1.1 --- a/src/share/vm/utilities/globalDefinitions.hpp Wed Jul 03 20:04:13 2019 +0800
1.2 +++ b/src/share/vm/utilities/globalDefinitions.hpp Wed Jul 03 20:42:37 2019 +0800
1.3 @@ -1145,10 +1145,10 @@
1.4
1.5 //* largest i such that 2^i <= x
1.6 // A negative value of 'x' will return '31'
1.7 -inline int log2_intptr(intptr_t x) {
1.8 +inline int log2_intptr(uintptr_t x) {
1.9 int i = -1;
1.10 uintptr_t p = 1;
1.11 - while (p != 0 && p <= (uintptr_t)x) {
1.12 + while (p != 0 && p <= x) {
1.13 // p = 2^(i+1) && p <= x (i.e., 2^(i+1) <= x)
1.14 i++; p *= 2;
1.15 }
1.16 @@ -1158,11 +1158,10 @@
1.17 }
1.18
1.19 //* largest i such that 2^i <= x
1.20 -// A negative value of 'x' will return '63'
1.21 -inline int log2_long(jlong x) {
1.22 +inline int log2_long(julong x) {
1.23 int i = -1;
1.24 julong p = 1;
1.25 - while (p != 0 && p <= (julong)x) {
1.26 + while (p != 0 && p <= x) {
1.27 // p = 2^(i+1) && p <= x (i.e., 2^(i+1) <= x)
1.28 i++; p *= 2;
1.29 }
1.30 @@ -1171,6 +1170,27 @@
1.31 return i;
1.32 }
1.33
1.34 +inline int log2_intptr(intptr_t x) {
1.35 + return log2_intptr((uintptr_t)x);
1.36 +}
1.37 +
1.38 +inline int log2_int(int x) {
1.39 + return log2_intptr((uintptr_t)x);
1.40 +}
1.41 +
1.42 +inline int log2_jint(jint x) {
1.43 + return log2_intptr((uintptr_t)x);
1.44 +}
1.45 +
1.46 +inline int log2_uint(uint x) {
1.47 + return log2_intptr((uintptr_t)x);
1.48 +}
1.49 +
1.50 +// A negative value of 'x' will return '63'
1.51 +inline int log2_jlong(jlong x) {
1.52 + return log2_long((julong)x);
1.53 +}
1.54 +
1.55 //* the argument must be exactly a power of 2
1.56 inline int exact_log2(intptr_t x) {
1.57 #ifdef ASSERT
1.58 @@ -1210,6 +1230,29 @@
1.59 inline bool is_odd (intx x) { return x & 1; }
1.60 inline bool is_even(intx x) { return !is_odd(x); }
1.61
1.62 +// abs methods which cannot overflow and so are well-defined across
1.63 +// the entire domain of integer types.
1.64 +static inline unsigned int uabs(unsigned int n) {
1.65 + union {
1.66 + unsigned int result;
1.67 + int value;
1.68 + };
1.69 + result = n;
1.70 + if (value < 0) result = 0-result;
1.71 + return result;
1.72 +}
1.73 +static inline julong uabs(julong n) {
1.74 + union {
1.75 + julong result;
1.76 + jlong value;
1.77 + };
1.78 + result = n;
1.79 + if (value < 0) result = 0-result;
1.80 + return result;
1.81 +}
1.82 +static inline julong uabs(jlong n) { return uabs((julong)n); }
1.83 +static inline unsigned int uabs(int n) { return uabs((unsigned int)n); }
1.84 +
1.85 // "to" should be greater than "from."
1.86 inline intx byte_size(void* from, void* to) {
1.87 return (address)to - (address)from;
1.88 @@ -1412,6 +1455,32 @@
1.89
1.90 #define ARRAY_SIZE(array) (sizeof(array)/sizeof((array)[0]))
1.91
1.92 +//----------------------------------------------------------------------------------------------------
1.93 +// Sum and product which can never overflow: they wrap, just like the
1.94 +// Java operations. Note that we don't intend these to be used for
1.95 +// general-purpose arithmetic: their purpose is to emulate Java
1.96 +// operations.
1.97 +
1.98 +// The goal of this code to avoid undefined or implementation-defined
1.99 +// behaviour. The use of an lvalue to reference cast is explicitly
1.100 +// permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1.101 +// 15 in C++03]
1.102 +#define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1.103 +inline TYPE NAME (TYPE in1, TYPE in2) { \
1.104 + UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1.105 + ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1.106 + return reinterpret_cast<TYPE&>(ures); \
1.107 +}
1.108 +
1.109 +JAVA_INTEGER_OP(+, java_add, jint, juint)
1.110 +JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1.111 +JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1.112 +JAVA_INTEGER_OP(+, java_add, jlong, julong)
1.113 +JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1.114 +JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1.115 +
1.116 +#undef JAVA_INTEGER_OP
1.117 +
1.118 // Dereference vptr
1.119 // All C++ compilers that we know of have the vtbl pointer in the first
1.120 // word. If there are exceptions, this function needs to be made compiler
