[llvm-commits] CVS: llvm/lib/Transforms/IPO/FunctionResolution.cpp
Chris Lattner
lattner at cs.uiuc.edu
Wed Oct 9 16:11:01 PDT 2002
Changes in directory llvm/lib/Transforms/IPO:
FunctionResolution.cpp updated: 1.12 -> 1.13
---
Log message:
Almost a complete rewrite of FunctionResolution to now resolve functions
and global variables.
This fixes bug: FuncResolve/2002-08-19-ResolveGlobalVarsEasier.ll
And bug: SingleSource/UnitTests/2002-10-09-ArrayResolution.c
Note that this does not fix bug:
FunctionResolve/2002-08-19-ResolveGlobalVars.ll because replaceAllUsesWith
breaks when a constantexpr is pointing to the thing being replaced. This
is more of an infrastructure problem than anything.
---
Diffs of the changes:
Index: llvm/lib/Transforms/IPO/FunctionResolution.cpp
diff -u llvm/lib/Transforms/IPO/FunctionResolution.cpp:1.12 llvm/lib/Transforms/IPO/FunctionResolution.cpp:1.13
--- llvm/lib/Transforms/IPO/FunctionResolution.cpp:1.12 Tue Oct 1 17:38:36 2002
+++ llvm/lib/Transforms/IPO/FunctionResolution.cpp Wed Oct 9 16:10:06 2002
@@ -17,7 +17,7 @@
#include "llvm/DerivedTypes.h"
#include "llvm/Pass.h"
#include "llvm/iOther.h"
-#include "llvm/Constant.h"
+#include "llvm/Constants.h"
#include "Support/Statistic.h"
#include <algorithm>
@@ -27,6 +27,7 @@
namespace {
Statistic<>NumResolved("funcresolve", "Number of varargs functions resolved");
+ Statistic<> NumGlobals("funcresolve", "Number of global variables resolved");
struct FunctionResolvingPass : public Pass {
bool run(Module &M);
@@ -111,144 +112,234 @@
}
+static bool ResolveFunctions(Module &M, vector<GlobalValue*> &Globals,
+ Function *Concrete) {
+ bool Changed = false;
+ for (unsigned i = 0; i != Globals.size(); ++i)
+ if (Globals[i] != Concrete) {
+ Function *Old = cast<Function>(Globals[i]);
+ const FunctionType *OldMT = Old->getFunctionType();
+ const FunctionType *ConcreteMT = Concrete->getFunctionType();
+
+ assert(OldMT->getParamTypes().size() <=
+ ConcreteMT->getParamTypes().size() &&
+ "Concrete type must have more specified parameters!");
+
+ // Check to make sure that if there are specified types, that they
+ // match...
+ //
+ for (unsigned i = 0; i < OldMT->getParamTypes().size(); ++i)
+ if (OldMT->getParamTypes()[i] != ConcreteMT->getParamTypes()[i]) {
+ cerr << "Parameter types conflict for" << OldMT
+ << " and " << ConcreteMT;
+ return Changed;
+ }
+
+ // Attempt to convert all of the uses of the old function to the
+ // concrete form of the function. If there is a use of the fn that
+ // we don't understand here we punt to avoid making a bad
+ // transformation.
+ //
+ // At this point, we know that the return values are the same for
+ // our two functions and that the Old function has no varargs fns
+ // specified. In otherwords it's just <retty> (...)
+ //
+ for (unsigned i = 0; i < Old->use_size(); ) {
+ User *U = *(Old->use_begin()+i);
+ if (CastInst *CI = dyn_cast<CastInst>(U)) {
+ // Convert casts directly
+ assert(CI->getOperand(0) == Old);
+ CI->setOperand(0, Concrete);
+ Changed = true;
+ ++NumResolved;
+ } else if (CallInst *CI = dyn_cast<CallInst>(U)) {
+ // Can only fix up calls TO the argument, not args passed in.
