llvm-project/llvm/lib/Analysis/AssumptionTracker.cpp

114 lines
3.9 KiB
C++

//===- AssumptionTracker.cpp - Track @llvm.assume -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a pass that keeps track of @llvm.assume intrinsics in
// the functions of a module.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/AssumptionTracker.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
using namespace llvm::PatternMatch;
void AssumptionTracker::FunctionCallbackVH::deleted() {
AT->forgetCachedAssumptions(cast<Function>(getValPtr()));
// 'this' now dangles!
}
void AssumptionTracker::forgetCachedAssumptions(Function *F) {
CachedAssumeCalls.erase(F);
}
void AssumptionTracker::CallCallbackVH::deleted() {
assert(F && "delete callback called on dummy handle");
FunctionCallsMap::iterator I = AT->CachedAssumeCalls.find(F);
assert(I != AT->CachedAssumeCalls.end() &&
"Function cleared from the map without removing the values?");
I->second->erase(*this);
// 'this' now dangles!
}
AssumptionTracker::FunctionCallsMap::iterator
AssumptionTracker::scanFunction(Function *F) {
auto IP =
CachedAssumeCalls.insert(std::make_pair(FunctionCallbackVH(F, this),
std::unique_ptr<CallHandleSet>(
new CallHandleSet())));
assert(IP.second && "Scanning function already in the map?");
FunctionCallsMap::iterator I = IP.first;
// Go through all instructions in all blocks, add all calls to @llvm.assume
// to our cache.
for (BasicBlock &B : *F)
for (Instruction &II : B)
if (match(cast<Value>(&II), m_Intrinsic<Intrinsic::assume>(m_Value())))
I->second->insert(CallCallbackVH(&II, this));
return I;
}
void AssumptionTracker::verifyAnalysis() const {
#ifndef NDEBUG
for (const auto &I : CachedAssumeCalls) {
for (const BasicBlock &B : cast<Function>(*I.first))
for (const Instruction &II : B) {
Instruction *C = const_cast<Instruction*>(&II);
if (match(C, m_Intrinsic<Intrinsic::assume>(m_Value()))) {
assert(I.second->count(CallCallbackVH(C,
const_cast<AssumptionTracker*>(this))) &&
"Assumption in scanned function not in cache");
}
}
}
#endif
}
void AssumptionTracker::registerAssumption(CallInst *CI) {
assert(match(cast<Value>(CI),
m_Intrinsic<Intrinsic::assume>(m_Value())) &&
"Registered call does not call @llvm.assume");
assert(CI->getParent() &&
"Cannot register @llvm.assume call not in a basic block");
Function *F = CI->getParent()->getParent();
assert(F && "Cannot register @llvm.assume call not in a function");
FunctionCallsMap::iterator I = CachedAssumeCalls.find(F);
if (I == CachedAssumeCalls.end()) {
// If this function has not already been scanned, then don't do anything
// here. This intrinsic will be found, if it still exists, if the list of
// assumptions in this function is requested at some later point. This
// maintains the following invariant: if a function is present in the
// cache, then its list of assumption intrinsic calls is complete.
return;
}
I->second->insert(CallCallbackVH(CI, this));
}
AssumptionTracker::AssumptionTracker() : ImmutablePass(ID) {
initializeAssumptionTrackerPass(*PassRegistry::getPassRegistry());
}
AssumptionTracker::~AssumptionTracker() {}
INITIALIZE_PASS(AssumptionTracker, "assumption-tracker", "Assumption Tracker",
false, true)
char AssumptionTracker::ID = 0;