forked from OSchip/llvm-project
951 lines
33 KiB
C++
951 lines
33 KiB
C++
//===- FunctionComparator.h - Function Comparator -------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the FunctionComparator and GlobalNumberState classes
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// which are used by the MergeFunctions pass for comparing functions.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/Utils/FunctionComparator.h"
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#include "llvm/ADT/APFloat.h"
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#include "llvm/ADT/APInt.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/Hashing.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/SmallSet.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/IR/Attributes.h"
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#include "llvm/IR/BasicBlock.h"
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#include "llvm/IR/CallSite.h"
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#include "llvm/IR/Constant.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DerivedTypes.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/GlobalValue.h"
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#include "llvm/IR/InlineAsm.h"
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#include "llvm/IR/InstrTypes.h"
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#include "llvm/IR/Instruction.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/Metadata.h"
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#include "llvm/IR/Module.h"
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#include "llvm/IR/Operator.h"
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#include "llvm/IR/Type.h"
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#include "llvm/IR/Value.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/raw_ostream.h"
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#include <cassert>
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#include <cstddef>
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#include <cstdint>
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#include <utility>
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using namespace llvm;
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#define DEBUG_TYPE "functioncomparator"
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int FunctionComparator::cmpNumbers(uint64_t L, uint64_t R) const {
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if (L < R) return -1;
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if (L > R) return 1;
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return 0;
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}
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int FunctionComparator::cmpOrderings(AtomicOrdering L, AtomicOrdering R) const {
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if ((int)L < (int)R) return -1;
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if ((int)L > (int)R) return 1;
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return 0;
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}
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int FunctionComparator::cmpAPInts(const APInt &L, const APInt &R) const {
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if (int Res = cmpNumbers(L.getBitWidth(), R.getBitWidth()))
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return Res;
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if (L.ugt(R)) return 1;
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if (R.ugt(L)) return -1;
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return 0;
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}
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int FunctionComparator::cmpAPFloats(const APFloat &L, const APFloat &R) const {
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// Floats are ordered first by semantics (i.e. float, double, half, etc.),
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// then by value interpreted as a bitstring (aka APInt).
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const fltSemantics &SL = L.getSemantics(), &SR = R.getSemantics();
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if (int Res = cmpNumbers(APFloat::semanticsPrecision(SL),
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APFloat::semanticsPrecision(SR)))
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return Res;
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if (int Res = cmpNumbers(APFloat::semanticsMaxExponent(SL),
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APFloat::semanticsMaxExponent(SR)))
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return Res;
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if (int Res = cmpNumbers(APFloat::semanticsMinExponent(SL),
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APFloat::semanticsMinExponent(SR)))
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return Res;
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if (int Res = cmpNumbers(APFloat::semanticsSizeInBits(SL),
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APFloat::semanticsSizeInBits(SR)))
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return Res;
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return cmpAPInts(L.bitcastToAPInt(), R.bitcastToAPInt());
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}
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int FunctionComparator::cmpMem(StringRef L, StringRef R) const {
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// Prevent heavy comparison, compare sizes first.
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if (int Res = cmpNumbers(L.size(), R.size()))
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return Res;
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// Compare strings lexicographically only when it is necessary: only when
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// strings are equal in size.
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return L.compare(R);
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}
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int FunctionComparator::cmpAttrs(const AttributeList L,
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const AttributeList R) const {
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if (int Res = cmpNumbers(L.getNumAttrSets(), R.getNumAttrSets()))
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return Res;
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for (unsigned i = L.index_begin(), e = L.index_end(); i != e; ++i) {
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AttributeSet LAS = L.getAttributes(i);
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AttributeSet RAS = R.getAttributes(i);
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AttributeSet::iterator LI = LAS.begin(), LE = LAS.end();
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AttributeSet::iterator RI = RAS.begin(), RE = RAS.end();
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for (; LI != LE && RI != RE; ++LI, ++RI) {
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Attribute LA = *LI;
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Attribute RA = *RI;
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if (LA < RA)
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return -1;
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if (RA < LA)
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return 1;
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}
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if (LI != LE)
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return 1;
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if (RI != RE)
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return -1;
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}
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return 0;
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}
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int FunctionComparator::cmpRangeMetadata(const MDNode *L,
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const MDNode *R) const {
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if (L == R)
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return 0;
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if (!L)
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return -1;
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if (!R)
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return 1;
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// Range metadata is a sequence of numbers. Make sure they are the same
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// sequence.
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// TODO: Note that as this is metadata, it is possible to drop and/or merge
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// this data when considering functions to merge. Thus this comparison would
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// return 0 (i.e. equivalent), but merging would become more complicated
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// because the ranges would need to be unioned. It is not likely that
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// functions differ ONLY in this metadata if they are actually the same
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// function semantically.
