libpayload: Add simple 32.32 fixed-point math API

struct fraction is slooooooooooow. This patch adds a simple 64-bit
(32-bits integral, 32-bits fractional) fixed-point math API that is
*much* faster (observed roughly 5x speed-up) when doing intensive
graphics operations. It is optimized for speed over accuracy so some
operations may lose a bit more precision than expected, but overall it's
still plenty of bits for most use cases.

Also includes support for basic trigonometric functions with a small
lookup table.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: Id0f9c23980e36ce0ac0b7c5cd0bc66153bca1fd0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42993
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>

0 files changed, 0 insertions, 0 deletions