(Difference between revisions)
Revision as of 10:06, 17 January 2011
Date and Time
Friday 2011-01-14 @8.00 - 9.00 UTC
- Patch for RPM armv7hl and armv7nhl architecture exist (done by Carsten Munk)
ARM RunFast in glibc?
Do we have a patch for glibc-2.11-12-g24c0bf7 and/or glibc-2.12.1 that enables ARM RunFast mode by default anywhere? Would be good to push it along with hardfp while we're at it and getting things tested through.
- Juha made final patch
- By default the RunFast is used
- Floats are improved, doubles not change.
- Negative: numbers close of 0 but still > 0 are interpreted as 0
- We can take this together with glibc
- Juha Kallioinen will submit the patch(?)
- will be in glibc-2.12.1 (verify with Juha)
- Comments from Austin:
austin: which version is the patch made against?
austin: glibc2.12 building had failed in OBS for a long time under ARM (x86 is ok)
austin: and so far, I am afraid we don't have enough time for glibc update.
austin: so it is important to have this patch for 2.11
Comments from Carsten Munk to Communication material
- The OBS name for this architecture will be 'armv7hl', so you may have to re-add repositories in orer
In "Default set"
- NEON instructions are not allowed unless guarded, ie checks for NEON capability in /proc/self/auxv
- Thumb not allowed (-mno-thumb)
Some questions to Carsten:
- Why Thumb is not allowed?? Thumb should be allowed.
- Cortex has been optimized for Thumb
In practice, the cross compilers has float-abi=hard hardcoded so maybe we should downplay that. You can't have mfloat-abi=hard with a softfp libgcc anyway.