1 files changed, 110 insertions, 0 deletions
diff --git a/lib/Analysis/AssumptionTracker.cpp b/lib/Analysis/AssumptionTracker.cpp
new file mode 100644
index 0000000..775ce1d
--- /dev/null
+++ b/lib/Analysis/AssumptionTracker.cpp
@@ -0,0 +1,110 @@
+//===- 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) {
+  auto I = CachedAssumeCalls.find_as(F);
+  if (I != CachedAssumeCalls.end())
+    CachedAssumeCalls.erase(I);
+}
+
+void AssumptionTracker::CallCallbackVH::deleted() {
+  assert(F && "delete callback called on dummy handle");
+  FunctionCallsMap::iterator I = AT->CachedAssumeCalls.find_as(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), llvm::make_unique<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(&II, m_Intrinsic<Intrinsic::assume>()))
+        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) {
+        if (match(&II, m_Intrinsic<Intrinsic::assume>())) {
+          assert(I.second->find_as(&II) != I.second->end() &&
+                 "Assumption in scanned function not in cache");
+        }
+    }
+  }
+#endif
+}
+
+void AssumptionTracker::registerAssumption(CallInst *CI) {
+  assert(match(CI, m_Intrinsic<Intrinsic::assume>()) &&
+         "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_as(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;
+