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if (int Res = cmpNumbers(L->getNumOperands(), R->getNumOperands()))
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return Res;
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for (size_t I = 0; I < L->getNumOperands(); ++I) {
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ConstantInt *LLow = mdconst::extract<ConstantInt>(L->getOperand(I));
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ConstantInt *RLow = mdconst::extract<ConstantInt>(R->getOperand(I));
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if (int Res = cmpAPInts(LLow->getValue(), RLow->getValue()))
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return Res;
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}
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return 0;
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}
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int FunctionComparator::cmpOperandBundlesSchema(const Instruction *L,
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const Instruction *R) const {
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ImmutableCallSite LCS(L);
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ImmutableCallSite RCS(R);
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assert(LCS && RCS && "Must be calls or invokes!");
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assert(LCS.isCall() == RCS.isCall() && "Can't compare otherwise!");
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if (int Res =
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cmpNumbers(LCS.getNumOperandBundles(), RCS.getNumOperandBundles()))
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return Res;
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for (unsigned i = 0, e = LCS.getNumOperandBundles(); i != e; ++i) {
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auto OBL = LCS.getOperandBundleAt(i);
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auto OBR = RCS.getOperandBundleAt(i);
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if (int Res = OBL.getTagName().compare(OBR.getTagName()))
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return Res;
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if (int Res = cmpNumbers(OBL.Inputs.size(), OBR.Inputs.size()))
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return Res;
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}
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return 0;
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}
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/// Constants comparison:
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/// 1. Check whether type of L constant could be losslessly bitcasted to R
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/// type.
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/// 2. Compare constant contents.
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/// For more details see declaration comments.
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int FunctionComparator::cmpConstants(const Constant *L,
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const Constant *R) const {
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Type *TyL = L->getType();
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Type *TyR = R->getType();
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// Check whether types are bitcastable. This part is just re-factored
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// Type::canLosslesslyBitCastTo method, but instead of returning true/false,
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// we also pack into result which type is "less" for us.
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int TypesRes = cmpTypes(TyL, TyR);
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if (TypesRes != 0) {
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// Types are different, but check whether we can bitcast them.
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if (!TyL->isFirstClassType()) {
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if (TyR->isFirstClassType())
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return -1;
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// Neither TyL nor TyR are values of first class type. Return the result
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// of comparing the types
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return TypesRes;
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}
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if (!TyR->isFirstClassType()) {
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if (TyL->isFirstClassType())
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return 1;
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return TypesRes;
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}
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// Vector -> Vector conversions are always lossless if the two vector types
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// have the same size, otherwise not.
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unsigned TyLWidth = 0;
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unsigned TyRWidth = 0;
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if (auto *VecTyL = dyn_cast<VectorType>(TyL))
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TyLWidth = VecTyL->getBitWidth();
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if (auto *VecTyR = dyn_cast<VectorType>(TyR))
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TyRWidth = VecTyR->getBitWidth();
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if (TyLWidth != TyRWidth)
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return cmpNumbers(TyLWidth, TyRWidth);
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// Zero bit-width means neither TyL nor TyR are vectors.
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if (!TyLWidth) {
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PointerType *PTyL = dyn_cast<PointerType>(TyL);
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PointerType *PTyR = dyn_cast<PointerType>(TyR);
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if (PTyL && PTyR) {
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unsigned AddrSpaceL = PTyL->getAddressSpace();
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unsigned AddrSpaceR = PTyR->getAddressSpace();
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if (int Res = cmpNumbers(AddrSpaceL, AddrSpaceR))
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return Res;
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}
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if (PTyL)
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return 1;
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if (PTyR)
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return -1;
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// TyL and TyR aren't vectors, nor pointers. We don't know how to
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// bitcast them.
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return TypesRes;
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}
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}
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// OK, types are bitcastable, now check constant contents.
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if (L->isNullValue() && R->isNullValue())
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return TypesRes;
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if (L->isNullValue() && !R->isNullValue())
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return 1;
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if (!L->isNullValue() && R->isNullValue())
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return -1;
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auto GlobalValueL = const_cast<GlobalValue *>(dyn_cast<GlobalValue>(L));
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auto GlobalValueR = const_cast<GlobalValue *>(dyn_cast<GlobalValue>(R));
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if (GlobalValueL && GlobalValueR) {
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return cmpGlobalValues(GlobalValueL, GlobalValueR);
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}
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if (int Res = cmpNumbers(L->getValueID(), R->getValueID()))
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return Res;
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if (const auto *SeqL = dyn_cast<ConstantDataSequential>(L)) {
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const auto *SeqR = cast<ConstantDataSequential>(R);
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// This handles ConstantDataArray and ConstantDataVector. Note that we
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// compare the two raw data arrays, which might differ depending on the host
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// endianness. This isn't a problem though, because the endiness of a module
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// will affect the order of the constants, but this order is the same
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// for a given input module and host platform.