+ if (CI->getCalledValue() == Old) {
+ ConvertCallTo(CI, Concrete);
+ Changed = true;
+ ++NumResolved;
+ } else {
+ cerr << "Couldn't cleanup this function call, must be an"
+ << " argument or something!" << CI;
+ ++i;
+ }
+ } else {
+ cerr << "Cannot convert use of function: " << U << "\n";
+ ++i;
+ }
+ }
+ }
+ return Changed;
+}
+
+
+static bool ResolveGlobalVariables(Module &M, vector<GlobalValue*> &Globals,
+ GlobalVariable *Concrete) {
+ bool Changed = false;
+ assert(isa<ArrayType>(Concrete->getType()->getElementType()) &&
+ "Concrete version should be an array type!");
+
+ // Get the type of the things that may be resolved to us...
+ const Type *AETy =
+ cast<ArrayType>(Concrete->getType()->getElementType())->getElementType();
+
+ std::vector<Constant*> Args;
+ Args.push_back(Constant::getNullValue(Type::LongTy));
+ Args.push_back(Constant::getNullValue(Type::LongTy));
+ ConstantExpr *Replacement =
+ ConstantExpr::getGetElementPtr(ConstantPointerRef::get(Concrete), Args);
+
+ for (unsigned i = 0; i != Globals.size(); ++i)
+ if (Globals[i] != Concrete) {
+ GlobalVariable *Old = cast<GlobalVariable>(Globals[i]);
+ if (Old->getType()->getElementType() != AETy) {
+ std::cerr << "WARNING: Two global variables exist with the same name "
+ << "that cannot be resolved!\n";
+ return false;
+ }
+
+ // In this case, Old is a pointer to T, Concrete is a pointer to array of
+ // T. Because of this, replace all uses of Old with a constantexpr
+ // getelementptr that returns the address of the first element of the
+ // array.
+ //
+ Old->replaceAllUsesWith(Replacement);
+ // Since there are no uses of Old anymore, remove it from the module.
+ M.getGlobalList().erase(Old);
+
+ ++NumGlobals;
+ Changed = true;
+ }
+ return Changed;
+}
+
+static bool ProcessGlobalsWithSameName(Module &M,
+ vector<GlobalValue*> &Globals) {
+ assert(!Globals.empty() && "Globals list shouldn't be empty here!");
+
+ bool isFunction = isa<Function>(Globals[0]); // Is this group all functions?
+ bool Changed = false;
+ GlobalValue *Concrete = 0; // The most concrete implementation to resolve to
+
+ assert((isFunction ^ isa<GlobalVariable>(Globals[0])) &&
+ "Should either be function or gvar!");
+
+ for (unsigned i = 0; i != Globals.size(); ) {
+ if (isa<Function>(Globals[i]) != isFunction) {
+ std::cerr << "WARNING: Found function and global variable with the "
+ << "same name: '" << Globals[i]->getName() << "'.\n";
+ return false; // Don't know how to handle this, bail out!
+ }
+
+ // Ignore globals that are never used so they don't cause spurious
+ // warnings... here we will actually DCE the function so that it isn't used
+ // later.
+ //
+ if (Globals[i]->isExternal() && Globals[i]->use_empty()) {
+ if (isFunction)
+ M.getFunctionList().erase(cast<Function>(Globals[i]));
+ else
+ M.getGlobalList().erase(cast<GlobalVariable>(Globals[i]));
+
+ Globals.erase(Globals.begin()+i);
+ Changed = true;
+ ++NumResolved;
+ } else if (isFunction) {
+ // For functions, we look to merge functions definitions of "int (...)"
+ // to 'int (int)' or 'int ()' or whatever else is not completely generic.
+ //
+ Function *F = cast<Function>(Globals[i]);
+ if (!F->getFunctionType()->isVarArg() ||
+ F->getFunctionType()->getNumParams()) {
+ if (Concrete)
+ return false; // Found two different functions types. Can't choose!
