialInfo, ErrBits, StringRef>
|
||||
HashRecognize::recognizeCRC() const {
|
||||
if (!L.isInnermost())
|
||||
return "Loop is not innermost";
|
||||
unsigned TC = SE.getSmallConstantMaxTripCount(&L);
|
||||
if (!TC || TC > 256)
|
||||
return "Unable to find a small constant trip count";
|
||||
BasicBlock *Latch = L.getLoopLatch();
|
||||
BasicBlock *Exit = L.getExitBlock();
|
||||
const PHINode *IndVar = L.getCanonicalInductionVariable();
|
||||
if (!Latch || !Exit || !IndVar)
|
||||
return "Loop not in canonical form";
|
||||
|
||||
auto R = getRecurrences(Latch, IndVar, L);
|
||||
if (!R)
|
||||
return "Found stray PHI";
|
||||
auto [SimpleRecurrence, ConditionalRecurrence] = *R;
|
||||
if (!ConditionalRecurrence)
|
||||
return "Unable to find conditional recurrence";
|
||||
|
||||
// Make sure that all recurrences are either all SCEVMul with two or SCEVDiv
|
||||
// with two, or in other words, that they're single bit-shifts.
|
||||
std::optional<bool> ByteOrderSwapped =
|
||||
isBigEndianBitShift(SE.getSCEV(ConditionalRecurrence.BO));
|
||||
if (!ByteOrderSwapped)
|
||||
return "Loop with non-unit bitshifts";
|
||||
if (SimpleRecurrence) {
|
||||
if (isBigEndianBitShift(SE.getSCEV(SimpleRecurrence.BO)) !=
|
||||
ByteOrderSwapped)
|
||||
return "Loop with non-unit bitshifts";
|
||||
if (!arePHIsIntertwined(SimpleRecurrence.Phi, ConditionalRecurrence.Phi, L,
|
||||
Instruction::BinaryOps::Xor))
|
||||
return "Simple recurrence doesn't use conditional recurrence with XOR";
|
||||
}
|
||||
|
||||
// Make sure that the computed value is used in the exit block: this should be
|
||||
// true even if it is only really used in an outer loop's exit block, since
|
||||
// the loop is in LCSSA form.
|
||||
auto *ComputedValue = cast<SelectInst>(ConditionalRecurrence.Step);
|
||||
if (none_of(ComputedValue->users(), [Exit](User *U) {
|
||||
auto *UI = dyn_cast<Instruction>(U);
|
||||
return UI && UI->getParent() == Exit;
|
||||
}))
|
||||
return "Unable to find use of computed value in loop exit block";
|
||||
|
||||
assert(ConditionalRecurrence.ExtraConst &&
|
||||
"Expected ExtraConst in conditional recurrence");
|
||||
const APInt &GenPoly = *ConditionalRecurrence.ExtraConst;
|
||||
|
||||
// PhiEvolutions are pairs of PHINodes along with their incoming value from
|
||||
// within the loop, which we term as their step. Note that in the case of a
|
||||
// Simple Recurrence, Step is an operand of the BO, while in a Conditional
|
||||
// Recurrence, it is a SelectInst.
|
||||
SmallVector<PhiStepPair, 2> PhiEvolutions;
|
||||
PhiEvolutions.emplace_back(ConditionalRecurrence.Phi, ComputedValue);
|
||||
if (SimpleRecurrence)
|
||||
PhiEvolutions.emplace_back(SimpleRecurrence.Phi, SimpleRecurrence.BO);
|
||||
|
||||
ValueEvolution VE(TC, *ByteOrderSwapped);
|
||||
if (!VE.computeEvolutions(PhiEvolutions))
|
||||
return VE.getError();
|
||||
KnownBits ResultBits = VE.KnownPhis.at(ConditionalRecurrence.Phi);
|
||||
|
||||
auto IsZero = [](const KnownBits &K) { return K.isZero(); };
|
||||
if (!checkExtractBits(ResultBits, TC, IsZero, *ByteOrderSwapped))
|
||||
return ErrBits(ResultBits, TC, *ByteOrderSwapped);
|
||||
|
||||
const Value *LHSAux = SimpleRecurrence ? SimpleRecurrence.Start : nullptr;
|
||||
return PolynomialInfo(TC, ConditionalRecurrence.Start, GenPoly, ComputedValue,
|
||||
*ByteOrderSwapped, LHSAux);
|
||||
}
|
||||
|
||||
void CRCTable::print(raw_ostream &OS) const {
|
||||
for (unsigned I = 0; I < 256; I++) {
|
||||
(*this)[I].print(OS, false);
|
||||
OS << (I % 16 == 15 ? '\n' : ' ');
|
||||
}
|
||||
}
|
||||
|
||||
void HashRecognize::print(raw_ostream &OS) const {
|
||||
if (!L.isInnermost())
|
||||
return;
|
||||
OS << "HashRecognize: Checking a loop in '"
|
||||
<< L.getHeader()->getParent()->getName() << "' from " << L.getLocStr()
|
||||
<< "\n";
|
||||
auto Ret = recognizeCRC();
|
||||
if (!std::holds_alternative<PolynomialInfo>(Ret)) {
|
||||
OS << "Did not find a hash algorithm\n";
|
||||
if (std::holds_alternative<StringRef>(Ret))
|
||||
OS << "Reason: " << std::get<StringRef>(Ret) << "\n";
|
||||
if (std::holds_alternative<ErrBits>(Ret)) {
|
||||
auto [Actual, Iter, ByteOrderSwapped] = std::get<ErrBits>(Ret);
|
||||
OS << "Reason: Expected " << (ByteOrderSwapped ? "bottom " : "top ")
|
||||
<< Iter << " bits zero (";
|
||||
Actual.print(OS);
|
||||
OS << ")\n";
|
||||
}
|
||||
return;
|
||||
}
|
||||
|
||||
auto Info = std::get<PolynomialInfo>(Ret);
|
||||
OS << "Found" << (Info.ByteOrderSwapped ? " big-endian " : " little-endian ")
|
||||
<< "CRC-" << Info.RHS.getBitWidth() << " loop with trip count "
|
||||
<< Info.TripCount << "\n";
|
||||
OS.indent(2) << "Initial CRC: ";
|
||||
Info.LHS->print(OS);
|
||||
OS << "\n";
|
||||
OS.indent(2) << "Generating polynomial: ";
|
||||
Info.RHS.print(OS, false);
|
||||
OS << "\n";
|
||||
OS.indent(2) << "Computed CRC: ";
|
||||
Info.ComputedValue->print(OS);
|
||||
OS << "\n";
|
||||
if (Info.LHSAux) {
|
||||
OS.indent(2) << "Auxiliary data: ";
|
||||
Info.LHSAux->print(OS);
|
||||
OS << "\n";
|
||||
}
|
||||
OS.indent(2) << "Computed CRC lookup table:\n";
|
||||
genSarwateTable(Info.RHS, Info.ByteOrderSwapped).print(OS);
|
||||
}
|
||||
|
||||
HashRecognize::HashRecognize(const Loop &L, ScalarEvolution &SE)
|
||||
: L(L), SE(SE) {}
|
||||
|
||||
PreservedAnalyses HashRecognizePrinterPass::run(Loop &L,
|
||||
LoopAnalysisManager &AM,
|
||||
LoopStandardAnalysisResults &AR,
|
||||
LPMUpdater &) {
|
||||