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return cmpMem(SeqL->getRawDataValues(), SeqR->getRawDataValues());
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}
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switch (L->getValueID()) {
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case Value::UndefValueVal:
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case Value::ConstantTokenNoneVal:
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return TypesRes;
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case Value::ConstantIntVal: {
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const APInt &LInt = cast<ConstantInt>(L)->getValue();
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const APInt &RInt = cast<ConstantInt>(R)->getValue();
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return cmpAPInts(LInt, RInt);
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}
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case Value::ConstantFPVal: {
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const APFloat &LAPF = cast<ConstantFP>(L)->getValueAPF();
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const APFloat &RAPF = cast<ConstantFP>(R)->getValueAPF();
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return cmpAPFloats(LAPF, RAPF);
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}
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case Value::ConstantArrayVal: {
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const ConstantArray *LA = cast<ConstantArray>(L);
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const ConstantArray *RA = cast<ConstantArray>(R);
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uint64_t NumElementsL = cast<ArrayType>(TyL)->getNumElements();
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uint64_t NumElementsR = cast<ArrayType>(TyR)->getNumElements();
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if (int Res = cmpNumbers(NumElementsL, NumElementsR))
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return Res;
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for (uint64_t i = 0; i < NumElementsL; ++i) {
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if (int Res = cmpConstants(cast<Constant>(LA->getOperand(i)),
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cast<Constant>(RA->getOperand(i))))
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return Res;
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}
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return 0;
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}
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case Value::ConstantStructVal: {
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const ConstantStruct *LS = cast<ConstantStruct>(L);
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const ConstantStruct *RS = cast<ConstantStruct>(R);
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unsigned NumElementsL = cast<StructType>(TyL)->getNumElements();
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unsigned NumElementsR = cast<StructType>(TyR)->getNumElements();
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if (int Res = cmpNumbers(NumElementsL, NumElementsR))
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return Res;
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for (unsigned i = 0; i != NumElementsL; ++i) {
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if (int Res = cmpConstants(cast<Constant>(LS->getOperand(i)),
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cast<Constant>(RS->getOperand(i))))
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return Res;
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}
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return 0;
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}
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case Value::ConstantVectorVal: {
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const ConstantVector *LV = cast<ConstantVector>(L);
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const ConstantVector *RV = cast<ConstantVector>(R);
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unsigned NumElementsL = cast<VectorType>(TyL)->getNumElements();
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unsigned NumElementsR = cast<VectorType>(TyR)->getNumElements();
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if (int Res = cmpNumbers(NumElementsL, NumElementsR))
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return Res;
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for (uint64_t i = 0; i < NumElementsL; ++i) {
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if (int Res = cmpConstants(cast<Constant>(LV->getOperand(i)),
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cast<Constant>(RV->getOperand(i))))
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return Res;
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}
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return 0;
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}
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case Value::ConstantExprVal: {
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const ConstantExpr *LE = cast<ConstantExpr>(L);
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const ConstantExpr *RE = cast<ConstantExpr>(R);
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unsigned NumOperandsL = LE->getNumOperands();
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unsigned NumOperandsR = RE->getNumOperands();
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if (int Res = cmpNumbers(NumOperandsL, NumOperandsR))
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return Res;
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for (unsigned i = 0; i < NumOperandsL; ++i) {
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if (int Res = cmpConstants(cast<Constant>(LE->getOperand(i)),
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cast<Constant>(RE->getOperand(i))))
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return Res;
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}
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return 0;
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}
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case Value::BlockAddressVal: {
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const BlockAddress *LBA = cast<BlockAddress>(L);
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const BlockAddress *RBA = cast<BlockAddress>(R);
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if (int Res = cmpValues(LBA->getFunction(), RBA->getFunction()))
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return Res;
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if (LBA->getFunction() == RBA->getFunction()) {
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// They are BBs in the same function. Order by which comes first in the
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// BB order of the function. This order is deterministic.
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Function* F = LBA->getFunction();
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BasicBlock *LBB = LBA->getBasicBlock();
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BasicBlock *RBB = RBA->getBasicBlock();
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if (LBB == RBB)
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return 0;
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for(BasicBlock &BB : F->getBasicBlockList()) {
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if (&BB == LBB) {
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assert(&BB != RBB);
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return -1;
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}
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if (&BB == RBB)
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return 1;
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}
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llvm_unreachable("Basic Block Address does not point to a basic block in "
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"its function.");
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return -1;
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} else {
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// cmpValues said the functions are the same. So because they aren't
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// literally the same pointer, they must respectively be the left and
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// right functions.
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assert(LBA->getFunction() == FnL && RBA->getFunction() == FnR);
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// cmpValues will tell us if these are equivalent BasicBlocks, in the
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// context of their respective functions.
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return cmpValues(LBA->getBasicBlock(), RBA->getBasicBlock());
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}
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}
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default: // Unknown constant, abort.
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DEBUG(dbgs() << "Looking at valueID " << L->getValueID() << "\n");
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llvm_unreachable("Constant ValueID not recognized.");
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return -1;
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}
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}
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int FunctionComparator::cmpGlobalValues(GlobalValue *L, GlobalValue *R) const {
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uint64_t LNumber = GlobalNumbers->getNumber(L);
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uint64_t RNumber = GlobalNumbers->getNumber(R);
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return cmpNumbers(LNumber, RNumber);
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}
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/// cmpType - compares two types,
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/// defines total ordering among the types set.
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/// See method declaration comments for more details.
