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/IndMemRemoval.cpp b/lib/Transforms/IPO/IndMemRemoval.cpp
new file mode 100644
index 0000000..6b06469
--- /dev/null
+++ b/lib/Transforms/IPO/IndMemRemoval.cpp
@@ -0,0 +1,89 @@
+//===-- IndMemRemoval.cpp - Remove indirect allocations and frees ----------===//
+//
+// 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 pass finds places where memory allocation functions may escape into
+// indirect land. Some transforms are much easier (aka possible) only if free
+// or malloc are not called indirectly.
+// Thus find places where the address of memory functions are taken and construct
+// bounce functions with direct calls of those functions.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "indmemrem"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Pass.h"
+#include "llvm/Module.h"
+#include "llvm/Instructions.h"
+#include "llvm/Type.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Compiler.h"
+using namespace llvm;
+
+STATISTIC(NumBounceSites, "Number of sites modified");
+STATISTIC(NumBounce , "Number of bounce functions created");
+
+namespace {
+ class VISIBILITY_HIDDEN IndMemRemPass : public ModulePass {
+ public:
+ static char ID; // Pass identification, replacement for typeid
+ IndMemRemPass() : ModulePass((intptr_t)&ID) {}
+
+ virtual bool runOnModule(Module &M);
+ };
+ char IndMemRemPass::ID = 0;
+ RegisterPass<IndMemRemPass> X("indmemrem","Indirect Malloc and Free Removal");
+} // end anonymous namespace
+
+
+bool IndMemRemPass::runOnModule(Module &M) {
+ //in Theory, all direct calls of malloc and free should be promoted
+ //to intrinsics. Therefor, this goes through and finds where the
+ //address of free or malloc are taken and replaces those with bounce
+ //functions, ensuring that all malloc and free that might happen
+ //happen through intrinsics.
+ bool changed = false;
+ if (Function* F = M.getFunction("free")) {
+ assert(F->isDeclaration() && "free not external?");
+ if (!F->use_empty()) {
+ Function* FN = new Function(F->getFunctionType(),
+ GlobalValue::LinkOnceLinkage,
+ "free_llvm_bounce", &M);
+ BasicBlock* bb = new BasicBlock("entry",FN);
+ Instruction* R = new ReturnInst(bb);
+ new FreeInst(FN->arg_begin(), R);
+ ++NumBounce;
+ NumBounceSites += F->getNumUses();
+ F->replaceAllUsesWith(FN);
+ changed = true;
+ }
+ }
+ if (Function* F = M.getFunction("malloc")) {
+ assert(F->isDeclaration() && "malloc not external?");
+ if (!F->use_empty()) {
+ Function* FN = new Function(F->getFunctionType(),
+ GlobalValue::LinkOnceLinkage,
+ "malloc_llvm_bounce", &M);
+ BasicBlock* bb = new BasicBlock("entry",FN);
+ Instruction* c = CastInst::createIntegerCast(
+ FN->arg_begin(), Type::Int32Ty, false, "c", bb);
+ Instruction* a = new MallocInst(Type::Int8Ty, c, "m", bb);
+ new ReturnInst(a, bb);
+ ++NumBounce;
+ NumBounceSites += F->getNumUses();
+ F->replaceAllUsesWith(FN);
+ changed = true;
+ }
+ }
+ return changed;
+}
+
+ModulePass *llvm::createIndMemRemPass() {
+ return new IndMemRemPass();
+}