#ifndef LLVM_ANALYSIS_VALUETRACKING_H
#define LLVM_ANALYSIS_VALUETRACKING_H
+#include "llvm/System/DataTypes.h"
+#include <string>
+
namespace llvm {
class Value;
+ class Instruction;
class APInt;
class TargetData;
+ class LLVMContext;
/// ComputeMaskedBits - Determine which of the bits specified in Mask are
/// known to be either zero or one and return them in the KnownZero/KnownOne
/// bit sets. This code only analyzes bits in Mask, in order to short-circuit
/// processing.
+ ///
+ /// This function is defined on values with integer type, values with pointer
+ /// type (but only if TD is non-null), and vectors of integers. In the case
+ /// where V is a vector, the mask, known zero, and known one values are the
+ /// same width as the vector element, and the bit is set only if it is true
+ /// for all of the elements in the vector.
void ComputeMaskedBits(Value *V, const APInt &Mask, APInt &KnownZero,
- APInt &KnownOne, TargetData *TD = 0,
+ APInt &KnownOne, const TargetData *TD = 0,
unsigned Depth = 0);
+ /// MaskedValueIsZero - Return true if 'V & Mask' is known to be zero. We use
+ /// this predicate to simplify operations downstream. Mask is known to be
+ /// zero for bits that V cannot have.
+ ///
+ /// This function is defined on values with integer type, values with pointer
+ /// type (but only if TD is non-null), and vectors of integers. In the case
+ /// where V is a vector, the mask, known zero, and known one values are the
+ /// same width as the vector element, and the bit is set only if it is true
+ /// for all of the elements in the vector.
bool MaskedValueIsZero(Value *V, const APInt &Mask,
- TargetData *TD = 0, unsigned Depth = 0);
+ const TargetData *TD = 0, unsigned Depth = 0);
/// ComputeNumSignBits - Return the number of times the sign bit of the
///
/// 'Op' must have a scalar integer type.
///
- unsigned ComputeNumSignBits(Value *Op, TargetData *TD = 0,
+ unsigned ComputeNumSignBits(Value *Op, const TargetData *TD = 0,
unsigned Depth = 0);
+ /// CannotBeNegativeZero - Return true if we can prove that the specified FP
+ /// value is never equal to -0.0.
+ ///
+ bool CannotBeNegativeZero(const Value *V, unsigned Depth = 0);
+
+ /// FindScalarValue - Given an aggregrate and an sequence of indices, see if
+ /// the scalar value indexed is already around as a register, for example if
+ /// it were inserted directly into the aggregrate.
+ ///
+ /// If InsertBefore is not null, this function will duplicate (modified)
+ /// insertvalues when a part of a nested struct is extracted.
+ Value *FindInsertedValue(Value *V,
+ const unsigned *idx_begin,
+ const unsigned *idx_end,
+ LLVMContext &Context,
+ Instruction *InsertBefore = 0);
+
+ /// This is a convenience wrapper for finding values indexed by a single index
+ /// only.
+ inline Value *FindInsertedValue(Value *V, const unsigned Idx,
+ LLVMContext &Context,
+ Instruction *InsertBefore = 0) {
+ const unsigned Idxs[1] = { Idx };
+ return FindInsertedValue(V, &Idxs[0], &Idxs[1], Context, InsertBefore);
+ }
+
+ /// GetConstantStringInfo - This function computes the length of a
+ /// null-terminated C string pointed to by V. If successful, it returns true
+ /// and returns the string in Str. If unsuccessful, it returns false. If
+ /// StopAtNul is set to true (the default), the returned string is truncated
+ /// by a nul character in the global. If StopAtNul is false, the nul
+ /// character is included in the result string.
+ bool GetConstantStringInfo(Value *V, std::string &Str, uint64_t Offset = 0,
+ bool StopAtNul = true);
} // end namespace llvm
#endif