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int FunctionComparator::cmpTypes(Type *TyL, Type *TyR) const {
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PointerType *PTyL = dyn_cast<PointerType>(TyL);
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PointerType *PTyR = dyn_cast<PointerType>(TyR);
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const DataLayout &DL = FnL->getParent()->getDataLayout();
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if (PTyL && PTyL->getAddressSpace() == 0)
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TyL = DL.getIntPtrType(TyL);
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if (PTyR && PTyR->getAddressSpace() == 0)
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TyR = DL.getIntPtrType(TyR);
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if (TyL == TyR)
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return 0;
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if (int Res = cmpNumbers(TyL->getTypeID(), TyR->getTypeID()))
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return Res;
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switch (TyL->getTypeID()) {
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default:
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llvm_unreachable("Unknown type!");
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// Fall through in Release mode.
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LLVM_FALLTHROUGH;
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case Type::IntegerTyID:
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return cmpNumbers(cast<IntegerType>(TyL)->getBitWidth(),
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cast<IntegerType>(TyR)->getBitWidth());
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// TyL == TyR would have returned true earlier, because types are uniqued.
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case Type::VoidTyID:
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case Type::FloatTyID:
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case Type::DoubleTyID:
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case Type::X86_FP80TyID:
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case Type::FP128TyID:
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case Type::PPC_FP128TyID:
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case Type::LabelTyID:
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case Type::MetadataTyID:
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case Type::TokenTyID:
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return 0;
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case Type::PointerTyID:
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assert(PTyL && PTyR && "Both types must be pointers here.");
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return cmpNumbers(PTyL->getAddressSpace(), PTyR->getAddressSpace());
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case Type::StructTyID: {
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StructType *STyL = cast<StructType>(TyL);
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StructType *STyR = cast<StructType>(TyR);
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if (STyL->getNumElements() != STyR->getNumElements())
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return cmpNumbers(STyL->getNumElements(), STyR->getNumElements());
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if (STyL->isPacked() != STyR->isPacked())
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return cmpNumbers(STyL->isPacked(), STyR->isPacked());
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for (unsigned i = 0, e = STyL->getNumElements(); i != e; ++i) {
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if (int Res = cmpTypes(STyL->getElementType(i), STyR->getElementType(i)))
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return Res;
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}
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return 0;
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}
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case Type::FunctionTyID: {
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FunctionType *FTyL = cast<FunctionType>(TyL);
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FunctionType *FTyR = cast<FunctionType>(TyR);
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if (FTyL->getNumParams() != FTyR->getNumParams())
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return cmpNumbers(FTyL->getNumParams(), FTyR->getNumParams());
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if (FTyL->isVarArg() != FTyR->isVarArg())
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return cmpNumbers(FTyL->isVarArg(), FTyR->isVarArg());
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if (int Res = cmpTypes(FTyL->getReturnType(), FTyR->getReturnType()))
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return Res;
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for (unsigned i = 0, e = FTyL->getNumParams(); i != e; ++i) {
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if (int Res = cmpTypes(FTyL->getParamType(i), FTyR->getParamType(i)))
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return Res;
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}
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return 0;
|
|
}
|
|
|
|
case Type::ArrayTyID:
|
|
case Type::VectorTyID: {
|
|
auto *STyL = cast<SequentialType>(TyL);
|
|
auto *STyR = cast<SequentialType>(TyR);
|
|
if (STyL->getNumElements() != STyR->getNumElements())
|
|
return cmpNumbers(STyL->getNumElements(), STyR->getNumElements());
|
|
return cmpTypes(STyL->getElementType(), STyR->getElementType());
|
|
}
|
|
}
|
|
}
|
|
|
|
// Determine whether the two operations are the same except that pointer-to-A
|
|
// and pointer-to-B are equivalent. This should be kept in sync with
|
|
// Instruction::isSameOperationAs.
|
|
// Read method declaration comments for more details.
|
|
int FunctionComparator::cmpOperations(const Instruction *L,
|
|
const Instruction *R,
|
|
bool &needToCmpOperands) const {
|
|
needToCmpOperands = true;
|
|
if (int Res = cmpValues(L, R))
|
|
return Res;
|
|
|
|
// Differences from Instruction::isSameOperationAs:
|
|
// * replace type comparison with calls to cmpTypes.
|
|
// * we test for I->getRawSubclassOptionalData (nuw/nsw/tail) at the top.
|
|
// * because of the above, we don't test for the tail bit on calls later on.
|
|
if (int Res = cmpNumbers(L->getOpcode(), R->getOpcode()))
|
|
return Res;
|
|
|
|
if (const GetElementPtrInst *GEPL = dyn_cast<GetElementPtrInst>(L)) {
|
|
needToCmpOperands = false;
|
|
const GetElementPtrInst *GEPR = cast<GetElementPtrInst>(R);
|
|
if (int Res =
|
|
cmpValues(GEPL->getPointerOperand(), GEPR->getPointerOperand()))
|
|
return Res;
|
|
return cmpGEPs(GEPL, GEPR);
|
|
}
|
|
|
|
if (int Res = cmpNumbers(L->getNumOperands(), R->getNumOperands()))
|
|
return Res;
|
|
|
|
if (int Res = cmpTypes(L->getType(), R->getType()))
|
|
return Res;
|
|
|
|
if (int Res = cmpNumbers(L->getRawSubclassOptionalData(),
|
|
R->getRawSubclassOptionalData()))
|
|
return Res;
|
|
|
|
// We have two instructions of identical opcode and #operands. Check to see
|
|
// if all operands are the same type
|
|
for (unsigned i = 0, e = L->getNumOperands(); i != e; ++i) {
|
|
if (int Res =
|
|
cmpTypes(L->getOperand(i)->getType(), R->getOperand(i)->getType()))
|
|
return Res;
|
|
}
|
|
|
|
// Check special state that is a part of some instructions.
