It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/RaiseAllocations.cpp b/lib/Transforms/IPO/RaiseAllocations.cpp
new file mode 100644
index 0000000..5d2d9dd
--- /dev/null
+++ b/lib/Transforms/IPO/RaiseAllocations.cpp
@@ -0,0 +1,249 @@
+//===- RaiseAllocations.cpp - Convert %malloc & %free calls to insts ------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the RaiseAllocations pass which convert malloc and free
+// calls to malloc and free instructions.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "raiseallocs"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/Instructions.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/CallSite.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/ADT/Statistic.h"
+#include <algorithm>
+using namespace llvm;
+
+STATISTIC(NumRaised, "Number of allocations raised");
+
+namespace {
+ // RaiseAllocations - Turn %malloc and %free calls into the appropriate
+ // instruction.
+ //
+ class VISIBILITY_HIDDEN RaiseAllocations : public ModulePass {
+ Function *MallocFunc; // Functions in the module we are processing
+ Function *FreeFunc; // Initialized by doPassInitializationVirt
+ public:
+ static char ID; // Pass identification, replacement for typeid
+ RaiseAllocations()
+ : ModulePass((intptr_t)&ID), MallocFunc(0), FreeFunc(0) {}
+
+ // doPassInitialization - For the raise allocations pass, this finds a
+ // declaration for malloc and free if they exist.
+ //
+ void doInitialization(Module &M);
+
+ // run - This method does the actual work of converting instructions over.
+ //
+ bool runOnModule(Module &M);
+ };
+
+ char RaiseAllocations::ID = 0;
+ RegisterPass<RaiseAllocations>
+ X("raiseallocs", "Raise allocations from calls to instructions");
+} // end anonymous namespace
+
+
+// createRaiseAllocationsPass - The interface to this file...
+ModulePass *llvm::createRaiseAllocationsPass() {
+ return new RaiseAllocations();
+}
+
+
+// If the module has a symbol table, they might be referring to the malloc and
+// free functions. If this is the case, grab the method pointers that the
+// module is using.
+//
+// Lookup %malloc and %free in the symbol table, for later use. If they don't
+// exist, or are not external, we do not worry about converting calls to that
+// function into the appropriate instruction.
+//
+void RaiseAllocations::doInitialization(Module &M) {
+
+ // Get Malloc and free prototypes if they exist!
+ MallocFunc = M.getFunction("malloc");
+ if (MallocFunc) {
+ const FunctionType* TyWeHave = MallocFunc->getFunctionType();
+
+ // Get the expected prototype for malloc
+ const FunctionType *Malloc1Type =
+ FunctionType::get(PointerType::get(Type::Int8Ty),
+ std::vector<const Type*>(1, Type::Int64Ty), false);
+
+ // Chck to see if we got the expected malloc
+ if (TyWeHave != Malloc1Type) {
+ // Check to see if the prototype is wrong, giving us sbyte*(uint) * malloc
+ // This handles the common declaration of: 'void *malloc(unsigned);'
+ const FunctionType *Malloc2Type =
+ FunctionType::get(PointerType::get(Type::Int8Ty),
+ std::vector<const Type*>(1, Type::Int32Ty), false);
+ if (TyWeHave != Malloc2Type) {
+ // Check to see if the prototype is missing, giving us
+ // sbyte*(...) * malloc
+ // This handles the common declaration of: 'void *malloc();'
+ const FunctionType *Malloc3Type =
+ FunctionType::get(PointerType::get(Type::Int8Ty),
+ std::vector<const Type*>(), true);
+ if (TyWeHave != Malloc3Type)
+ // Give up
+ MallocFunc = 0;
+ }
+ }
+ }
+
+ FreeFunc = M.getFunction("free");
+ if (FreeFunc) {
+ const FunctionType* TyWeHave = FreeFunc->getFunctionType();
+
+ // Get the expected prototype for void free(i8*)
+ const FunctionType *Free1Type = FunctionType::get(Type::VoidTy,
+ std::vector<const Type*>(1, PointerType::get(Type::Int8Ty)), false);
+
+ if (TyWeHave != Free1Type) {
+ // Check to see if the prototype was forgotten, giving us
+ // void (...) * free
+ // This handles the common forward declaration of: 'void free();'
+ const FunctionType* Free2Type = FunctionType::get(Type::VoidTy,
+ std::vector<const Type*>(),true);
+
+ if (TyWeHave != Free2Type) {
+ // One last try, check to see if we can find free as
+ // int (...)* free. This handles the case where NOTHING was declared.
+ const FunctionType* Free3Type = FunctionType::get(Type::Int32Ty,
+ std::vector<const Type*>(),true);
+
+ if (TyWeHave != Free3Type) {
+ // Give up.