AM.getResult<HashRecognizeAnalysis>(L, AR).print(OS);
|
||||
return PreservedAnalyses::all();
|
||||
}
|
||||
|
||||
HashRecognize HashRecognizeAnalysis::run(Loop &L, LoopAnalysisManager &AM,
|
||||
LoopStandardAnalysisResults &AR) {
|
||||
return {L, AR.SE};
|
||||
}
|
||||
|
||||
AnalysisKey HashRecognizeAnalysis::Key;
|
||||
@ -42,6 +42,7 @@
|
||||
#include "llvm/Analysis/EphemeralValuesCache.h"
|
||||
#include "llvm/Analysis/FunctionPropertiesAnalysis.h"
|
||||
#include "llvm/Analysis/GlobalsModRef.h"
|
||||
#include "llvm/Analysis/HashRecognize.h"
|
||||
#include "llvm/Analysis/IR2Vec.h"
|
||||
#include "llvm/Analysis/IRSimilarityIdentifier.h"
|
||||
#include "llvm/Analysis/IVUsers.h"
|
||||
|
||||
@ -662,6 +662,7 @@ LOOPNEST_PASS("no-op-loopnest", NoOpLoopNestPass())
|
||||
#define LOOP_ANALYSIS(NAME, CREATE_PASS)
|
||||
#endif
|
||||
LOOP_ANALYSIS("ddg", DDGAnalysis())
|
||||
LOOP_ANALYSIS("hash-recognize", HashRecognizeAnalysis())
|
||||
LOOP_ANALYSIS("iv-users", IVUsersAnalysis())
|
||||
LOOP_ANALYSIS("no-op-loop", NoOpLoopAnalysis())
|
||||
LOOP_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis(PIC))
|
||||
@ -695,6 +696,7 @@ LOOP_PASS("loop-versioning-licm", LoopVersioningLICMPass())
|
||||
LOOP_PASS("no-op-loop", NoOpLoopPass())
|
||||
LOOP_PASS("print", PrintLoopPass(errs()))
|
||||
LOOP_PASS("print<ddg>", DDGAnalysisPrinterPass(errs()))
|
||||
LOOP_PASS("print<hash-recognize>", HashRecognizePrinterPass(errs()))
|
||||
LOOP_PASS("print<iv-users>", IVUsersPrinterPass(errs()))
|
||||
LOOP_PASS("print<loop-cache-cost>", LoopCachePrinterPass(errs()))
|
||||
LOOP_PASS("print<loopnest>", LoopNestPrinterPass(errs()))
|
||||
|
||||
899
llvm/test/Analysis/HashRecognize/cyclic-redundancy-check.ll
Normal file
899
llvm/test/Analysis/HashRecognize/cyclic-redundancy-check.ll
Normal file
@ -0,0 +1,899 @@
|
||||
; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 5
|
||||
; RUN: opt -passes='print<hash-recognize>' -disable-output %s 2>&1 | FileCheck %s
|
||||
|
||||
define i16 @crc16.le.tc8(i8 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'crc16.le.tc8'
|
||||
; CHECK-NEXT: Found little-endian CRC-16 loop with trip count 8
|
||||
; CHECK-NEXT: Initial CRC: i16 %checksum
|
||||
; CHECK-NEXT: Generating polynomial: 40961
|
||||
; CHECK-NEXT: Computed CRC: %crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %xor
|
||||
; CHECK-NEXT: Auxiliary data: i8 %msg
|
||||
; CHECK-NEXT: Computed CRC lookup table:
|
||||
; CHECK-NEXT: 0 49345 49537 320 49921 960 640 49729 50689 1728 1920 51009 1280 50625 50305 1088
|
||||
; CHECK-NEXT: 52225 3264 3456 52545 3840 53185 52865 3648 2560 51905 52097 2880 51457 2496 2176 51265
|
||||
; CHECK-NEXT: 55297 6336 6528 55617 6912 56257 55937 6720 7680 57025 57217 8000 56577 7616 7296 56385
|
||||
; CHECK-NEXT: 5120 54465 54657 5440 55041 6080 5760 54849 53761 4800 4992 54081 4352 53697 53377 4160
|
||||
; CHECK-NEXT: 61441 12480 12672 61761 13056 62401 62081 12864 13824 63169 63361 14144 62721 13760 13440 62529
|
||||
; CHECK-NEXT: 15360 64705 64897 15680 65281 16320 16000 65089 64001 15040 15232 64321 14592 63937 63617 14400
|
||||
; CHECK-NEXT: 10240 59585 59777 10560 60161 11200 10880 59969 60929 11968 12160 61249 11520 60865 60545 11328
|
||||
; CHECK-NEXT: 58369 9408 9600 58689 9984 59329 59009 9792 8704 58049 58241 9024 57601 8640 8320 57409
|
||||
; CHECK-NEXT: 40961 24768 24960 41281 25344 41921 41601 25152 26112 42689 42881 26432 42241 26048 25728 42049
|
||||
; CHECK-NEXT: 27648 44225 44417 27968 44801 28608 28288 44609 43521 27328 27520 43841 26880 43457 43137 26688
|
||||
; CHECK-NEXT: 30720 47297 47489 31040 47873 31680 31360 47681 48641 32448 32640 48961 32000 48577 48257 31808
|
||||
; CHECK-NEXT: 46081 29888 30080 46401 30464 47041 46721 30272 29184 45761 45953 29504 45313 29120 28800 45121
|
||||
; CHECK-NEXT: 20480 37057 37249 20800 37633 21440 21120 37441 38401 22208 22400 38721 21760 38337 38017 21568
|
||||
; CHECK-NEXT: 39937 23744 23936 40257 24320 40897 40577 24128 23040 39617 39809 23360 39169 22976 22656 38977
|
||||
; CHECK-NEXT: 34817 18624 18816 35137 19200 35777 35457 19008 19968 36545 36737 20288 36097 19904 19584 35905
|
||||
; CHECK-NEXT: 17408 33985 34177 17728 34561 18368 18048 34369 33281 17088 17280 33601 16640 33217 32897 16448
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i8 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%crc.trunc = trunc i16 %crc to i8
|
||||
%xor.data.crc = xor i8 %data, %crc.trunc
|
||||
%and.data.crc = and i8 %xor.data.crc, 1
|
||||
%data.next = lshr i8 %data, 1
|
||||
%check.sb = icmp eq i8 %and.data.crc, 0
|
||||
%crc.lshr = lshr i16 %crc, 1
|
||||
%xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @crc16.le.tc8.udiv(i8 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'crc16.le.tc8.udiv'
|
||||
; CHECK-NEXT: Found little-endian CRC-16 loop with trip count 8
|
||||
; CHECK-NEXT: Initial CRC: i16 %checksum
|
||||
; CHECK-NEXT: Generating polynomial: 40961
|
||||
; CHECK-NEXT: Computed CRC: %crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %xor
|
||||
; CHECK-NEXT: Auxiliary data: i8 %msg
|
||||
; CHECK-NEXT: Computed CRC lookup table:
|
||||
; CHECK-NEXT: 0 49345 49537 320 49921 960 640 49729 50689 1728 1920 51009 1280 50625 50305 1088
|
||||
; CHECK-NEXT: 52225 3264 3456 52545 3840 53185 52865 3648 2560 51905 52097 2880 51457 2496 2176 51265
|
||||
; CHECK-NEXT: 55297 6336 6528 55617 6912 56257 55937 6720 7680 57025 57217 8000 56577 7616 7296 56385