|
|
if (const AllocaInst *AI = dyn_cast<AllocaInst>(L)) {
|
|
if (int Res = cmpTypes(AI->getAllocatedType(),
|
|
cast<AllocaInst>(R)->getAllocatedType()))
|
|
return Res;
|
|
return cmpNumbers(AI->getAlignment(), cast<AllocaInst>(R)->getAlignment());
|
|
}
|
|
if (const LoadInst *LI = dyn_cast<LoadInst>(L)) {
|
|
if (int Res = cmpNumbers(LI->isVolatile(), cast<LoadInst>(R)->isVolatile()))
|
|
return Res;
|
|
if (int Res =
|
|
cmpNumbers(LI->getAlignment(), cast<LoadInst>(R)->getAlignment()))
|
|
return Res;
|
|
if (int Res =
|
|
cmpOrderings(LI->getOrdering(), cast<LoadInst>(R)->getOrdering()))
|
|
return Res;
|
|
if (int Res = cmpNumbers(LI->getSyncScopeID(),
|
|
cast<LoadInst>(R)->getSyncScopeID()))
|
|
return Res;
|
|
return cmpRangeMetadata(LI->getMetadata(LLVMContext::MD_range),
|
|
cast<LoadInst>(R)->getMetadata(LLVMContext::MD_range));
|
|
}
|
|
if (const StoreInst *SI = dyn_cast<StoreInst>(L)) {
|
|
if (int Res =
|
|
cmpNumbers(SI->isVolatile(), cast<StoreInst>(R)->isVolatile()))
|
|
return Res;
|
|
if (int Res =
|
|
cmpNumbers(SI->getAlignment(), cast<StoreInst>(R)->getAlignment()))
|
|
return Res;
|
|
if (int Res =
|
|
cmpOrderings(SI->getOrdering(), cast<StoreInst>(R)->getOrdering()))
|
|
return Res;
|
|
return cmpNumbers(SI->getSyncScopeID(),
|
|
cast<StoreInst>(R)->getSyncScopeID());
|
|
}
|
|
if (const CmpInst *CI = dyn_cast<CmpInst>(L))
|
|
return cmpNumbers(CI->getPredicate(), cast<CmpInst>(R)->getPredicate());
|
|
if (const CallInst *CI = dyn_cast<CallInst>(L)) {
|
|
if (int Res = cmpNumbers(CI->getCallingConv(),
|
|
cast<CallInst>(R)->getCallingConv()))
|
|
return Res;
|
|
if (int Res =
|
|
cmpAttrs(CI->getAttributes(), cast<CallInst>(R)->getAttributes()))
|
|
return Res;
|
|
if (int Res = cmpOperandBundlesSchema(CI, R))
|
|
return Res;
|
|
return cmpRangeMetadata(
|
|
CI->getMetadata(LLVMContext::MD_range),
|
|
cast<CallInst>(R)->getMetadata(LLVMContext::MD_range));
|
|
}
|
|
if (const InvokeInst *II = dyn_cast<InvokeInst>(L)) {
|
|
if (int Res = cmpNumbers(II->getCallingConv(),
|
|
cast<InvokeInst>(R)->getCallingConv()))
|
|
return Res;
|
|
if (int Res =
|
|
cmpAttrs(II->getAttributes(), cast<InvokeInst>(R)->getAttributes()))
|
|
return Res;
|
|
if (int Res = cmpOperandBundlesSchema(II, R))
|
|
return Res;
|
|
return cmpRangeMetadata(
|
|
II->getMetadata(LLVMContext::MD_range),
|
|
cast<InvokeInst>(R)->getMetadata(LLVMContext::MD_range));
|
|
}
|
|
if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(L)) {
|
|
ArrayRef<unsigned> LIndices = IVI->getIndices();
|
|
ArrayRef<unsigned> RIndices = cast<InsertValueInst>(R)->getIndices();
|
|
if (int Res = cmpNumbers(LIndices.size(), RIndices.size()))
|
|
return Res;
|
|
for (size_t i = 0, e = LIndices.size(); i != e; ++i) {
|
|
if (int Res = cmpNumbers(LIndices[i], RIndices[i]))
|
|
return Res;
|
|
}
|
|
return 0;
|
|
}
|
|
if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(L)) {
|
|
ArrayRef<unsigned> LIndices = EVI->getIndices();
|
|
ArrayRef<unsigned> RIndices = cast<ExtractValueInst>(R)->getIndices();
|
|
if (int Res = cmpNumbers(LIndices.size(), RIndices.size()))
|
|
return Res;
|
|
for (size_t i = 0, e = LIndices.size(); i != e; ++i) {
|
|
if (int Res = cmpNumbers(LIndices[i], RIndices[i]))
|
|
return Res;
|
|
}
|
|
}
|
|
if (const FenceInst *FI = dyn_cast<FenceInst>(L)) {
|
|
if (int Res =
|
|
cmpOrderings(FI->getOrdering(), cast<FenceInst>(R)->getOrdering()))
|
|
return Res;
|
|
return cmpNumbers(FI->getSyncScopeID(),
|
|
cast<FenceInst>(R)->getSyncScopeID());
|
|
}
|
|
if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(L)) {
|
|
if (int Res = cmpNumbers(CXI->isVolatile(),
|
|
cast<AtomicCmpXchgInst>(R)->isVolatile()))
|
|
return Res;
|
|
if (int Res = cmpNumbers(CXI->isWeak(),
