在大多数现代 64 位处理器上，“mulq"的速度是否取决于操作数? [英] On most modern 64-bit processors, does the speed of `mulq` depend on the operands?

问题描述

在大多数现代 64 位处理器(例如 Intel Core 2 Duo 或 Intel i7 系列)上，x86_64 命令 mulq 及其变体的速度是否取决于操作数?例如，乘以 11 * 13 会比 11111111 * 13131313 快吗?还是总要经历最坏的情况?

On most moder 64-bit processors (such as Intel Core 2 Duo or the Intel i7 series), does the speed of the x86_64 command mulq and its variants depend on the operands? For example, will multiplying 11 * 13 be faster than 11111111 * 13131313? Or does it always take the time of the worst case?

推荐答案

我没有任何关于手的参考，但我会把钱放在延迟/吞吐量上，因为操作数的值是不变的.否则，日程安排将是一场噩梦.

I don't have any reference to hand, but I would place money on the latency/throughput being invariant of the values of the operands. Otherwise, it would be a nightmare to schedule.

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