Fix the non-gcc 4.0 paths for countleadingzeros

Patch fixed by Jim Laskey


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22598 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-08-02 20:21:33 +00:00
parent 591083a5c7
commit e6ec587059

View File

@ -72,36 +72,41 @@ 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.)
// 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.
// 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) {
Count |= Shift;
Value = Tmp;
}
#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
}
#endif
return Count;
}
@ -111,13 +116,13 @@ inline unsigned CountLeadingZeros_32(unsigned Value) {
// 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 __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;
@ -125,8 +130,9 @@ inline unsigned CountLeadingZeros_64(uint64_t Value) {
for (uint64_t Shift = 64 >> 1; Shift; Shift >>= 1) {
uint64_t Tmp = Value >> Shift;
if (Tmp) {
Count |= Shift;
Value = Tmp;
} else {
Count |= Shift;
}
}
} else {