|
||||
; CHECK-NEXT: 5120 54465 54657 5440 55041 6080 5760 54849 53761 4800 4992 54081 4352 53697 53377 4160
|
||||
; CHECK-NEXT: 61441 12480 12672 61761 13056 62401 62081 12864 13824 63169 63361 14144 62721 13760 13440 62529
|
||||
; CHECK-NEXT: 15360 64705 64897 15680 65281 16320 16000 65089 64001 15040 15232 64321 14592 63937 63617 14400
|
||||
; CHECK-NEXT: 10240 59585 59777 10560 60161 11200 10880 59969 60929 11968 12160 61249 11520 60865 60545 11328
|
||||
; CHECK-NEXT: 58369 9408 9600 58689 9984 59329 59009 9792 8704 58049 58241 9024 57601 8640 8320 57409
|
||||
; CHECK-NEXT: 40961 24768 24960 41281 25344 41921 41601 25152 26112 42689 42881 26432 42241 26048 25728 42049
|
||||
; CHECK-NEXT: 27648 44225 44417 27968 44801 28608 28288 44609 43521 27328 27520 43841 26880 43457 43137 26688
|
||||
; CHECK-NEXT: 30720 47297 47489 31040 47873 31680 31360 47681 48641 32448 32640 48961 32000 48577 48257 31808
|
||||
; CHECK-NEXT: 46081 29888 30080 46401 30464 47041 46721 30272 29184 45761 45953 29504 45313 29120 28800 45121
|
||||
; CHECK-NEXT: 20480 37057 37249 20800 37633 21440 21120 37441 38401 22208 22400 38721 21760 38337 38017 21568
|
||||
; CHECK-NEXT: 39937 23744 23936 40257 24320 40897 40577 24128 23040 39617 39809 23360 39169 22976 22656 38977
|
||||
; CHECK-NEXT: 34817 18624 18816 35137 19200 35777 35457 19008 19968 36545 36737 20288 36097 19904 19584 35905
|
||||
; CHECK-NEXT: 17408 33985 34177 17728 34561 18368 18048 34369 33281 17088 17280 33601 16640 33217 32897 16448
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i8 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%crc.trunc = trunc i16 %crc to i8
|
||||
%xor.data.crc = xor i8 %data, %crc.trunc
|
||||
%and.data.crc = and i8 %xor.data.crc, 1
|
||||
%data.next = udiv i8 %data, 2
|
||||
%check.sb = icmp eq i8 %and.data.crc, 0
|
||||
%crc.lshr = udiv i16 %crc, 2
|
||||
%xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @crc16.le.tc16(i16 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'crc16.le.tc16'
|
||||
; CHECK-NEXT: Found little-endian CRC-16 loop with trip count 16
|
||||
; CHECK-NEXT: Initial CRC: i16 %checksum
|
||||
; CHECK-NEXT: Generating polynomial: 40961
|
||||
; CHECK-NEXT: Computed CRC: %crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %crc.xor
|
||||
; CHECK-NEXT: Auxiliary data: i16 %msg
|
||||
; CHECK-NEXT: Computed CRC lookup table:
|
||||
; CHECK-NEXT: 0 49345 49537 320 49921 960 640 49729 50689 1728 1920 51009 1280 50625 50305 1088
|
||||
; CHECK-NEXT: 52225 3264 3456 52545 3840 53185 52865 3648 2560 51905 52097 2880 51457 2496 2176 51265
|
||||
; CHECK-NEXT: 55297 6336 6528 55617 6912 56257 55937 6720 7680 57025 57217 8000 56577 7616 7296 56385
|
||||
; CHECK-NEXT: 5120 54465 54657 5440 55041 6080 5760 54849 53761 4800 4992 54081 4352 53697 53377 4160
|
||||
; CHECK-NEXT: 61441 12480 12672 61761 13056 62401 62081 12864 13824 63169 63361 14144 62721 13760 13440 62529
|
||||
; CHECK-NEXT: 15360 64705 64897 15680 65281 16320 16000 65089 64001 15040 15232 64321 14592 63937 63617 14400
|
||||
; CHECK-NEXT: 10240 59585 59777 10560 60161 11200 10880 59969 60929 11968 12160 61249 11520 60865 60545 11328
|
||||
; CHECK-NEXT: 58369 9408 9600 58689 9984 59329 59009 9792 8704 58049 58241 9024 57601 8640 8320 57409
|
||||
; CHECK-NEXT: 40961 24768 24960 41281 25344 41921 41601 25152 26112 42689 42881 26432 42241 26048 25728 42049
|
||||
; CHECK-NEXT: 27648 44225 44417 27968 44801 28608 28288 44609 43521 27328 27520 43841 26880 43457 43137 26688
|
||||
; CHECK-NEXT: 30720 47297 47489 31040 47873 31680 31360 47681 48641 32448 32640 48961 32000 48577 48257 31808
|
||||
; CHECK-NEXT: 46081 29888 30080 46401 30464 47041 46721 30272 29184 45761 45953 29504 45313 29120 28800 45121
|
||||
; CHECK-NEXT: 20480 37057 37249 20800 37633 21440 21120 37441 38401 22208 22400 38721 21760 38337 38017 21568
|
||||
; CHECK-NEXT: 39937 23744 23936 40257 24320 40897 40577 24128 23040 39617 39809 23360 39169 22976 22656 38977
|
||||
; CHECK-NEXT: 34817 18624 18816 35137 19200 35777 35457 19008 19968 36545 36737 20288 36097 19904 19584 35905
|
||||
; CHECK-NEXT: 17408 33985 34177 17728 34561 18368 18048 34369 33281 17088 17280 33601 16640 33217 32897 16448
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i16 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%xor.crc.data = xor i16 %crc, %data
|
||||
%and.crc.data = and i16 %xor.crc.data, 1
|
||||
%data.next = lshr i16 %data, 1
|
||||
%check.sb = icmp eq i16 %and.crc.data, 0
|
||||
%crc.lshr = lshr i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 15
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @crc16.be.tc8.crc.init.li(i16 %checksum, i8 %msg) {
|
||||
; CHECK-LABEL: 'crc16.be.tc8.crc.init.li'
|
||||
; CHECK-NEXT: Found big-endian CRC-16 loop with trip count 8
|
||||
; CHECK-NEXT: Initial CRC: %crc.init = xor i16 %msg.shl, %checksum
|
||||
; CHECK-NEXT: Generating polynomial: 4129
|
||||
; CHECK-NEXT: Computed CRC: %crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.shl
|
||||
; CHECK-NEXT: Computed CRC lookup table:
|
||||
; CHECK-NEXT: 0 256 512 768 1024 1280 1536 1792 2048 2304 2560 2816 3072 3328 3584 3840
|
||||
; CHECK-NEXT: 4096 4352 4608 4864 5120 5376 5632 5888 6144 6400 6656 6912 7168 7424 7680 7936
|
||||
; CHECK-NEXT: 8192 8448 8704 8960 9216 9472 9728 9984 10240 10496 10752 11008 11264 11520 11776 12032
|
||||
; CHECK-NEXT: 12288 12544 12800 13056 13312 13568 13824 14080 14336 14592 14848 15104 15360 15616 15872 16128
