1.1 --- a/src/share/vm/utilities/globalDefinitions.hpp Wed Jan 30 17:32:47 2019 +0000
1.2 +++ b/src/share/vm/utilities/globalDefinitions.hpp Fri Feb 01 10:47:30 2019 +0100
1.3 @@ -1403,6 +1403,32 @@
1.4
1.5 #define ARRAY_SIZE(array) (sizeof(array)/sizeof((array)[0]))
1.6
1.7 +//----------------------------------------------------------------------------------------------------
1.8 +// Sum and product which can never overflow: they wrap, just like the
1.9 +// Java operations. Note that we don't intend these to be used for
1.10 +// general-purpose arithmetic: their purpose is to emulate Java
1.11 +// operations.
1.12 +
1.13 +// The goal of this code to avoid undefined or implementation-defined
1.14 +// behaviour. The use of an lvalue to reference cast is explicitly
1.15 +// permitted by Lvalues and rvalues [basic.lval]. [Section 3.10 Para
1.16 +// 15 in C++03]
1.17 +#define JAVA_INTEGER_OP(OP, NAME, TYPE, UNSIGNED_TYPE) \
1.18 +inline TYPE NAME (TYPE in1, TYPE in2) { \
1.19 + UNSIGNED_TYPE ures = static_cast<UNSIGNED_TYPE>(in1); \
1.20 + ures OP ## = static_cast<UNSIGNED_TYPE>(in2); \
1.21 + return reinterpret_cast<TYPE&>(ures); \
1.22 +}
1.23 +
1.24 +JAVA_INTEGER_OP(+, java_add, jint, juint)
1.25 +JAVA_INTEGER_OP(-, java_subtract, jint, juint)
1.26 +JAVA_INTEGER_OP(*, java_multiply, jint, juint)
1.27 +JAVA_INTEGER_OP(+, java_add, jlong, julong)
1.28 +JAVA_INTEGER_OP(-, java_subtract, jlong, julong)
1.29 +JAVA_INTEGER_OP(*, java_multiply, jlong, julong)
1.30 +
1.31 +#undef JAVA_INTEGER_OP
1.32 +
1.33 // Dereference vptr
1.34 // All C++ compilers that we know of have the vtbl pointer in the first
1.35 // word. If there are exceptions, this function needs to be made compiler
