A C Compiler for ARM with Differences

1
A C Compiler for ARM with Differences

• by
• ImageCraft
• Richard Man, Technical Director
• Richard_at_imagecraft.com

2
Why?

• Perfect timing
• ARM7 price competition with 8/16-bit
  microcontrollers
• Flash based easy to use
• Atmel AT91 SAM7
• Philips LPC2K
• Own the hobbyist market and you will become a
  market leader (e.g. Microchip)
• No low-cost professional tools until now!

3
Competitive Landscape

• Stratospherically priced tools
• (with a performance to match?)
• ARM, Green Hills, IAR
• free GNU GCC
• Commercial IDEs on top of GNU
• Keil (now have their own compiler too)
• Hitech
• Rowley Associates
• etc.

4
ICCV7 for ARM Product Summary

• Simple-to-use IDE with powerful features
• Optimizing compiler
• Ability to work with industrial standard debug
  tools
• Price performance leader

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The Differences (1)

• IDE with Application Builder
• Point and click to initialize IO registers

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The Differences (2, IDE AppBuilder)
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Optimizing Compiler

• (Surprise?) Non-GNU
• More user friendly
• Control our own destiny - features, bug fixes
  etc.
• Global Register Allocator
• ARM is a RISC machine, use registers as much as
  possible
• ARM features
• p etc. gt pre / post indexed modes
• Conditional execution
• Thumb mode (1Q05)
• Uses APCS (ARM Procedure Calling Convention)

8
Unmatched Price Performance

• 3 Versions
• STD (Nov. 04)
• IDE, ARM code generation
• 199
• ADV (Jan. 05)
• 349
• Thumb code generation
• PRO (Jan. 05)
• 749
• Global Optimizer

9
Debugger Support

• Nohau EMUL-ARM emulator and Seehau debugger
• GNU ELF/Insight
• (TBA) ImageCraft branded low cost (200)
  debugger (1Q05)

10
Support

• 10,000 licenses sold since 1994
• Its not easy ?
• but it can be handled effectively
• Easy to upgrade download and install the latest
  demo
• Web resources, FAQ, mailing list
• Email
• We are a US company in the Silicon Valley!
  Telephone if you really must.

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Global Optimizer (1)

• Priorities
• Safety fast wrong code is wrong code. BE
  CONSERVATIVE!
• Effective goal - 10 to 20 better code
• Speed slow optimizer does not get used until
  late in development cycles. Make it fast so that
  it is used from the beginning
• New Virtual Pass
• Low impact on rest of the compiler infrastructure
• Function at a time optimizations
• Machine Independent Optimizations optimizer
  will be introduced to platforms (ICCV7 for AVR)

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Global Optimizer (2)

• Technology (we know the buzzwords!)
• SSA, Static Single Assignment
• State of the arts technique, for example, it is
  the same infrastructure chosen by the GNU team
  for GCC4.0
• Dominator Graphs
• Control flow information
• Global Value Numbering
• Common subexpression
• Constant Propagation
• Code Motion
• Move code out of loop
• Code Hoisting
• Merge common code
• (others...)

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Future

• Short / medium term ADV, PRO, debugger
• More ARM7 devices supported
• Builtin Flash ISP?
• ARM9?
• EC sometimes in 2H05