|
||||
; CHECK-NEXT: 16384 16640 16896 17152 17408 17664 17920 18176 18432 18688 18944 19200 19456 19712 19968 20224
|
||||
; CHECK-NEXT: 20480 20736 20992 21248 21504 21760 22016 22272 22528 22784 23040 23296 23552 23808 24064 24320
|
||||
; CHECK-NEXT: 24576 24832 25088 25344 25600 25856 26112 26368 26624 26880 27136 27392 27648 27904 28160 28416
|
||||
; CHECK-NEXT: 28672 28928 29184 29440 29696 29952 30208 30464 30720 30976 31232 31488 31744 32000 32256 32512
|
||||
; CHECK-NEXT: 32768 33024 33280 33536 33792 34048 34304 34560 34816 35072 35328 35584 35840 36096 36352 36608
|
||||
; CHECK-NEXT: 36864 37120 37376 37632 37888 38144 38400 38656 38912 39168 39424 39680 39936 40192 40448 40704
|
||||
; CHECK-NEXT: 40960 41216 41472 41728 41984 42240 42496 42752 43008 43264 43520 43776 44032 44288 44544 44800
|
||||
; CHECK-NEXT: 45056 45312 45568 45824 46080 46336 46592 46848 47104 47360 47616 47872 48128 48384 48640 48896
|
||||
; CHECK-NEXT: 49152 49408 49664 49920 50176 50432 50688 50944 51200 51456 51712 51968 52224 52480 52736 52992
|
||||
; CHECK-NEXT: 53248 53504 53760 54016 54272 54528 54784 55040 55296 55552 55808 56064 56320 56576 56832 57088
|
||||
; CHECK-NEXT: 57344 57600 57856 58112 58368 58624 58880 59136 59392 59648 59904 60160 60416 60672 60928 61184
|
||||
; CHECK-NEXT: 61440 61696 61952 62208 62464 62720 62976 63232 63488 63744 64000 64256 64512 64768 65024 65280
|
||||
;
|
||||
entry:
|
||||
%msg.ext = zext i8 %msg to i16
|
||||
%msg.shl = shl nuw i16 %msg.ext, 8
|
||||
%crc.init = xor i16 %msg.shl, %checksum
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp slt i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.shl
|
||||
%iv.next = add nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @crc16.be.tc8.crc.init.arg(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'crc16.be.tc8.crc.init.arg'
|
||||
; CHECK-NEXT: Found big-endian CRC-16 loop with trip count 8
|
||||
; CHECK-NEXT: Initial CRC: i16 %crc.init
|
||||
; CHECK-NEXT: Generating polynomial: 4129
|
||||
; CHECK-NEXT: Computed CRC: %crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.shl
|
||||
; CHECK-NEXT: Computed CRC lookup table:
|
||||
; CHECK-NEXT: 0 256 512 768 1024 1280 1536 1792 2048 2304 2560 2816 3072 3328 3584 3840
|
||||
; CHECK-NEXT: 4096 4352 4608 4864 5120 5376 5632 5888 6144 6400 6656 6912 7168 7424 7680 7936
|
||||
; CHECK-NEXT: 8192 8448 8704 8960 9216 9472 9728 9984 10240 10496 10752 11008 11264 11520 11776 12032
|
||||
; CHECK-NEXT: 12288 12544 12800 13056 13312 13568 13824 14080 14336 14592 14848 15104 15360 15616 15872 16128
|
||||
; CHECK-NEXT: 16384 16640 16896 17152 17408 17664 17920 18176 18432 18688 18944 19200 19456 19712 19968 20224
|
||||
; CHECK-NEXT: 20480 20736 20992 21248 21504 21760 22016 22272 22528 22784 23040 23296 23552 23808 24064 24320
|
||||
; CHECK-NEXT: 24576 24832 25088 25344 25600 25856 26112 26368 26624 26880 27136 27392 27648 27904 28160 28416
|
||||
; CHECK-NEXT: 28672 28928 29184 29440 29696 29952 30208 30464 30720 30976 31232 31488 31744 32000 32256 32512
|
||||
; CHECK-NEXT: 32768 33024 33280 33536 33792 34048 34304 34560 34816 35072 35328 35584 35840 36096 36352 36608
|
||||
; CHECK-NEXT: 36864 37120 37376 37632 37888 38144 38400 38656 38912 39168 39424 39680 39936 40192 40448 40704
|
||||
; CHECK-NEXT: 40960 41216 41472 41728 41984 42240 42496 42752 43008 43264 43520 43776 44032 44288 44544 44800
|
||||
; CHECK-NEXT: 45056 45312 45568 45824 46080 46336 46592 46848 47104 47360 47616 47872 48128 48384 48640 48896
|
||||
; CHECK-NEXT: 49152 49408 49664 49920 50176 50432 50688 50944 51200 51456 51712 51968 52224 52480 52736 52992
|
||||
; CHECK-NEXT: 53248 53504 53760 54016 54272 54528 54784 55040 55296 55552 55808 56064 56320 56576 56832 57088
|
||||
; CHECK-NEXT: 57344 57600 57856 58112 58368 58624 58880 59136 59392 59648 59904 60160 60416 60672 60928 61184
|
||||
; CHECK-NEXT: 61440 61696 61952 62208 62464 62720 62976 63232 63488 63744 64000 64256 64512 64768 65024 65280
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp slt i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.shl
|
||||
%iv.next = add nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @crc16.be.tc8.crc.init.arg.flipped.sb.check(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'crc16.be.tc8.crc.init.arg.flipped.sb.check'
|
||||
; CHECK-NEXT: Found big-endian CRC-16 loop with trip count 8
|
||||
; CHECK-NEXT: Initial CRC: i16 %crc.init
|
||||
; CHECK-NEXT: Generating polynomial: 4129
|
||||
; CHECK-NEXT: Computed CRC: %crc.next = select i1 %check.sb, i16 %crc.shl, i16 %crc.xor
|
||||
; CHECK-NEXT: Computed CRC lookup table:
|
||||
; CHECK-NEXT: 0 256 512 768 1024 1280 1536 1792 2048 2304 2560 2816 3072 3328 3584 3840
|
||||
; CHECK-NEXT: 4096 4352 4608 4864 5120 5376 5632 5888 6144 6400 6656 6912 7168 7424 7680 7936
|
||||
; CHECK-NEXT: 8192 8448 8704 8960 9216 9472 9728 9984 10240 10496 10752 11008 11264 11520 11776 12032
|
||||
; CHECK-NEXT: 12288 12544 12800 13056 13312 13568 13824 14080 14336 14592 14848 15104 15360 15616 15872 16128
|
||||
; CHECK-NEXT: 16384 16640 16896 17152 17408 17664 17920 18176 18432 18688 18944 19200 19456 19712 19968 20224
|
||||
; CHECK-NEXT: 20480 20736 20992 21248 21504 21760 22016 22272 22528 22784 23040 23296 23552 23808 24064 24320
|
||||
; CHECK-NEXT: 24576 24832 25088 25344 25600 25856 26112 26368 26624 26880 27136 27392 27648 27904 28160 28416
|
||||
