mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-25 00:29:20 +00:00
a cache of assumptions for a single function, and an immutable pass that manages those caches. The motivation for this change is two fold. Immutable analyses are really hacks around the current pass manager design and don't exist in the new design. This is usually OK, but it requires that the core logic of an immutable pass be reasonably partitioned off from the pass logic. This change does precisely that. As a consequence it also paves the way for the *many* utility functions that deal in the assumptions to live in both pass manager worlds by creating an separate non-pass object with its own independent API that they all rely on. Now, the only bits of the system that deal with the actual pass mechanics are those that actually need to deal with the pass mechanics. Once this separation is made, several simplifications become pretty obvious in the assumption cache itself. Rather than using a set and callback value handles, it can just be a vector of weak value handles. The callers can easily skip the handles that are null, and eventually we can wrap all of this up behind a filter iterator. For now, this adds boiler plate to the various passes, but this kind of boiler plate will end up making it possible to port these passes to the new pass manager, and so it will end up factored away pretty reasonably. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225131 91177308-0d34-0410-b5e6-96231b3b80d8
126 lines
4.4 KiB
C++
126 lines
4.4 KiB
C++
//===- AssumptionCache.cpp - Cache finding @llvm.assume calls -------------===//
|
|
//
|
|
// 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/AssumptionCache.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 AssumptionCache::scanFunction() {
|
|
assert(!Scanned && "Tried to scan the function twice!");
|
|
assert(AssumeHandles.empty() && "Already have assumes when scanning!");
|
|
|
|
// Go through all instructions in all blocks, add all calls to @llvm.assume
|
|
// to this cache.
|
|
for (BasicBlock &B : F)
|
|
for (Instruction &II : B)
|
|
if (match(&II, m_Intrinsic<Intrinsic::assume>()))
|
|
AssumeHandles.push_back(&II);
|
|
|
|
// Mark the scan as complete.
|
|
Scanned = true;
|
|
}
|
|
|
|
void AssumptionCache::registerAssumption(CallInst *CI) {
|
|
assert(match(CI, m_Intrinsic<Intrinsic::assume>()) &&
|
|
"Registered call does not call @llvm.assume");
|
|
|
|
// If we haven't scanned the function yet, just drop this assumption. It will
|
|
// be found when we scan later.
|
|
if (!Scanned)
|
|
return;
|
|
|
|
AssumeHandles.push_back(CI);
|
|
|
|
#ifndef NDEBUG
|
|
assert(CI->getParent() &&
|
|
"Cannot register @llvm.assume call not in a basic block");
|
|
assert(&F == CI->getParent()->getParent() &&
|
|
"Cannot register @llvm.assume call not in this function");
|
|
|
|
// We expect the number of assumptions to be small, so in an asserts build
|
|
// check that we don't accumulate duplicates and that all assumptions point
|
|
// to the same function.
|
|
SmallPtrSet<Value *, 16> AssumptionSet;
|
|
for (auto &VH : AssumeHandles) {
|
|
if (!VH)
|
|
continue;
|
|
|
|
assert(&F == cast<Instruction>(VH)->getParent()->getParent() &&
|
|
"Cached assumption not inside this function!");
|
|
assert(match(cast<CallInst>(VH), m_Intrinsic<Intrinsic::assume>()) &&
|
|
"Cached something other than a call to @llvm.assume!");
|
|
assert(AssumptionSet.insert(VH).second &&
|
|
"Cache contains multiple copies of a call!");
|
|
}
|
|
#endif
|
|
}
|
|
|
|
void AssumptionCacheTracker::FunctionCallbackVH::deleted() {
|
|
auto I = ACT->AssumptionCaches.find_as(cast<Function>(getValPtr()));
|
|
if (I != ACT->AssumptionCaches.end())
|
|
ACT->AssumptionCaches.erase(I);
|
|
// 'this' now dangles!
|
|
}
|
|
|
|
AssumptionCache &AssumptionCacheTracker::getAssumptionCache(Function &F) {
|
|
// We probe the function map twice to try and avoid creating a value handle
|
|
// around the function in common cases. This makes insertion a bit slower,
|
|
// but if we have to insert we're going to scan the whole function so that
|
|
// shouldn't matter.
|
|
auto I = AssumptionCaches.find_as(&F);
|
|
if (I != AssumptionCaches.end())
|
|
return *I->second;
|
|
|
|
// Ok, build a new cache by scanning the function, insert it and the value
|
|
// handle into our map, and return the newly populated cache.
|
|
auto IP = AssumptionCaches.insert(std::make_pair(
|
|
FunctionCallbackVH(&F, this), llvm::make_unique<AssumptionCache>(F)));
|
|
assert(IP.second && "Scanning function already in the map?");
|
|
return *IP.first->second;
|
|
}
|
|
|
|
void AssumptionCacheTracker::verifyAnalysis() const {
|
|
#ifndef NDEBUG
|
|
SmallPtrSet<const CallInst *, 4> AssumptionSet;
|
|
for (const auto &I : AssumptionCaches) {
|
|
for (auto &VH : I.second->assumptions())
|
|
if (VH)
|
|
AssumptionSet.insert(cast<CallInst>(VH));
|
|
|
|
for (const BasicBlock &B : cast<Function>(*I.first))
|
|
for (const Instruction &II : B)
|
|
if (match(&II, m_Intrinsic<Intrinsic::assume>()))
|
|
assert(AssumptionSet.count(cast<CallInst>(&II)) &&
|
|
"Assumption in scanned function not in cache");
|
|
}
|
|
#endif
|
|
}
|
|
|
|
AssumptionCacheTracker::AssumptionCacheTracker() : ImmutablePass(ID) {
|
|
initializeAssumptionCacheTrackerPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
AssumptionCacheTracker::~AssumptionCacheTracker() {}
|
|
|
|
INITIALIZE_PASS(AssumptionCacheTracker, "assumption-cache-tracker",
|
|
"Assumption Cache Tracker", false, true)
|
|
char AssumptionCacheTracker::ID = 0;
|