New issue
Advanced search Search tips
Note: Color blocks (like or ) mean that a user may not be available. Tooltip shows the reason.

Issue 687624 link

Starred by 1 user

Issue metadata

Status: Assigned
Owner:
Last visit > 30 days ago
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: ----
Pri: 2
Type: Bug



Sign in to add a comment

ec: Consider replacing int_sqrtf() with sqrtf()

Project Member Reported by sha...@chromium.org, Feb 1 2017

Issue description

If CONFIG_FPU is defined, we can throw away our inefficient int_sqrtf() function and replace it with sqrtf(), which takes just 14 CPU clock cycles to compute.
 

Comment 1 by sha...@chromium.org, Apr 12 2017

Components: OS>Firmware>EC
Labels: Hotlist-GoodFirstBug
Status: Available (was: Untriaged)

Comment 2 by sha...@chromium.org, Jun 21 2017

Status: Verified (was: Available)
https://chromium-review.googlesource.com/#/c/537734/

Comment 3 by sha...@chromium.org, Jun 21 2017

Status: Assigned (was: Verified)
jbruneau@ pointed out that although nds32 has an FPU, it doesn't seem to have a HW sqrt instruction, so sqrtf() is probably less efficient than our int_sqrtf() binary search. Let's change our condition for using sqrtf().

Comment 4 by sha...@chromium.org, Jun 21 2017

Cc: jbruneau@chromium.org

Comment 5 by sha...@chromium.org, Jun 21 2017

Owner: sha...@chromium.org

Sign in to add a comment