|
|
cast<AtomicCmpXchgInst>(R)->isWeak()))
|
|
return Res;
|
|
if (int Res =
|
|
cmpOrderings(CXI->getSuccessOrdering(),
|
|
cast<AtomicCmpXchgInst>(R)->getSuccessOrdering()))
|
|
return Res;
|
|
if (int Res =
|
|
cmpOrderings(CXI->getFailureOrdering(),
|
|
cast<AtomicCmpXchgInst>(R)->getFailureOrdering()))
|
|
return Res;
|
|
return cmpNumbers(CXI->getSyncScopeID(),
|
|
cast<AtomicCmpXchgInst>(R)->getSyncScopeID());
|
|
}
|
|
if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(L)) {
|
|
if (int Res = cmpNumbers(RMWI->getOperation(),
|
|
cast<AtomicRMWInst>(R)->getOperation()))
|
|
return Res;
|
|
if (int Res = cmpNumbers(RMWI->isVolatile(),
|
|
cast<AtomicRMWInst>(R)->isVolatile()))
|
|
return Res;
|
|
if (int Res = cmpOrderings(RMWI->getOrdering(),
|
|
cast<AtomicRMWInst>(R)->getOrdering()))
|
|
return Res;
|
|
return cmpNumbers(RMWI->getSyncScopeID(),
|
|
cast<AtomicRMWInst>(R)->getSyncScopeID());
|
|
}
|
|
if (const PHINode *PNL = dyn_cast<PHINode>(L)) {
|
|
const PHINode *PNR = cast<PHINode>(R);
|
|
// Ensure that in addition to the incoming values being identical
|
|
// (checked by the caller of this function), the incoming blocks
|
|
// are also identical.
|
|
for (unsigned i = 0, e = PNL->getNumIncomingValues(); i != e; ++i) {
|
|
if (int Res =
|
|
cmpValues(PNL->getIncomingBlock(i), PNR->getIncomingBlock(i)))
|
|
return Res;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
// Determine whether two GEP operations perform the same underlying arithmetic.
|
|
// Read method declaration comments for more details.
|
|
int FunctionComparator::cmpGEPs(const GEPOperator *GEPL,
|
|
const GEPOperator *GEPR) const {
|
|
unsigned int ASL = GEPL->getPointerAddressSpace();
|
|
unsigned int ASR = GEPR->getPointerAddressSpace();
|
|
|
|
if (int Res = cmpNumbers(ASL, ASR))
|
|
return Res;
|
|
|
|
// When we have target data, we can reduce the GEP down to the value in bytes
|
|
// added to the address.
|
|
const DataLayout &DL = FnL->getParent()->getDataLayout();
|
|
unsigned BitWidth = DL.getPointerSizeInBits(ASL);
|
|
APInt OffsetL(BitWidth, 0), OffsetR(BitWidth, 0);
|
|
if (GEPL->accumulateConstantOffset(DL, OffsetL) &&
|
|
GEPR->accumulateConstantOffset(DL, OffsetR))
|
|
return cmpAPInts(OffsetL, OffsetR);
|
|
if (int Res = cmpTypes(GEPL->getSourceElementType(),
|
|
GEPR->getSourceElementType()))
|
|
return Res;
|
|
|
|
if (int Res = cmpNumbers(GEPL->getNumOperands(), GEPR->getNumOperands()))
|
|
return Res;
|
|
|
|
for (unsigned i = 0, e = GEPL->getNumOperands(); i != e; ++i) {
|
|
if (int Res = cmpValues(GEPL->getOperand(i), GEPR->getOperand(i)))
|
|
return Res;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int FunctionComparator::cmpInlineAsm(const InlineAsm *L,
|
|
const InlineAsm *R) const {
|
|
// InlineAsm's are uniqued. If they are the same pointer, obviously they are
|
|
// the same, otherwise compare the fields.
|
|
if (L == R)
|
|
return 0;
|
|
if (int Res = cmpTypes(L->getFunctionType(), R->getFunctionType()))
|
|
return Res;
|
|
if (int Res = cmpMem(L->getAsmString(), R->getAsmString()))
|
|
return Res;
|
|
if (int Res = cmpMem(L->getConstraintString(), R->getConstraintString()))
|
|
return Res;
|
|
if (int Res = cmpNumbers(L->hasSideEffects(), R->hasSideEffects()))
|
|
return Res;
|
|
if (int Res = cmpNumbers(L->isAlignStack(), R->isAlignStack()))
|
|
return Res;
|
|
if (int Res = cmpNumbers(L->getDialect(), R->getDialect()))
|
|
return Res;
|
|
llvm_unreachable("InlineAsm blocks were not uniqued.");
|
|
return 0;
|
|
}
|
|
|
|
/// Compare two values used by the two functions under pair-wise comparison. If
|
|
/// this is the first time the values are seen, they're added to the mapping so
|
|
/// that we will detect mismatches on next use.
