An interprocedural analysis pass that computes flow-insensitive
IP Mod and Ref information for every function and every call site.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4567 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/IPModRef.cpp b/lib/Analysis/DataStructure/IPModRef.cpp
new file mode 100644
index 0000000..e4d0062
--- /dev/null
+++ b/lib/Analysis/DataStructure/IPModRef.cpp
@@ -0,0 +1,218 @@
+//===- IPModRef.cpp - Compute IP Mod/Ref information ------------*- C++ -*-===//
+//
+// See high-level comments in include/llvm/Analysis/IPModRef.h
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/DataStructure.h"
+#include "llvm/Analysis/DSGraph.h"
+#include "llvm/Analysis/IPModRef.h"
+#include "llvm/Module.h"
+#include "llvm/Function.h"
+#include "llvm/iOther.h"
+#include "llvm/Pass.h"
+#include "Support/Statistic.h"
+#include "Support/STLExtras.h"
+#include "Support/StringExtras.h"
+
+#include <algorithm>
+#include <utility>
+#include <vector>
+
+
+//----------------------------------------------------------------------------
+// Private constants and data
+//----------------------------------------------------------------------------
+
+static RegisterAnalysis<IPModRef>
+Z("ipmodref", "Interprocedural mod/ref analysis");
+
+
+//----------------------------------------------------------------------------
+// class ModRefInfo
+//----------------------------------------------------------------------------
+
+void ModRefInfo::print(std::ostream &O) const
+{
+ O << std::endl << "Modified nodes = " << modNodeSet;
+ O << "Referenced nodes = " << refNodeSet << std::endl;
+}
+
+void ModRefInfo::dump() const
+{
+ print(std::cerr);
+}
+
+//----------------------------------------------------------------------------
+// class FunctionModRefInfo
+//----------------------------------------------------------------------------
+
+
+// This constructor computes a node numbering for the TD graph.
+//
+FunctionModRefInfo::FunctionModRefInfo(const Function& func,
+ const DSGraph& tdg,
+ const DSGraph& ldg)
+ : F(func),
+ funcTDGraph(tdg),
+ funcLocalGraph(ldg),
+ funcModRefInfo(tdg.getGraphSize())
+{
+ for (unsigned i=0, N = funcTDGraph.getGraphSize(); i < N; ++i)
+ NodeIds[funcTDGraph.getNodes()[i]] = i;
+}
+
+
+FunctionModRefInfo::~FunctionModRefInfo()
+{
+ for(std::map<const CallInst*, ModRefInfo*>::iterator
+ I=callSiteModRefInfo.begin(), E=callSiteModRefInfo.end(); I != E; ++I)
+ delete(I->second);
+
+ // Empty map just to make problems easier to track down
+ callSiteModRefInfo.clear();
+}
+
+
+// Dummy function that will be replaced with one that inlines
+// the callee's BU graph into the caller's TD graph.
+//
+const DSGraph* ResolveGraphForCallSite(const DSGraph& funcTDGraph,
+ const CallInst& callInst)
+{
+ return &funcTDGraph; // TEMPORARY
+}
+
+
+// Compute Mod/Ref bit vectors for the entire function.
+// These are simply copies of the Read/Write flags from the nodes of
+// the top-down DS graph.
+//
+void FunctionModRefInfo::computeModRef(const Function &func)
+{
+ // Mark all nodes in the graph that are marked MOD as being mod
+ // and all those marked REF as being ref.
+ for (unsigned i = 0, N = funcTDGraph.getGraphSize(); i < N; ++i)
+ {
+ if (funcTDGraph.getNodes()[i]->isModified())
+ funcModRefInfo.setNodeIsMod(i);
+ if (funcTDGraph.getNodes()[i]->isRead())
+ funcModRefInfo.setNodeIsRef(i);
+ }
+
+ // Compute the Mod/Ref info for all call sites within the function
+ // Use the Local DSgraph, which includes all the call sites in the
+ // original program.