; CHECK-NEXT: 28672 28928 29184 29440 29696 29952 30208 30464 30720 30976 31232 31488 31744 32000 32256 32512
|
||||
; CHECK-NEXT: 32768 33024 33280 33536 33792 34048 34304 34560 34816 35072 35328 35584 35840 36096 36352 36608
|
||||
; CHECK-NEXT: 36864 37120 37376 37632 37888 38144 38400 38656 38912 39168 39424 39680 39936 40192 40448 40704
|
||||
; CHECK-NEXT: 40960 41216 41472 41728 41984 42240 42496 42752 43008 43264 43520 43776 44032 44288 44544 44800
|
||||
; CHECK-NEXT: 45056 45312 45568 45824 46080 46336 46592 46848 47104 47360 47616 47872 48128 48384 48640 48896
|
||||
; CHECK-NEXT: 49152 49408 49664 49920 50176 50432 50688 50944 51200 51456 51712 51968 52224 52480 52736 52992
|
||||
; CHECK-NEXT: 53248 53504 53760 54016 54272 54528 54784 55040 55296 55552 55808 56064 56320 56576 56832 57088
|
||||
; CHECK-NEXT: 57344 57600 57856 58112 58368 58624 58880 59136 59392 59648 59904 60160 60416 60672 60928 61184
|
||||
; CHECK-NEXT: 61440 61696 61952 62208 62464 62720 62976 63232 63488 63744 64000 64256 64512 64768 65024 65280
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp sge i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.shl, i16 %crc.xor
|
||||
%iv.next = add nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i8 @crc8.be.tc8.ptr.nested.loop(ptr %msg, i32 %loop.limit) {
|
||||
; CHECK-LABEL: 'crc8.be.tc8.ptr.nested.loop'
|
||||
; CHECK-NEXT: Found big-endian CRC-8 loop with trip count 8
|
||||
; CHECK-NEXT: Initial CRC: %crc.init = xor i8 %msg.load, %crc.outer
|
||||
; CHECK-NEXT: Generating polynomial: 29
|
||||
; CHECK-NEXT: Computed CRC: %crc.next = select i1 %check.sb, i8 %crc.xor, i8 %crc.shl
|
||||
; CHECK-NEXT: Computed CRC lookup table:
|
||||
; CHECK-NEXT: 0 29 58 39 116 105 78 83 232 245 210 207 156 129 166 187
|
||||
; CHECK-NEXT: 205 208 247 234 185 164 131 158 37 56 31 2 81 76 107 118
|
||||
; CHECK-NEXT: 135 154 189 160 243 238 201 212 111 114 85 72 27 6 33 60
|
||||
; CHECK-NEXT: 74 87 112 109 62 35 4 25 162 191 152 133 214 203 236 241
|
||||
; CHECK-NEXT: 19 14 41 52 103 122 93 64 251 230 193 220 143 146 181 168
|
||||
; CHECK-NEXT: 222 195 228 249 170 183 144 141 54 43 12 17 66 95 120 101
|
||||
; CHECK-NEXT: 148 137 174 179 224 253 218 199 124 97 70 91 8 21 50 47
|
||||
; CHECK-NEXT: 89 68 99 126 45 48 23 10 177 172 139 150 197 216 255 226
|
||||
; CHECK-NEXT: 38 59 28 1 82 79 104 117 206 211 244 233 186 167 128 157
|
||||
; CHECK-NEXT: 235 246 209 204 159 130 165 184 3 30 57 36 119 106 77 80
|
||||
; CHECK-NEXT: 161 188 155 134 213 200 239 242 73 84 115 110 61 32 7 26
|
||||
; CHECK-NEXT: 108 113 86 75 24 5 34 63 132 153 190 163 240 237 202 215
|
||||
; CHECK-NEXT: 53 40 15 18 65 92 123 102 221 192 231 250 169 180 147 142
|
||||
; CHECK-NEXT: 248 229 194 223 140 145 182 171 16 13 42 55 100 121 94 67
|
||||
; CHECK-NEXT: 178 175 136 149 198 219 252 225 90 71 96 125 46 51 20 9
|
||||
; CHECK-NEXT: 127 98 69 88 11 22 49 44 151 138 173 176 227 254 217 196
|
||||
;
|
||||
entry:
|
||||
br label %outer.loop
|
||||
|
||||
outer.loop: ; preds = %inner.exit, %entry
|
||||
%crc.outer = phi i8 [ 0, %entry ], [ %crc.next, %inner.exit ]
|
||||
%outer.iv = phi i32 [ 0, %entry ], [ %outer.iv.next, %inner.exit ]
|
||||
%outer.exit.cond = icmp ult i32 %outer.iv, %loop.limit
|
||||
br i1 %outer.exit.cond, label %ph, label %exit
|
||||
|
||||
ph: ; preds = %outer.loop
|
||||
%outer.iv.ext = sext i32 %outer.iv to i64
|
||||
%msg.outer.iv = getelementptr inbounds i8, ptr %msg, i64 %outer.iv.ext
|
||||
%msg.load = load i8, ptr %msg.outer.iv, align 1
|
||||
%crc.init = xor i8 %msg.load, %crc.outer
|
||||
br label %inner.loop
|
||||
|
||||
inner.loop: ; preds = %inner.loop, %ph
|
||||
%inner.iv = phi i32 [ 0, %ph ], [ %inner.iv.next, %inner.loop ]
|
||||
%crc = phi i8 [ %crc.init, %ph ], [ %crc.next, %inner.loop ]
|
||||
%crc.shl = shl i8 %crc, 1
|
||||
%crc.xor = xor i8 %crc.shl, 29
|
||||
%check.sb = icmp slt i8 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i8 %crc.xor, i8 %crc.shl
|
||||
%inner.iv.next = add nuw nsw i32 %inner.iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %inner.iv, 7
|
||||
br i1 %exit.cond, label %inner.loop, label %inner.exit
|
||||
|
||||
inner.exit: ; preds = %inner.loop
|
||||
%outer.iv.next = add i32 %outer.iv, 1
|
||||
br label %outer.loop
|
||||
|
||||
exit: ; preds = %outer.loop
|
||||
ret i8 %crc.outer
|
||||
}
|
||||
|
||||
define i32 @crc32.le.tc8.data32(i32 %checksum, i32 %msg) {
|
||||
; CHECK-LABEL: 'crc32.le.tc8.data32'
|
||||
; CHECK-NEXT: Found little-endian CRC-32 loop with trip count 8
|
||||
; CHECK-NEXT: Initial CRC: i32 %checksum
|
||||
; CHECK-NEXT: Generating polynomial: 33800
|
||||
; CHECK-NEXT: Computed CRC: %crc.next = select i1 %check.sb, i32 %crc.lshr, i32 %crc.xor
|
||||
; CHECK-NEXT: Auxiliary data: i32 %msg
|
||||
; CHECK-NEXT: Computed CRC lookup table:
|
||||
; CHECK-NEXT: 0 4489 8978 12955 17956 22445 25910 29887 35912 40385 44890 48851 51820 56293 59774 63735
|
||||
; CHECK-NEXT: 4225 264 13203 8730 22181 18220 30135 25662 40137 36160 49115 44626 56045 52068 63999 59510
|
||||
; CHECK-NEXT: 8450 12427 528 5017 26406 30383 17460 21949 44362 48323 36440 40913 60270 64231 51324 55797
|
||||
; CHECK-NEXT: 12675 8202 4753 792 30631 26158 21685 17724 48587 44098 40665 36688 64495 60006 55549 51572
|
||||
; CHECK-NEXT: 16900 21389 24854 28831 1056 5545 10034 14011 52812 57285 60766 64727 34920 39393 43898 47859
|
||||
; CHECK-NEXT: 21125 17164 29079 24606 5281 1320 14259 9786 57037 53060 64991 60502 39145 35168 48123 43634