|
|
/// See comments in declaration for more details.
|
|
int FunctionComparator::cmpValues(const Value *L, const Value *R) const {
|
|
// Catch self-reference case.
|
|
if (L == FnL) {
|
|
if (R == FnR)
|
|
return 0;
|
|
return -1;
|
|
}
|
|
if (R == FnR) {
|
|
if (L == FnL)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
const Constant *ConstL = dyn_cast<Constant>(L);
|
|
const Constant *ConstR = dyn_cast<Constant>(R);
|
|
if (ConstL && ConstR) {
|
|
if (L == R)
|
|
return 0;
|
|
return cmpConstants(ConstL, ConstR);
|
|
}
|
|
|
|
if (ConstL)
|
|
return 1;
|
|
if (ConstR)
|
|
return -1;
|
|
|
|
const InlineAsm *InlineAsmL = dyn_cast<InlineAsm>(L);
|
|
const InlineAsm *InlineAsmR = dyn_cast<InlineAsm>(R);
|
|
|
|
if (InlineAsmL && InlineAsmR)
|
|
return cmpInlineAsm(InlineAsmL, InlineAsmR);
|
|
if (InlineAsmL)
|
|
return 1;
|
|
if (InlineAsmR)
|
|
return -1;
|
|
|
|
auto LeftSN = sn_mapL.insert(std::make_pair(L, sn_mapL.size())),
|
|
RightSN = sn_mapR.insert(std::make_pair(R, sn_mapR.size()));
|
|
|
|
return cmpNumbers(LeftSN.first->second, RightSN.first->second);
|
|
}
|
|
|
|
// Test whether two basic blocks have equivalent behaviour.
|
|
int FunctionComparator::cmpBasicBlocks(const BasicBlock *BBL,
|
|
const BasicBlock *BBR) const {
|
|
BasicBlock::const_iterator InstL = BBL->begin(), InstLE = BBL->end();
|
|
BasicBlock::const_iterator InstR = BBR->begin(), InstRE = BBR->end();
|
|
|
|
do {
|
|
bool needToCmpOperands = true;
|
|
if (int Res = cmpOperations(&*InstL, &*InstR, needToCmpOperands))
|
|
return Res;
|
|
if (needToCmpOperands) {
|
|
assert(InstL->getNumOperands() == InstR->getNumOperands());
|
|
|
|
for (unsigned i = 0, e = InstL->getNumOperands(); i != e; ++i) {
|
|
Value *OpL = InstL->getOperand(i);
|
|
Value *OpR = InstR->getOperand(i);
|
|
if (int Res = cmpValues(OpL, OpR))
|
|
return Res;
|
|
// cmpValues should ensure this is true.
|
|
assert(cmpTypes(OpL->getType(), OpR->getType()) == 0);
|
|
}
|
|
}
|
|
|
|
++InstL;
|
|
++InstR;
|
|
} while (InstL != InstLE && InstR != InstRE);
|
|
|
|
if (InstL != InstLE && InstR == InstRE)
|
|
return 1;
|
|
if (InstL == InstLE && InstR != InstRE)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
int FunctionComparator::compareSignature() const {
|
|
if (int Res = cmpAttrs(FnL->getAttributes(), FnR->getAttributes()))
|
|
return Res;
|
|
|
|
if (int Res = cmpNumbers(FnL->hasGC(), FnR->hasGC()))
|
|
return Res;
|
|
|
|
if (FnL->hasGC()) {
|
|
if (int Res = cmpMem(FnL->getGC(), FnR->getGC()))
|
|
return Res;
|
|
}
|
|
|
|
if (int Res = cmpNumbers(FnL->hasSection(), FnR->hasSection()))
|
|
return Res;
|
|
|
|
if (FnL->hasSection()) {
|
|
if (int Res = cmpMem(FnL->getSection(), FnR->getSection()))
|
|
return Res;
|
|
}
|
|
|
|
if (int Res = cmpNumbers(FnL->isVarArg(), FnR->isVarArg()))
|
|
return Res;
|
|
|
|
// TODO: if it's internal and only used in direct calls, we could handle this
|
|
// case too.
|
|
if (int Res = cmpNumbers(FnL->getCallingConv(), FnR->getCallingConv()))
|
|
return Res;
|
|
|
|
if (int Res = cmpTypes(FnL->getFunctionType(), FnR->getFunctionType()))
|
|
return Res;
|
|
|
|
assert(FnL->arg_size() == FnR->arg_size() &&
|
|
"Identically typed functions have different numbers of args!");
|
|
|
|
// Visit the arguments so that they get enumerated in the order they're
|
|
// passed in.
|
|
for (Function::const_arg_iterator ArgLI = FnL->arg_begin(),
|
|
ArgRI = FnR->arg_begin(),
|
|
ArgLE = FnL->arg_end();
|
|
ArgLI != ArgLE; ++ArgLI, ++ArgRI) {
|
|
if (cmpValues(&*ArgLI, &*ArgRI) != 0)
|
|
llvm_unreachable("Arguments repeat!");
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
// Test whether the two functions have equivalent behaviour.
