You can use the Machine Interface's (MI) Compare and Swap (CMPSWP) instruction to access data in a multithreaded program. The CMPSWP instruction compares the value of a first compare operand to the value of a second compare operand. If the two values are equal, the swap operand is stored...
PURPOSE:To shorten the instruction execution time and to simplify a control circuit by providing an ECC circuit in a CPU and using the read modify write function of the ECC circuit to execute a compare and swap function in hardware. CONSTITUTION:Data is read out from a memory 20 and is ...
内容提示: __sync_bool_compare_and_swap汇编实现https://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html#Atomic-Builtins带有C/C++表达式的内联汇编格式为:__asm__ __volatile__("Instruction List" : Output : Input : Clobber/Modify);其中每项的概念及功能⽤法描述如下:1、 __asm___...
Prior to the instruction the status of the two value are read at the locations to be swapped. During the instruction these locations are checked again to ensure that no change has occurred at these locations before the instruction performs the swap of the two new values. The instruction then ...
If thecntloperand is not specified, the instruction proceeds as if the default value had been specified. The machine does not enforce that only the values enumerated above are used for thecntloperand. When specified, use of any value other than those enumerated above may result in unpredictable...
In Linux, the `cmpxchg` instruction is used to implement CAS operations. This instruction takes three operands: a memory location (specified by a memory address), an expected value, and a new value. The `cmpxchg` instruction compares the current value in the specified memory location with the...
This instruction can be used with a LOCK prefix to allow the instruction to be executed atomi-cally. To simplify the interface to the processor’s bus, the destination operand receives a write cycle without regard to the result of the comparison. The destination operand is written back if the...
// Adding a lock prefix to an instruction on MP machine // VC++ doesn't like the lock prefix to be on a single line // so we can't insert a label after the lock prefix. // By emitting a lock prefix, we can define a label after it. ...
// Adding a lock prefix to an instruction on MP machine// VC++ doesn't like the lock prefix to be on a single line// so we can't insert a label after the lock prefix.// By emitting a lock prefix, we can define a label after it.#define LOCK_IF_MP(mp) __asm cmp mp, 0 \...
Embodiments of the disclosure serializing wrapping of a circularly wrapping trace buffer via a compare-and-swap (CS) instruction by a method including executing a CS loop to advance