是否有专门设计用于以跨平台方式使用汇编指令对位操作进行 1 到 1 编译的 C 函数或宏? [英] Are there C functions or macros specifically designed to compile 1 to 1 with assembly instructions for bit manipulations in a cross-platform manner?

问题描述

我有一个涉及仿真的项目(如果您查看我的帖子历史记录，您会看到我走了多远！)并且我正在寻找使用 C 进行伪二进制翻译并使用优化器和/或编译器使用 C 代码将我的 switch 语句内容编译为单个汇编指令，主要用于非常标准的指令，例如 movs、add、SR 和其他简单的位操作和算术指令.我希望同时为 ARM 和 x86-64 执行此操作，并在两个程序集中尽可能少地编写它.

I've got a project involving emulation (If you look at my post history, you'll see how far I've come!) and I'm looking to do pseudo-binary-translation using C and playing with the optimizers and/or compilers to use C code that compiles my switch statement contents to a single assembly instruction, primarily for very standard instructions such as movs, add, SR and other simple bit manipulations and arithmetic instructions. I'm hoping to do this for ARM and x86-64 at the same time, writing as little of it in both assemblies as possible.

如果我描述的东西不存在，那么我想知道是否有某种汇编语言"可以用来编写我的代码，然后将该程序集编译为 x86-64 和 ARM.

If the thing I'm describing doesn't exist, then I wonder if there's some sort of "assembly language" that I can use to write my code and then compile that assembly into x86-64 and ARM.

推荐答案

明确回答这部分:

...然后我想知道是否有某种我可以使用的汇编语言"用于编写我的代码，然后将该程序集编译为 x86-64 和ARM.

... then I wonder if there's some sort of "assembly language" that I can use to write my code and then compile that assembly into x86-64 and ARM.

这正是 LLVM IR 的目标.

LLVM 表示的目标是轻量级和低级，同时同时具有表现力、类型化和可扩展性.它旨在通过处于足够低的水平，成为某种通用 IR"高层次的想法可以清晰地映射到它(类似于如何微处理器是通用 IR"，允许使用多种源语言映射到它们).

The LLVM representation aims to be light-weight and low-level while being expressive, typed, and extensible at the same time. It aims to be a "universal IR" of sorts, by being at a low enough level that high-level ideas may be cleanly mapped to it (similar to how microprocessors are "universal IR’s", allowing many source languages to be mapped to them).

对于示例:

你可以代表这个C函数

int mul_add(int x, int y, int z) {
  return x * y + z;
}

使用这个 LLVM IR

with this LLVM IR

define i32 @mul_add(i32 %x, i32 %y, i32 %z) {
entry:
  %tmp = mul i32 %x, %y
  %tmp2 = add i32 %tmp, %z
  ret i32 %tmp2
}

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