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This commit is contained in:
Vladimir Kozlov 2015-02-26 10:56:54 -08:00
commit 239370b736
1382 changed files with 52370 additions and 23387 deletions
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9
hotspot/src/share/vm/utilities/globalDefinitions.hpp
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@ -1150,17 +1150,18 @@ inline bool is_power_of_2_long(jlong x) {
return ((x != NoLongBits) && (mask_long_bits(x, x - 1) == NoLongBits));
}
//* largest i such that 2^i <= x
// A negative value of 'x' will return '31'
// Returns largest i such that 2^i <= x.
// If x < 0, the function returns 31 on a 32-bit machine and 63 on a 64-bit machine.
// If x == 0, the function returns -1.
inline int log2_intptr(intptr_t x) {
int i = -1;
uintptr_t p = 1;
uintptr_t p = 1;
while (p != 0 && p <= (uintptr_t)x) {
// p = 2^(i+1) && p <= x (i.e., 2^(i+1) <= x)
i++; p *= 2;
}
// p = 2^(i+1) && x < p (i.e., 2^i <= x < 2^(i+1))
// (if p = 0 then overflow occurred and i = 31)
// If p = 0, overflow has occurred and i = 31 or i = 63 (depending on the machine word size).
return i;
}