+ FreeFunc = 0;
+ }
+ }
+ }
+ }
+
+ // Don't mess with locally defined versions of these functions...
+ if (MallocFunc && !MallocFunc->isDeclaration()) MallocFunc = 0;
+ if (FreeFunc && !FreeFunc->isDeclaration()) FreeFunc = 0;
+}
+
+// run - Transform calls into instructions...
+//
+bool RaiseAllocations::runOnModule(Module &M) {
+ // Find the malloc/free prototypes...
+ doInitialization(M);
+
+ bool Changed = false;
+
+ // First, process all of the malloc calls...
+ if (MallocFunc) {
+ std::vector<User*> Users(MallocFunc->use_begin(), MallocFunc->use_end());
+ std::vector<Value*> EqPointers; // Values equal to MallocFunc
+ while (!Users.empty()) {
+ User *U = Users.back();
+ Users.pop_back();
+
+ if (Instruction *I = dyn_cast<Instruction>(U)) {
+ CallSite CS = CallSite::get(I);
+ if (CS.getInstruction() && CS.arg_begin() != CS.arg_end() &&
+ (CS.getCalledFunction() == MallocFunc ||
+ std::find(EqPointers.begin(), EqPointers.end(),
+ CS.getCalledValue()) != EqPointers.end())) {
+
+ Value *Source = *CS.arg_begin();
+
+ // If no prototype was provided for malloc, we may need to cast the
+ // source size.
+ if (Source->getType() != Type::Int32Ty)
+ Source =
+ CastInst::createIntegerCast(Source, Type::Int32Ty, false/*ZExt*/,
+ "MallocAmtCast", I);
+
+ MallocInst *MI = new MallocInst(Type::Int8Ty, Source, "", I);
+ MI->takeName(I);
+ I->replaceAllUsesWith(MI);
+
+ // If the old instruction was an invoke, add an unconditional branch
+ // before the invoke, which will become the new terminator.
+ if (InvokeInst *II = dyn_cast<InvokeInst>(I))
+ new BranchInst(II->getNormalDest(), I);
+
+ // Delete the old call site
+ MI->getParent()->getInstList().erase(I);
+ Changed = true;
+ ++NumRaised;
+ }
+ } else if (GlobalValue *GV = dyn_cast<GlobalValue>(U)) {
+ Users.insert(Users.end(), GV->use_begin(), GV->use_end());
+ EqPointers.push_back(GV);
+ } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(U)) {
+ if (CE->isCast()) {
+ Users.insert(Users.end(), CE->use_begin(), CE->use_end());
+ EqPointers.push_back(CE);
+ }
+ }
+ }
+ }
+
+ // Next, process all free calls...
+ if (FreeFunc) {
+ std::vector<User*> Users(FreeFunc->use_begin(), FreeFunc->use_end());
+ std::vector<Value*> EqPointers; // Values equal to FreeFunc
+
+ while (!Users.empty()) {
+ User *U = Users.back();
+ Users.pop_back();
+
+ if (Instruction *I = dyn_cast<Instruction>(U)) {
+ CallSite CS = CallSite::get(I);
+ if (CS.getInstruction() && CS.arg_begin() != CS.arg_end() &&
+ (CS.getCalledFunction() == FreeFunc ||
+ std::find(EqPointers.begin(), EqPointers.end(),
+ CS.getCalledValue()) != EqPointers.end())) {
+
+ // If no prototype was provided for free, we may need to cast the
+ // source pointer. This should be really uncommon, but it's necessary
+ // just in case we are dealing with weird code like this:
+ // free((long)ptr);
+ //
+ Value *Source = *CS.arg_begin();
+ if (!isa<PointerType>(Source->getType()))
+ Source = new IntToPtrInst(Source, PointerType::get(Type::Int8Ty),
+ "FreePtrCast", I);
+ new FreeInst(Source, I);
+
+ // If the old instruction was an invoke, add an unconditional branch
+ // before the invoke, which will become the new terminator.
+ if (InvokeInst *II = dyn_cast<InvokeInst>(I))
+ new BranchInst(II->getNormalDest(), I);
+
+ // Delete the old call site
+ if (I->getType() != Type::VoidTy)
+ I->replaceAllUsesWith(UndefValue::get(I->getType()));
+ I->eraseFromParent();
+ Changed = true;
+ ++NumRaised;
+ }
+ } else if (GlobalValue *GV = dyn_cast<GlobalValue>(U)) {
+ Users.insert(Users.end(), GV->use_begin(), GV->use_end());
+ EqPointers.push_back(GV);
+ } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(U)) {
+ if (CE->isCast()) {
+ Users.insert(Users.end(), CE->use_begin(), CE->use_end());
+ EqPointers.push_back(CE);
+ }
+ }
+ }
+ }
+
+ return Changed;
+}