Pull RaiseAllocations stuff out of the CleanGCC pass into it's own pass in

the ChangeAllocations.h header file.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1522 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 66 insertions, 5 deletions

diff --git a/lib/Transforms/Utils/LowerAllocations.cpp b/lib/Transforms/Utils/LowerAllocations.cpp
index 1acaea7d29..59323431af 100644
--- a/lib/Transforms/Utils/LowerAllocations.cpp
+++ b/lib/Transforms/Utils/LowerAllocations.cpp
@@ -1,9 +1,9 @@
-//===- LowerAllocations.cpp - Remove Malloc & Free Instructions -------------=//
+//===- ChangeAllocations.cpp - Modify %malloc & %free calls -----------------=//
 //
-// This file implements a pass that lowers malloc and free instructions to
-// calls to %malloc & %free functions.  This transformation is a target
-// dependant tranformation because we depend on the size of data types and
-// alignment constraints.
+// This file defines two passes that convert malloc and free instructions to
+// calls to and from %malloc & %free function calls.  The LowerAllocations
+// transformation is a target dependant tranformation because it depends on the
+// size of data types and alignment constraints.
 //
 //===----------------------------------------------------------------------===//
 
@@ -14,6 +14,7 @@
 #include "llvm/iOther.h"
 #include "llvm/SymbolTable.h"
 #include "llvm/ConstantVals.h"
+#include "TransformInternals.h"
 using std::vector;
 
 
@@ -120,3 +121,63 @@ bool LowerAllocations::runOnBasicBlock(BasicBlock *BB) {
   return Changed;
 }
 
+bool RaiseAllocations::doInitialization(Module *M) {
+  SymbolTable *ST = M->getSymbolTable();
+  if (!ST) return false;
+
+  // 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.
+  //
+  const PointerType *MallocType =   // Get the type for malloc
+    PointerType::get(MethodType::get(PointerType::get(Type::SByteTy),
+                                  vector<const Type*>(1, Type::UIntTy), false));
+  MallocMeth = cast_or_null<Method>(ST->lookup(MallocType, "malloc"));
+  if (MallocMeth && !MallocMeth->isExternal())
+    MallocMeth = 0;  // Don't mess with locally defined versions of the fn
+
+  const PointerType *FreeType =     // Get the type for free
+    PointerType::get(MethodType::get(Type::VoidTy,
+            vector<const Type*>(1, PointerType::get(Type::SByteTy)), false));
+  FreeMeth = cast_or_null<Method>(ST->lookup(FreeType, "free"));
+  if (FreeMeth && !FreeMeth->isExternal())
+    FreeMeth = 0;  // Don't mess with locally defined versions of the fn
+
+  return false;
+}
+
+// doOneCleanupPass - Do one pass over the input method, fixing stuff up.
+//
+bool RaiseAllocations::runOnBasicBlock(BasicBlock *BB) {
+  bool Changed = false;
+  BasicBlock::InstListType &BIL = BB->getInstList();
+
+  for (BasicBlock::iterator BI = BB->begin(); BI != BB->end();) {
+    Instruction *I = *BI;
+
+    if (CallInst *CI = dyn_cast<CallInst>(I)) {
+      if (CI->getCalledValue() == MallocMeth) {      // Replace call to malloc?
+        const Type *PtrSByte = PointerType::get(Type::SByteTy);
+        MallocInst *MallocI = new MallocInst(PtrSByte, CI->getOperand(1),
+                                             CI->getName());
+        CI->setName("");
+        BI = BIL.insert(BI, MallocI)+1;
+        ReplaceInstWithInst(BIL, BI, new CastInst(MallocI, PtrSByte));
+        Changed = true;
+        continue;  // Skip the ++BI
+      } else if (CI->getCalledValue() == FreeMeth) { // Replace call to free?
+        ReplaceInstWithInst(BIL, BI, new FreeInst(CI->getOperand(1)));
+        Changed = true;
+        continue;  // Skip the ++BI
+      }
+    }
+
+    ++BI;
+  }
+
+  return Changed;
+}