-//===-- InstructionSimplify.h - Fold instructions into simpler forms ------===//
+//===-- InstructionSimplify.h - Fold instrs into simpler forms --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// ("and i32 %x, %x" -> "%x"). If the simplification is also an instruction
// then it dominates the original instruction.
//
+// These routines implicitly resolve undef uses. The easiest way to be safe when
+// using these routines to obtain simplified values for existing instructions is
+// to always replace all uses of the instructions with the resulting simplified
+// values. This will prevent other code from seeing the same undef uses and
+// resolving them to different values.
+//
+// These routines are designed to tolerate moderately incomplete IR, such as
+// instructions that are not connected to basic blocks yet. However, they do
+// require that all the IR that they encounter be valid. In particular, they
+// require that all non-constant values be defined in the same function, and the
+// same call context of that function (and not split between caller and callee
+// contexts of a directly recursive call, for example).
+//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
#define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
+#include "llvm/IR/User.h"
+
namespace llvm {
template<typename T>
class ArrayRef;
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
+ /// \brief Given a function and iterators over arguments, see if we can fold
+ /// the result.
+ ///
+ /// If this call could not be simplified returns null.
+ Value *SimplifyCall(Value *V, User::op_iterator ArgBegin,
+ User::op_iterator ArgEnd, const DataLayout *TD = 0,
+ const TargetLibraryInfo *TLI = 0,
+ const DominatorTree *DT = 0);
+
+ /// \brief Given a function and set of arguments, see if we can fold the
+ /// result.
+ ///
+ /// If this call could not be simplified returns null.
+ Value *SimplifyCall(Value *V, ArrayRef<Value *> Args,
+ const DataLayout *TD = 0,
+ const TargetLibraryInfo *TLI = 0,
+ const DominatorTree *DT = 0);
+
/// SimplifyInstruction - See if we can compute a simplified version of this
/// instruction. If not, this returns null.
Value *SimplifyInstruction(Instruction *I, const DataLayout *TD = 0,