SDK/Toolchains/Meetings/Notes20101108

Latest revision as of 14:15, 17 January 2011

Date and Time

Monday 2010-11-08 @8.30 - 9.30 UTC

Agenda

• Status
• Optimization flags (mail discussion regarding NEON, VFPv3 D16/D32)
• AOB

Status

• Common base for the MeeGo Toolchain in Release 1.2 is gcc-4.5.1

ARM:

• Move to hardfp for 1.2, but building hard+soft for grace time.
• Nokia wants hardfp support to ARM toolchain (option -mfloat-abi=hardfp) -> Binary break compared to Release 1.1
• Effects also to RPM package manager (must be capable to detect hardfp architecture)
• Change Proposal is needed to get approval from MeeGo TSG. Jarmo will prepare.
• Communication material needed
• Linaro ARM backports to gcc-4.5.1
• Do we need backport also to binutils?

x86:

• Austin tested 4.5.1 and found no issues so far for x86 (main repo). More tests on applications as Browser needed -> rebenchmark. Which benchmarks to use ?
• Bootsrap is needed for gcc-4.5.1
• New toolchain is needed to OBS devel:base and to trunk:testing at 12/2010

Optimization flags (mail discussion regarding NEON, VFPv3 D16/D32)

Short Background:

• VFPv3 = VFPv3-D32 (32 registers). Tegra and Dove only have -D16
• Pointer: http://wiki.debian.org/ArmHardFloatPort , https://wiki.linaro.org/Linaro-arm-hardfloat
• Least common denominator would be vfpv3-d16, and no neon (tegra2) - currently.
• Currently we use VFPv3(-d32) which would mean we don't run on these.

Proposal:

• softfloat port could do vfpv3-d16 and hardfp port can do vfpv3(-d32) or even neon. Thus we get board board support (including tegra2/dove) and maximum speed for hardfp

Decision:

• Two modes: VFPv3-D16 for hardfp (-mfpu=vfpv3-d16) and optional set NEON enabled (-mfpu=neon) -> two architectures

AOB

• Do we need to import some patches for binutils for ARM hardfp?