算术求反是否算作浮点运算？
我目前正在测量一些代码在 FLOPS 中的性能。此代码提供了一些算术求反指令，如下所示：
d = -a
其中 d 和 a 是浮点变量。 我当前使用的架构确实有特定的否定指令。我是否应该考虑这种操作来测量 FLOPS？什么样的操作会导致 FLOPS？有什么约定吗？
I'm currently measuring the performance of some code in FLOPS. This code presents some arithmetic negate instructions like this one:
d = -a
where d and a are floating point variables. The architecture I'm currently using does have specific negate instructions. Should I have to take into account this kind of operations to measure FLOPS? What kind of operations account for FLOPS? Is there a convention or anything?
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尝试反汇编代码并检查该操作是如何执行的。
如果它使用指令
FCHS（改变符号）那么你可以认为它是浮点运算。MSVC (Visual Studio 2008)
fchs - 看到了吗？
try to disassemble the code and check how this operation is performed.
if it uses instruction
FCHS(Change sign) then you can consider it floating point operation.MSVC (Visual Studio 2008)
fchs - see that?
正如@Andrey所说，为了确保你应该检查反汇编代码。
但一般来说，是的，该指令可能会在 FPU 上执行。它只是翻转一点，所以它也可以在整数单元上完成，但由于您正在操作浮点值，这些很可能已经加载到 FP 寄存器中，所以就这样了。将它们移动到通用寄存器、翻转该位并将它们移回需要相当大的开销。
我不知道是否有一个完整的通用指南来说明“什么应该算作 FLOP”，但这很可能是在 FPU 上执行的指令，因此它与其他 FP 指令竞争 CPU 上的资源，所以是的，我会将其包含在 FLOPS 计数中。
As @Andrey said, to be sure you should check the disassembled code.
But in general, yes, the instruction would likely execute on a FPU. It simply flips a bit, so it could be done on an integer unit as well, but since you're operating on floating point values, these are most likely already loaded into FP registers, and so there'd be a fair amount of overhead to moving them to general purpose registers, flipping the bit and moving them back.
I don't know if there is a complete universal guide to "what should be counted as a FLOP", but this is most likely an instruction which executes on a FPU, and so it is competing with other FP instructions for resources on the CPU, so yes, I would include it in a FLOPS count.
有一种使用 LINPACK 作为一种标准基准来计算 FLOPS 的约定。
There is a kind of convention to calculate the FLOPS using LINPACK as a kind of standard benchmark.