CUDA原子操作

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  1. atomicAdd(dst, src)：*dst += src

  2. atomicSub(dst, src)：*dst -= src

  3. atomicOr(dst, src)：*dst |= src

  1. atomicAnd(dst, src)：*dst &= src

  2. atomicXor(dst, src)：*dst ^= src

  3. atomicMax(dst, src)：dst = std::max(dst, src)

  4. atomicMin(dst, src)：dst = std::min(dst, src)

以上原子操作均会返回旧值。

  1. old = atomicExch(dst, src) ：old = dst; dst = src; 不返回旧值，对标std::atomic的exchange函数

  2. atomicCAS：判断是否相等，相等则写入，并读取旧值

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    old = atomicCAS(dst, cmp, src)

    Like below:

    old = *dst;
    if (old == cmp)
      *dst = src;

    通过atomicCAS可以实现一些CUDA并未原生提供的原子操作，例如：读-修改-写回，乘

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    old = atomicCAS(dst, expect, expect + src);

    old = atomicCAS(dst, expect, expect * src);