+
+ Concrete = Globals[i];
+ }
+ ++i;
+ } else {
+ // For global variables, we have to merge C definitions int A[][4] with
+ // int[6][4]
+ GlobalVariable *GV = cast<GlobalVariable>(Globals[i]);
+ if (Concrete == 0) {
+ if (isa<ArrayType>(GV->getType()->getElementType()))
+ Concrete = GV;
+ } else { // Must have different types... one is an array of the other?
+ const ArrayType *AT =
+ dyn_cast<ArrayType>(GV->getType()->getElementType());
+
+ // If GV is an array of Concrete, then GV is the array.
+ if (AT && AT->getElementType() == Concrete->getType()->getElementType())
+ Concrete = GV;
+ else {
+ // Concrete must be an array type, check to see if the element type of
+ // concrete is already GV.
+ AT = cast<ArrayType>(Concrete->getType()->getElementType());
+ if (AT->getElementType() != GV->getType()->getElementType())
+ Concrete = 0; // Don't know how to handle it!
+ }
+ }
+
+ ++i;
+ }
+ }
+
+ if (Globals.size() > 1) { // Found a multiply defined global...
+ // We should find exactly one concrete function definition, which is
+ // probably the implementation. Change all of the function definitions and
+ // uses to use it instead.
+ //
+ if (!Concrete) {
+ cerr << "WARNING: Found function types that are not compatible:\n";
+ for (unsigned i = 0; i < Globals.size(); ++i) {
+ cerr << "\t" << Globals[i]->getType()->getDescription() << " %"
+ << Globals[i]->getName() << "\n";
+ }
+ cerr << " No linkage of globals named '" << Globals[0]->getName()
+ << "' performed!\n";
+ return Changed;
+ }
+
+ if (isFunction)
+ return Changed | ResolveFunctions(M, Globals, cast<Function>(Concrete));
+ else
+ return Changed | ResolveGlobalVariables(M, Globals,
+ cast<GlobalVariable>(Concrete));
+ }
+ return Changed;
+}
+
bool FunctionResolvingPass::run(Module &M) {
SymbolTable *ST = M.getSymbolTable();
if (!ST) return false;
- std::map<string, vector<Function*> > Functions;
+ std::map<string, vector<GlobalValue*> > Globals;
// Loop over the entries in the symbol table. If an entry is a func pointer,
// then add it to the Functions map. We do a two pass algorithm here to avoid
// problems with iterators getting invalidated if we did a one pass scheme.
//
for (SymbolTable::iterator I = ST->begin(), E = ST->end(); I != E; ++I)
- if (const PointerType *PT = dyn_cast<PointerType>(I->first))
- if (isa<FunctionType>(PT->getElementType())) {
- SymbolTable::VarMap &Plane = I->second;
- for (SymbolTable::type_iterator PI = Plane.begin(), PE = Plane.end();
- PI != PE; ++PI) {
- Function *F = cast<Function>(PI->second);
- assert(PI->first == F->getName() &&
- "Function name and symbol table do not agree!");
- if (F->hasExternalLinkage()) // Only resolve decls to external fns
- Functions[PI->first].push_back(F);
- }
+ if (const PointerType *PT = dyn_cast<PointerType>(I->first)) {
+ SymbolTable::VarMap &Plane = I->second;
+ for (SymbolTable::type_iterator PI = Plane.begin(), PE = Plane.end();
+ PI != PE; ++PI) {
+ GlobalValue *GV = cast<GlobalValue>(PI->second);
+ assert(PI->first == GV->getName() &&
+ "Global name and symbol table do not agree!");
+ if (GV->hasExternalLinkage()) // Only resolve decls to external fns
+ Globals[PI->first].push_back(GV);
}
+ }
bool Changed = false;
// Now we have a list of all functions with a particular name. If there is
// more than one entry in a list, merge the functions together.
