HiPE%20version%201.0

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HiPEversion 1.0

• Kostis Sagonas
• Uppsala University

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Structure of this talk

• 1. Recent past
• 2. Present
• 3. Near future

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Part 1 Recent Past
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Historical introduction

• During the last few years, the following people
• Erik Happi Johansson
• Mikael Pettersson
• Richard Carlsson
• Kostis Sagonas
• have been having fun developing and maintaining
  the HiPE system...

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HiPE High Performance Erlang

• A just-in-time native code compiler for Erlang
• Allows flexible, user-controlled compilation of
  Erlang programs to native machine code
• Fine-grained Compilation unit is a single
  function
• HiPE 0.92 released as open-source in March 2000
  (see also www.csd.uu.se/projects/hipe)
• Released version was JAM-based (Erlang R4)
• Available only for SPARC machines

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HiPE Technical Details

• Both virtual machine code and native code can
  happily co-exist in the runtime system
• HiPE optimizes calls to functions which execute
  in the same mode
• Preserves tail-calls
• The generated native code is quite efficient
• HiPE significantly outperforms all other Erlang
  implementations
• has similar performance to e.g. Concurrent SML/NJ

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Old HiPE Architecture
SymbolicJAM
Code area
JAM Bytecode
JAMDissassembler
Icode
OtherData
JAMEmulator
RTL
NativeCode
HiPELoader
SPARC
Erlang Run-Time System
HiPE Compiler
The HiPE system
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Speedup of HiPE (0.92) over other Erlang
implementations
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Success of HiPE Lets take a quick poll...

• Who has used HiPE ?
• My educated guess A few
• Who is using HiPE instead of using Erlang/OTP ?
• Most probable answer None!

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Part 2 Present
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HiPE version 1.0 The current HiPE team

• At Uppsala University
• Erik Happi Johansson
• Mikael Pettersson
• Richard Carlsson
• Kostis Sagonas
• Jesper Wilhelmsson
• Recent addition from the Erlang/OTP team
• Bjorn Gustavsson

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HiPE version 1.0 Main Features of Interest

• HiPE is fully and tightly integrated within Open
  Source Erlang/OTP Release 8
• Handles the full Erlang language
• Back-ends for
• SPARC
• x86-based machines running Linux or Solaris
• Usually very reasonable compilation times
• Acceptable sizes of object code

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New HiPE Architecture
SymbolicBEAM
Code area
BEAM Bytecode
BEAMDissassembler
Icode
OtherData
BEAMEmulator
RTL
NativeCode
HiPELoader
SPARC
X86
Erlang Run-Time System
HiPE Compiler
A HiPE-enabled Erlang/OTP system
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HiPE version 1.0 Installation Guide

• 1. Get Open Source Erlang/OTP R8
• 2. If on SPARC or x86, instead of typing
• ./configure
• ./make
• type
• ./configure
  --enable-hipe
• ./make

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HiPE Invoking the compiler (novice user)

• Instead of typing
• 1gt c(Module, Options).
• types
• 1gt c(Module,
  nativeOptions).
• Alternatively, instead of typing
• erlc File
• types
• erlc native File

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HiPE Invoking the compiler (seasoned user)

• Instead of typing
• 1gt c(Module, Options).
• types
• 1gt c(Module, native,hipe,O3
  ,...Options).
• Learns about the full set of HiPE compiler
  options by typing
• 1gt hipehelp().

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HiPE Invoking the compiler (expert user)

• Selectively and dynamically compiles individual
  Erlang functions using
• 1gt c(M).
• 42gt hipec(M,F,A,
  HiPE_Opts).
• Reports bugs to hipe-bugs_at_csd.uu.se

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HiPE Invoking the compiler (HiPE hacker)

• Sends bug fixes and compiler improvements to
  hipe_at_csd.uu.se

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HiPE version 1.0 Currently known limitations

• Native code will not be unloaded once loaded into
  the system (slight memory leak)
• Tracing and debugging support is non-existent
• Hint Use HiPE once your application is debugged!
• Floating point arithmetic slower than in BEAM
• Exception information often slightly differs
  between BEAM and HiPE
• in particular, no tracelist is provided
• Fixed size (i.e., non-resizable) constant pool

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HiPE version 1.0 Performance Expectations
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HiPE version 1.0 Useful Hints

• To get the most out of HiPE
• Compile all time-critical parts of your Erlang
  application into native code
• Separate hot from cold code
  (perhaps by placing them into different
  modules)
• Avoid easily avoidable mode-switches

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Part 3 Near Future
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HiPE Current Work

• Optimization of inter-process communication and
  efficient memory management for concurrent
  processes
• Formal specification of the Core Erlang language
  and its full integration within HiPE and
  Erlang/OTP
• New inliner for the BEAM compiler
• Experimental extensions of the Erlang language

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Alternative Memory Architectures for Erlang

• Erlang/OTP has a process-centric view of memory
  management
• each process allocates each own memory area

Interprocess communication is quite expensive
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Alternative Memory Architectures for Erlang

• We (mainly Jesper Wilhelmsson) have designed and
  implemented an Erlang/OTP system where
• the heap is shared between all processes
• but each process allocates its own stack

Process 1
Process 2
Process n
...
stack
stack
stack
Global ETS Table
Global Heap
Interprocess communication does not involve
copying of messages
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Unified Heap Architecture Installation Guide

• 1. Get Erlang/OTP R8
• 2. Install by typing
• ./configure
  --enable-unified-heap
• ./make
• Warnings
• Highly experimental at this point!
• Does not work with HiPE
• Request
• Send us your favourite concurrent Erlang
  application

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Core ErlangFormal Specification and Use in OSE

• A small and relatively clean subset of Erlang
• Syntactic sugar is removed
• Resembles other core FP languages
• An appropriate medium to
• base the compilers front-end (already part of
  R8)
• apply high-level transformations such as
• inlining (currently under development)
• deforestation (prototype results so far
  inconclusive)
• base work of static analysis or verification
• A formal definition of Core Erlang is currently
  available as a tech report (Richard Carlsson et
  al)

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Core Erlang Inliner Users Manual

• Instead of typing
• 1gt c(Module, Options).
• type
• 1gt c(Module,
  inlineOptions).

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Extensions of the Erlang language

• Parameterized Erlang modules
• Design laid out issue is efficient
  implementation
• Current work by Richard Carlsson Mikael
  Pettersson
• User-defined parametric datatypes (a la ML)
• Structured module system for Erlang