Resource: LCA13 Name: GCC Performance Date: 04-03-2013 Speaker: Matthew Gretton-Dann

1. ASIA 2013 (LCA13)
Toolchain Working Group
GCC Update
Matthew Gretton-Dann
Technical Lead - Toolchain Working Group

2. ASIA 2013 (LCA13)
www.linaro.org
Agenda
Who are we?
Purpose of session
What we've done since LCE'12
AArch64 Enablement
ARMv7-A Performance
What we're going to do next
AArch64 Enablement
ARMv7-A Performance
Discussions on Performance issues

3. ASIA 2013 (LCA13)
www.linaro.org
Who are We?

4. ASIA 2013 (LCA13)
www.linaro.org
Purpose of Session
Report on what we've done
Start discussions on what we're going to do next iteration
These are ARMv7-A Performance focused
These will carry on into hacking sessions
Session on Friday will wrap-up these discussions and deliver tasks for
the next quarter.
What about AArch64?
We'll do enablement work as necessary
We won't focus on AArch64 for performance as we have no hardware.
However, we expect most ARMv7-A performance work to also have
some benefits for AArch64.

5. ASIA 2013 (LCA13)
www.linaro.org
What We've Done
AArch64 Enablement
Boehm GC & Libatomic
GC Sections
ARMv7-A Performance Improvements
Vectorizer Cost Model
Branch Cost Investigations
Improved support for REV intrinsics
Improved core to Neon register transfers
Better 64-bit shifts in Neon
Improved costs model for 64-bit ops in Neon vs Core registers

6. ASIA 2013 (LCA13)
www.linaro.org
What We're Going To Do – A Plea
What matters to you?
Give us your poor code!

7. ASIA 2013 (LCA13)
www.linaro.org
What We're Going To Do
ARMv7-A Performance
Disable Peeling for alignment in the Vectorizer
Improve Neon Intrinsic code generation
Jump Threading
Remove redundant zero/sign extensions
Shrinkwrapping
Improve model for Branches vs Conditional Execution

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ASIA 2013 (LCA13)