topic Re: Instruction set latency in Intel® ISA Extensions

Instruction set latency

sebitab — Thu, 16 Apr 2009 21:51:43 GMT

Hello, I am working on assembly code optimization, I already read the code optimization manual, but I am interested in a list with the instruction set latencies. I search the intel site but I could not find it.

Where can I found this?.

Thanks for your answers.

Re: Instruction set latency

Thomas_W_Intel — Fri, 17 Apr 2009 19:17:10 GMT

Quoting - sebitab

The latencies are listed in Appendix C of the "Intel 64 and IA-32 Architectures Optimization Reference Manual", which can be downloaded here.

Kind regards
Thomas

Re: Instruction set latency

jancino — Wed, 29 Apr 2009 20:19:44 GMT

Quoting - sebitab

You can use instruction latencies only for very rough approximation of real number of cycles taken, because actual results depends on whetevera operands are loaded to cache, other instructions in pipeline (conditions) and so on....

Re: Instruction set latency

craigj0 — Mon, 12 Oct 2009 11:47:02 GMT

I find the instruction tables found here: http://www.agner.org/optimize/ to be very helpful. They are not perfect but they provide a pretty good estimate.

Re: Instruction set latency

Tal_U_Intel — Thu, 22 Oct 2009 08:40:46 GMT

Quoting - craigj0

I find the instruction tables found here: http://www.agner.org/optimize/ to be very helpful. They are not perfect but they provide a pretty good estimate.

You can also try using Intel Architecture Code Analyzer available on:
http://software.intel.com/en-us/articles/intel-architecture-code-analyzer/

It can help you find the dependency chains in your code.

Tal