//
- for (std::map<string, vector<Function*> >::iterator I = Functions.begin(),
- E = Functions.end(); I != E; ++I) {
- vector<Function*> &Functions = I->second;
- Function *Implementation = 0; // Find the implementation
- Function *Concrete = 0;
- for (unsigned i = 0; i < Functions.size(); ) {
- if (!Functions[i]->isExternal()) { // Found an implementation
- if (Implementation != 0)
- assert(Implementation == 0 && "Multiple definitions of the same"
- " function. Case not handled yet!");
- Implementation = Functions[i];
- } else {
- // Ignore functions that are never used so they don't cause spurious
- // warnings... here we will actually DCE the function so that it isn't
- // used later.
- //
- if (Functions[i]->use_empty()) {
- M.getFunctionList().erase(Functions[i]);
- Functions.erase(Functions.begin()+i);
- Changed = true;
- ++NumResolved;
- continue;
- }
- }
-
- if (Functions[i] && (!Functions[i]->getFunctionType()->isVarArg())) {
- if (Concrete) { // Found two different functions types. Can't choose
- Concrete = 0;
- break;
- }
- Concrete = Functions[i];
- }
- ++i;
- }
-
- if (Functions.size() > 1) { // Found a multiply defined function...
- // We should find exactly one non-vararg function definition, which is
- // probably the implementation. Change all of the function definitions
- // and uses to use it instead.
- //
- if (!Concrete) {
- cerr << "Warning: Found functions types that are not compatible:\n";
- for (unsigned i = 0; i < Functions.size(); ++i) {
- cerr << "\t" << Functions[i]->getType()->getDescription() << " %"
- << Functions[i]->getName() << "\n";
- }
- cerr << " No linkage of functions named '" << Functions[0]->getName()
- << "' performed!\n";
- } else {
- for (unsigned i = 0; i < Functions.size(); ++i)
- if (Functions[i] != Concrete) {
- Function *Old = Functions[i];
- const FunctionType *OldMT = Old->getFunctionType();
- const FunctionType *ConcreteMT = Concrete->getFunctionType();
- bool Broken = false;
-
- assert(OldMT->getParamTypes().size() <=
- ConcreteMT->getParamTypes().size() &&
- "Concrete type must have more specified parameters!");
-
- // Check to make sure that if there are specified types, that they
- // match...
- //
- for (unsigned i = 0; i < OldMT->getParamTypes().size(); ++i)
- if (OldMT->getParamTypes()[i] != ConcreteMT->getParamTypes()[i]) {
- cerr << "Parameter types conflict for" << OldMT
- << " and " << ConcreteMT;
- Broken = true;
- }
- if (Broken) break; // Can't process this one!
-
-
- // Attempt to convert all of the uses of the old function to the
- // concrete form of the function. If there is a use of the fn that
- // we don't understand here we punt to avoid making a bad
- // transformation.
- //
- // At this point, we know that the return values are the same for
- // our two functions and that the Old function has no varargs fns
- // specified. In otherwords it's just <retty> (...)
- //
- for (unsigned i = 0; i < Old->use_size(); ) {
- User *U = *(Old->use_begin()+i);
- if (CastInst *CI = dyn_cast<CastInst>(U)) {
- // Convert casts directly
- assert(CI->getOperand(0) == Old);
- CI->setOperand(0, Concrete);
- Changed = true;
- ++NumResolved;
- } else if (CallInst *CI = dyn_cast<CallInst>(U)) {
- // Can only fix up calls TO the argument, not args passed in.
- if (CI->getCalledValue() == Old) {
- ConvertCallTo(CI, Concrete);
- Changed = true;
- ++NumResolved;
- } else {
- cerr << "Couldn't cleanup this function call, must be an"
- << " argument or something!" << CI;
- ++i;
- }
- } else {
- cerr << "Cannot convert use of function: " << U << "\n";
- ++i;
- }
- }
- }
- }
- }
- }
+ for (std::map<string, vector<GlobalValue*> >::iterator I = Globals.begin(),
+ E = Globals.end(); I != E; ++I)
+ Changed |= ProcessGlobalsWithSameName(M, I->second);
return Changed;
}
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