[cairo] [PATCH] Rely less on FPU for common matrix funcs.

Jonathan Morton jonathan.morton at movial.com
Wed Jun 2 05:05:45 PDT 2010

On Wed, 2010-06-02 at 13:31 +0200, Arjen Nienhuis wrote:
> Are FP values always normalized in RAM? I mean can 0.0 be stored as
> 0.0E1 and would memcmp still work?

Zero and Infinity have special representations outside the valid range
of exponents.  See the IEEE-754 spec for details, but specifically,
+1.0, -1.0 and +0 have well-defined binary representations in memory.

In any case, _is_identity() and _is_translation() are used to quickly
identify common cases which can be handled more efficiently than a full
generic transform.  It's possible to fool them, but the possible
implications are only for performance and not for correctness.

From: Jonathan Morton
      jonathan.morton at movial.com

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