function::regparm - Linux

Overview

function::regparm is a utility for annotating C functions with register parameters. It allows programmers to specify which function arguments should be passed in registers, optimizing code performance for specific CPU architectures.

Syntax

function::regparm [options] function-name [args...]

Options/Flags

• -n: Do not generate code, only print it.
• -o file: Write output to a file instead of stdout.

Examples

Passing the first argument in a register:

function::regparm -n foo int x

This will generate code like:

int foo(register int x) { ... }

Passing multiple arguments in registers:

function::regparm -n foo int x, float y

This will generate code like:

int foo(register int x, register float y) { ... }

Common Issues

• Incorrect register parameter specification: Ensure that the specified register parameters match the function’s calling convention.
• Syntax errors: Check for typos and missing arguments in the command invocation.
• Mismatched argument types: Make sure that the arguments specified in the command match the function’s parameter types.

Integration

function::regparm can be used with compilers that support register parameter annotations. It can be integrated into build systems to automate the annotation process.

Related Commands

• gcc: The GNU C compiler supports register parameter annotations.
• clang: The LLVM compiler supports register parameter annotations.