haskell - LLVM 对 GHC 的调用约定

Question

这是LLVM's doc "langref"中的文字:

"cc 10" - GHC convention

This calling convention has been implemented specifically for use by the Glasgow Haskell Compiler (GHC). It passes everything in registers, going to extremes to achieve this by disabling callee save registers. This calling convention should not be used lightly but only for specific situations such as an alternative to the register pinning performance technique often used when implementing functional programming languages.At the moment only X86 supports this convention and it has the following limitations:

• On X86-32 only supports up to 4 bit type parameters. No floating point types are supported.
• On X86-64 only supports up to 10 bit type parameters and 6 floating point parameters.

问:

“寄存器固定”是否意味着或指“通过寄存器中的所有内容”，可能。

什么是“4 位类型参数”？我刚刚搜索了英特尔的 IA 手册，但没有找到任何东西。它是英特尔 CPU 的功能吗？

Answer 1

“寄存器固定”似乎是指将特定的东西分配给特定的硬件寄存器；见"Register Pinning" section of these GHC LLVM back-end notes和 linked discussion .

Dirk 是对的——你可以在 LLVM tblgen code which defines these conventions 中清楚地看到它。 (寻找 CC_X86_64_GHC 和 CC_X86_32_GHC )。