llvm-6502/include/llvm/Support/MathExtras.h
2004-06-23 00:25:24 +00:00

49 lines
1.1 KiB
C++

//===-- Support/MathExtras.h - Useful math functions ------------*- C++ -*-===//
//
// 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 file contains some functions that are useful for math stuff.
//
//===----------------------------------------------------------------------===//
#ifndef SUPPORT_MATHEXTRAS_H
#define SUPPORT_MATHEXTRAS_H
#include "Support/DataTypes.h"
namespace llvm {
#if defined(log2)
# undef log2
#endif
inline unsigned log2(uint64_t C) {
unsigned getPow;
for (getPow = 0; C > 1; ++getPow)
C >>= 1;
return getPow;
}
inline bool isPowerOf2(int64_t C, unsigned &getPow) {
if (C < 0) C = -C;
if (C > 0 && C == (C & ~(C - 1))) {
getPow = log2(static_cast<uint64_t>(C));
return true;
}
return false;
}
// Platform-independent wrappers for the C99 isnan() function.
int IsNAN (float f);
int IsNAN (double d);
} // End llvm namespace
#endif