|
||||
; CHECK-NEXT: 25350 29327 16404 20893 9506 13483 1584 6073 61262 65223 52316 56789 43370 47331 35448 39921
|
||||
; CHECK-NEXT: 29575 25102 20629 16668 13731 9258 5809 1848 65487 60998 56541 52564 47595 43106 39673 35696
|
||||
; CHECK-NEXT: 33800 38273 42778 46739 49708 54181 57662 61623 2112 6601 11090 15067 20068 24557 28022 31999
|
||||
; CHECK-NEXT: 38025 34048 47003 42514 53933 49956 61887 57398 6337 2376 15315 10842 24293 20332 32247 27774
|
||||
; CHECK-NEXT: 42250 46211 34328 38801 58158 62119 49212 53685 10562 14539 2640 7129 28518 32495 19572 24061
|
||||
; CHECK-NEXT: 46475 41986 38553 34576 62383 57894 53437 49460 14787 10314 6865 2904 32743 28270 23797 19836
|
||||
; CHECK-NEXT: 50700 55173 58654 62615 32808 37281 41786 45747 19012 23501 26966 30943 3168 7657 12146 16123
|
||||
; CHECK-NEXT: 54925 50948 62879 58390 37033 33056 46011 41522 23237 19276 31191 26718 7393 3432 16371 11898
|
||||
; CHECK-NEXT: 59150 63111 50204 54677 41258 45219 33336 37809 27462 31439 18516 23005 11618 15595 3696 8185
|
||||
; CHECK-NEXT: 63375 58886 54429 50452 45483 40994 37561 33584 31687 27214 22741 18780 15843 11370 7921 3960
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%crc = phi i32 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i32 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%xor.crc.data = xor i32 %crc, %data
|
||||
%sb.crc.data = and i32 %xor.crc.data, 1
|
||||
%check.sb = icmp eq i32 %sb.crc.data, 0
|
||||
%crc.lshr = lshr i32 %crc, 1
|
||||
%crc.xor = xor i32 %crc.lshr, 33800
|
||||
%crc.next = select i1 %check.sb, i32 %crc.lshr, i32 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%data.next = lshr i32 %data, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i32 %crc.next
|
||||
}
|
||||
|
||||
; Negative tests
|
||||
|
||||
define i16 @not.crc.non.const.tc(i16 %crc.init, i32 %loop.limit) {
|
||||
; CHECK-LABEL: 'not.crc.non.const.tc'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Unable to find a small constant trip count
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp sge i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.shl, i16 %crc.xor
|
||||
%iv.next = add nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %iv, %loop.limit
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.non.canonical.loop(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'not.crc.non.canonical.loop'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Loop not in canonical form
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 7, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp slt i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.shl
|
||||
%iv.next = sub nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign eq i32 %iv, 0
|
||||
br i1 %exit.cond, label %exit, label %loop
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.tc.limit(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'not.crc.tc.limit'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Unable to find a small constant trip count
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp slt i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.shl
|
||||
%iv.next = add nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %iv, 512
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.no.conditional.recurrence(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'not.crc.no.conditional.recurrence'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Unable to find conditional recurrence
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%shl = shl i16 %crc, 1
|
||||
%crc.next = xor i16 %shl, 258
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
|
||||
define i16 @not.crc.bad.shift.recurrence(i16 %checksum, i8 %msg) {
|
||||
; CHECK-LABEL: 'not.crc.bad.shift.recurrence'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Loop with non-unit bitshifts
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%data = phi i8 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%crc.lshr = lshr i16 %crc, 8
|
||||
%data.ext = zext i8 %data to i16
|
||||
%xor.crc.data = xor i16 %crc.lshr, %data.ext
|
||||
%check.sb = icmp samesign ult i16 %xor.crc.data, 128
|
||||
%crc.and = and i16 %crc, 32767
|
||||
%crc.xor = xor i16 %crc.and, 258
|
||||
%crc.next = select i1 %check.sb, i16 %crc.and, i16 %crc.xor
|
||||
%data.next = shl i8 %data, 1
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.nonunit.shifts(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'not.crc.nonunit.shifts'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Loop with non-unit bitshifts
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 2
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp slt i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.shl
|
||||
%iv.next = add nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.result.unused(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'not.crc.result.unused'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Unable to find use of computed value in loop exit block
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp slt i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.shl
|
||||
%iv.next = add nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc
|
||||
}
|
||||
|
||||
define i16 @not.crc.wrong.sb.check.const(i8 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'not.crc.wrong.sb.check.const'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Simple recurrence doesn't use conditional recurrence with XOR
