Stories
Slash Boxes
Comments

SoylentNews is people

SoylentNews is powered by your submissions, so send in your scoop. Only 14 submissions in the queue.
posted by LaminatorX on Sunday March 16 2014, @03:28AM   Printer-friendly
from the premature-optimization-is-the-root-of-all-evil dept.

Subsentient writes:

"I've been writing C for quite some time, but I never followed good conventions I'm afraid, and I never payed much attention to the optimization tricks of the higher C programmers. Sure, I use const when I can, I use the pointer methods for manual string copying, I even use register for all the good that does with modern compilers, but now, I'm trying to write a C-string handling library for personal use, but I need speed, and I really don't want to use inline ASM. So, I am wondering, what would other Soylenters do to write efficient, pure, standards-compliant C?"

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 1) by smellotron on Sunday March 16 2014, @08:30PM

    by smellotron (3346) on Sunday March 16 2014, @08:30PM (#17260)

    For compilers on the order of gcc and clang, and probably even Visual C++, the compiler writers know more than you could possibly imagine about creating efficient machine code.

    When optimizing, a large part of the value in inspecting the compiler-generated object code is in identifying pessimizations that the compiler was forced to make to follow the language standard. It is very common in code that I write (not games, but still latency-sensitive) that some trivial reordering of operations in the C code will reduce or remove stack usage, or replace a nested function call with a tail call. Especially because compiler writers tend to be the sharpest optimizers in the room, there is value in double-checking their output to detect data-dependency/optimization bugs in your code.