mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-19 19:29:31 +00:00
last night. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22630 91177308-0d34-0410-b5e6-96231b3b80d8
182 lines
6.0 KiB
C++
182 lines
6.0 KiB
C++
//===-- llvm/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 LLVM_SUPPORT_MATHEXTRAS_H
|
|
#define LLVM_SUPPORT_MATHEXTRAS_H
|
|
|
|
#include "llvm/Support/DataTypes.h"
|
|
|
|
namespace llvm {
|
|
|
|
// NOTE: The following support functions use the _32/_64 extensions instead of
|
|
// type overloading so that signed and unsigned integers can be used without
|
|
// ambiguity.
|
|
|
|
|
|
// Hi_32 - This function returns the high 32 bits of a 64 bit value.
|
|
inline unsigned Hi_32(uint64_t Value) {
|
|
return (unsigned)(Value >> 32);
|
|
}
|
|
|
|
// Lo_32 - This function returns the low 32 bits of a 64 bit value.
|
|
inline unsigned Lo_32(uint64_t Value) {
|
|
return (unsigned)Value;
|
|
}
|
|
|
|
// is?Type - these functions produce optimal testing for integer data types.
|
|
inline bool isInt8 (int Value) { return ( signed char )Value == Value; }
|
|
inline bool isUInt8 (int Value) { return (unsigned char )Value == Value; }
|
|
inline bool isInt16 (int Value) { return ( signed short)Value == Value; }
|
|
inline bool isUInt16(int Value) { return (unsigned short)Value == Value; }
|
|
inline bool isInt32 (int64_t Value) { return ( signed int )Value == Value; }
|
|
inline bool isUInt32(int64_t Value) { return (unsigned int )Value == Value; }
|
|
|
|
// isMask_32 - This function returns true if the argument is a sequence of ones
|
|
// starting at the least significant bit with the remainder zero (32 bit version.)
|
|
// Ex. isMask_32(0x0000FFFFU) == true.
|
|
inline const bool isMask_32(unsigned Value) {
|
|
return Value && ((Value + 1) & Value) == 0;
|
|
}
|
|
|
|
// isMask_64 - This function returns true if the argument is a sequence of ones
|
|
// starting at the least significant bit with the remainder zero (64 bit version.)
|
|
inline const bool isMask_64(uint64_t Value) {
|
|
return Value && ((Value + 1) & Value) == 0;
|
|
}
|
|
|
|
// isShiftedMask_32 - This function returns true if the argument contains a
|
|
// sequence of ones with the remainder zero (32 bit version.)
|
|
// Ex. isShiftedMask_32(0x0000FF00U) == true.
|
|
inline const bool isShiftedMask_32(unsigned Value) {
|
|
return isMask_32((Value - 1) | Value);
|
|
}
|
|
|
|
// isShiftedMask_64 - This function returns true if the argument contains a
|
|
// sequence of ones with the remainder zero (64 bit version.)
|
|
inline const bool isShiftedMask_64(uint64_t Value) {
|
|
return isMask_64((Value - 1) | Value);
|
|
}
|
|
|
|
// isPowerOf2_32 - This function returns true if the argument is a power of
|
|
// two > 0. Ex. isPowerOf2_32(0x00100000U) == true (32 bit edition.)
|
|
inline bool isPowerOf2_32(unsigned Value) {
|
|
return Value && !(Value & (Value - 1));
|
|
}
|
|
|
|
// isPowerOf2_64 - This function returns true if the argument is a power of two
|
|
// > 0 (64 bit edition.)
|
|
inline bool isPowerOf2_64(uint64_t Value) {
|
|
return Value && !(Value & (Value - 1LL));
|
|
}
|
|
|
|
// CountLeadingZeros_32 - this function performs the platform optimal form of
|
|
// counting the number of zeros from the most significant bit to the first one
|
|
// bit. Ex. CountLeadingZeros_32(0x00F000FF) == 8.
|
|
// Returns 32 if the word is zero.