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%data = phi i8 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%crc.lshr = lshr i16 %crc, 8
|
||||
%data.ext = zext i8 %data to i16
|
||||
%xor.crc.data = xor i16 %crc.lshr, %data.ext
|
||||
%check.sb = icmp samesign ult i16 %xor.crc.data, 128
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 258
|
||||
%crc.next = select i1 %check.sb, i16 %crc.shl, i16 %crc.xor
|
||||
%data.next = shl i8 %data, 1
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.wrong.sb.check.pred(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'not.crc.wrong.sb.check.pred'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Bad RHS of significant-bit-check
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%crc.shl = shl i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.shl, 4129
|
||||
%check.sb = icmp sgt i16 %crc, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.shl, i16 %crc.xor
|
||||
%iv.next = add nuw nsw i32 %iv, 1
|
||||
%exit.cond = icmp samesign ult i32 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.excess.tc(i16 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'not.crc.excess.tc'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Loop iterations exceed bitwidth of result
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i16 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%xor.crc.data = xor i16 %crc, %data
|
||||
%and.crc.data = and i16 %xor.crc.data, 1
|
||||
%data.next = lshr i16 %data, 1
|
||||
%check.sb = icmp eq i16 %and.crc.data, 0
|
||||
%crc.lshr = lshr i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 20
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i32 @not.crc.unknown.icmp.rhs(i32 %checksum, i32 %msg, i32 %unknown) {
|
||||
; CHECK-LABEL: 'not.crc.unknown.icmp.rhs'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Bad LHS of significant-bit-check
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%crc = phi i32 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i32 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%xor.crc.data = xor i32 %crc, %data
|
||||
%sb.crc.data = or i32 %xor.crc.data, 1
|
||||
%check.sb = icmp eq i32 %sb.crc.data, %unknown
|
||||
%crc.lshr = lshr i32 %crc, 1
|
||||
%crc.xor = xor i32 %crc.lshr, 33800
|
||||
%crc.next = select i1 %check.sb, i32 %crc.lshr, i32 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%data.next = lshr i32 %data, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i32 %crc.next
|
||||
}
|
||||
|
||||
define i32 @not.crc.unknown.icmp.lhs(i32 %checksum, i32 %msg, i32 %unknown) {
|
||||
; CHECK-LABEL: 'not.crc.unknown.icmp.lhs'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Bad LHS of significant-bit-check
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%crc = phi i32 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i32 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%xor.crc.data = xor i32 %crc, %data
|
||||
%sb.crc.data = or i32 %xor.crc.data, %unknown
|
||||
%check.sb = icmp eq i32 %sb.crc.data, 0
|
||||
%crc.lshr = lshr i32 %crc, 1
|
||||
%crc.xor = xor i32 %crc.lshr, 33800
|
||||
%crc.next = select i1 %check.sb, i32 %crc.lshr, i32 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%data.next = lshr i32 %data, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i32 %crc.next
|
||||
}
|
||||
|
||||
|
||||
define i16 @not.crc.stray.or(i16 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'not.crc.stray.or'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Bad LHS of significant-bit-check
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i16 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%xor.crc.data = xor i16 %crc, %data
|
||||
%and.crc.data = and i16 %xor.crc.data, 1
|
||||
%crc.corrupt = or i16 %and.crc.data, 1
|
||||
%data.next = lshr i16 %data, 1
|
||||
%check.sb = icmp ne i16 %crc.corrupt, 0
|
||||
%crc.lshr = lshr i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 15
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.inverse.sb.check(i16 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'not.crc.inverse.sb.check'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Expected top 16 bits zero (1100000000000001)
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i16 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%xor.crc.data = xor i16 %crc, %data
|
||||
%and.crc.data = and i16 %xor.crc.data, 1
|
||||
%data.next = lshr i16 %data, 1
|
||||
%check.sb = icmp ne i16 %and.crc.data, 0
|
||||
%crc.lshr = lshr i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 15
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @crc1.tc8.sb.check.endian.mismatch(i8 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'crc1.tc8.sb.check.endian.mismatch'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Bad RHS of significant-bit-check
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i8 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%crc.trunc = trunc i16 %crc to i8
|
||||
%xor.data.crc = xor i8 %data, %crc.trunc
|
||||
%and.data.crc = and i8 %xor.data.crc, 1
|
||||
%data.next = mul i8 %data, 2
|
||||
%check.sb = icmp eq i8 %and.data.crc, 0
|
||||
%crc.lshr = mul i16 %crc, 2
|
||||
%xor = xor i16 %crc.lshr, 0
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.init.arg.inverted.select(i16 %crc.init) {
|
||||
; CHECK-LABEL: 'not.crc.init.arg.inverted.select'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Expected top 8 bits zero (11000000????????)
