[FFmpeg-devel] Inline ASM vs. Intrinsics

Måns Rullgård mans
Fri May 11 15:29:15 CEST 2007

Guillaume POIRIER wrote:
> Yep. I'd like to note though that, inline ASM syntax being so
> horrible, I bet many people just never bothered to write any SIMD code

It is horrible indeed.  I'm never quite confident I've got all the
constraints right.  For the ARM SIMD optimisations I put all the assembler
code in pure assembler (.S) files.  This allowed me to use all the registers
the way I wanted, something gcc simply wouldn't let me otherwise.  I could
also create a few functions with nonstandard calling convention to further
optimise register usage.

M?ns Rullg?rd
mans at mansr.com

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