|
|
// CountLeadingZeros_32 - this function performs the platform optimal form
|
|
// of counting the number of zeros from the most significant bit to the first
|
|
// one bit. Ex. CountLeadingZeros_32(0x00F000FF) == 8.
|
|
// Returns 32 if the word is zero.
|
|
inline unsigned CountLeadingZeros_32(unsigned Value) {
|
|
unsigned Count; // result
|
|
#if __GNUC__ >= 4
|
|
// PowerPC is defined for __builtin_clz(0)
|
|
#if !defined(__ppc__) && !defined(__ppc64__)
|
|
if (!Value) return 32;
|
|
#endif
|
|
Count = __builtin_clz(Value);
|
|
#else
|
|
if (!Value) return 32;
|
|
Count = 0;
|
|
// bisecton method for count leading zeros
|
|
for (unsigned Shift = 32 >> 1; Shift; Shift >>= 1) {
|
|
unsigned Tmp = Value >> Shift;
|
|
if (Tmp) {
|
|
Value = Tmp;
|
|
} else {
|
|
Count |= Shift;
|
|
}
|
|
}
|
|
#endif
|
|
return Count;
|
|
}
|
|
|
|
// CountLeadingZeros_64 - This function performs the platform optimal form
|
|
// of counting the number of zeros from the most significant bit to the first
|
|
// one bit (64 bit edition.)
|
|
// Returns 64 if the word is zero.
|
|
inline unsigned CountLeadingZeros_64(uint64_t Value) {
|
|
unsigned Count; // result
|
|
#if __GNUC__ >= 4
|
|
// PowerPC is defined for __builtin_clzll(0)
|
|
#if !defined(__ppc__) && !defined(__ppc64__)
|
|
if (!Value) return 64;
|
|
#endif
|
|
Count = __builtin_clzll(Value);
|
|
#else
|
|
if (sizeof(long) == sizeof(int64_t)) {
|
|
if (!Value) return 64;
|
|
Count = 0;
|
|
// bisecton method for count leading zeros
|
|
for (uint64_t Shift = 64 >> 1; Shift; Shift >>= 1) {
|
|
uint64_t Tmp = Value >> Shift;
|
|
if (Tmp) {
|
|
Value = Tmp;
|
|
} else {
|
|
Count |= Shift;
|
|
}
|
|
}
|
|
} else {
|
|
// get hi portion
|
|
unsigned Hi = Hi_32(Value);
|
|
|
|
// if some bits in hi portion
|
|
if (Hi) {
|
|
// leading zeros in hi portion plus all bits in lo portion
|
|
Count = CountLeadingZeros_32(Hi);
|
|
} else {
|
|
// get lo portion
|
|
unsigned Lo = Lo_32(Value);
|
|
// same as 32 bit value
|
|
Count = CountLeadingZeros_32(Lo)+32;
|
|
}
|
|
}
|
|
#endif
|
|
return Count;
|
|
}
|
|
|
|
// Log2_32 - This function returns the floor log base 2 of the specified value,
|
|
// -1 if the value is zero. (32 bit edition.)
|
|
// Ex. Log2_32(32) == 5, Log2_32(1) == 0, Log2_32(0) == -1
|
|
inline unsigned Log2_32(unsigned Value) {
|
|
return 31 - CountLeadingZeros_32(Value);
|
|
}
|
|
|
|
// Log2_64 - This function returns the floor log base 2 of the specified value,
|
|
// -1 if the value is zero. (64 bit edition.)
|
|
inline unsigned Log2_64(uint64_t Value) {
|
|
return 63 - CountLeadingZeros_64(Value);
|
|
}
|
|
|
|
// Platform-independent wrappers for the C99 isnan() function.
|
|
int IsNAN (float f);
|
|
int IsNAN (double d);
|
|
|
|
// Platform-independent wrappers for the C99 isinf() function.
|
|
int IsInf (float f);
|
|
int IsInf (double d);
|
|
|
|
} // End llvm namespace
|
|
|
|
#endif
|