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %crc.init, %entry ], [ %crc.next, %loop ]
|
||||
%sb.crc = and i16 %crc, 1
|
||||
%check.sb = icmp eq i16 %sb.crc, 0
|
||||
%crc.lshr = lshr i16 %crc, 1
|
||||
%crc.xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.xor, i16 %crc.lshr
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
|
||||
define i32 @not.crc.dead.msg.bad.use(i32 %checksum, i32 %msg) {
|
||||
; CHECK-LABEL: 'not.crc.dead.msg.bad.use'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Simple recurrence doesn't use conditional recurrence with XOR
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%crc = phi i32 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i32 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%data.or = or i32 %data, -1
|
||||
%xor.crc.data = xor i32 %crc, %data.or
|
||||
%sb.crc.data = and i32 %xor.crc.data, 1
|
||||
%check.sb = icmp eq i32 %sb.crc.data, 0
|
||||
%crc.lshr = lshr i32 %crc, 1
|
||||
%crc.xor = xor i32 %crc.lshr, 33800
|
||||
%crc.next = select i1 %check.sb, i32 %crc.lshr, i32 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%data.next = lshr i32 %data, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i32 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.dead.msg.no.use(i8 %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'not.crc.dead.msg.no.use'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Simple recurrence doesn't use conditional recurrence with XOR
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i8 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%crc.trunc = trunc i16 %crc to i8
|
||||
%and.crc = and i8 %crc.trunc, 1
|
||||
%data.next = lshr i8 %data, 1
|
||||
%check.sb = icmp eq i8 %and.crc, 0
|
||||
%crc.lshr = lshr i16 %crc, 1
|
||||
%xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
%data.zext = zext i8 %data.next to i16
|
||||
%ret = xor i16 %crc.next, %data.zext
|
||||
ret i16 %ret
|
||||
}
|
||||
|
||||
define i32 @not.crc.dead.msg.wrong.op(i32 %checksum, i32 %msg) {
|
||||
; CHECK-LABEL: 'not.crc.dead.msg.wrong.op'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Simple recurrence doesn't use conditional recurrence with XOR
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%crc = phi i32 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi i32 [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%or.crc.data = or i32 %crc, %data
|
||||
%sb.crc.data = and i32 %or.crc.data, 1
|
||||
%check.sb = icmp eq i32 %sb.crc.data, 0
|
||||
%crc.lshr = lshr i32 %crc, 1
|
||||
%crc.xor = xor i32 %crc.lshr, 33800
|
||||
%crc.next = select i1 %check.sb, i32 %crc.lshr, i32 %crc.xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%data.next = lshr i32 %data, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i32 %crc.next
|
||||
}
|
||||
|
||||
define i16 @not.crc.float.simple.recurrence(float %msg, i16 %checksum) {
|
||||
; CHECK-LABEL: 'not.crc.float.simple.recurrence'
|
||||
; CHECK-NEXT: Did not find a hash algorithm
|
||||
; CHECK-NEXT: Reason: Found stray PHI
|
||||
;
|
||||
entry:
|
||||
br label %loop
|
||||
|
||||
loop: ; preds = %loop, %entry
|
||||
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
|
||||
%crc = phi i16 [ %checksum, %entry ], [ %crc.next, %loop ]
|
||||
%data = phi float [ %msg, %entry ], [ %data.next, %loop ]
|
||||
%crc.conv = sitofp i16 %crc to float
|
||||
%frem.data.crc = frem float %data, %crc.conv
|
||||
%and.data.crc = fdiv float %frem.data.crc, 2.0
|
||||
%data.next = fdiv float %data, 2.0
|
||||
%check.sb = fcmp oeq float %and.data.crc, 0.0
|
||||
%crc.lshr = lshr i16 %crc, 1
|
||||
%xor = xor i16 %crc.lshr, -24575
|
||||
%crc.next = select i1 %check.sb, i16 %crc.lshr, i16 %xor
|
||||
%iv.next = add nuw nsw i8 %iv, 1
|
||||
%exit.cond = icmp samesign ult i8 %iv, 7
|
||||
br i1 %exit.cond, label %loop, label %exit
|
||||
|
||||
exit: ; preds = %loop
|
||||
ret i16 %crc.next
|
||||
}
|
||||
@ -56,6 +56,7 @@ static_library("Analysis") {
|
||||
"FunctionPropertiesAnalysis.cpp",
|
||||
"GlobalsModRef.cpp",
|
||||
"GuardUtils.cpp",
|
||||
"HashRecognize.cpp",
|
||||
"HeatUtils.cpp",
|
||||
"IR2Vec.cpp",
|
||||
"IRSimilarityIdentifier.cpp",
|
||||
|
||||
@ -109,10 +109,13 @@ def update_test(opt_basename: str, ti: common.TestInfo):
|
||||
prefixes,
|
||||
)
|
||||
elif (
|
||||
re.search(r"(LV|LDist): Checking a loop in ", raw_tool_outputs) is not None
|
||||
re.search(
|
||||
r"(LV|LDist|HashRecognize): Checking a loop in ", raw_tool_outputs
|
||||
)
|
||||
is not None
|
||||
):
|
||||
for raw_tool_output in re.split(
|
||||
r"(LV|LDist): Checking a loop in ", raw_tool_outputs
|
||||
r"(LV|LDist|HashRecognize): Checking a loop in ", raw_tool_outputs
|
||||
):
|
||||
builder.process_run_line(
|
||||
common.LOOP_PASS_DEBUG_RE,
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user