|
|
int FunctionComparator::compare() {
|
|
beginCompare();
|
|
|
|
if (int Res = compareSignature())
|
|
return Res;
|
|
|
|
// We do a CFG-ordered walk since the actual ordering of the blocks in the
|
|
// linked list is immaterial. Our walk starts at the entry block for both
|
|
// functions, then takes each block from each terminator in order. As an
|
|
// artifact, this also means that unreachable blocks are ignored.
|
|
SmallVector<const BasicBlock *, 8> FnLBBs, FnRBBs;
|
|
SmallPtrSet<const BasicBlock *, 32> VisitedBBs; // in terms of F1.
|
|
|
|
FnLBBs.push_back(&FnL->getEntryBlock());
|
|
FnRBBs.push_back(&FnR->getEntryBlock());
|
|
|
|
VisitedBBs.insert(FnLBBs[0]);
|
|
while (!FnLBBs.empty()) {
|
|
const BasicBlock *BBL = FnLBBs.pop_back_val();
|
|
const BasicBlock *BBR = FnRBBs.pop_back_val();
|
|
|
|
if (int Res = cmpValues(BBL, BBR))
|
|
return Res;
|
|
|
|
if (int Res = cmpBasicBlocks(BBL, BBR))
|
|
return Res;
|
|
|
|
const TerminatorInst *TermL = BBL->getTerminator();
|
|
const TerminatorInst *TermR = BBR->getTerminator();
|
|
|
|
assert(TermL->getNumSuccessors() == TermR->getNumSuccessors());
|
|
for (unsigned i = 0, e = TermL->getNumSuccessors(); i != e; ++i) {
|
|
if (!VisitedBBs.insert(TermL->getSuccessor(i)).second)
|
|
continue;
|
|
|
|
FnLBBs.push_back(TermL->getSuccessor(i));
|
|
FnRBBs.push_back(TermR->getSuccessor(i));
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
namespace {
|
|
|
|
// Accumulate the hash of a sequence of 64-bit integers. This is similar to a
|
|
// hash of a sequence of 64bit ints, but the entire input does not need to be
|
|
// available at once. This interface is necessary for functionHash because it
|
|
// needs to accumulate the hash as the structure of the function is traversed
|
|
// without saving these values to an intermediate buffer. This form of hashing
|
|
// is not often needed, as usually the object to hash is just read from a
|
|
// buffer.
|
|
class HashAccumulator64 {
|
|
uint64_t Hash;
|
|
|
|
public:
|
|
// Initialize to random constant, so the state isn't zero.
|
|
HashAccumulator64() { Hash = 0x6acaa36bef8325c5ULL; }
|
|
|
|
void add(uint64_t V) {
|
|
Hash = hashing::detail::hash_16_bytes(Hash, V);
|
|
}
|
|
|
|
// No finishing is required, because the entire hash value is used.
|
|
uint64_t getHash() { return Hash; }
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
// A function hash is calculated by considering only the number of arguments and
|
|
// whether a function is varargs, the order of basic blocks (given by the
|
|
// successors of each basic block in depth first order), and the order of
|
|
// opcodes of each instruction within each of these basic blocks. This mirrors
|
|
// the strategy compare() uses to compare functions by walking the BBs in depth
|
|
// first order and comparing each instruction in sequence. Because this hash
|
|
// does not look at the operands, it is insensitive to things such as the
|
|
// target of calls and the constants used in the function, which makes it useful
|
|
// when possibly merging functions which are the same modulo constants and call
|
|
// targets.
|
|
FunctionComparator::FunctionHash FunctionComparator::functionHash(Function &F) {
|
|
HashAccumulator64 H;
|
|
H.add(F.isVarArg());
|
|
H.add(F.arg_size());
|
|
|
|
SmallVector<const BasicBlock *, 8> BBs;
|
|
SmallSet<const BasicBlock *, 16> VisitedBBs;
|
|
|
|
// Walk the blocks in the same order as FunctionComparator::cmpBasicBlocks(),
|
|
// accumulating the hash of the function "structure." (BB and opcode sequence)
|
|
BBs.push_back(&F.getEntryBlock());
|
|
VisitedBBs.insert(BBs[0]);
|
|
while (!BBs.empty()) {
|
|
const BasicBlock *BB = BBs.pop_back_val();
|
|
// This random value acts as a block header, as otherwise the partition of
|
|
// opcodes into BBs wouldn't affect the hash, only the order of the opcodes
|
|
H.add(45798);
|
|
for (auto &Inst : *BB) {
|
|
H.add(Inst.getOpcode());
|
|
}
|
|
const TerminatorInst *Term = BB->getTerminator();
|
|
for (unsigned i = 0, e = Term->getNumSuccessors(); i != e; ++i) {
|
|
if (!VisitedBBs.insert(Term->getSuccessor(i)).second)
|
|
continue;
|
|
BBs.push_back(Term->getSuccessor(i));
|
|
}
|
|
}
|
|
return H.getHash();
|
|
}
|