llvm/llvm/lib/Transforms/Utils/VNCoercion.cpp

#include "llvm/Transforms/Utils/VNCoercion.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/Support/Debug.h"

#define DEBUG_TYPE …

namespace llvm {
namespace VNCoercion {

static bool isFirstClassAggregateOrScalableType(Type *Ty) { … }

/// Return true if coerceAvailableValueToLoadType will succeed.
bool canCoerceMustAliasedValueToLoad(Value *StoredVal, Type *LoadTy,
                                     const DataLayout &DL) { … }

/// If we saw a store of a value to memory, and
/// then a load from a must-aliased pointer of a different type, try to coerce
/// the stored value.  LoadedTy is the type of the load we want to replace.
/// IRB is IRBuilder used to insert new instructions.
///
/// If we can't do it, return null.
Value *coerceAvailableValueToLoadType(Value *StoredVal, Type *LoadedTy,
                                      IRBuilderBase &Helper,
                                      const DataLayout &DL) { … }

/// This function is called when we have a memdep query of a load that ends up
/// being a clobbering memory write (store, memset, memcpy, memmove).  This
/// means that the write *may* provide bits used by the load but we can't be
/// sure because the pointers don't must-alias.
///
/// Check this case to see if there is anything more we can do before we give
/// up.  This returns -1 if we have to give up, or a byte number in the stored
/// value of the piece that feeds the load.
static int analyzeLoadFromClobberingWrite(Type *LoadTy, Value *LoadPtr,
                                          Value *WritePtr,
                                          uint64_t WriteSizeInBits,
                                          const DataLayout &DL) { … }

/// This function is called when we have a
/// memdep query of a load that ends up being a clobbering store.
int analyzeLoadFromClobberingStore(Type *LoadTy, Value *LoadPtr,
                                   StoreInst *DepSI, const DataLayout &DL) { … }

/// This function is called when we have a
/// memdep query of a load that ends up being clobbered by another load.  See if
/// the other load can feed into the second load.
int analyzeLoadFromClobberingLoad(Type *LoadTy, Value *LoadPtr, LoadInst *DepLI,
                                  const DataLayout &DL) { … }

int analyzeLoadFromClobberingMemInst(Type *LoadTy, Value *LoadPtr,
                                     MemIntrinsic *MI, const DataLayout &DL) { … }

static Value *getStoreValueForLoadHelper(Value *SrcVal, unsigned Offset,
                                         Type *LoadTy, IRBuilderBase &Builder,
                                         const DataLayout &DL) { … }

Value *getValueForLoad(Value *SrcVal, unsigned Offset, Type *LoadTy,
                       Instruction *InsertPt, const DataLayout &DL) { … }

Constant *getConstantValueForLoad(Constant *SrcVal, unsigned Offset,
                                  Type *LoadTy, const DataLayout &DL) { … }

/// This function is called when we have a
/// memdep query of a load that ends up being a clobbering mem intrinsic.
Value *getMemInstValueForLoad(MemIntrinsic *SrcInst, unsigned Offset,
                              Type *LoadTy, Instruction *InsertPt,
                              const DataLayout &DL) { … }

Constant *getConstantMemInstValueForLoad(MemIntrinsic *SrcInst, unsigned Offset,
                                         Type *LoadTy, const DataLayout &DL) { … }
} // namespace VNCoercion
} // namespace llvm