+ const std::vector<DSCallSite>& callSites = funcLocalGraph.getFunctionCalls();
+ for (unsigned i = 0, N = callSites.size(); i < N; ++i)
+ computeModRef(callSites[i].getCallInst());
+}
+
+
+// Compute Mod/Ref bit vectors for a single call site.
+// These are copies of the Read/Write flags from the nodes of
+// the graph produced by clearing all flags in teh caller's TD graph
+// and then inlining the callee's BU graph into the caller's TD graph.
+//
+void
+FunctionModRefInfo::computeModRef(const CallInst& callInst)
+{
+ // Allocate the mod/ref info for the call site. Bits automatically cleared.
+ ModRefInfo* callModRefInfo = new ModRefInfo(funcTDGraph.getGraphSize());
+ callSiteModRefInfo[&callInst] = callModRefInfo;
+
+ // Get a copy of the graph for the callee with the callee inlined
+ const DSGraph* csgp = ResolveGraphForCallSite(funcTDGraph, callInst);
+ assert(csgp && "Unable to compute callee mod/ref information");
+
+ // For all nodes in the graph, extract the mod/ref information
+ const std::vector<DSNode*>& csgNodes = csgp->getNodes();
+ const std::vector<DSNode*>& origNodes = funcTDGraph.getNodes();
+ assert(csgNodes.size() == origNodes.size());
+ for (unsigned i=0, N = csgNodes.size(); i < N; ++i)
+ {
+ if (csgNodes[i]->isModified())
+ callModRefInfo->setNodeIsMod(getNodeId(origNodes[i]));
+ if (csgNodes[i]->isRead())
+ callModRefInfo->setNodeIsRef(getNodeId(origNodes[i]));
+ }
+}
+
+
+// Print the results of the pass.
+// Currently this just prints bit-vectors and is not very readable.
+//
+void FunctionModRefInfo::print(std::ostream &O) const
+{
+ O << "---------- Mod/ref information for function "
+ << F.getName() << "---------- \n\n";
+
+ O << "Mod/ref info for function body:\n";
+ funcModRefInfo.print(O);
+
+ for (std::map<const CallInst*, ModRefInfo*>::const_iterator
+ CI = callSiteModRefInfo.begin(), CE = callSiteModRefInfo.end();
+ CI != CE; ++CI)
+ {
+ O << "Mod/ref info for call site " << CI->first << ":\n";
+ CI->second->print(O);
+ }
+
+ O << "\n";
+}
+
+void FunctionModRefInfo::dump() const
+{
+ print(std::cerr);
+}
+
+
+//----------------------------------------------------------------------------
+// class IPModRef: An interprocedural pass that computes IP Mod/Ref info.
+//----------------------------------------------------------------------------
+
+
+// Free the FunctionModRefInfo objects cached in funcToModRefInfoMap.
+//
+void IPModRef::releaseMemory()
+{
+ for(std::map<const Function*, FunctionModRefInfo*>::iterator
+ I=funcToModRefInfoMap.begin(), E=funcToModRefInfoMap.end(); I != E; ++I)
+ delete(I->second);
+
+ // Clear map so memory is not re-released if we are called again
+ funcToModRefInfoMap.clear();
+}
+
+
+// Run the "interprocedural" pass on each function. This needs to do
+// NO real interprocedural work because all that has been done the
+// data structure analysis.
+//
+bool IPModRef::run(Module &theModule)
+{
+ M = &theModule;
+ for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
+ if (! FI->isExternal())
+ getFuncInfo(*FI, /*computeIfMissing*/ true);
+ return true;
+}
+
+
+void IPModRef::print(std::ostream &O) const
+{
+ O << "\n========== Results of Interprocedural Mod/Ref Analysis ==========\n";
+
+ for (std::map<const Function*, FunctionModRefInfo*>::const_iterator
+ mapI = funcToModRefInfoMap.begin(), mapE = funcToModRefInfoMap.end();
+ mapI != mapE; ++mapI)
+ mapI->second->print(O);
+
+ O << "\n";
+}
+
+
+void IPModRef::dump() const
+{
+ print(std::cerr);
+}